Suddenly no throttle

[dbrannon79]

I believe you should have 3 grounds at the back passenger side. 1 is for the PCM 1 is for the transmission and the last one I can't remember at the moment

There was only two that I could see. One large maybe 10awg wire and one small about 16awg wire. I might need to study the wire diagram I found online and give a good look in the daytime. Someone tapped into the smaller wire and ran an additional ground over to the inner fender as if there was a previous ground problem

 

[Stoney]

When you replaced app did you get DELCO...if not that could still be your problem

 

[dbrannon79]

When you replaced app did you get DELCO...if not that could still be your problem

no, I had purchased it through Advanced auto since I have a commercial account with them. I do have the old one incase I need to put it back

Update: this morning on the way to work I noticed a difference in how the truck drove! after cleaning the grounds, (which I did before when replacing the flywheel and re-doing the fuel lines to the IP and the remote mount fuel filter) she seemed to drive with a bit more pep in her step! shifts were slightly firmer and even when I was climbing a small hill at a slower speed once I hit 45 and the TCC activated I felt a good change in the engine RPM as if another gear had been found! the only thing I did other than clean them was when I found that the owner before me had tapped into the smaller ground wire by the tranny dipstick tube and ran it over to the inner fender, the wire was just wrapped around a bolt so I cut the end off and attached a ring terminal! I still plan to look over the wiring real good and make sure there isn't any other grounds or bad wires. I may end up pulling off all the plastic loom and re-doing it all cinching up all the loose harness. while I was in there I discovered there was two wires one black and one green that was tied together and stuffed back behind the harness where it T's on the center of the firewall. they are long enough to reach to the AC compressor and look like they went to a pressure sensor that would have been mounted to the rear of the compressor. Of course there isn't a sensor there, not sure if that is what they were for.

 

[dbrannon79]

Just a question, on the attached wiring diagram for my truck this copy shows Vin S. are they referring to the 8th or 10th letter of the vin? if it's the 8th I will need to locate one for vin F instead of S. if this is the case, does anyone have one that they would be willing to share? mine the 8th is F and the 10th is S.

 

[ak diesel driver]

One other thing you might consider is the OEM placement for those ground wires is on a wet hole. You can move it forward to the intake manifold bolt and they're dry. You'll make better contact

 

[MrMarty51]

Just a question, on the attached wiring diagram for my truck this copy shows Vin S. are they referring to the 8th or 10th letter of the vin? if it's the 8th I will need to locate one for vin F instead of S. if this is the case, does anyone have one that they would be willing to share? mine the 8th is F and the 10th is S.

8th vin F.

 

[dbrannon79]

One other thing you might consider is the OEM placement for those ground wires is on a wet hole. You can move it forward to the intake manifold bolt and they're dry. You'll make better contact

I did just that! I didn't like the nut on nut situation on that back stud with the grounds below and then the ear for the trans dipstick. I moved them to the next one sticking out off the intake

8th vin F.

Would you or anyone for that matter have any diagrams for the 1995 model vin F (OBD1) to share by chance?

 

[MrMarty51]

I did just that! I didn't like the nut on nut situation on that back stud with the grounds below and then the ear for the trans dipstick. I moved them to the next one sticking out off the intake


Would you or anyone for that matter have any diagrams for the 1995 model vin F (OBD1) to share by chance?

About all I could do would be to take a pic of the book and post it up. Probably not the best method. I dont think the diagram in the book is diesel specific but has the different options sort of drawn in.

 

[dbrannon79]

About all I could do would be to take a pic of the book and post it up. Probably not the best method. I dont think the diagram in the book is diesel specific but has the different options sort of drawn in.

Anything is better than nothing! if I am able to blow it up to the size sheet of paper and be able to read it, that will be an even better plus

I'm curious how much different it is compared to the vin "S" I found online, or if the vin F would be shown in one of the "poor man's" repair manuals like the Chilton or Haynes books we find in the parts stores.

 

[JMJNet]

At DieselPlace forum, there is a member name Glagulator.
He is the electrical guru on this truck.
There may be some wiring diagram in their FAQ also, not sure if that ever makes it into the Technical Library in this forum.

 

[dbrannon79]

At DieselPlace forum, there is a member name Glagulator.
He is the electrical guru on this truck.
There may be some wiring diagram in their FAQ also, not sure if that ever makes it into the Technical Library in this forum.

Thank you! I found a boat load of info on a sticky thread even a complete service manual and OBD code diagnostic procedures now I have some work to do.

 

[MrMarty51]

Thank you! I found a boat load of info on a sticky thread even a complete service manual and OBD code diagnostic procedures now I have some work to do.

I’m just now getting back into the house and seeing whut I been missing. Happy that You found a source.

 

[Jaryd]

I have some factory service manuals for that truck that I’d sell if you need them.

 

[WarWagon]

they are long enough to reach to the AC compressor and look like they went to a pressure sensor that would have been mounted to the rear of the compressor. Of course there isn't a sensor there, not sure if that is what they were for.

You really answered your own question. Lazy SOB removed the high pressure compressor cut out, or replaced the compressor without swapping over the switch. You are looking at the shipping plug in the compressor. (Only R12 systems didn't have the switch.) AC, clutch, should not work without this switch. If it does it can blow up (yes, an explosion) the high side of the system. Been there done that when the switch went bad and glad the hood was closed as the cloud appeared... Get a new switch, but, the AC system needs to be discharged to install it.

An AC shop is the cheapest choice if you do not have the tools to charge the system by weight. NO you can't charge it correctly any other way than using a scale. High or low levels ruin compressors. The can with the gauge is not correct and 50% the cost of a good AC shop labor.

Sounds like the TCC is worn out if it's slipping. This is a weak area on the 4L80E as in being the first part to slip. A triple disc billet converter is a good solution.