chunkychicken

i have a 94 grand cherokee with the 5.2 in it and i think that it may be losing compression.. it will start up fine and will drive a little while but if you stop at a stop sign it will die? i was just wondering what this could be i was kinda thinking it was a head gasket but not losing any coolant.. could it be vacuum any ideas?

melloyello

Usually low compression causes a vehicle to be hard to start but once they warm up they run okay.

chunkychicken

any ideas on why it would die when i come to a stop?

RRAM

does it have rough idle. or smoke a lot when idleing for bit. the plenum gasket sometimes leaks and can cause bad stuff like that. vacumn leak will cause stalling too, but will have the sign of bad idle.

ol"blue

Check to see if any codes are stored in the ECM by turning the key to the On position (not start), off, on, off, on... within 3 seconds. Look at your odometer. It should go from miles to a two digit code. 55 is No Codes, End of Test. 12 is battery voltage recently lost. If any other codes appear, write them down and a repair manual will have a list of the codes for your vehicle.
'98 was the last year this was possible without a DRBII scan tool.

melloyello

Could be that plenum gasket leaking. I assume your engine has an Idle Air Control Valve also. Could be it is dirty. Normally that happens on start up and pretty much anytime at idle though. I guess anythig is possible.

chunkychicken

what exactly is the plenum gasket?