97 No Start Problems

PSDEng · Dec 20, 2011

This all started in early October, so my truck has been down for a few months. Initially the truck would have a very hard time starting but after it fired up it would run and start perfectly. Eventually it just would not start. I pulled the codes on it and got a high/low side open #1 and an IDM failure. I changed the injector harnesses on the passenger side to no avail. I have a modded IDM so I expected the failure code but I sent it away to have it looked at and it checked out fine. Still no start.

I monitored ICP and Duty Cylce while cranking and it built up to ~3800psi at 11-15% DC so I have ruled out my IPR. I changed the CPS once and the truck started after that but never again. I have confirmed the CPS is working properly as I am getting a RPM reading on the scanner.

I'm all but out of ideas. The only other two things I can think of are a PCM problem or MAYBE a bad CKS, but I don't know how probable these two issues are. I guess there's also the possibility that I have a bad pump, but once again I'm not sure how likely that is.

Any input would be a great help.

Tom S · Dec 20, 2011

Does it pass a buzz test?

PSDEng · Dec 20, 2011

Yes sir everything buzzes fine. I've buzz tested it multiple times and it has passed every time.

Tom S · Dec 20, 2011

I would probably try swapping in known good PCM and IDM if I could just to rule that out. Do you have fuel pressure?

jschildm · Dec 20, 2011

Have you checked fuel pressure. Mine was hard to start once it got cold and I believe its a fuel pump issue that the cold brought out. Runs fine when started or warm but starts hard when cold. I have about 11 psi at idle.

PSDEng · Dec 21, 2011

Yes I have e-fuel and the regulator built up to the fuel pressure I have it set at. The weird thing is that the first day this happened it wouldn't start up in the heat of the day, however it did start up later in the night when it cooled down a bit and has only started once since then. It was around 35 degrees when it started.

PSDEng · Dec 21, 2011

Also, I have never been able to get the truck warmed up enought to run a cct. I have tried running a KOEO but the scanner would just sit in the initializing phase and never actually run the test. I tried pulling codes off of it and the high/low side open #1 code has mysteriously vanished, even though I got it right after I changed the harnesses and a few times thereafter.

PSDEng · Dec 22, 2011

Still looking for some insight on this.

Tom S · Dec 22, 2011

When you have fuel pressure, oil pressure and a CPS signal that sure makes me think either a wiring or a PCM, IDM issue. Only other one I can thing of is too low of voltage to fire the IDM off.

PSDEng · Dec 23, 2011

I know where I can borrow a PCM to try out, so I think I will start with that route. I have already had the idm checked in another truck so if it is an IDM issue it would be a low voltage issue. Thanks for your help.

PSDEng · Dec 27, 2011

I have a PCM on the way to try that out next, I'll report back with the results.

Tom S · Dec 27, 2011

Post up what you find. Good luck

PSDEng · Dec 28, 2011

I changed the PCM and the truck still wouldn't start. I pulled the CPS for laughs and it was rubbed off like the cam gear hit it. I know my cam gear is walking but I still got a RPM reading both in the truck and on the scanner with the sensor I pulled.

Tom S · Dec 28, 2011

Yikes on the cam gear.

PSDEng · Dec 29, 2011

Yeah I hear ya! That sensor was only in the truck for about 20 minutes of run time. Here's the carnage.

PSDEng · Dec 30, 2011

Truck started with another new CPS for about five seconds. It shut off and I pulled the CPS and found it looked like this.

Looks like I have to weight my options now as to what I want to do with the truck.

Thanks for everybody's help.

Tom S · Dec 30, 2011

Have you considered shimming the cam sensor out to get it to run? There were shims available at one time and info online on setting the depth of the sensor. I realize that would be a short term fix most likely.

PSDEng · Dec 31, 2011

Yes I have considered the shim kits but I can't be certain on how long the truck will run. I wouldn't want to get half way home from the shop with the truck and be left sitting. I suppose it would allow me to run it long enough to get it up on a trailer though.