This car is kicking my ass!

[80 hate]

So I bought a 1992 vert the first of Jan. It ran great and very strong. It has a Stage 1 cam, heads and intake. So about a month ago a started it up and back out the garage. I let it idle in the drive for a few minutes while I cleaned the garage up and it shut off on its own. When I went to start it again it was VERY hard to start and was missing really bad.
I'm not a mechanic but I can hold my own and I'm trying to keep costs down. So I started doing some research on line and talking to friends.
Found out the computer was fired (fuel pump wouldn't cycle off) so replaced it. Did some more research and checked for a bad ground. I also installed a fire wall ground and ran a separate ground from the negative of the battery to the computer just to be safe. No change.
So I started replacing the usual suspects.
TFI module
Ignition switch
New distributor and have timing at 14 degrees
Cap and rotor
Wires and plugs
No change. When the car starts its missing like crazy and once it gets warm it wont start unless it cools completely down.
So back to the drawing board. I found a "No start check" list on line and just ran through it. Everything checked good. So at this point I'm lost. I really don't wont to take this thing to a shop just to find out its something simple. Now I'm just pissed and don't know where to check next.

[NXcoupe]

Bring it up and i will fix it for u. Its worth it to just enjoy the car rather than beat your head against the wall. First thing, ck your tps voltage and report back.

[80 hate]

4.2 volts off the green wire. isn't this supposed to be under 1 volt?

[86gt40]

.5 to 1.1. Closer to 1 the better. But that's the range ford states

[80 hate]

I'm getting 4.2 from the green to the black wire. WTF does that mean????

[86gt40]

See if u can slightly loosen the screws and turn it slightly to get it in range

[CNTLOSE]

.97 is what Ford says is optimal....although like Jason said getting close will work. If you are 4.2 you are way off. Try rotating the TPS a little. You might have to elongate the holes...I had to do that on one.

[Kwik92GT]

.97 is what Ford says is optimal....although like Jason said getting close will work. If you are 4.2 you are way off. Try rotating the TPS a little. You might have to elongate the holes...I had to do that on one.

THIS ^^ Have had to do that several times.

[chad393na]

You wont get that much adjustment out of the tps. I bet its shorted internally.

[draggin50]

Yeah 4.2 is a lot. Id say its shot. I don't think you can get that much out of it even if the holes are slotted.

[chad393na]

Yea, 4.2 volts is pretty close to clear flood mode, which would shut off fuel while cranking. If its not in clear flood mode it would be doing the opposite, and dump way too much fuel.

[NXcoupe]

4.2 volts off the green wire. isn't this supposed to be under 1 volt?

Computer is fried again. Bring it back and I'll see what I can do for you.

[COOP]

It doesn't happen to be a T5 swap car does it?

According to corral if you put a T5 ecu on a car with the automatic harness, it will fry the ECU

http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor-harnesses-manual-auto-differences-year-differences.html#/forumsite/20549/topics/1094179?page=2

[80 hate]

At this point this thread may need to be moved to the tech section.
Well tonight was a night of little victories. I bought a new TPS and had no change in voltage. So I decided to see if I bypassed the computer ground to a firewall ground and guess what... I now have .98volts at TPS. The car will now start and run. Tomorrow I'm pulling ECU and checking my "pin 46" for a short in the wire. Can only be two things now. The harness is bad or the computer is fired. Right?

[COOP]

Sounds like you have it narrowed down.

Good luck, hope you get it sorted out

[NXcoupe]

It doesn't happen to be a T5 swap car does it?

According to corral if you put a T5 ecu on a car with the automatic harness, it will fry the ECU

http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor-harnesses-manual-auto-differences-year-differences.html#/forumsite/20549/topics/1094179?page=2
Exactly what I thought too, but it would have fried it instantly if that was the case, they don't go gradually. I told him to disconnect the O2 harness anyways and after I fix the computer for him, see if it fries again. If it doesn't and it works well, then he's got an issue in the 02 harness somewhere. Could be melted or shorted wires there.

[80 hate]

Its alive!
Well after almost two months of beating my head against the wall it fired up and ran good today. Hell I even took it for a small drive (5miles) to blow all the dust off of it.
It turns out it had two problems that kept causing me to fix the same things over and over.
1. O2 harness had a short in it. This blew the computer.
2. Brand new distributor had a bad TFI in it.
I owe Mike Bell and Dayton Performance a big THANK YOU for walking me through the sensor check and repairing my computer twice because my dumb ass kept blowing it.
And Thank You to all the guys that posted up with advice. Stangbangerz has always been great anytime I needed help. You guys ROCK!

[redfirepearlgt]

Good to hear Rusty. Hope to see you at the cruise in 4/17/2016

[draggin50]

Good to hear its back up and running without issues. They become a lot less fun if your working out bugs all the time.

[80 hate]

it will be there even if I have to tow it. lol

[redfirepearlgt]

AWESOME!