Offroad-Express

Hi peoples.

my 97 Wrangler has start to form a problem. not all the time, but enough to worry me it, after starting up will idle rough, followed by starting to drive it having to push the foot further and further down to get it to move. Followed by a pop under the bonnet, then its all fine for the remainder of the drive. It doesnt throw up any check engine lights or nothing.

I was thinking it might be the fuel pump playing up and not sending enough petrol down the line after start up.


Has anyone had this problem before and might be able to point me in the right direction? Last thing i want to do is find out its an o2 sensor or something and melt a piston from leaning it out.

EGR valve stuck open?

I didn't think the 4l engines had egr valves?

Had a similar issue
It's was the laser on the electronic ignition and dust on the plate that that the laser would read.
Gave it a blow out and sweet this was after I put new fuel pump in which is what diagnosis was telling me
This was on a pathfinder but worth check your dissy anyway.

is she auto .....May be TPS

Check you fuel system.

http://www.justanswer.com/dodge/7mfz1-cherokee-97-jeep-cherokee-4-0l-loss-power-full-throttle.html

Sorry for the slow replies guys, Generator at work decided it wanted to catch on fire and I been a busy boy pulling it apart.

I think it might be an o2 sensor as it only does it when its cold, and for maybe 500 meters drive down the road. Once that stage is over its fine.

I think the o2 sensors have little heater coils in them for when you start the car from cold to give them a correct reading untill the gasses in the exhuast heat it up enough. which may explain why its fine after a short drive down the road.

Might have to order some new sensors and replace all the tps, o2, crank etc at once and hope for the best