VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => Non VW Group Diesel => Topic started by: R.O.R-2.0 on March 14, 2011, 07:39:37 pm
-
ok, so my grandpas 95 chevy diesel started to randomly die on me.. whenever i get on the power a little, then get back off of it, the thing dies.. usually when going up hills or something like that.
am i on the right track thinking that the fuel filter needs to be replaced?
it will start back up after a fashion..
maybe the lift pump is dead/dieing?
-
Start with the fuel filter as that never hurts.... Could be a lift pump, but typically they either work or don't.. Could also be an oil pressure sender as that also controls the lift pump, but again they either work, or don't, usually.. I've seen the fuel lines coming off the sending unit in the fuel tank rust and get pin holes in them too.. But be prepared to replace the PMD..
-
I don't know much about those 6.2 and 6.5 motors, except that the PMD is a common fail point. There are re-routing kits to help keep them cooler and last longer.
I really want to get me a 6.5 Suburban.
-
The relocation kit is worth every dollar!! Aside from preventing future failures, it's much easier than yanking the intake and turning the IP to change these things.. I also HIGHLY recommend the D-Tech PMD over the Stanadyne one.. Even the most recent revision of the Stanadyne PMD doesn't seem to hold up like the D-Tech unit...
Kevin, check the other stuff to be sure, but I'd pretty much bet crucial organs that the PMD is taking a
crap..
You'd be surprised how many IP's get rebuilt on these things when it's just the PMD having PMS.. It's also surprising how many rebuilders don't replace it when they rebuild a pump...
-
+1 PMD vote
-
Start with the fuel filter as that never hurts.... Could be a lift pump, but typically they either work or don't.. Could also be an oil pressure sender as that also controls the lift pump, but again they either work, or don't, usually.. I've seen the fuel lines coming off the sending unit in the fuel tank rust and get pin holes in them too.. But be prepared to replace the PMD..
fuel filter is 2 weeks old.
lift pump is 3 weeks old.
PMD was replaced and relocated when we got the truck a few years back, its now under the front bumper..
-
isnt there a grey pmd, and a black pmd? he bought the black one.. idk if he knew you could get better ones.. he bought his off ebay.
its getting weird.. at first you would just have to hit the key and fire it back up..
now you have to crank and crank and crank, till it finally catches, then you have to pedal it till it smoothes out..
it will not idle on its own till you pedal the throttle a bit after it dies..
it has also been kinda hard starting ever since he did the last set of head gaskets..
-
I think the latest Stanadyne revision is grey.. The earlier one's were black, as well as the D-tech ones.... Either one of those have the brand stamped on them.. If it's a black box with no writing it's a China knock off..
Has it flipped a CEL at all?? The speed sensor in the pump can cause hard starting and rough running, but it will almost always set the cel.. I'm still kinda leaning towards the PMD even though it is relocated and fairly new.. I replaced 2 Stanadyne units on the '98 I had within a few years.. Even with the relocation.. I found the D-tech module on ebay for around $200 and mine as well as a few other of these trucks haven't had a problem since..
-
lol @ CEL..
my grandpa says you have to get the computer reset to clear the codes, so its been throwing a code since weve had the truck.. hes a million-aire, but wont spend the few bucks to have the stealership reset the ECU..
so, yea, its constantly running with the CEL on..
usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..
-
hes a million-aire, but wont spend the few bucks to have the stealership reset the ECU..
How do you think he got to be a millionaire?
The richest people I know do all their shopping at Walmart, Aldo, and the cheapest supermarkets in town.
-
he got to be a millionaire by working his ass off for 70 years, not pinching pennies.. lol.
they live comfortably.. but my grandpa refuses to spend any more money than he has to.. he re-uses his head gaskets hes so cheap..
when my grandmas cadillac breaks, it gets fixed to the fullest, not a cent spared.. but his own cars.. nah..
his caddy has worn out front suspension, and instead of fixing it, he puts new tires on it.
-
usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..
That's screaming PMD..
