94 6.5td bad IP, wrong pcm or wrong prom?
#1
11-11-2014, 05:50 PM
94 6.5td bad IP, wrong pcm or wrong prom?
I've posted a few threads about this truck, and its gotten better little by little. Here is the problem I am running into;
1. The pcm with prom and IP are from a sister truck. I went to the GM dealership to see if I had the correct matching parts, all they could tell me is based off my engine code (yyh) I should have a 5068 pump.
2. I purchased the GMTD Scan Tech, on the timing window I am showing a desired timing of .4, actual and tdco are at 0. I have moved the pump back and forth and nothing changes, when I give it a TDCO reset command the truck sputters and dies.
3. Truck is showing codes 17 (high res pulse signal) and 44 (egr pulse width error) 62 (boost pressure sensor) and one about the accelerator position 3 (I forget the code)
4. On the dashboard of GMTD it shows the engine coolant temp randomly jumping between 35.5deg F and 127.5 deg F it also shows the speed at 22 at a stand still and the rpm's at 19 when the tach shows 900ish. I do have the aldl cable with the 10k ohm switch, it doesn't make a difference either way.
5. The truck that the computer/prom/pump came out of was a non-running truck, a friend picked it up really cheap for parts because it had blown head gaskets and $1000 in back due registration so theres no telling if the parts match up or not. I've even tried the pmd from the parts truck and it ran worse!
6. GMTD cant reset the codes, I've disconnected the battery for 1/2hr and the low res pule signal and egr codes come back right away - even before I've started the truck.
It has a 5068 pump on it, the computer is an ac delco replacement part number 88961136 (gm number 99961135) and a prom code of bxpw 1624 4781. Before I go spending $900 to replace the ip I would like to know if the pcm and the prom are correct for the truck. Again, even the dealership has no idea, and if I were to order a new prom or pcm I would need the original numbers off the factory one which I don't have! I do have a 5521 pump aswell and I did put that on the truck and it wouldn't even start so I am guessing the numbers are correct however with the computer throwing 2 codes that could be computer related and 1 of the codes (being the egr) not even applicable to this motor I don't know what to do!
1. The pcm with prom and IP are from a sister truck. I went to the GM dealership to see if I had the correct matching parts, all they could tell me is based off my engine code (yyh) I should have a 5068 pump.
2. I purchased the GMTD Scan Tech, on the timing window I am showing a desired timing of .4, actual and tdco are at 0. I have moved the pump back and forth and nothing changes, when I give it a TDCO reset command the truck sputters and dies.
3. Truck is showing codes 17 (high res pulse signal) and 44 (egr pulse width error) 62 (boost pressure sensor) and one about the accelerator position 3 (I forget the code)
4. On the dashboard of GMTD it shows the engine coolant temp randomly jumping between 35.5deg F and 127.5 deg F it also shows the speed at 22 at a stand still and the rpm's at 19 when the tach shows 900ish. I do have the aldl cable with the 10k ohm switch, it doesn't make a difference either way.
5. The truck that the computer/prom/pump came out of was a non-running truck, a friend picked it up really cheap for parts because it had blown head gaskets and $1000 in back due registration so theres no telling if the parts match up or not. I've even tried the pmd from the parts truck and it ran worse!
6. GMTD cant reset the codes, I've disconnected the battery for 1/2hr and the low res pule signal and egr codes come back right away - even before I've started the truck.
It has a 5068 pump on it, the computer is an ac delco replacement part number 88961136 (gm number 99961135) and a prom code of bxpw 1624 4781. Before I go spending $900 to replace the ip I would like to know if the pcm and the prom are correct for the truck. Again, even the dealership has no idea, and if I were to order a new prom or pcm I would need the original numbers off the factory one which I don't have! I do have a 5521 pump aswell and I did put that on the truck and it wouldn't even start so I am guessing the numbers are correct however with the computer throwing 2 codes that could be computer related and 1 of the codes (being the egr) not even applicable to this motor I don't know what to do!
Last edited by jjbced; 11-11-2014 at 05:57 PM.
#2
11-12-2014, 11:24 AM
#3
11-12-2014, 01:46 PM
The guy who owned it before me bought it cheap because it didnt have a computer so he also bought a twin sister truck to it for parts and used the computer out of that. From what i am gathering my prom may be a 95 which would mate with the 5521 pump but when i put a 5521 in it (it was reman in 06) it wont run at all it just burps and gurgles but wont fully light. It runs and drives with the 5068 but not like it should, best way to describe it as it feels like a gasser thats retarded... Not limp mode status, just gutless, and its to my understanding (and i may be wrong) that it wont run at all with a mismatched prom/ip
#5
07-18-2015, 07:35 PM
Did you get it running??
