Can it be?????

[clodracer2000]

Sup yo, i just put a paxton sn89 on my 1990 mustang. the car runs good driving normal but when i get on the gas under boost it sputters like its not gettin fuel. The fmu i have was sitting up for a few years the previous owner told me. Is it possible tat the fmu can be sticking?????/

 

[Kdubslugga]

Did you re-gap the spark plugs? If not you could be blowing out the spark. Spark plug gap should be 0.030-0.035

 

[clodracer2000]

there autolite 24 with 30 gap

 

[Mustang5L5]

First off...run the codes and see if there Are any hints to be had.

It's a little early to blame the fmu and go rebuild it first without doing some more diagnostic work.

What else in on the car? Aftermarket ignition? Have you checked the wiring and other wires? If seem the same issue caused by arcing spark plug wires.

 

[clodracer2000]

The check engine isnt on, but it does work. The car runs normal just until the boost hits

 

[clodracer2000]

I didnt have 2 touch any wiring 2 put it on. It ran meant before and after the install. Checked for vaccum leaks, plug wires, an anything else i could think of lol. Ignition is stock also, with msd coil.

 

[Mustang5L5]

Check engine light only comes on for 11 specific codes....out of 99 or so. So in other words, there are many codes which will not trip the cel.

For example, you could get an egr code which might suggest your egr is hanging open, or run the cylinder balance test and discover #4 cylinder has a misfire.

My point is there is some diagnostic work you can do before just throwing money at the car and hoping that's the issue.

 

[clodracer2000]

I try an see, this is my first efi mustang and first sc car, so its all new to me. Not quite sure how 2 figure out some efi problems yet lol. U stay i mass? I live ct, ill drive it 2 u if ud look at it for me, if worse comes to worse and i cant figure it out