'95 is still OBD1.. Chuck a paper clip in the ALDL terminals A and B, click the key to run, and the DTC's will blink out on the CEL.. It'll flash each code 3 times, starting with 12.. If you haven't done it before you may need to read em a few times (Hell I still have to).. TO start over, turn they key off, wait a few seconds, and turn 'er back on..
The codes will be blinked out something like this:
For a 12
Blink (short pause) Blink Blink (Longer Pause) then it repeats 2x more times and moves to the next code..
Pull the ECM fuse or disconnect the batteries for 10 mins to clear the codes... IF you clear the codes, start the truck and the light comes right back on you have a hard fault for that component..
-
usually, when it runs, it runs good but when it starts acting up, you can feel it, it starts losing power, or hesitating/bucking then it just goes dead, just like you turned the key off..
That's screaming PMD..
'95 is still OBD1.. Chuck a paper clip in the ALDL terminals A and B, click the key to run, and the DTC's will blink out on the CEL.. It'll flash each code 3 times, starting with 12.. If you haven't done it before you may need to read em a few times (Hell I still have to).. TO start over, turn they key off, wait a few seconds, and turn 'er back on..
The codes will be blinked out something like this:
For a 12
Blink (short pause) Blink Blink (Longer Pause) then it repeats 2x more times and moves to the next code..
Pull the ECM fuse or disconnect the batteries for 10 mins to clear the codes... IF you clear the codes, start the truck and the light comes right back on you have a hard fault for that component..
does it matter any that its a non-egr engine, and that its in a 3500HD chevy dump truck?
my grandpa has no idea how to fix this thing, guess im gonna have to learn how to work on chevy diesels too..
-
Nope, Chevy is about the best there is as far as not making changes.
-
Nope, Chevy is about the best there is as far as not making changes.
Even when they should, and only when they shouldn't.. ::)
Once you dive into it you'll find that pre OBDII GM electronics are cake.. Even the diesels.. Lord how I long for the days of their TBI....
-
TBI is cake.. you cant really hook it up wrong..
i liked TBI for the smaller engines, but they should have made a bigger version for the big small blocks, and big blocks..
-
IMHO GM TBI was one of the best fuel systems on the planet.. Simple, reliable, and performed decently for power and economy.. That's probably why they stopped using it.. ::) And it was available on small and big blocks.. The 305 and 350 used it from '87 to '95.. The 454 used it from '87 till I think '96.. The very early TBI 454's didn't even have a special intake.. They had an adapter that fit the throttle body to the quadrajet intake..
-
it was very economical, but nothing for power..
look at what happened when they came out with Whoretec in 96, there engines made 100 more HP..
-
Great power it wasn't, but acceptable.. Better than the electronic q-jets before it.. ::) The TBI 305 in my '93 Caprice runs circles around the '83 Caprice with a 350 with it's stock carb..
The fuel system on the whoretech can take some of the credit for power gains, but the majority of the improvement was in the cam, intake and heads.. IIRC that all brought the compression back up to respectable levels again..
I suspect that the improved fuel system was was allowed them to get away with the other improvements.. Otherwise I'm sure they'd have been too "dirty"..
-
Great power it wasn't, but acceptable.. Better than the electronic q-jets before it.. ::) The TBI 305 in my '93 Caprice runs circles around the '83 Caprice with a 350 with it's stock carb..
The fuel system on the whoretech can take some of the credit for power gains, but the majority of the improvement was in the cam, intake and heads.. IIRC that all brought the compression back up to respectable levels again..
I suspect that the improved fuel system was was allowed them to get away with the other improvements.. Otherwise I'm sure they'd have been too "dirty"..
Roller cam..
VASTLY improved heads (they have a spiral ramp above the intake valve, very cool design)
intake had short intake runners, and a large plenum.. but the single fuel injector was a downfall, they make about 40 more HP with the multi-point conversion kit.
the TBI engines had ~9:1 comp didnt they? and i think the vortec engines were 10, or even 10.25:1?
