Engine trouble light

[jdozier]

OK, I have recently purchased a 1994 GMC 2500 that has been recently installed in 2005 "New 6.5" turbo powerhouse and newly rebuilt auto transmission.

Here is my question upon accelleration the engine trouble light comes on, and the Cruise control will now not work consistently as it shuts down when I give it the pedal.
I took it to the local dealer (which I believe was a mistake) because they say the fuel injection pump is defective due to the fact that the code is indicating a fault of "extended fuel injection pause error" or "prolonged injector shut-off" or something like that.The previous owner had added many of the things you all suggest. (larger exhaust, electric cooling fans, new intake and others) and that this defective pump is sending metal shavings into and through-out my fuel system.

The truck runs really strong, and milage seems alright but I just want to know that driving it is not going to wreck this thing as it appears that these engines can be highly technical, and complicated to trouble shoot. Love the truck, and have rebuilt multiple gas engines over my years but this is my first diesel.

Can someone give me some idea of what I should do other than just drive it till it breaksdown...? Do I have something to worry about...?

[94Mule]

Find out what the DTC are & e-mail Walt. He will help better than anyone.

[christja]

OK, I have recently purchased a 1994 GMC 2500 that has been recently installed in 2005 "New 6.5" turbo powerhouse and newly rebuilt auto transmission.

Here is my question upon accelleration the engine trouble light comes on, and the Cruise control will now not work consistently as it shuts down when I give it the pedal.
I took it to the local dealer (which I believe was a mistake) because they say the fuel injection pump is defective due to the fact that the code is indicating a fault of "extended fuel injection pause error" or "prolonged injector shut-off" or something like that.The previous owner had added many of the things you all suggest. (larger exhaust, electric cooling fans, new intake and others) and that this defective pump is sending metal shavings into and through-out my fuel system.

The truck runs really strong, and milage seems alright but I just want to know that driving it is not going to wreck this thing as it appears that these engines can be highly technical, and complicated to trouble shoot. Love the truck, and have rebuilt multiple gas engines over my years but this is my first diesel.

Can someone give me some idea of what I should do other than just drive it till it breaksdown...? Do I have something to worry about...?



# Q: How do I read my DTC (Diagnostic Trouble Codes) on my 94-95 truck??
# A: Locate the "Data Link" connector below the steering wheel on the rim of the dash. With the key in the "OFF" position, jumper the top two right terminal pins (termnals A&B) with a paperclip or short piece of wire. Turn the key to the "RUN" position, but DO NOT START. The check engine light will begin flashing a sequence of codes. If the diagnostics are working and there are no codes in memory, a code 12 will flash 3 times. A code 12 is a flash once, followed by a quick flash two times. Basically a 1-2 flash is a code 12. If no codes, only the 12 will flash. If codes present, the sequence will start with the 12, then flash each code 3 times before moving onto the next in numerical order. When 12 flashes again, you are done. Again, count the flashes and write them down, they will flash 3 times each code. To clear the codes, depress the brake pedel and accelerator pedel simultaniously for 15 seconds while still in diagnostic mode. NOW shut off the key and remove the jumper. The codes are now cleared. NEVER-EVER remove the jumper while still in the diagnostic mode, turn key to off first. NEVER-EVER start the truck with the jumper in place. ECM damage may result. Let me know the code numbers that came up along with symptoms and I will help you diagnose your truck

[jdozier]

OK, I am getting error codes # 34 and # 35....

What does that mean, is my injector pump really bad...?

[Chevylover]

OK, I am getting error codes # 34 and # 35....

What does that mean, is my injector pump really bad...?


DTC 34 - Injection Timing Stepper Motor Fault
DTC 35 - Injection Pulse Width Error (Response Time Short)


Code 35 - fried PMD
Code 34 - Stepper Motor at the IP failure
I don't know if it is possible to get one without the complete IP.

