Even the Dealer is Stumped

[jchandler]

Well after suffering intermittent stalling over the past 9 months. The truck finally gave me some codes. I called the dealer (one of the best diesel mechanics, and the second oldest Chevy dealer in the country) and they said the soonest we can get it in was 1.5 mos. I finally took it in last week and the damn thing wouldn't mess up. Oh, and by the way I din't know that the codes are erased after 40 start cycles. Anyway, I picked up the truck last Tuesday and on Thursday it finally gave up the ghost. Stopped dead in the middle of the road(ever tried to push a 6100lb. C3500 off the road?) We towed the truck in and they replaced the pump. The truck still will not start. They have checked the lift pump, the OP sending switch and are still stumped. The only thing I can think of is a faulty pump from the factory. Does anyone have any suggestions that I can pass on to the dealer?

Stuck without a Truck! redface.gif

Jeff Chandler
1998 Chevy C3500 6.5TD
101,000 miles and sitting still
gofaster@bigfoot.com

[markrinker]

1) What codes did you get?
2) Was it stalling dead, or surging/sputtering?
3) Any other clues from last day running?

[Turbine Doc]

JC what Pump; lift pump on frame rail or injection pump center front on engine, PMD/FSD comes to mind here they die give no fault code and may not start or intermittently stall/stop a truck.

[tom.mcinerney]

-OK mechanically [compression]?
-fuel flow estab from tank to FIP?
-injectors have been 'bled'?
-check fuel shut-off sol for click ON/OFF
-carefully 'wiggle', maybe reseat all FIP electronic connectors
-Follow Helm Manual troubleshooting; suspect open/shorted harness
-PCM crapped out

[jchandler]

The engine would stall dead everytime. Most of the time I could through the truck into neutral and restart the engine drop it and drive and keep going. Other times I would be on the side of the road a minute or so, then I could refire and be on my way. Only 2 times did it stop and not refire for hours. Then the last time it just died and hasn't refired since.

The codes were P0251 and the other was P1216. The dealer told me that since the codes had cleared that we needed some data to get GM to authorize a FI Pump replacement. The only info I could get for them was:

Inj. Closer Time........ 279.03ms
TDC Offset.............. -3.2
Inj. Pulse width........ ?? (engine not running)
Timing (Actual)......... 16.5
Timing (Desired)........ 16.5

These readings were all taken with the engine not running. I could turn over fine but would not fire. After calling these into the dealer they said they added some more data to the equation and GM sent the new FI pump. I was informed that the PMD/FSD comes with the new FI pump. I don't know this for a fact though.

There is fuel flowing from the bleeder up by the Thermostat housing and from the filter housing, with the ignition turned on. This tells me that the lift pump is good as well as the OPS.

Now, I don't know how hard it is to replace the FI pump but, their certified diesel mechanic is on vacation and his protoge' is doing the work. This might have something to do with my situation.

Stuck without a Truck! :mad:

Jeff Chandler
1998 Chevy C3500 6.5TD
101,000 miles and sitting still
gofaster@bigfoot.com

[CareyWeber]

Originally posted by jchandler:
The engine would stall dead everytime. Most of the time I could through the truck into neutral and restart the engine drop it and drive and keep going. Other times I would be on the side of the road a minute or so, then I could refire and be on my way. Only 2 times did it stop and not refire for hours. Then the last time it just died and hasn't refired since.

The codes were P0251 and the other was P1216. The dealer told me that since the codes had cleared that we needed some data to get GM to authorize a FI Pump replacement. The only info I could get for them was:

Inj. Closer Time........ 279.03ms
TDC Offset.............. -3.2
Inj. Pulse width........ ?? (engine not running)
Timing (Actual)......... 16.5
Timing (Desired)........ 16.5

These readings were all taken with the engine not running. I could turn over fine but would not fire. After calling these into the dealer they said they added some more data to the equation and GM sent the new FI pump. I was informed that the PMD/FSD comes with the new FI pump. I don't know this for a fact though.

There is fuel flowing from the bleeder up by the Thermostat housing and from the filter housing, with the ignition turned on. This tells me that the lift pump is good as well as the OPS.

Now, I don't know how hard it is to replace the FI pump but, their certified diesel mechanic is on vacation and his protoge' is doing the work. This might have something to do with my situation.

