: 93 sts running rough only when hot



silver duke
07-12-06, 02:03 AM
hi everybody, my 93 sts begins to run rough and basically miss,shake at idle and under load when it is hot about 45 minutes of driving. the rpm does not drop off however. the traction disabled/abs warning goes on as well when it starts running rough. could the abs/module/computer be causing this bad miss? the exhaust smells very rich when missing. so far i have changed,8 plugs,ign wires ,fuel filter,3 of the 4 coil packs,checked egr passages --look clean. the service engine lamp never lights up and there are no current pcm codes.i also cleaned the throttle body. i am starting to suspect the fuel pump. but the car runs fine when cool to warm, no miss,but a little power loss. i can hear the pump it seems a little noisy but not excessive. what do you guys think? maybe icm?

Ranger
07-12-06, 10:22 PM
Check the FPR when this condition exists. If it is not leaking, then get a fuel pressure guage on it to condem or rule out the fuel pump.

silver duke
07-15-06, 02:31 PM
what should the fuel pressure be ? i am finding it impossible to get on to the schraeder valve for the fuel press because the master cylinder has a hose that runs directly in front of the valve.

Ranger
07-15-06, 09:48 PM
I think the fuel pressure should run about 45 psi if I remember correctly.