RNH524

I just bought a 89 Mustang GT and like the title says its running rich, popping through the intake when you get on it, and runs shugglish at idle and not responsive like it should be but sometimes runs fine for a few minutes after it seems to clean itself out.. Also after giving gas and it coming down it will stall and when I start it I have to give it gas for a minute in order to keep it stay running at idle. Fuel is at 34-35psi at idle. Thinking Timing is off ??

Not sure of the internals (Bought car at auction)

The specs that I know of...
Trickflow upper and lower intake
BBK Cold Air intake
Bigger T/B (Not sure of size possibly 70-75mm doesn't say on it)
Mild Cam
Edelbrock Heads
Stock MAF
Stock injectors (19lbs)
Ford Racing Headers to dumps (No Cats)
Mallory Ignition Box
Fuel Regulator



Any ideas?? I don't understand how its running rich but seems like its not getting enough gas?

Thanks in advance!

LCBlackDep183

Yea, I'd start with timing. That's how it would act if its way out of efficient timing. Fuel pressure sounds right. Check for vacuum leaks too. I'm of the thought pool that thinks everyone should have a vacuum gauge.

Timing lights are like 30 bucks. Buy/borrow one.

Mike T

Run a KOEO test...http://oldfuelinjection.com/?p=13 and/or a KOER test...http://oldfuelinjection.com/?p=94. You'll wind up throwing a lot of unnecessary parts at this if you don't.

RNH524

Thanks I will do that tomorrow to see what comes up.. I didnt have time to adjust the timing going to do that tomorrow, checked for vacuum leaks but couldn't find anything.. Keep you guys posted!! Again thanks for all the help !

RNH524

Sorry I haven't kept you guys posted.. But we messed with the timing but still coudlnt get it to run correctly. Think I might have a injector problem, smelt gas pretty strong coming back back of the engine. Going to do those self tests tonight. I'll be back on here tonight to post the codes if any come up.

RNH524

So we messed with the timing so much but still cant get it to run correctly. I did the self test with the engine off and the codes I got were...
23
67
81
85

Cant get the car to stay running long enough to do the KOER.

dawson1112

23 - Throttle Position Sensor Out Of Self Test Range
67 - Park Neutral Position Switch Circuit Open; A/C On -Manual , Manual Lever Position Sensor Out Of Range/A/C On Clutch Switch Circuit Failure
81 - Secondary Air Diverter Circuit Failure
84 - EGR Vacuum Regulator (EVR) Control Circuit Failure

Out of those the egr vacuum regulator controls the egr opening and closing If it is stuck partially open then its allowing vacuum to the egr all the time keeping it partially open. That is assuming it still has the egr. Im guessing though that it has been deleted along with the smog air diverter.

The TPS appears to be your likely culprit here.

RNH524

Smog is gone but EGR is still there.. Check the volts to the TPS and it only came up with 1. something so going to replace that..

RNH524

And the last code is 85 not 84

dawson1112

lol ohh I missed that

85 - CANP Circuit Failure
that's your charcoal canister for collecting fuel vapour. Most likely it unplugged I doubt that would cause your problems unless the vacuum line is off an leaking vacuum

the tps should be .98 at idle.