Checking injector balance?

[Duraswede]

Hi everyone, i'm glad that i found this forum, i have just too much trouble with my new GMC sierra 3500 -03, i bought it on e-bay and recieved it here to Sweden just a week ago and got a coolant leak, its leaking into the cylinders, so my first hours with this truck will be in the garage:mad:

i would like to check if my injectors are perfect, i will remove both heads to change gaskets, so when i do all that major job i will change the injectors too, and the glowplugs, but i would like to scan my computer to see what's going on (i like to have control over my vehicles) i have bought a Hypertech programmer from summit (HYP-32003) that is on its way over the ocean, and i dont know how much i can check with it, only trouble codes or any more?
is there some software that i could use in my laptop so i can get all the info?
and of course, where could i buy that software, and an interface cable, too?

and, after i change the injectors, is there something in the computer i should reset? maby it will reset itself when i take the battery cables of?
i'm just so worried about all this electronics in modern vehicles, what if all that will go crazy at the same time.. i'm just a diesel mechanic, not a computer nerd.. http://gm-diesel.com/diesel/vbull/ubb/frown.gif

by the way, i just read about the extended injector warranty, my truck has 95K miles and is 5 years old, so it will be covered, but i just dont know if it is covered outside US.. i hope so..
Regards
Oskar;)

[doodad]

I could not resist replying to your post, my parents are both from Sweden.

Injectors are expensive, unless you are having trouble with them I'd leave them alone. Unless you have money to burn, then save it for fuel. Besides, they can be changed without removing the heads. Note there is a sleeve that causes problems sometimes, but careful work helps. LB7s are the worst, but manageable.

Glow plugs, maybe, but you can probably check them electrically to be sure. It might not be a bad idea to break them free and clean them up, since they have a habit of breaking off due to rusting into place. This would be optimum if you have the heads off anyway. Besides, they are relatively cheap.

Balance rates are checked only when the engine is running and only at idle. You will get a set of numbers when in park/neutral, and another set when in drive holding the brake. You should see within +/- 4 in neutral, +/- 6 in drive. As soon as you give a little throttle, all the numbers go to zero. It is not really stored, and doesn't need to be reset. It is a dynamic adjustment performed by the ECM to smooth the idle.

I won't recommend running the engine with a coolant leak, but if you already have and do continue to run it, check the balance rates before you tear into it. I bent a rod on a gas engine that had a coolant leak, I had low compression on two adjacent cylinders and let it sit for a while before I pulled it into the garage. Just starting it up and pop, I was done.

How do you know you have a coolant leak, if I may ask?

To read balance rates I use an obd 2 diagnostic tool by alex peper at obd-2.com, but many programmers also have the capability. If not, a tech2 at a dealer can do it for you, probably for a fee.

If you have a legit GM dealer there, then talk to them about warranty support. I can't see why it would be restricted, unless duramaxes were never officially exported and thus no support.

Search around here, there are a lot of people with similar problems and lots of good information. For example, if you are ever thinking about power/performance increases, maybe using studs instead of stock bolts might be in the cards if you have the heads off anyway.

Good luck, post any progress for those who are interested.

[Duraswede]

I could not resist replying to your post, my parents are both from Sweden.

Injectors are expensive, unless you are having trouble with them I'd leave them alone. Unless you have money to burn, then save it for fuel. Besides, they can be changed without removing the heads. Note there is a sleeve that causes problems sometimes, but careful work helps. LB7s are the worst, but manageable.

Glow plugs, maybe, but you can probably check them electrically to be sure. It might not be a bad idea to break them free and clean them up, since they have a habit of breaking off due to rusting into place. This would be optimum if you have the heads off anyway. Besides, they are relatively cheap.

Balance rates are checked only when the engine is running and only at idle. You will get a set of numbers when in park/neutral, and another set when in drive holding the brake. You should see within +/- 4 in neutral, +/- 6 in drive. As soon as you give a little throttle, all the numbers go to zero. It is not really stored, and doesn't need to be reset. It is a dynamic adjustment performed by the ECM to smooth the idle.

I won't recommend running the engine with a coolant leak, but if you already have and do continue to run it, check the balance rates before you tear into it. I bent a rod on a gas engine that had a coolant leak, I had low compression on two adjacent cylinders and let it sit for a while before I pulled it into the garage. Just starting it up and pop, I was done.

How do you know you have a coolant leak, if I may ask?

