1996 Jeep Grand Cherokee stock except for 30x9.50r15 AT tires, This I call my cheap Jeep cause I only paid 300$ for it.

Well so it starts runs and drives ok but the acceleation is a problem and I have narrowed it down to the map sensor, I have checked the ground 5v feed and the sensor gives erronous readings to the ecu.

Replaced the sensor nothing changes. checked with an anologue vacuume guage and the readings look accurate but the ecu is seeing completly diff readings.

problems with the vacuume port or somthing else?

edit: ohh and no CEL

 

Hows fuel pressure? I had the same problem. Swapped out map and wow. Like a new engine. From what ive read up on check fuel pressure at rail with key on not running. Should read around 30 psi. 50 psi at running idle. Maybe fuel filter/regulater or weak fuel pump if pressure isnt up to snuff.

 

Im assuming you know the reading at map is supposed to fluctuate when revving or different rpms. Then according to the reading the ecu adjusts fuel. Maybe im telling you things you know.

 

Change the distributor rotor.

 

No distributor. MAP sensor? No cel or codes

 

2 year old thread, I fell for it.

 

me too lol