Stuck without a Truck! :mad:

Jeff Chandler
1998 Chevy C3500 6.5TD
101,000 miles and sitting still
gofaster@bigfoot.com Jeff,

My P0251 code was caused by wiring issues read this thread. ;)

http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006367

Carey

[Cowracer]

JChandeler-

This was exactly what my truck was doing before I tightened up the transistor screws. Sometimes, it would come back quickly enough that the tranny would bump start it.

It was a free (but time consuming) fix for me!

Tim

[gmctd]

Disconnect Optical Sensor plug - truck will start in 'limp' mode.

Let it run for about 15 mins to clear lines.

Kill engine, reconnect OS plug, try getting data from there

[markrinker]

Sounds like an FSD to me, but hey, a new IP at over 100K miles is probably saving you another trip to the dealer, and a BIG bill after 120K miles.

I'd say your in good shape, assuming they get it back running to you.

If it continues to stall after IP replacement (likely, based on your codes), I'd insist that they inspect, clean and replace every electrical ground, connector and connection from the battery to the computer to the IP - FREE of charge for the labor bill you are about to pay or the IP installation.

Might be interesting to see if they'll let you keep the old IP and/or the FSD. If they do, you can test the FSD by connecting it to the harness (after everything is back running normally), and see if that was the culprit after all.

[jchandler]

Went by the dealer on Friday to get some things out of the truck. While I was there I talked to the guy that changed out the Inj. Pump. He said that the PMD was definatly a problem and that they were sure that the IP needed to be replaced as well. However, since the truck still will not start, they started looking elsewhere. When I was there they had the dash ripped out trying to look for something in the "Theft Circuit" saying that they believe that something had activated it. I asked how did we go from an IP to the "Theft Circuit"? all they could do was shrug their shoulders. I believe they are barking up the wrong tree. If something in the electronics is bad then it would most likely be the ECM in my book.

[jchandler]

Originally posted by gmctd:
Disconnect Optical Sensor plug - truck will start in 'limp' mode.

Let it run for about 15 mins to clear lines.

Kill engine, reconnect OS plug, try getting data from there I will talk to the dealer today and let them know of this trick. I guess if it still won't start then it is definately somewhere in the ECM.

[charliepeterson]

I hope those numbers from the dealer are a miss print.

279ms for the injectors and -3.2 TDC are WAY too high.

Have the tech turn the pump down to -2.90TDC and restart the truck.

[FarmerDale]

JC
I had a similar problem with my '95 this spring. After 2 new FSD's and a new IP, we also found a problem with the connectors that the FSD plugs into. A couple of the sleeves inside the plug had become loose and good contact was not being made. Also the ground from the FSD was poor.
This diagnosis was made at a dealer, and the tech, definitely not an expert, had spent a couple hours on the Tech Line with GM. GM wasn't going to put another new pump on it until all these other little things were cleared up. The only unfortunate thing that happened is that the truck got de-tuned to -0.25 TDC :mad: , but it starts up and runs without missing a beat now. :D

[jchandler]

I hope those numbers from the dealer are a miss print.

279ms for the injectors and -3.2 TDC are WAY too high.

Have the tech turn the pump down to -2.90TDC and restart the truck.

--------------------
Charlie P.
95 Tahoe 6.5 TD
Those numbers were the ones that were being read with the bad pump. These readings were what convinced GM to authorize the replacement pump.

Still Stuck without a Truck! :mad:

Jeff Chandler
1998 Chevy C3500 6.5TD
101,000 miles and sitting still
gofaster@bigfoot.com

[jchandler]

Well, I finally got the truck back from the dealer. After replacing the original FIP they said that my theft module had gone bad and that the ignistion switch needed to be replaced. They blamed this on my remote start system. I was told that the Security light was flashing and that is why they had to replace the module. The Security light wasn't flashing when I had it towed into the dealer. Anyway after replaceing the IP, the theft module and ignition switch, the Service manager took the truck on a test frive. About 5 miles from the dealership the truck quit running. Further investigation revealed that the gear drive had sheared(Thanks for the info Jim B.) They replaced the IP again and the gear drive and everything now seems to work good. I don't even feel those misses while running down the road. Now it is time for an FSD cooler. smile.gif

Got my truck back!!! :D

Jeff Chandler
1998 Chevy C3500 6.5TD
102,000 miles
gofaster@bigfoot.com