Code 13 Engine shutoff Sol Ughhh...

[RadioMan]

Not sure if the Tahoe is the same, but schematic for the 95 PU shows ESO and Fuel Solenoid on a 20A fuse. Lift pump on a totaly different circuit.

 

[Acesneights1]

ok So after reading much and agonizin overwhat to do this is what I'm thinking.
Isolate ESO by unplugging it and make temporary tie in to different circut(possibly LP or anything keyed) Drive truck.
fuse blows=fuel sol bad time for IP $$$$$:sad:
Fuse doesn't blows then ESO is bad):h):h):h
Can't see any other easy way to diagnose. MAybe I'll try that first but the more I think about it , two things bothering me.
1) I moved wired under intake before putting last fuse in which didn't blow which could mean chaffed wires under intake
2)Truck did feel at one point under heavy throttle that when I let off throttle, truck didn't right away. Maybe I imagined that, maybe I didn't which could point to Fuel sol or PMD issue.
How my doin ?

 

[Acesneights1]

Also Tim(accurate dsl) told me to unhook PMD ground. I have read how important that ground is and not to move it with extension. Can this be done safely for test ? .
Chris, I hear what you said but the problem is it's not blowing the fuse right away so I really need ESO hooked up to run the truck until it blows which is making me revisit other possiblities now. If ESO was shorted could it be intermitent or would it die in a "will blow fuse right away" kind of way ?

 

[gmctd]

Black ground wire on top of the IP is only source for grounding the Fuel Solenoid - FSD module is ungrounded, isolated by epoxy and polyurethane - module electrical ground is thru that same black ground wire, so requires no external grounding

Fuel Shutoff Solenoid - solenoid internal to the DB2 - kills engine by shutting off fuel supply to rotor - powered by +12v from 10a ECM-B fuse

Fuel Solenoid - external solenoid located on lower rear of DS4, driven by the FSD\PMD - controls injection event by metering fuel to the rotor\pumping plungers - powered by +12v from 20a FSol Fuse (supplied thru FSD\PMD) and......

Engine Shut Off solenoid - another solenoid, mounted vertically on top of the DS4 - blocks off fuel supply to IP - powered by +12v from 20a FSOL fuse

 

[Acesneights1]

so if I unplug the ESO and provide temp key power to it from another source and fuel sol fuse still blows then I'm looking at an IP?

 

[gmctd]

Or wiring\harness\connector - maybe the IP harness is shorting to the IP, down in and under there, where you cannot see it

 

[Acesneights1]

Or wiring\harness\connector - maybe the IP harness is shorting to the IP, down in and under there, where you cannot see it

Boy you aint kidding. Well I thought about how to attack this and basically like I said before, once I jiggled the harness under the intake last night the third fuse didnt blow all the way home.. That weighed heavily on my decision to say F'it and pull the intake. Wow were those wires nasty. Didn't see anything obviuos so now I'm pissed I did all this. Wires were Covered in oil or something so I unplugged from firewall and everything by pump and pulled the whole harness out thinking screw it. I got the intake off let's be sure. so once I got the harness on the bench pulled the loom off it and washed it down with starting fluid(was out of brakecleen and carb cleaner I thought not good for wire.) Well low and behold I see a chaff mark with bare wire right at the big plug. In actuality I could have fixed it without pulling intake but it was so nasty that by cleaning the harness up I found it and I did look there before hand. I put it all back together and took for 15 min road test. No blown fuse so far. The fact that i found a rubbed wire makes me very happy because in all reality by movng the wires around last night I probably moved it out of harms way and could have easily went months or maybe even never blew a fuse but always wondering when is it going to f'up. So I'm glad I found something. It only makes sense that I blew the fuse within minutes of replacing it the first time but after moving the harness around it never blew another one. Also I traced the wire that was chaffed and it was the B+ for the ESO. Makes sense. Another nice thing I got out of it was since I wanted to cut the timing back a tad anyway it was easy to move the IP with intake off. Also since my EGR went to the back of a milk carton look how nice and clean my intake is. Oh BTW what a MF ballbuster to get that wireloom back on. Stuff is steel reinforced or something.

 

[gmctd]

Replacement IP harness is NASA-style teflon-insulated fine-strand silvered-wire with crimped and soldered connections - usually ~35bucks from reputable vendors such as Bill, Stanadyne included the upgraded harness with each new IP, also with each rebuilt IP - very few vendors sent that new harness to the customer along with the purchased IP - just imagine how many of those harnesses, intended to solve any of several failures, wound up in the trashcan

 

[RadioMan]

I'd look into replacing that harness now. Not sure what type of insulation they used on the stock harness, but most insulations don't like aeromatic cleaners. It dries them out and then they crack and fall off. If the stock stuff is teflon you might be OK though.

On edit -- T&B (and others) make a soap known as *wire pulling compound*. You can safely use this stuff on any insulation without causing any harm. It is a mess to use though.