my mustang feels really under powered its got consistant compression afr heads x cam but feels weaker sinse?

I purchased it, i know the mechanic i took it too to make sure it was in good condition said the timing was way retarded as well as running rich, he tried to fix it by hand but i still fees like its slower than it should be, can the timing and fuel still be so bad that it would be considerably slower,do i need to have it dyno tuned. The compression according to him was pretty even, The psi was between 132 and 140 on a cool engine at 4500 feet , when i do the math for altitude it should be151-160 and that not accounting for the engine not being totally warmed up,so im guessing more like 160-170 psi. What can make the car still feel slow.

3 Answers

  • Geo
    Lv 6
    6 years ago
    Favorite Answer

    You'll never get power out of any car unless you have good IGNITION ADVANCE. When people say "timing" it's either cam or ignition, and I wish they would say which it is. Assuming your cam timing, which is also critical to performance, is correct, you need to get your ignition timing to advance correctly.

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  • 6 years ago

    You didn't list what year mustang it is or what engine but one part that comes to mind is your knock sensor.When its faulty,it falsely detects detonation and retards the ignition timing.Instead of temporarily reducing timing,its constantly reduces timing which also leads to a rich fuel mixture .An 87-95 model is set at 10°-14° so the timing shouldn't be below that.Not sure what a 96-present year stang is set to.If its a 94-2014 model,try to locate the knock sensor.Its installed in the block or head.Start engine,use a wrench and tap lightly near the sensor.You need to connect a timing light up too.As you tap,watch the timing mark to see if its retards as you're doin this.If it doesn't retard or if it continuously retards instead of temporarily doing so,its faulty.You didn't list the intake runner cc size,but if you're using a AFR 205-225 head,you're losing torque in the low-midrange area and the X cam is causing the same problem.Both are made for more top end power,so its a dog down low

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  • 6 years ago

    You aren't exactly driving a Camaro. Just a Mustang with a discontinued engine.

    #1. Change the fuel filter.

    #2. Have the fuel pressure tested at a Ford Dealership. This is a very inexpensive test BUY the fuel filter must be clean to get an accurate fuel pressure reading.

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