92cobra

Hey ive got a 1990 mustang gt that is surging really bad from 3k+ rpms, i have changed the plugs wires and had a fuel injection cleaning done. It was also idling ruff and driving ruff and surging abit, but the fuel injection cleaning did the trick there, but my 3k+rpm range is still unusable, it surges REALLY violently. I also had the fuel filter changed, and my fuel pressure checked, it was fine.


What fixes the surging at 3k+ rpms?

5.0stanger

Get your codes read

mattdel

your fuel pump is probably on its way out. get yourself a gauge that has a long enough hose to where you can attach it to the fuel rail, run the hose under the hood near the windshield, and duct tape the gauge to the windshield, monitor while driving. shouldn't fluctuate much around 39 psi. if it drops below 40 at WOT, replace it.

92cobra

there were no codes, and the tech said that the fuel pump was fine, should i do the above anyways, or no? When he changed the fuel filter he checked the fuel pressure and said it was good.

5.0stanger

Check your ground cables.

5.0stanger

Also, what plugs are you running and what is the gap set at?

92cobra

i know there platinum plugs, dunno what kind, i will have to check, and i have no idea about the gap, i had a mechanic do all the work, i know NOTHING about cars lol.

mattdel

get rid of the platinums. no good for EEC ignition.

5.0stanger

If you aren't blown or running nitrous, get autolite 25's and gap them at .049. They are cheap and effective and are worth a try.

tmajikman

What is a good plug for these cars, since platinums are not recommended?