To read balance rates I use an obd 2 diagnostic tool by alex peper at obd-2.com, but many programmers also have the capability. If not, a tech2 at a dealer can do it for you, probably for a fee.

If you have a legit GM dealer there, then talk to them about warranty support. I can't see why it would be restricted, unless duramaxes were never officially exported and thus no support.

Search around here, there are a lot of people with similar problems and lots of good information. For example, if you are ever thinking about power/performance increases, maybe using studs instead of stock bolts might be in the cards if you have the heads off anyway.

Good luck, post any progress for those who are interested.

nice to hear that you have viking blood!

yes i do know that injectors are REAL expensive! therefore i wondered if i could get them on warranty, because when i do all that work with the headgasket change, i just dont want to reuse my old injectors, and then get a injector failure some months later..
same with the glowplugs, they are relative cheap compared to the major work to replace them, not to mention how much work it would be if a tip breaks and falls into the cylinder!
if i push down the accelerator just a 1/4" it will idle very rough, so i think i have some bad injector, but i havn't got my hypertech yet so i havn't checked wich one.. if i can do that with the scanner??

there is duramax's sold new here, but only in light-duty trucks, they dont sell any 3500, all those is only imports.
and the dealer with duramax-service is 250 miles away, and they take ~$150 /hour so i dont have the money to get it towed that distance and pay for a headgasket change just to get the injectors on warranty.

i know that i have a coolant leak because there's escaping coolant from the system and i got a hydrolock condition once i started it.
so i'll try with a cooling system stop-leak additive first, if it works, then i can take it apart later in the summer on my vacation, otherwise, i must let it stand 'til i have the time..
i started a thread about this on another forum too,
http://www.gm-diesel.com/diesel/vbull/showthread.php?t=23798
but it seems that there's more activity and knowledge about duramax here

i was very excited about to get some more HP with a programmer, but now when i read about all the problems wyth those LB7's i'll let it be!
i will mount a shiftkit and deep pan on the Allison to make it last longer with the stock engine, and i will buy a MBRP stainless-stack exhaust for appearance purposes, but i'm happy if i get a few more HP in the process..
but first i must fix this coolant problem before i spend a lot more money..
i have already bought lamps, 6 alu rims and other styling parts in US for ~2000$ that is on its way in a container..

by the way, have someone mounted the lubrication specialist fuel filter that is mentioned in a article here:
http://www.thedieselpage.com/reviews/landuytfuelfilter.htm
do you think it's worth the cost or should i buy a better filter (2-3 micron) for the stock filter holder? i dont want to mess up my new injectors with any dirt!!
and, the diesel here has ZERO sulfur, should i be worried about that or will the LB7 run fine?, in all my other diesels (volvo 940, chevy 3500 6.5TD..) i used a little 2-stroke oil in every full tank, but the D-max is so new so maby it will run on ultra low-sulfur diesel, as you call it over there (but yours still have 15ppm of the goodie, ours havn't got any since 10 years back)
Have a nice day!
Oskar

[DmaxMaverick]

Welcome aboard, Duraswede!

It does sound like you have at least one injector failed. It is pointless to find out which one. They should all be replaced, under warranty or not. If you don't, you will likely have to do it again in your near future.

Your 3500 is "light duty". Medium duty begins with the 4500 series. If your dealer can service the 2500HD with a Duramax (the only other GM light duty truck with the Duramax), then they can service your 3500. Problem is, they may have an "import clause", preventing them from warranty servicing a vehicle not originally delivered to your area. You'll have to get the dealer to work with you on this. They can do it, but that's no guarantee they will. As far as the work is concerned, there is no difference servicing a 3500, compared to a 2500HD. They are the same, other than suspension components.

Your coolant issue may not be the head gasket, at all. Duramax head gasket failure is very rare, although it does happen. You very likely have an issue with the injector cup(s). If they crack or lose their seat seal, coolant can leave the cooling circuit and enter the cylinder. Be very careful with the coolant issue. A hydrolock can mean game over for the engine. You can find which cylinder has the coolant, easily. Run the engine up to temp, then let it sit until it cools to ambient temp. pull ALL the glow plugs. The suspect cylinder(s) may show coolant (or evidence of it) on the plug immediately. If not, have someone crank the engine while you watch one bank, and have someone watch the other bank for the coolant to spray out. Do yourself a favor and identify the source of the coolant before you pull the heads. If the dealer starts an injector replacement, they will be able to tell if a cup has cracked or unseated. You can, at that time, decide to pull the head(s) or not. The cup(s) can be sealed and the cooling system tested before the top end is reassembled. If a cup seal job cures the coolant leak, then the head gaskets are good.

