99 Mustang gt running rough and stalling

CALEB221777

MEMBER
1999 FORD MUSTANG

My car is a 1999 Mustang GT 5 spd with 40,000 miles. The mods possibly concerning this problem are a BBK cai and a diablo chip, both installed by the previous owner( a Ford mechanic, whose abilities I'm beginning to doubt). Approxiamtely 1 month ago the car had to get the fuel pump, spark plug, and plug wires replaced(total cost $700) for a similar feeling problem. Now the car feels like its running on only a couple cylinders. It is very underpowered and the engine shakes, sounds like its missing and rough, and the car stalls when idling at a stop light. Also, when I rev it up and let it drop back down the idle dips to 500 then slowly recovers. The car ran fine today until I used some engine degreaser and hosed off the engine. I let it sit for 1.5 hrs in the sun with the hood up before driving it somewhere, but after driving down my hill I noticed the problem. Please help!

1 Reply

NAI1ER

MEMBER
15 POSTS

Problem could be as easy as plug wires.
If the mechanic put a cheap set on they could be shorting to the engine.
Easy way to check is park somewhere very dark, start the engine and pop the hood. If it looks like a christmas tree twinkling all over then there is your problem. If not try moving plug wires around ( engine off so YOU don't light up )where ever the wires touch engine and see if the problem gets better.