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I hate intermittant error

66gt350

66gt350

Active Member
I almost ran out of the shop screaming tonight. It all started out with swapping over to serpentine belts. While the car was apart I figured I'd finish the efi computer wiring harness. When I initially installed everything in the car it ran decent...drove it to work for awhile, but there was way too much wires. Since the car was down for a bit, seemed like agood time to do some wire shortening. I finally get the car started tonight and it was running like crap, throwing a mil code. I grab the book to find it's the throttle position voltage. I grab the laptop to hook it to the computer to find it's stuck on 1.29 volts no matter the throttle. I mess with the wiring and everything looks good. I start it up and its running fine. Every now and then idling in the garage it goes to 1.29 volts, throws a code and runs like crap, then goes back to normal. I think I'm gonna scream. I guess it's time to yank the wiring and find the problem. AAAARRRRRGGGGGG

edit: BTW...for all you efi guys....did you know that if you don't reconnect one of the "salt and pepper shakers" the car won't start. Don't ask how long it too me to figure that one out. :cry

I don't know if it's related or not...probably is. For the mil light I'm using LED's. I rewired my panel with some nicer looking LED's. Now when the check engine light is off, the led is faintly lit. The trigger for the CEL light is ground, so there must be short with another ground....

I'm thinking now why the *BLEEP* did I decide to rewire. It wasn't broken...why futz with it?!?

Excuse me while I go into the other room and start dropping :fbomb :fbomb :fbomb :fbomb :fbomb
 
It sounds to me like the EEC is trying to correct whatever problem you're having. Have you tried disconnecting the BAT and letting it sit for a few minutes? I'd try that before I started chasing any wires. If it's still doing the same thing, do you have a spare TPS you can install?
 
The battery was disconnected for several days before starting, while I was doing the all the work. I ran codes this morning, and got the normal 85, since I yanked all the emissions stuff, but nothing for the tps. I may take it for a drive tonight to see if it pops back up or not.
 
I'd look into Daves suggestion of the TPS - I had one go in a Dodge, and it drove me crazy checking wiring. Finally changed it out, no further issues
 
Well, I think that I have found my problem. And it's my own doing. I bought a new TPS and installed it with no change. So, I figured that I messed something up when I shortened the wiring. I get under the dash, and I think I found my problem. There are several grounds in the wiring harness. On the case ground, I hooked it up and just ran the nut down to hold it in place. I tightened that nut and the TPS voltage is looking good. Good grief, I hate grounding problems!!!

But I think that I still need to yank the wiring harness. When I removed the plug for the EGR valve, I must have done something else...the Tweecer is no longer datalogging the Air to Fuel ratio, which uses that wire.

-rob
 
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