Cu,
Sven

[Husker 6.5]

DTC 34 - Injection Timing Stepper Motor Fault
DTC 35 - Injection Pulse Width Error (Response Time Short)


Code 35 - fried PMD
Code 34 - Stepper Motor at the IP failure
I don't know if it is possible to get one without the complete IP.

Cu,
Sven

:) :) :D Check SSD. Walt has the stepper motor SSD 407 for $159.00 + shipping. PMD fried, then get the FSD, #9 and cooler kit SSD 006 for $420 + shipping. Before buying a new stepper motor, since your engine/IP is reman, it is very possible that your IP is not properly timed to your engine. SSD FAQ has the procedure to retime the IP as well as Haines Diesel Manual. Happy motoring!

[Chevylover]

Check SSD. Walt has the stepper motor SSD 407 for $159.00 + shipping.



:D Oh, I'm so sorry ! :eek: I must have overlooked that ! Next time i will be better. :mad:

Cu,
Sven

[RckyMtNDeZL]

You may be able to rule out the PMD if you say the previous owner "hopped" it up a bit. Check and see if it has a heat sync or relocation kit in place. I am leaning towards your stepper motor, my rig did the same thing when I first inherited it. Dropped it off at the dealer, the replaced all kinds of stuff, and my rear end hurt after that venture.

[jdozier]

Yes, the previous owner replaced and relocated the heatsync it has the newer version of the Injector Pump for the 6.5. An improved Chip. Downpipe, new exhaust, and two electric cooling fans with new radiator.

What exactly is the stepper motor, and what does it do ?
Will my truck die if I do not replace ?

[jdozier]

Hey another issue I am having is that I am getting no signal to my EGR... could this also be creating some of the DTC I am getting, and how do I fix this ?

[Husker 6.5]

Yes, the previous owner replaced and relocated the heatsync it has the newer version of the Injector Pump for the 6.5. An improved Chip. Downpipe, new exhaust, and two electric cooling fans with new radiator.

What exactly is the stepper motor, and what does it do ?
Will my truck die if I do not replace ?

It is the motor in/on the injection pump that times and sequences the injection pulse. Think of it similarily as ignition timing/dwell in relation to a distributor. Instead of sending a spark, it sends a shot of #2 to each injector. If you install a dist too far off, you can't compensate by changing vacuum/mechanical advance and dwell. Same with the IP!! the stepper motor works within its design parameters to control "advance and dwell" of the shot of juice. If the IP is not installed within a narrow tollerance of dead time to the engine, the stepper motor can't compensate, the computer senses this and, voila! Error codes like yours. Failure of the PMD does not throw codes in and of itself. CHECK THE IP TIMING FIRST! Especially since you say it was replaced by P.O. It could (probably is) off. It's easy to do (like setting timing on a gas-burner). No, it won't die, but it will run like crap and throw codes like it is doing, now.

Bad EGR valve. I have an "F" engine, no EGR!

[Husker 6.5]

Yes, the previous owner replaced and relocated the heatsync it has the newer version of the Injector Pump for the 6.5. An improved Chip. Downpipe, new exhaust, and two electric cooling fans with new radiator.

What exactly is the stepper motor, and what does it do ?
Will my truck die if I do not replace ?

It is the motor in/on the injection pump that times and sequences the injection pulse. Think of it similarily as ignition timing/dwell in relation to a distributor. Instead of sending a spark, it sends a shot of #2 to each injector. If you install a dist too far off, you can't compensate by changing vacuum/mechanical advance and dwell. Same with the IP!! the stepper motor works within its design parameters to control "advance and dwell" of the shot of juice. If the IP is not installed within a narrow tollerance of dead time to the engine, the stepper motor can't compensate, the computer senses this and, voila! Error codes like yours. Failure of the PMD does not throw codes in and of itself. CHECK THE IP TIMING FIRST! Especially since you say it was replaced by P.O. It could (probably is) off. It's easy to do (like setting timing on a gas-burner). No, it won't die, but it will run like crap and throw codes like it is doing, now.

