'95 Chevy K2500 Basic Mods?

[stezloco]

Hello ,
having only driven jap pickups and landrovers i was pleasantly surprised to discover the power available in this old chevy.......
a recent purchase of a '95 chevy k2500 6.5td/auto trans, 134,000 mls prompted me to search out the experts and from what ive read so far you're well versed on this motor.....ive got a 4 book set of manuals on the way from the U.S.A to blighty, to help me out as well,cant wait.
have been thumbing through a Chilton manual to read up on some basics ..i'm expecting to be parting with some cash to get this thing to a good useable standard to pull my trailer..so here goes ..
blowby ......its got some...
injectors ..apparently have never been changed...
k+n airfilter fitted...woo hoo
turbo kicks out black smoke on/off/on/off when accelerating.....read its vacuum controlled, not what i'm used to ...can it perform better without the smoke? is there a fault present i'm not yet aware of...i'm not looking for a hotrod or i'd have bought a petrol(gasoline) engined truck ,just want it to run clean and healthy..
looking to change injectors asap and remove the cat section of exhaust.
auto trans seems rough/clunky changing through to drive from park when cold, and the shift light goes out every other position moving from park position.
havent had a chance to get a good look at it yet and its parked up doing nothing.
would like to think its fixable (maybe 'cept the blowby) any comments on basic improvements to this engine would be helpful...i'll be reading through the forum as i get chance and may come across these answers anyway....
lastly ...think yourselves lucky .....we currently pay £1.07 per litre for diesel...x4.5..thats £4.81 a gallon (imp gallon) divide by 0.82 converts that to £/U.S gallon ,x 1.62 current exchange rate, = $6.39 a gallon...(my math correct?)..hows that for ya? its expected to rise in the new year after the V.A.T, (tax) re-instatement back to 17.5% from the current 15%....you dont have it so bad.....yet ....is it time i emigrated ? ;)

[6.5 Detroit Diesel]

welcome to the TDP. your right, everyone here will help you get your truck running best.

a few things. that black smoke is fine and normal. some of us like black smoke and will go to great and sometimes expensive lengths to be able to have black smoke on "tap". :D

injectors at 134,000, their getting up there. might be time to get some new ones along with a tune from Kennedy or Heath if you are looking to make it run in top form. just a thought. ;)

we've felt the diesel pinch up here in canada. currently in my town, it's more expensive than gas. :mad: last year it was up around $5.63 a gallon for a while. kinda makes you think about whether it's worth it to have all that extra power. of course, once you get to working with your truck, there can be no question. :)

[Artworks]

My mods are in my sig. Black smoke is not normal for these trucks, it may suggest that it is not getting enough ait. Filter & air intake first thing to look at. Then check waste gate operations, linkage / selonoid. My truck will only put out lot of black if I realy put my foot in it and accelorate hard under load. Check out this site with a search for your problems , ask the right questions and someone will usually have answer. I have gotten a lot of hel[p over the 5 yrs. I have had my truck. I would have gotten rid of it years ago without the help of many people on this site. Good luck.

[Robyn]

The 95 6.5 is electronically injected and the turbo wastegate is vacuum actuated and controled by the ECM (Computer)

There is a vacuum pump on the RH front of the engine under the AC compressor.

Make sure you have a good steady vacuum at the pump with the engine running. 26" HG is normal.

The needle on the gauge should not flutter or bounce around. A bouncing needle indicates a bad pump.

If the pump is OK then check to be sure you have a steady vacuum at the wastegate solenoid (Small device at the rear of the LH Valve cover)

Incoming line from the pump should show the same 26" HG just like the pump.

The oultlet side of the solenoid will generally see less vacuum.

Make sure the vacuum lines that go from the pump to the solenoid and then on to the waste gate actuator (on the turbo) are not cracked and leaking.

Check with the engine off to see that the wastegate actuator arm on the turbo moves freely back and forth.

There should be about 15-20" HG vacuum at the actuator when the engine is running and the waste gate arm should be in the closed position and you should not be able to move it.

