[antl14]

My mustang is a 1990 hatchback. it has a 8.8 with 3.73 gears,cobra posi diff., hardened 31 spline axles, and 5 lug conversion. the engine is new with a stock block, afr 165cc heads, trick flow track heat intake, anderson cam (not sure which one). it has been converted to MAF. I did not put the engine in and unfortunately the guy who helped me out has closed down. my problem is a rough start. i found a vacuum leak and put a cap on it and now my car take 3-5 times to start it up. on a cold start it will actually start right up but idle wildly until warm. without the cap i can hear the leak and my car definitely rides the same with and without the cap. Also, I always smell gas and the mechanic who fixed my car said its because my gas tank is broken. apparently the piece by where the fuel pump sits (walboro 190lph). another concern is the idle. it always seems to fall back at 1100 rpm and when i come to a stop it idles at 1500-1700 for at least 20-30 seconds before falling back to 1100. the computer was also tuned by the same mechanic with an sct chip. it is supposed to have 8 different tunes but he only gave me one for now. if someone could help me with advice i would greatly appreciate it

[antl14]

The car also has no airconditioning or egr. i just plugged up the holes coming from the throttle body.

[powerstand89]

I am no mechanic, but I had similar problems and it was the throttle positioning sensor. Apparently, they are very fragile.

[antl14]

OK. i was going to switch the tps and iat sensor. when i do that ill hopefully see an improvement

[88 347 stroker]

Pull the idle air controller off and cleaning it out as best as possible. They tend to get clogged up and can add to the problem or mask other problems. It's easy to do and won't cost you anything more than some brake clean.

[antl14]

Would a spacer between the iac work? Where could I get the right one?

[Bubba95SN]

Check fuel pressure do the EEC1V tests and cylinder balance. Post results.

[antl14]

Ok I'll give it a try

[antl14]

Originally Posted by Bubba95SN Check fuel pressure do the EEC1V tests and cylinder balance. Post results.

Sorry thought i was more competent. How are these tests performed. I have cleaned every sensor and still no better. after plugging the vacuum leak with a cap my cars cold start is 100% better. however, anytime i attempt to start it up after it wont start unless i hit the gas pedal. Do I need to get it re-tuned? the vacuum line i capped was the closest vacuum port to the drivers side under the intake manifold. if that helps

[sspmustang]

That sounds more like a Fuel issue rather then a IAC or TPS problem. This may sound stupid, but have you checked the fuel filter?

[Bubba95SN]

SBFTech has test proceedures.

[antl14]

I realize sbftech has the procedures but I can never seem to find them. Can someone post a direct link to this procedure? I also believe it needs to be retuned after plugging up the vacuum leak. I'm going to have to find a new shop