I know it's been a while since this was posted, but I'd like to know if you got it running. If not I may have some pointers from my own experience with a similar animal.
My truck was purchased in 11/13, wrecked and not running. Spent countless hours on numerous forums researching the glitches common to 6.5 EFI engines.
Cut the rusted out fuel lines where they were still solid. Attached a fuel can in the bed with a couple lengths of rubber fuel hose. Made sure the lift pump was still working and bypassed the OPS.
Dealt with a missing front starter bracket by building a beefy one myself out of angle iron. Had the benefit of having bought a parts block, so I had that on the engine stand to dummy it up. Had to replace the bendix gear because of the starter pushing back one time when I was attempting to get it to start, which is the whole reason I became aware of the missing bracket.
Got it to fire up on Resurrection Sunday 2014 with the help of a heat gun on the intake manifold, almost a half gallon of WD-40, my TDI with a ski pole on the accelerator to keep the batteries charged, and a garden hose with a shower-head type attachment keeping the starter cool. Used a jumper to give unlimited glow time. We finally got it to fire up after a couple hours of that - it revved up to around 2500-3000 until all the WD-40 burned out of the intake manifold and then went right down to an idle and settled out there. Sounded funny and smoked a lot but ran.
First issue - if you hit the accelerator it acted very doggy in neutral or park, and it did not respond at all in any forward or reverse gear.
Second issue - loud rap, sounded like a bad injector.
Third issue - timing sounded VERY advanced.
Fourth issue - excessive smoke from one cylinder, verified by revving with cell phone recording video of downpipe with cat removed and bright flashlight.
First thing I solved was the timing. I rotated the pump back to the level position - it was all the way advanced in the slots. Believe it or not, with the top of the pump as level as I could eyeball it, once I finally broke down and bought an ALDL cable and a GMTD Scan Tech license I did TDCO and it was almost spot on.
A set of harbor freight S-wrenches were instrumental in setting timing.
Second thing I worked on was the rap, and I figured that the smoke was connected to that issue. I bought a bunch of "tested used" injectors off e-Bay for about $7 a piece. Put them all in and it ran better but still rapped. I swapped in another IP and it still rapped. Ripped some of my hair out, talked to everyone I could think of, tested transfer pump pressure in the IP, posted videos on YouTube asking for help, asked in forums, turned injectors on and off with GMTD Scan Tech, and finally a phone conversation with a new friend who is familiar with 6.5's revealed the problem - wrong firing order, and the lines were bent to fit. I went line-for-line when I swapped the pumps so I didn't notice then. Swapped the lines into the right places and the rap and smoke were GONE. Still wouldn't rev up in gear.
So lastly I worked on the throttle response issue. I assumed that the ECU was bad due to the accident having severed the PMD lines while the engine was running (it was bumper mounted) so I bought another one from a similar truck but it ran the same. Swapped in my original prom to the new ECU, same thing. Again, pursued every avenue I could and kept asking if I had the right PROM. Finally someone told me that I did not have the right one. No one could tell me which was the correct prom, though, so I was still out of luck. I have an early '94 truck, which should have a 5068 pump like yours. My prom was BJAX. My pump, and all three spares I have obtained, are 5521.
Luckily, I stumbled on a forum thread where a fellow by the handle Fermanator was working on modifying a prom for mild performance improvement. He had a similar truck to mine but different ECU model no. Asked and asked but no one knew if it would work. So I had to answer the question myself. Figuring that the worst that could happen was that it wouldn't start or would run wrong, I bought a new chip programmer (my kit that I put together in HS never worked well...) and erased a half dozen 386 keyboard BIOS chips. Put one in the burner, wrote a program to it, dissected a chip carrier and popped in my new chip with a BPAA stock tune. I didn't solder the leads back to the contacts.
Put it in the ECU,
prayed,
turned key,
put in gear,
touched accelerator....
...and smiled. Almost cried I was so happy. This was in September 2014. I had been working on this thing all summer, spent thousands on parts and hundreds of hours of labor and research. I hope that this post saves someone from that headache. There are still some BPAA BIN files out there, and they'll work with the readily available 5521 pump on automatic 4wd trucks. I think that an auto trans tune will work on a stick and a 4x4 will work on 2wd, but not the other way around in either case. That being said, BPAA MAY be a good universal PROM for a 5521 IP. Takes some patience and time to burn your own, but well worth it as there are a few tunes floating around too. Hope that you've already got your truck running, but if not maybe this will help you (or others) avoid spending unnecessary time and money.