If the arm can be moved easily when the engine is running then the waste gate actuator is faulty (bad diaphram)

The ECM varies the vacuum to the wastegate actuator (pulses it) to allow the gate to open and close thus maintaining the desired manifold pressure (boost)

These vacuum systems are fine WHEN THEY WORK.

The pumps, lines, solenoid and the actuator are all parts that can and do fail.

The tail pipe should stay fairly clean on these even under hard throttle.

A common mod here is to install a turbo master (spring device that replaces the gate actuator.

A computer chip that will allow more boost and also keeps the computer from complaining if things stray from what it thinks it should be is needed to make this mod work the best.

If you use a turbo master and set it so the boost never goes over about 5-6 PSI you can use it fine with a stock chip.

I would recommned a Pyro and boost gauge.

With the boost gauge you can se what is happening too.

A malfunctioning wastegate system (vacuum or ???? bad) will result in BLACK SMOKE, poor performance and high exhaust gas temperature.

At the present time Diesel here in Oregon is costing me about $2.50 a gallon for ULSD commercial fuel.

Far better than summer before last at $4.50

Running big trucks that get 5 MPG at those prices is insanly expensive.

Check out the system and keep us posted.


Robyn

[6.5 Detroit Diesel]

i would beg to differ that a puff of black smoke coming out the exhaust under throttle is quite normal. excessive smoke if not built for, would point towards something with the vacuum.

[Robyn]

A little "PUFF" just before the turbo spools is fine but if I read the question right, the reference is to periods of smoke while accelerating.

Once the turbo spools a stock truck should run a clean stack all the while its being pushed.

On and off the skinny pedal and allowing the turbo to slow down will see some smoke everytime it has to spool back up.

If the truck has the soot trap (cat) it should run clean.

My 94 is stock and with a totally worn out original cat will kick out a little bit of "haze" but no black SMOKE

Even DaHooooley with the chip and the Turbo master will not cough out BLACK smoke.


Missy

[6.5 Detroit Diesel]

sorry, my bad. i read it again. if i understand it right now, it is spitting out smoke intermintently under throttle.

[stezloco]

Thanks for the quick replies, very much appreciated.
yes it is spitting out black intermittently under heavy throttle...it seems ok when accelerating gently,from what i can see looking out of the passenger side mirror but when you throttle hard it does it.....the Police dont take too kindly to black clouds and joe public has been made aware of the health risks , theres even a telephone number to ring to rat someone out...basically its a no no over here...seen the black stacks on youtube, just wasted fuel as far as i'm concerned im afraid... am i being too sensible?
I'll be looking at the air intake and vacuum system this weekend....first time ive come across a vac controlled turbo before, i thought the spring was missing when i first moved the actuator arm by hand.....
ive seen the turbo master kit available from Heath but wondered if an adapted actuator from a jap pickup would do the same job...i could cutout the back of the actator and fit an adjuster screw/plate on the base of the spring, and pipe to the inlet manifold. with a guage i could set it up to the 5-6psi Robyn recommends....that kit looks as though it relies on the pressure on the wastegate valve area itself to overcome the spring ??unless theyre not showing all the parts...... ive got a boost guage but would have to source a pyro from your side of the water cos ive never seen the like advertised in any of the usual places over here....if i can get the standard vac system to work well and run clean, i may just leave well alone...chasing power means lost mpg...i bought this truck mainly to pull a mini digger trailer at 3500kg, something the jap pickups just wont do legally here, they're only rated to pull a 2 tonne trailer and ive passed some heavy lookin loads going the other way, just plain dangerous.........i once came off the road in a modified range rover pickup with a trailer full of dolomite , approx 2 ton , and lived to regret it...needless to say 7 years later i'm back to towing trailers again but with a good heavy truck as a traction unit.... .i'll let you know how i get on with these checks..... thanks again to you all,
oh yeah.......it cost me £105 to fill the fuel tank for the first time...(approx. $170 ?).....i'm going to the bank to get a mortgage for the next tank full and see if i can spread the payments over 6 months or something ..........he he he :p

[DaveBr]

You have a boost guage so when it's blowing smoke is there a difference in pressure as you state it's intermittent under power. My truck is starting to do this but it is due to a high mile turbo that is being retired as soon as it warms up. (sometime in April or May)

[JohnC]

Yes, pressure in the turbine housing pushes the wastegate open, against either vacuum or spring tension.

