also yeah, called the mechanic today and the new ECM didn’t fix the communication issue. We agreed together if he can’t figure anything out by end of Monday I’m gonna go pick it up.
Then I’ll sort out the grounds and stuff.
Ok so I’ll try to get it to the back of the cyl head.
I don’t think there’s any on the drivers side, everything seems to be on passenger side according to the 94 FSM.
Boy… I got a lot of wiring to redo,
- adding these grounds
- direct wiring the coil to the battery for testing
- temporarily cutting the tach output wire for testing then reconnecting it
- possibly new coil connector
- there’s a pcm ground I want to redo coming off the harness to intake. I...
I might have better luck going from below, haven’t really thought of that lol.
If I can’t get the strap onto the back of the passenger cylinder head would the farthest back intake manifold bolt stud work aswell? Or would that be a no go?
On my 94 TBI the alternator is actually on the drivers side.
So real quick question. Is there any decent alternative location to put the ground from the firewall under the heater hoses to the cylinder head? Particularly the cylinder head side.
It’s a total pain to reach back there to get a ground strap in, any other more reasonable place that’s somewhat...
Wow! Thank you so much for this write up, it is extremely appreciated. Can pretty much rule everything out but the connection between pin M and F9 on the PCM. Seeing as the SES light functions completely normal and also the paperclip in pins A & B do show the codes. I'm hoping that throwing this...
I decided to let him put in the used ECM I picked up from the junkyard. Just came back from the shop.
There is power at the ALDL connector but his scan tool doesn’t connect, and he’s done it many times on these trucks. ECM does look suspect putting it that way.
He seems to be doing a decent...
I don’t think the connector is deformed at all, I never bent the pins, just slight pressure so the paper clip would stay.
My local junkyard has a compatible ECM so I’m going to pick it up and let them try it out.
So another update, shop is still having a hard time.
They’re trying to get my ECM connected to a scan tool, and the ECM seems to not want to communicate with their tool. Odd right?
The ALDL port did work I was always able to use a paper clip to get codes.
Think the ECM is going bad?
Wow that’s quite the story! I bet that guy was happy.
Really does show how important grounds are lol.
I’m giving the mechanic
with my truckthe rest of the week to figure something out, if I don’t hear anything by next Monday I’m going to pick it up.