No power when I give gas...

[impulse001]

So this has been happening for awhile, but my Mustang has been sitting in the garage so I never fixed it..

While I am driving, I will press the gas pedal does say 50% and hold it, I will get minimal pull from the car, like I am only holding it 10% but after holding it for 2-3 seconds, it will jump to normal feeling. This happens no matter how far I push the pedal down.

Also, sometimes when I floor it from a slow roll, I will get some backfire and hardly any power.

When I pop the hood with the car running, it sounds like there is a large air leak from somewhere behind the upper intake, could it be a bad gasket on the upper intake?

 

[zachpierce]

yes it could be. take it off and look to be for sure. if thats not your problem then maybe its your fuel injectors. maybe only 1 or 2 are bad. just an ideal to think about and check. i know it could be a million different things but also try and change your fuel fillter. if its still now working right it could be your fuel pump. thats what it sounds like to me. i had one start to go bad and lasted for a 400 mile trip b4 it went all the way out on me. hope this helps you man. i have had so many damn headaces doing my 4c to 5.0 swap i just finshed this past week. took me 3 months to do it all even rebuilding, cleaning and painting everything on the motor. and only thing left is to fix the blinkers and wippers, besides that it runns soooooooo great !!! well worth it. my old 5.0 for the swap was wreck by my brother, but was still driveable.


fromer owner of 1968 mustang, own 1990 lx, 5.0,1989 lx, & a 1995 v6 . the one im swapping is the 1989 it has trick flow intake, mac shorty pipes, h-pipe, flowmasters, pro 5.0 shifter, t-5(5yrs. old), all msd ing. mds spark plug wires 8.5, no smog, elec. fan, rebuit engine, 3.73 gears, underdrive pulleys.

 

[HISSIN50]

Pull codes first.

Agreed with looking for a vac leak. Make sure your PCV didn't pop out of the lower intake.

 

[Tanus]

is there a sticky about pulling codes?

 

[MustangLX-5.0]

It kind of sounds like a bad or disconnected MAF sensor. How does it run when cold? does it idls ok?

 

[MustangLX-5.0]

is there a sticky about pulling codes?

What do you need to know? Just get a $20 Actron scanner. All the info you need is in the Actron manual.

 

[Tanus]

What do you need to know? Just get a $20 Actron scanner. All the info you need is in the Actron manual.

thanks for the tip, autozone/checker has those?

 

[MustangLX-5.0]

thanks for the tip, autozone/checker has those?

Any major auto parts store will carry them. There are a few different test funtions available, the manual will explain all those features. If you just want to get codes, plug the scanner in (both plugs), turn the ignition switch on but dont start it, then turn the switch on the scanner and wait..then count the flashes after the test sequence. Simple.