[Duraswede]

Welcome aboard, Duraswede!

It does sound like you have at least one injector failed. It is pointless to find out which one. They should all be replaced, under warranty or not. If you don't, you will likely have to do it again in your near future.
Thanks! i appreciate all the help i can get here!
i have already decided to change the injectors, even if i have to pay for them, it's such a common failure, and can lead to such a big mess if negligated, so i dont want to take that risk.


Your 3500 is "light duty". Medium duty begins with the 4500 series. If your dealer can service the 2500HD with a Duramax (the only other GM light duty truck with the Duramax), then they can service your 3500. Problem is, they may have an "import clause", preventing them from warranty servicing a vehicle not originally delivered to your area. You'll have to get the dealer to work with you on this. They can do it, but that's no guarantee they will. As far as the work is concerned, there is no difference servicing a 3500, compared to a 2500HD. They are the same, other than suspension components.
i thought that 1500 was light duty, 2500 medium and 3500 and up was HD, but i was obviously wrong!
however, they sell 2500's here, so as you say, it's the same engine!
they will surely work on it, but in the end it's a matter of cost, as i wrote, they are 250 miles away..



Your coolant issue may not be the head gasket, at all. Duramax head gasket failure is very rare, although it does happen. You very likely have an issue with the injector cup(s). If they crack or lose their seat seal, coolant can leave the cooling circuit and enter the cylinder. Be very careful with the coolant issue. A hydrolock can mean game over for the engine. You can find which cylinder has the coolant, easily. Run the engine up to temp, then let it sit until it cools to ambient temp. pull ALL the glow plugs. The suspect cylinder(s) may show coolant (or evidence of it) on the plug immediately. If not, have someone crank the engine while you watch one bank, and have someone watch the other bank for the coolant to spray out. Do yourself a favor and identify the source of the coolant before you pull the heads. If the dealer starts an injector replacement, they will be able to tell if a cup has cracked or unseated. You can, at that time, decide to pull the head(s) or not. The cup(s) can be sealed and the cooling system tested before the top end is reassembled. If a cup seal job cures the coolant leak, then the head gaskets are good.

my first thought was of course the gaskets, as i didn't knew about those injector cups, and i know that i should be careful, therefore i will try with a sealant additive, because i must drive it 60 miles to a test facility at our department of motor vehices to get it registrated here, i want to have it insured and cannot do that before i have a registration plate..
but i just cant imagine that a starter motor torque could bend a rod even if hydrolocked, the rods are at a much higher stress while the engine is producing full power.
those injector cups you mention, are they replacable or are they a part of the cylinder head?, and if i can replace them, can i do it with the heads on the engine?
i could start with that of course, its a lot easier than pulling both heads..

I will anyway call the dealer and ask about the injector warranty, if it's covered, and they will replace all the injectors for free, i'll maby let them do the work and replace the cups at tha same time to see if it works. but the distance is a big problem!, it's 250 miles one way! i will try to find a dealer closer, i know a couple of chevy-dealers just 50 miles away, but i dont know if they are familiar with duramax, or maby they dont even know what a GMC is... most of the chevy dealers here are Saab/opel dealers that sell those crappy daewoos with a chevy sticker, so they will not do any work on my GMC.

[DmaxMaverick]

The injector cups are included in the warranty for the injectors. If they are unseated or cracked, they should be covered under the same policy and repair. They are normally reseated/replaced at the same time as the injectors (if needed), and head removal is not required. Our onboard techs can go into more detail, if necessary. You may try contacting GM customer service about this (either your local, or USA, or both). The can approve an action in your case, before you get to the dealer. If nothing else, they should have more helpful information. As long as your truck is not modified, you should not have an issue with this.

Hydrolock can, and does, cause catastrophic damage just from cranking. Many times, a dry cylinder will fire before the wet cylinder comes up, and bam! Less common with the Duramax, as it usually has to crank a bit to build fuel pressure. Also, the starter motor torque is sufficient to bend a rod, among other things, when the piston has nowhere to go. More often than not, that is when the major damage occurs, before the engine even has a chance to start. It might as well be a chunk of steel in the cylinder. Water/coolant doesn't compress any better than steel.

The Duramax engine was never installed in a 1500 series truck from the factory. It has been installed in 2500-3500 vans and cab/chassis trucks, though.