The wastegate solenoids get sluggish and fail to control the vacuum, allowing the boost to exceed the programmed limits. The PCM switches the solenoid off and this causes the boost to drop to neat zero and the black smoke comes. This condition will not reset itself until you let off the throttle, though, so it doesn't sound like it fits your symptoms.

[stezloco]

thanks again fellas,
ive just been in the members area and looked at some of Jim Bigleys write ups on turbos and wastegates and theres a great article im going to follow up about early wastegate mod to this truck using '92-'93 wastegate actuator, should be cheaper than the custom one from heath and do exactly the same thing......and should do away with the vac problem altogether and make it less prone to faults....
boost guage is sat here on my desk not yet fitted so those symptoms cant be proved until it is...going to get a pillar mounted guage pod and mount this along with a pyro ive seen in the same writeups...what a great source of info this is turning out to be.....:D thanks again for your input...

[Pipeline Mechanic]

IMHO the vacuum system is worthless, I have the same pickup as you and I periodically get it out and tinker with it. Today was one of those days.
I am eventually going to do away with all vacuum and EGR systems
and swap to a VIN F type setup. I get disgruntled with it and hide the truck
so I wont mess with it, so it has turned into a never ending project. Good Luck with yours.

[stezloco]

2 splits in the vac hose ...one over the 'bulbed' end of the pipe on the turbo wastegate and the other mid line to the solenoid....
what a difference though when it was sorted...as suggested, i could barely move the actuator arm with the engine ticking over so i knew it was fixed there n then...first it ran up the road under hard throttle and belched out a steady dirty flow until i let off the throttle and re applied it then it ran cleaner...john c...maybe youre right about sluggish solenoids and having to let off to reset it...bit naff having to do that, it should be controlling the boost situation itself without my intervention.....i'm still going to go down the road of changing the wastegate actuator to a pressure type and when it hits max boost , theres no system dumping off the boost when you need it most..theres no EGR on this engine ...only one solenoid for the turbo, thats it.....overall so far , im still pleased i bought this truck....as regards the 5mpg Robyns getting (was that a typo?) i must be getting better value from my fuel over here even at these prices?? soon as i'm happy with this truck's reliability , i'll be getting rid of my old vauxhall brava (and 30 mpg along with it!!!) i dont think i'll be chasing max power but all these tasty mods that improve this engine interest me greatly and i'll be scouring this forum with an eagle eye... injector change is next job, after xmas has come n gone tho' and ive got some more spare to chuck at it...
manuals came yesterday from America, ive got some heavy reading material now and it just leaves me thanking you all who replied....this is a great forum, no doubts...........all the best....

[twaddle]

Hi Stezloco,
Welcome to the Dieselpage. I'm originally from Scotland and moved over to Alberta almost two years ago so I know what you have to put up with regarding the HIGH fuel costs.
The only thing with living out here is that even though the fuel is way cheaper than Blighty you'll easily do more than double the mileage with the distances between everywhere, unless you're a citybound type.

Regarding the Ol' 6.5, you should be able to get a local diesel injection shop to overhaul the injectors without any hassle or speak to Dave (if he's still there) at West Midland American Vehicles from the West Midlands. They are a good bunch of Guys there, Genuine GM dealer too and sometimes break vehicles so will also have second hand parts at good prices. Tell them Jim Twaddle from Alberta, formally Scotland recommended them to ya. West Midland American vehicles should have new injectors in stock. You may find shipping parts from over here a little expensive with the Sterling pound falling in value like a stone dropping down a well, A buddy back in the UK calls it the "Zimbabwe Pound" nowadays.

