93 EB 4.0L Idle problems

[airbear406]

engine starts easily, runs very rough, shuts off, only way to keep running is to play with accelerator and try to keep idle over 1200 rpm. engine check lite comes on immediately sometimes, other times after 3 or 4 miles. black condensation comes out of tailpipe only when you start car when cold. no smoke. Runs fine on hwy. will idle fine most of the time. Once in a while at stoplight idle drops off and engine shuts down.Changed IAC valve with new one. no real change. car has 99000 miles, new plugs, no visible loose hoses or wires.... Thanks for your help.....

 

[wood1]

Replace your tune-up parts, clean the mass airflow sensor, check the vacuum lines for cracks and the vacuum tree for disconnected hoses. You might consider checking the TPS as well. You can hook it to an analog multimeter and as you open the throttle the voltage should increase smoothly, if not it is worn out.

Did you search for your problem in the forums? There is a great deal of information out there for the reading.

Good luck.

C.

I would check fuel pressure at idle as well...

 

[BrooklynBay]

Welcome to this forum! Have the codes read. You could go to Autozone to have them read for free.