Your use of 2 stroke oil in the fuel is a good idea. These engines were designed to use low sulfur fuel, but lubrication is still beneficial, IMO. I use it with 15 ppm fuel. Also, additional fuel filtration is good. Keep the original filter, and add a secondary, good system. There are several options offered by TDP Advertisers (http://www.thedieselpage.com/vendors/main.htm).

[Duraswede]

i called the dealer today, and asked about the price for headgasket exchange including injectors, he was calculating on the computer for a minute and then he said:
well, that was quite expensive, it will be 72.000SEK, thats 11000$ !!!!!!!
i just didn't know what to say, i asked him if he said 72 or 22, but yes he said 72... i asked how much they take /hour, but he didn't wanted to answer on that question, he just said that it's a "major job" Well i sure know it is, but i can nearly get a goodwrench engine for that price i told him..
Yes, in US, he said, but in sweden that engine would cost the double.. now i really understand why everybody with a US vehicle buys just everything overseas, even service parts..
i asked him about the injector warranty anyway, he should check that with GM europe and call back tomorrow, but i really dont think it will be covered..

it seems that i have no other choice than just take it apart myself, so i will do as you suggest, change the injectors&cups first, and see if it cures the leak.

another thing i noticed is that there is no compression going out in the coolant while the engine is running, i filled the reservoir all the way up to the opening, and started it, and the water did'nt rise or bubble out any air, that's also strange, is the intake ports close to any water port in the intake? like a chevy smallblock gasser? then it could be as easy as a intake gasket!!

[DmaxMaverick]

No problem with the intake/coolant issue. If it's leaking there, the head has porosity issues, which means new head.

If the coolant is leaking directly into the cylinder, it could be a head gasket, like any engine, but you should be seeing some coolant system pressure from it. The likelihood is high the problem is the injector cups. You will need a special tool to R/R them. There is a specific procedure to replace and reseal them. It must be followed to ensure a perfect seal. Duramaster or another tech should advise you on that. If you are competent under the hood, you should have no problem with this. Be sure to follow the procedures and allow for a lot of time. If you have a cracked injector cup, allow additional time for you to source one (or more). I have not done this myself, only observed.

If you don't have a service manual, get one. www.helminc.com (http://www.helminc.com) offers the published version of the manual, and a www.alldatadiy.com subscription offers the same in online form. They will have all the procedures, parts/tools and torque spec. recommendations needed to complete the repairs you are facing. Sounds like you will be on your own for much of the service needed for this truck, and I would not suggest doing that without a good manual. Don't bother with Chilton's, Haynes and the like. They are more trouble than they are worth.

[Duraswede]

No problem with the intake/coolant issue. If it's leaking there, the head has porosity issues, which means new head.

If the coolant is leaking directly into the cylinder, it could be a head gasket, like any engine, but you should be seeing some coolant system pressure from it. The likelihood is high the problem is the injector cups. You will need a special tool to R/R them. There is a specific procedure to replace and reseal them. It must be followed to ensure a perfect seal. Duramaster or another tech should advise you on that. If you are competent under the hood, you should have no problem with this. Be sure to follow the procedures and allow for a lot of time. If you have a cracked injector cup, allow additional time for you to source one (or more). I have not done this myself, only observed.

If you don't have a service manual, get one. www.helminc.com (http://www.helminc.com) offers the published version of the manual, and a www.alldatadiy.com (http://www.alldatadiy.com) subscription offers the same in online form. They will have all the procedures, parts/tools and torque spec. recommendations needed to complete the repairs you are facing. Sounds like you will be on your own for much of the service needed for this truck, and I would not suggest doing that without a good manual. Don't bother with Chilton's, Haynes and the like. They are more trouble than they are worth.

I always buy a real shop manual for every car i own, i bought one for my sierra from books4cars.com, but helm is also a good source, altough i dont think they ship overseas.
i have a couple of haynes manuals too, but it's the Techbook-series..

i havn't got the manual yet, it's on its way, but as soon as i get it i will check how the Dmax is built..
I would like to say that i have a lot of experience with diesels so there will be no problems to do the work, but its just boring to spend a lot of hours in the garage the first i do...
Edit:
the special tool that's required for injector cup replacement, where can i buy it?

[DmaxMaverick]

the special tool that's required for injector cup replacement, where can i buy it?

I don't know. You'll have to check with the tech's or GM. Once you get a part number, you should be able to source it.

[Duraswede]

Hi.
I will check if there's some number for that tool in my shop manual when i get it.

Called the dealer (stealer) today again and asked about the warranty, he told me that there was a warranty for my truck that expired in november-07, and he didn't knew anything about any extended warranty, i tried to explain that i have read that on several sites in US but he just said that GM-europe told him this..
I asked what the injectors would cost, just for fun, they would cost nearly $1500 EACH!!!!!!!! so i told him that if i buy them in US, i will get all eight plus the shipping plus the 25%tax plus the 10%toll fee's for UNDER that price!
I asked him if they have any customers with that prices, oh yes, he said, the police has a couple chevy vans, the road constructors drive chevy trucks and ford vans, and some of the ambulances is chevy 2500's , even the fire dept. has chevy crewcabs, and all of them do the services & reparations here, and they dont even ask the price first....:eek:
now i know where all the tax money is spent!!!!! :mad:
but it is'nt so much cheaper on other dealers either, the biggest US part supplier here has approximately double the prices in US on many parts, it hav'nt always been like that, the dollar has been going down a lot in some years now, and those companys havn't lowered the prices, so when the dollar goes down, their part of the cookie just grows..

i had some time to remove the glowplugs today, it was quite easy, not really what i thought it would be when i looked from above to locate them the first time..
But they were way longer than i expected, seemed like they would never end when i pulld'em out..
There was some wet signs on the Nr 5 plug, and nr 8 was oily, but when i removed nr 2, it dripped out water, so that is the worst one, but i'm still concerned about the other ones, OIL is not so good to see on a glowplug, altough it wasn't oily on the tip, just on the long "pipe" between the threads and the tip.

a photo and a video clip on the waterfilled cylinder "draining" :
http://i73.photobucket.com/albums/i221/_chevrolet_/DSC00436.jpg
http://s73.photobucket.com/albums/i221/_chevrolet_/?action=view&current=MOV00437.flv

[Duraswede]

after i reassembled it, i took a test-ride and it was smoking a lot the first 10 minutes, exactly as the first time, it has to do something with the oil on #8 glowplug.. but how can it be oil there, i see no other reason than bad piston rings, but it should have smoked even when it was warm then?
a video on the startup smoke:
http://s73.photobucket.com/albums/i221/_chevrolet_/?action=view&current=MOV00440.flv

however, i mixed the Bars-leaks in the coolant and drove it until thoroughly warmed up, lets see if it helps so i can start planning an injector change later..

i'm considering if i should take off the heads at the same time and send them in for leak-test it's only $400 for both so it might be a good idea, what do you think, is cracks in the heads anything that occur on d-max?

i made some video clips during the test drive, the first one is on the blue smoke, and you could also hear the knock from 0:10 to 0:02
http://s73.photobucket.com/albums/i221/_chevrolet_/?action=view&current=MOV00442.flv

here you can hear the knock better, i'm going uphill so it's much load on the engine, (altough the lockup is still engaged)
you can hear it from 0:23 to 0:14, then i slow down for some seconds and accelerate again at 0:11
http://s73.photobucket.com/albums/i221/_chevrolet_/?action=view&current=MOV00444.flv

[jbplock]

DS,

Your video clips are excellent.. http://www.thedieselpageforums.com/tdpforum/images/icons/icon14.gif I didn’t hear the knock too well in the driving clips but it’s noticeable in the first with the truck smoking at idle. Question on the smoking .. does it have a smell of diesel (i.e. un-burnt fuel) or oil? .. Smoking is a common DMAX symptom of a failing/leaky injector. Have you been able to check you balance rates? That may provide some clues. A compression check would help with your diagnosis too if you have access to a gauge. It’s clear from your posts that you’re a pro …No doubt you will get to the bottom of this .. Thanks for keeping us informed of you’re progress ..

:)

[DmaxMaverick]

Diesels generally won't smoke like gas engines with they "burn" oil (although they can). Oil, to a Diesel, is just another fuel. I suspect the oil you found may not be motor oil, but perhaps just a "wet" cylinder, wet with fuel. This can happen after shutdown, before the pressure is dumped, or static leaking of fuel through a bad injector (also explains the excessive smoke at startup). Mine did this before my last injector change. Also, when it starts up (on a warm engine, after it sits for a few minutes after shutdown), does it "ping" or sound like a gas engine "knock", just before it fires off (like a gasser with timing too advanced)? This would indicate the fuel leak after shutdown, and explain a fuel-wet glow plug. The presence of excessive engine oil in the cylinders is just not seen on these engines, not to say it can't happen. A lot of engine oil in the cylinder caused by bad rings would also have other symptoms. Like excessive blow-by to the point of making a huge mess under the truck from the crankcase vent.

