'83 blazer 6.2 IP issue?

[Ben613]

Hi all, I haven't been on the forums in awhile...because I haven't owned a Detroit since my last visit.

So here's what I got, 1983 k5 blazer 199,000ish miles, nice looking 6.2 n/a.
PO said he thought the IP was shot...I don't know if it is or not...he also said that OD is out in the 700r4...Suggestions?

The problem I'm having is that it won't start (yeah I know not a very common thing) I have everything primed up to the "out" line at the secondary filter. Lots of fuel pressure. Just that I have nothing coming out of the IP...do I need all eight lines open to get fuel?

Ben

[DmaxMaverick]

Welcome back!

No, you don't have to loosen all 8 injector lines. More helps, but it isn't required. Once you get a couple-few cylinders to fire, the others will follow. You should loosen at least 4. Choose the ones you can best reach. It also helps to remove all the glow plugs, or as many as you can (disable the GP system during this priming cycle), to help speed up the cranking. Make sure your batteries are up to the task. Keep them fully charged until you get it running. Slow cranking helps little, if at all. Watch for fuel weeping from the injector lines, then tighten them. Crank again until you see a fog/mist of fuel from the glow plug holes. Replace everything and tighten it up. Allow a full glow cycle and it should start. It may be rough and lope when it does start, but that should clear up quickly, less than a minute. It's also suggested to do this process during peak mosquito season.

[Ben613]

BTW...when you say weep how much fuel are we talking about? Will it spit out around the end of the line with the nut off?

Also, both "solenoids" in the IP click when given 12v separately...anything else to check?

Thanks for the help!

Ben

[Ben613]

Didn't mention this truck has new tires with less than 50mi on them and it came with a western 7.5ft Pro-guard snow plow! I wouldn't plow with this setup though...the plow is WAY to heavy for the little guy....front end is on the rubber stops!

Ben

[Ben613]

The battery's aren't up to snuff...they're 7yrs old and I know they sat for more than 100 days without a charge. I put in a new HO starter and it will crank fine with a jump....

Ben

[DmaxMaverick]

The injector lines should NOT be removed, only loosened about 1/2 turn. If they are removed, there is no way you will get it primed. The fuel will run out of the line. Slight loosening allows the fuel to "leak" out during an injection pulse, but not run out freely. Only a "wetness" of fuel is needed. Once the line/nut is wet with fuel, tighten it. Enough fuel is in the line to pop the injector. If the corresponding glow plug is removed, you should see a mist of fuel while cranking. Once you have that, it's primed (at least enough for a start).

While I do not recommend plowing with a K-Blazer, it can be done. Replace the original front springs with 3/4 ton springs and add a leaf. The K-Blazer is not the best platform for plowing, but they have the tightest turning radius of any 4x4 truck. I know of a couple in plow service, and they swear by them.

[DmaxMaverick]

The battery's aren't up to snuff...they're 7yrs old and I know they sat for more than 100 days without a charge. I put in a new HO starter and it will crank fine with a jump....

Ben

That's half the battle. Get some new batteries in it and it should be downhill from there. Keep them charged!

[Ben613]

Ok...I've been trying to start it all day...I believe I have fuel to the IP....If I pull the line off the top of the pump I get a slight pulse coming out???? Which, to my understanding is flowing backwards? Tell me I'm wrong.

Now like I said...I think both solenoids on the IP click...I can feel it when I R&R the wires. I did crank it with the injectors open and the GP's out...but I might have opened them too far. After that, I shut them and cranked it with nothing coming out the GP holes....

I'm kind of at a loss here...even your wildest suggestions are welcome!!!

Ben

[DmaxMaverick]

OK. The line at the top of the IP is the return line. It flows excess fuel back to the tank. It's normal to pulse some fuel while cranking. It also indicates the IP has fuel, and ESS (Engine Stop Solenoid) is working. The other (more rear) electrical connector is for the HPCA (Housing Pressure Cold Advance). It helps during cold starts by advancing the fuel injection timing a bit.

Now, once you have fuel weeping from the fuel injector line nuts, tighten them. If you removed them completely, repeat the priming steps from the beginning. They WILL NOT pop the injectors and inject fuel to the cylinders if they are off or loose. It is the high pressure fuel that causes the fuel injector to "pop", and inject the fuel to the cylinder. Loosening the injector line nut only a little, it allows the air in the line to escape, without having to go through the injector. It will, eventually, but takes a long time with no cylinders firing.