Bad EGR valve. I have an "F" engine, no EGR!

[Chevylover]

Bad EGR valve. I have an "F" engine, no EGR!

I got an "S" Engine with EGR Valve. Remove the hose from the valve on the upper intake and put a screw into the hose from there to the solenoid. Until modelyear 1996 the diesels doesn't remember if the EGR is "cut off" because these models don't have an MAF Sensor.

Cu,
Sven

[lumac]

hi i have a 96 2500 ext cab with 6.5 and i have the same problem more when i haul my 5000lbs trailer and my truck is original i have this trouble for 3 year i go to the dealer and i toll me the ip is bad and i toll me that 3 year ago and still the same pump in the truck , i make it rebuild and the find no trouble with the pump if you find something let me know please for resolve the probleme

[wyo6.5]

If I understand you correctly then youre telling me that your check engine light is coming on when you accelerate. Are you blowing a lot of black smoke and it seems like your truck is sluggish and has hardly any power? I had this problem when I first bought my 6.5. Pull your vacuum hose of your turbo while the engine is running and check for suction. turns out I had a bad vacuum pump. Truck was running like a natural 6.5 without a turbo. Thier about 120 bucks, made all the difference.

[jdozier]

Yes, the engine trouble light comes on, but only during excelleration. Engine runs strong, and only smokes more than expected at first crank up after not being run for a couple of days. I feel no noticible problems with running. Just that darn light. But it is throwing the code #34 & #35..... and the Cruise Control will not work, as it shuts down as soon as the engine light comes on upon accelleration.
I just want to make sure that I am not destroying anything but continuing to drive it, being that this is my first diesel engine.

[christja]

Yes, the engine trouble light comes on, but only during excelleration. Engine runs strong, and only smokes more than expected at first crank up after not being run for a couple of days. I feel no noticible problems with running. Just that darn light. But it is throwing the code #34 & #35..... and the Cruise Control will not work, as it shuts down as soon as the engine light comes on upon accelleration.
I just want to make sure that I am not destroying anything but continuing to drive it, being that this is my first diesel engine.

Check with walt, you got us stumped. The cruise control is set up to shut down when the computer throws a particular code. Some times when mine would light up it would kill the CC then others it would be fine. I put on a new FSD and i was getting code 36 ive run several quarts of 2 stroke oil through the fuel tank and it appears to have gone.

[jdozier]

How exactly do I email Walt...... he is a forum admin...?

[lumac]

hi when my truck do that i stop be side the road and i sut off the engine for 30 second arond and when i strart up again the engine light stay on but the engine run smooth and the cruise come on again i try put somethings oil fuel conditionner and no change next thing hi have ti try is check the timming

[wyo6.5]

I'm pretty sure it's your vacum pump because the symtoms that your telling me are the same ones that I had. Under acceleration my check engine light would come on and my engine would throw codes 34 and 35 and blow a lot of black smoke. I believe that one of those codes has to do with your turbo wastegate which is what mine came up as ( didn't know you could read the codes on a 95 without a code reader at the time) but if you havent checked your vacum pump out yet check it because that could very well be it. if it isn't, well then you have me stumped.

[Husker 6.5]

How exactly do I email Walt...... he is a forum admin...?

How to contact Walt: You're logged onto the Forum. Click up top where it says SSDiesel Supply in the red logo. You're now on SSDiesel supply's home page. Upper left of the page, click where it says CONTACT. You're on the contact page. Read the instructions and fill out the contact sheet. Submit. You have now just talked to Walt.

Alternate: Click on this URL www.ssdieselsupply.com (There's no place like home..)

How did you get to the 6.5 Forum? Did someone give you the web address directly? Most of us linked the first time through SSDiesel's web site.

Husker 6.5

[lumac]

i already have a trouble with this but the cruise still running