Best of luck.
My truck was purchased in 11/13, wrecked and not running. Spent countless hours on numerous forums researching the glitches common to 6.5 EFI engines.
Cut the rusted out fuel lines where they were still solid. Attached a fuel can in the bed with a couple lengths of rubber fuel hose. Made sure the lift pump was still working and bypassed the OPS.
Dealt with a missing front starter bracket by building a beefy one myself out of angle iron. Had the benefit of having bought a parts block, so I had that on the engine stand to dummy it up. Had to replace the bendix gear because of the starter pushing back one time when I was attempting to get it to start, which is the whole reason I became aware of the missing bracket.
Got it to fire up on Resurrection Sunday 2014 with the help of a heat gun on the intake manifold, almost a half gallon of WD-40, my TDI with a ski pole on the accelerator to keep the batteries charged, and a garden hose with a shower-head type attachment keeping the starter cool. Used a jumper to give unlimited glow time. We finally got it to fire up after a couple hours of that - it revved up to around 2500-3000 until all the WD-40 burned out of the intake manifold and then went right down to an idle and settled out there. Sounded funny and smoked a lot but ran.
First issue - if you hit the accelerator it acted very doggy in neutral or park, and it did not respond at all in any forward or reverse gear.
Second issue - loud rap, sounded like a bad injector.
Third issue - timing sounded VERY advanced.
Fourth issue - excessive smoke from one cylinder, verified by revving with cell phone recording video of downpipe with cat removed and bright flashlight.
First thing I solved was the timing. I rotated the pump back to the level position - it was all the way advanced in the slots. Believe it or not, with the top of the pump as level as I could eyeball it, once I finally broke down and bought an ALDL cable and a GMTD Scan Tech license I did TDCO and it was almost spot on.
A set of harbor freight S-wrenches were instrumental in setting timing.
Second thing I worked on was the rap, and I figured that the smoke was connected to that issue. I bought a bunch of "tested used" injectors off e-Bay for about $7 a piece. Put them all in and it ran better but still rapped. I swapped in another IP and it still rapped. Ripped some of my hair out, talked to everyone I could think of, tested transfer pump pressure in the IP, posted videos on YouTube asking for help, asked in forums, turned injectors on and off with GMTD Scan Tech, and finally a phone conversation with a new friend who is familiar with 6.5's revealed the problem - wrong firing order, and the lines were bent to fit. I went line-for-line when I swapped the pumps so I didn't notice then. Swapped the lines into the right places and the rap and smoke were GONE. Still wouldn't rev up in gear.
So lastly I worked on the throttle response issue. I assumed that the ECU was bad due to the accident having severed the PMD lines while the engine was running (it was bumper mounted) so I bought another one from a similar truck but it ran the same. Swapped in my original prom to the new ECU, same thing. Again, pursued every avenue I could and kept asking if I had the right PROM. Finally someone told me that I did not have the right one. No one could tell me which was the correct prom, though, so I was still out of luck. I have an early '94 truck, which should have a 5068 pump like yours. My prom was BJAX. My pump, and all three spares I have obtained, are 5521.
Luckily, I stumbled on a forum thread where a fellow by the handle Fermanator was working on modifying a prom for mild performance improvement. He had a similar truck to mine but different ECU model no. Asked and asked but no one knew if it would work. So I had to answer the question myself. Figuring that the worst that could happen was that it wouldn't start or would run wrong, I bought a new chip programmer (my kit that I put together in HS never worked well...) and erased a half dozen 386 keyboard BIOS chips. Put one in the burner, wrote a program to it, dissected a chip carrier and popped in my new chip with a BPAA stock tune. I didn't solder the leads back to the contacts.
Put it in the ECU,
prayed,
turned key,
put in gear,
touched accelerator....
...and smiled. Almost cried I was so happy. This was in September 2014. I had been working on this thing all summer, spent thousands on parts and hundreds of hours of labor and research. I hope that this post saves someone from that headache. There are still some BPAA BIN files out there, and they'll work with the readily available 5521 pump on automatic 4wd trucks. I think that an auto trans tune will work on a stick and a 4x4 will work on 2wd, but not the other way around in either case. That being said, BPAA MAY be a good universal PROM for a 5521 IP. Takes some patience and time to burn your own, but well worth it as there are a few tunes floating around too. Hope that you've already got your truck running, but if not maybe this will help you (or others) avoid spending unnecessary time and money.
Best of luck.
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