I have a 96 6.5 Suburban originally from Houston Texas, I shipped it out to Scotland where it lived for 6 years then shipped it out here to Northern Alberta when we moved out here.
The Sub is now clocking up just over 800 miles a week cummuting back and forth to Edmonton and is almost at 200,000 miles on the clock.

Oh, just when I remember if you are going to be pulling a trailer (what weight is the trailer including load going to be?) consider a larger diameter free flowing exhaust system as this will let the heat get away from the engine quicker. Just be careful what diameter you go for as it can end being a tad uncivilized. I fitted a 4 inch system which destroys any image of refinement that the suburban used to have. Also may attract the law regarding excessive noise levels etc etc.

I also recommend changing all oils and check the driveshaft U/J's etc while under it.

Good luck with the Ol' girl and as you've already found the DP is the best place for info and advice.

Happy Christmas when it arrives from the frozen North (windchill puts it somewhere below minus 40 this morning, Brrrrrrrr)

Jim
Formerly Biggar, Scotland Now residing near Evansburg, Alberta

[JohnC]

...it should be controlling the boost situation itself without my intervention.....

That is how it works, when it's working. If the solenoid is sticking, the boost slowly builds to beyond the program limit and the fault sets and it goes into "safe" mode. If the fuel rate drops below (IIRC) 20mm3 or the RPM drops below 1800 then it clears the condition as the engine cannot boost to unsafe levels under those conditions. When you get back on the throttle, all is well until it detects the overboost condition again, for something like 20 seconds, then it faults again.

[stezloco]

went on a little round trip today of only 68 miles, wasnt particularly careful with the throttle and floored it a couple of times...(paranoia still has me checking for clouds of smoke..) and cost me 35 quid....worked out at 9.43 mpg :eek:at todays price of 107.9pence per litre.....would definitely not want the fuel bills from the higher horsepower later models...on a lighter note... my bank loan came through today and i can now fill up the fuel tank.....he he he .
Robyn, I think your initial 'typo' on the 5mpg wasnt a typo after all mate...
Merry Christmas to you all...... ;)

[6.5 Detroit Diesel]

isn't 9.4 mpg ratherl low? all of my trucks get around 17-18 in the city and around 20 highway. just wondering

[stezloco]

maybe it is a little low , but i cold started it 4 times for 10mins warmup each time.the day before to clear the snow/ice, next morning to clear snow/ice and get to work , and in my lunch time to clear snow and allow me the quicker getaway at work finish time(4th warmup)...then i went and did the run.....so thats all included in those calcs....it should be better on a single start/single run out (i sincerely hope :eek:)...i went to my old fellas house on a round trip of 55 miles and it didnt come off the full mark, however i do fill it right up the neck to the same point each time....i'll only know what that run was when i go to top it up....
i'm looking to buy a scan tool and wondered if anybody could recommend a decent tool suitable for this truck which can also check inj timing. there are so many out there i dont know what i'm looking at really.
thanks again for your input.... ;)

[JohnC]

i'm looking to buy a scan tool and wondered if anybody could recommend a decent tool suitable for this truck which can also check inj timing.

Try this Dieselpage sponsor (http://www.enghmotors.com/)

[stezloco]

John C ....have you got this? does anybody you know have this and is it user friendly?......at first look, i'm not keen , i'd rather have a plug in box with all the gubbins already installed inside it....ive got a desktop computer and would need a 60 foot cable to get to the truck....hardly convenient.its cheap i'll give them that but it depends on how much they want you to donate for the free(?) software...they list the software for approx 1250 swedish krone($150) on their home site,is that what they want you to donate? or do you just chuck them a conscience payment?... so add that to your $85 interface cable .....so what do you pay?.....i hate it when they do that......i would rather they put a price on it...i dont want to be a skinflint or pay too much either....
i suppose a cheap laptops a must, and with software installed and the cable , im sorted???
whats the advantage if any of doing it this way? future updates maybe....wouldnt a handheld unit be better for garage use?
downside so far is i dont have a laptop......i'm stalled at the start line already.... ...do you know anybody who has this company's EM chip installed and running? i'll have to search old posts for that i suppose....i didnt want to get sucked into the 'chasing more power 'vortex because the next thing, your engine is running silly boost pressures and those cheap pistons are melted to the cylinder wall...but if a mild 'tune' can improve power and torque spread as well as improve mpg in an automatic without risking my old motor at this mileage, then i'd be interested.