I'd venture a confident guess your smoke is caused by bad injectors (excessive fuel), and/or coolant (steam), not oil. Like JB said, the smell can be a good indicator. The smoke conditions you describe and show are the most profound indications of bad injectors.

I think pulling the heads, at this point, is premature. You really need to get a look at the injector cups. If you have one leaking as much as is indicated by you photos and descriptions, there should be significant evidence of it on the cup. You may have to remove/repair/replace a head because of this alone. It will depend on the erosion that may be taking place. Head cracking is not common, at all, on the Duramax engines. From what I have seen, the Duramax engines have seen fewer head issues than any of their cast iron counterparts (Cummins, Powerstroke, 6.5L, etc.).

Good videos. However, I don't hear any "abnormal" knocking. Doesn't mean it isn't doing it. I just can't hear it. If you say it knocks, then it does. And, it shouldn't. Just another indicator of bad injectors.

Also, at this point, I think an injector balance test is not going to help you diagnosis. If the dealer wants to do it, they will. Don't pay for it, if that's an option. The balance test will not show which cylinder has bad injectors. The balance parameters (fuel offset and PWM) will be different for all cylinders, and other cylinders will be compensated to correct unbalanced combustion in cylinders with a bad injector. At this point, you know you have at least one bad injector (or reasonably suspect), and you are replacing all 8. There's no advantage to reading the balance rates, because they will be completely different after the replacement.

Your engine may have unique failures, and you bought a truck with baggage (preexisting problems). The previous owner may have known this, and unloaded their problem onto you. This happens, and is unfortunate. Could be the result of excessive use of power enhancing modifications or other abuses/problems. You really need to stay firm with GM on this. It's going to get very expensive, and GM is responsible for a lot (or all) of the burden, regardless of where you have it repaired. Even if you have to go 500 miles, find a dealer who will help you. It's inconvenient, at best, but the end result will be in your favor. We'll do what we can to help you with this, but the internet can only reach out so much.

I'd really like to get some comments from Duramaster. He sees these issues on a daily basis.

[Duraswede]

DS,

Your video clips are excellent.. http://www.thedieselpageforums.com/tdpforum/images/icons/icon14.gif I didn’t hear the knock too well in the driving clips but it’s noticeable in the first with the truck smoking at idle. Question on the smoking .. does it have a smell of diesel (i.e. un-burnt fuel) or oil? .. Smoking is a common DMAX symptom of a failing/leaky injector. Have you been able to check you balance rates? That may provide some clues. A compression check would help with your diagnosis too if you have access to a gauge. It’s clear from your posts that you’re a pro …No doubt you will get to the bottom of this .. Thanks for keeping us informed of you’re progress ..

:)
yes it's quite hard to hear it on the videos, i had to turn up the volume to max to hear it. and when it's idling i cant hear any knock, so it must have been something else you heard, maby the exhaust pulses sounds strange in the mic.
well, i can recognize the smell of unburnt diesel (when i start my fathers Fordson tractor;)) and it's not really that kind of "cold combustion" smell from my truck, it's more like it's burning oil. but it disappears when it's warmed up, and if i let it stand overnight it don't smoke anything, it only happens when it has been standing a couple of days.
As i wrote earlier, i havn't checked the balance rates yet, i have bought a scan tool from summit (HYP-32003) but it dosn't seem that i can check injectors with it, so i dont know how i should do it, as i mentioned earlier there is no dealer in my area, so i must do everything myself.
but i have read here that if i push down the accelerator just some millimeters i could be able to determine bad injectors if the idle will be rough, and so does mine, so i have at least one bad injector, and i'll replace them all anyway because there's so much trouble with the LB7 inj.
and at the same time i'll mount an auxilary fuel filter (post-OEM) rated to 2-3micron, so then i hope i get read of all further fuel system issues.

[Duraswede]

The sealing additive helped! it's no longer leaking, so i can wait until june when i take it apart, but i have to find some parts, i found rebuilt injectors for $149 on internet, are rebuild ones OK or should i rather buy new bosch? it's nearly half the price for rebuild...
and where can i buy the injector sleeves? only at a GM dealer?
I know a guy that is in US 2 weeks from now on and will ship a car to sweden, so i can get cheap shipping, but i have to find the parts now!