With all injector line nuts tight and glow plugs out, crank the engine. If the fuel lines are primed and injectors pop, you should get an indication of fuel from the glow plug holes. Not much, only a mist or fog. Hold a white paper towel near the hole while cranking. Once you have that, reinstall the glow plugs and connect them. Cycle the glow plugs and turn the key to start. It should, at least, try to start.

[Ben613]

I'll give it another go!!!!! Will let you know what happens....


Ben

[Ben613]

Ok, tried multiple times to get fuel at the injectors....to no avail....I have tried barely opening the lines...I've tried opening them completely....still nothing coming out! IP has fuel, both HPCA and ESS function as far as I can tell.

The only thing I think it could be is something internal to the pump? In my Haynes Manual it mentions the governor weight retainer ring...says if the OE ring comes in contact with water or alcohol it will disintegrate...possibly effecting the fuel return check valve...causing either rough idle or a no run situation.

So at this point I think it's something internal to the IP....suggestions?

Ben

[DmaxMaverick]

If you have fuel into the injection pump, but it won't push fuel to the injectors, the IP is suspect. It should, at least, push fuel to the loose fuel injector lines. If the IP can't pop the injectors, it's toast.

[Ben613]

Do you think the ESS could be opening only partially? Either way....I'm pulling the top cover off.

Ben

[DmaxMaverick]

DO NOT pull off the top cover!!! Incorrect replacement can cause a runaway engine revving to the moon (one way trip). If it has shown fuel flow at the return outlet, and at the injectors, at any time, it's working, and not partially. They very rarely fail.

[Ben613]

I have a hayne's manual for the 6.2 and 6.5 GM diesels...it covers the install of the IP top cover. I don't believe the IP has ever been off...So I'm betting the OE pellathane ring is still in there....possibly gone bye bye.

Also, Up to this point I have not had any fuel to the injectors! The only presence of fuel is the slight pulsing I get at the return outlet....FYI the system is primed up to the IP. I also have very good FP pressure. Unmeasured but, upon cracking the "out" line on the secondary, Plenty of fuel comes pulsing out....

BTW, PO owned it since '87 and has a complete parts and repair history!

Ben

[DmaxMaverick]

The Hayne's manuals are useful in the privy. Not much else.

It's important to follow the priming steps. Not only are they intended to get it primed, they are also diagnostic steps for when something is wrong.

If that is the original IP, it's long past it's useful life. If it can't produce enough fuel pressure to pop injectors, stop messing with it until you have new pump in hand.

[Ben613]

Little info....Just found the "E" tab on the right front corner of the IP...indicating the retaining ring now is an "EID".

Onward and upward!

Ben

[Ben613]

Well...got the pump down to the local rebuild shop. I was able to get a J code pump from a friends k30. It ran so, it should be a little easier to rebuild...(All the steel parts in the blazer pump are rusted?) Must've been A LOT of water in the fuel. Should have the k30 pump back next week. Woo hoo!
Maybe I'll get some pictures up...it's a rust bucket!
How much more HP will this J pump put out?

Ben

[DmaxMaverick]

The DB2 pumps are essentially all the same. Some updates and upgrades happened over the years, but nothing stellar. All DB pumps are capable of maximum HP in any N/A engine. Nothing really improves until you get into crazy high performance areas, and all of that begins with charging the intake air (turbo, blower, etc.). The K30 pump, whatever it is, will provide the HP according to the calibration set by the shop. If you tell them you are installing it in a 1983 Blazer, and they calibrate as such, it will produce no more power than your previous pump could have. If you want more HP, have them calibrate it for the late HD set, which will be in the area of 165 HP. However, your engine, collectively (heads, injectors, valves pre-cups, intake plenum, etc.), was never designed for that, so you may get more HP, but won't likely get close to that. The N/A 6.2L can be built to produce around 200 HP, but what you have will need a complete facelift to get anywhere close to that. 215 HP marine N/A engines aren't uncommon, but when you are floating on your cooling system, you can do a lot more. Your problem will be the cooling system and heat management. Unless you plan on some serious cooling system maintenance and upgrades, keep it around original power levels. If you get a lot of black smoke under load, you'll fry the heads, gaskets and pistons in a hurry. I strongly recommend installing an EGT gage to keep that in check. Also, a new injection pump coupled with old injectors is far from ideal. They should be replaced together, in any case.

[Ben613]

I know it's not a good idea...it will just be to get it running. If the motor is worth it my hope is to turbo it and put in a custom 4x4 Rock crawler. (Friends in the Rockies).....:D

Ben

[Ben613]

Here's some pictures of the beast....

[Ben613]

FINALLY got the IP back from the shop...(Loooong story)...Should have that baby runnin by noon tomorrow....

Ben