-
The roller cam didn't even do that much.. They debuted in '86 or '87 and still with a CCC they were a DAWG!
The single point injectors was indeed the downfall of TBI.. Not enough fuel and poor fuel distribution..
IIRC compression on L98's was 8 or 8.5 on the CCC engines, 9 on TBI engines, and 9.5 on Vortec engines.. LT1's had 10.25 on aluminum headed versions, 9.5 on cast head versions... The LS series are in the 10:1 range.. Pretty much anything over 9.5.1 on a run of the mill cast headed engine is gonna be trouble, especially on 87 octane...
Supposedly the '94 and '95 trucks got a version of the vortec heads with TBI, but still had the 9:1 compression, less agressive cam, and the crappy intake.. It was a poor combination as they seemed to get the worst mileage with little power gain..
-
The roller cam didn't even do that much.. They debuted in '86 or '87 and still with a CCC they were a DAWG!
The single point injectors was indeed the downfall of TBI.. Not enough fuel and poor fuel distribution..
IIRC compression on L98's was 8 or 8.5 on the CCC engines, 9 on TBI engines, and 9.5 on Vortec engines.. LT1's had 10.25 on aluminum headed versions, 9.5 on cast head versions... The LS series are in the 10:1 range.. Pretty much anything over 9.5.1 on a run of the mill cast headed engine is gonna be trouble, especially on 87 octane...
Supposedly the '94 and '95 trucks got a version of the vortec heads with TBI, but still had the 9:1 compression, less agressive cam, and the crappy intake.. It was a poor combination as they seemed to get the worst mileage with little power gain..
i have an engine that is a bit of a unique combination.. its a 4.3L V6, from a van, carburated, with VORTEC heads.. all original from what i can tell..
-
That is an interesting combo.. Probably a fun story to go with it at some point.. IIRC some of the vans kept the carb longer than everything else... I actually kinda forgot about the 4.3 having a carb in trucks and vans..
-
That is an interesting combo.. Probably a fun story to go with it at some point.. IIRC some of the vans kept the carb longer than everything else... I actually kinda forgot about the 4.3 having a carb in trucks and vans..
it was supposed to be from an 85 Astro.. it has no balance shaft either.. so i know its an early block.
-
I didn't even think the Vortec heads would fit the early block.. Wonder if it was some odd combo made for trucks and vans from back in the day.. A fully loaded Astro would need all the power it could get...
-
I didn't even think the Vortec heads would fit the early block.. Wonder if it was some odd combo made for trucks and vans from back in the day.. A fully loaded Astro would need all the power it could get...
they are truely weird Vortec heads.. they have the intake bolts perpendicular to the intake ports, not vertical like all the other vortec heads.
the DO have the center bolt valve covers, and DO have the vortec intake port, along with bigger valves than most 4.3 heads ive seen..
-
Kevin, you ever get the gremlins outta the 6.5???
-
Kevin, you ever get the gremlins outta the 6.5???
nope. my grandpa didnt seem real interested in me fixing it for him, so i just left it alone. he can just drive it like it is. if it doesnt bother him having to re-start it every mile or so, then i dont care either.
-
Good lord he sounds like my father.. I think the last one was "Yeah you can use the truck, but if you load the trailer real heavy be careful, there's no brakes on the truck" :o That rusted brake line got replaced 2 years later.. So much for the annual PA safety inspection....
-
Maybe this was covered, didn't check the whole thread. I saw someone selling a wiring kit and heat sink to move the electronic piece off the side of the pump with a 6 foot lead. He was claiming there's a heat problem with the 6.5? Mount it far enough from the motor end of problem (or so he said). Might be worth checking into.
-
Maybe this was covered, didn't check the whole thread. I saw someone selling a wiring kit and heat sink to move the electronic piece off the side of the pump with a 6 foot lead. He was claiming there's a heat problem with the 6.5? Mount it far enough from the motor end of problem (or so he said). Might be worth checking into.
PMD relocation kit was one of the first things we did..