1990 Msutang GT will not idle on its own and struggles to get even 25mph

Discussion in 'Fox 5.0 Mustang Tech' started by DSGB347, May 30, 2009.


  1. DSGB347

    DSGB347 New Member

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    I am having trouble getting my car drivable. I resently bought it with a super charger with 6lbs boost I believe. It will not idle on its own checked everywhere for vacuum leaks; found none. even temp duct taped around the couplings to make sure the where sealed good. I am not sure if the pipe that would usually dump smog/unspent fuel into the exhaust matters but the exhaust is after maket and there is no smog tube one it but i pluged the smog tube anyhow still no idle. I installed a Kirban adjustable regulator and no matter where it is set doesn't help. It does seem to smell rich if I turn it up high. I have a FMU I'm running the also. Right now I can only get the car running when its warm after a few tries of starting and feathering the gas. I've tried a new TPS the IAC is new EGR and EGR valve is new I tried to adjust the TPS voltage but it doesn't matter where it is it still won't idle. and turning the idle screw to far just makes the fast idle sore way too high only to drop off and not idle correctly. If I trie to drive I can only get to 25mph and that comes with poping in the exhase not matter where I adust the timing. It has a Walbro 255 lph fuel pump must recently today I got a code 87 and 95 I'm goin to change the fuel pump relay tomarrow but I don't think thats the problem. I just don't know what to do. Should I try to gut the smog stuf to make its simpler. It still has a smog pump. I am stopped I know this car has run set up the way it is before. I'm also using autolite 24s gapped and 35degress I don't think I'm getting spark blow out? 92octane gas, boost controller. What else should I do? I'm starting to miss my 347 stroker car.
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  2. 90bluegt

    90bluegt Founding Member

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    You need to get it tuned.. Just my opinion, but go get a moates Quarterhorse (Welcome to www.moates.net! : Moates.Net) and Clints BE/EA (EEC Analyzer) and tune that car. Also, hit the site EECTuning.org • Index page and you'll see what I mean.

    People will probably dis-agree with me, but after everything that I tried with my car to get it to run. I bought a tweecer first (got it running well) then sold that and got the moates QH and tuned it. Thing runs like stock now, just with a lot more horse.
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  3. stangbang302

    stangbang302 New Member

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    my car used to do that it hesitated to rev and wouldnt go fast at all, found out that my problem was clogged fuel injectors
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  4. 86turbo

    86turbo Member

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    sounds like fuel to me. I would take the blower off and try and get the car running right. Wouldn't be the first time i've heard of someone putting a sc on an engine that isn't running well anyway..

    just a thought

    Drew
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  5. ddonaca351

    ddonaca351 Active Member

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    (imho)
    Set the distributor to 10-12 degrees, no more.
    Set the fuel pressure regulator to 38-40 psi at idle
    Set the idle adj screw to 1 turn past first touch
    Set TPS voltage to .95vdc or less DO NOT go over 1v
    Make sure the MAF is the correct cal for the size of injectors that are in the car.
    Check the daiphram in the FMU to make sure it's correct for the injectors and boost level of the car. (blower manuf. web site / tech line should be able to help)

    If none of that helps, you could try a local tuner or remove the blower kit, but try the simple stuff first.
    #5

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