[stezloco]

is there a hand held obd1 scan tool thats popular and reasonably priced that will do all the tasks needed on this motor ?.......i'm gonna call it a day on this thread and thank you all for your input...:)cheers

[suburbanK-2500HD]

I have this(Gmtd scantech), it works great, saved me lot of money.
you can time the inj pump with it, read codes, delete codes, read data from alot of sensors.....i like it alot.

[phantom309]

my 94 dually will barf a black cloud out if you stomp the loud pedal,. but it spools up quick enough and is clean,.it has a hand me down chip in it,.good exhaust, good air intake, optical bump, welded wastegate etc,.


Nick

[stezloco]

OPTICAL BUMP? whats that? f.i.p. mod?:confused:
why do you have a welded wastegate? standard turbo? how do you control top end boost/overboost? do you have an inlet manifold 'blowoff' valve ? it would enable getting rid of vac pump and hose/solenoid unplug i reckon..... what power / response gain has this made ?
i dont have too much of a problem with boost because the contents of my wallet and the price of go-go juice prevents me putting my foot to the floor ...ha ha.:D

[stezloco]

looks like thats the one i'll have to get....just need a 1/2 decent laptop or a netbook with sufficient spec?
cheers .. ;)

[stezloco]

Bought a toshiba netbook, cables on the way from Engh....hope it all marries up and works.still unsure of their 'chip' though, since there are no dyno figures , how do they know it puts out 60 hp extra??? gonna look at other chips as well, need to do some reading.....:)

[stezloco]

Enghs softwares great , easy to play with , well recommended. ...looking at inj pump timing....88 code set ...timing too advanced, rattle rattle...14mpg...pump body wouldnt adj enough before bottoming on the slots...shouldve been retarded with chain slop surely...?someones been here before...
removed ancills/etc to get at timing chain/pump gear...going to fit a gear kit to do away with slop altogether, while i'm this far in .can i just fit a smaller water pump drive pulley to speed up the std pump to 'up' the flow? (and shorten its brg/seal life, yiknow) anybody done that? dont suppose theres a pump output curve for that...
big numb fans gone,as well as the mouses nest between the rads, leccy twins going in its place, the space is cavernous without the fan housing. enough space to slot in a big intercooler as well.radiator drains' inaccessible (and cracked) going to araldite that in forever...
go-go juice at an all time(and rising) high of £1.21 a litre...37 U.S. gallon tank ...x139.86 L = £169.23 for a fill up...$258.1 at todays rate...boo hoo yogi. off now to look at KD's offerings.... see ya... ;)

[stezloco]

bought a phazer timing gear kit from K.D's, came yesterday, pretty rapid postage from over your side for a change....stung for 80 quid at customs on this side of the water, makes for an expensive 'fix', thats not a slur on you J.K. if youre reading this,i'm happy with the product, its just everythings a FORTUNE posted from America.
next job is a set of injector tips,(and manifold gaskets/retn tubing etc) to be set up at my local diesel pump shop, i'm just getting the cheap ones to see how they rate. then i'll buy a set of quality recon standard setting injectors for spares. ..... hadnt planned on all these spends but i love the power out of this old thing, just wish it wasnt so THIRSTY.my old jap pickup didnt register on the wallet scale as far as fuel mileage was concerned and wasnt really an issue.
after that will come the twin stat and x-over pipe mod and that will be the last i hope....apart from the oil leaking from the rear of the transfer case, which is a complete bodge by the previous owner, Carl if youre reading this , I MEAN YOU ! !...i havent even thought about that yet.:mad: