1993 Grand Cherokee

rollbar

Stupid Question: Does the 4.0 have an external ignition module? I can't find one in the book. It takes a little to start it in the morning but then it idles smooth, once it get's hot it missses & it is harder to start. Sometimes I push on the accelerator just a little & it starts quicker. I fugured it's the module getting hot. It runs smooth above 1100 rpm (in drive) but sitting @ a light it misses sometimes & rough (in drive). Thanks, RollBar P.S. I changed the wires, TPS (throttle position sensor). Some say it's the O2 sensor but.....

mrtazwrench

maybe check the fuel pressure, and I think this one has the fuel regulator on the fuel rail, check for fuel leakage at the vac port.

rollbar

No leakage. I think I'll just take it to Jeep & let them put it on the computer.

rollbar

O.k. I turned a corner today & the Jeep died, I waited 5 min & cranked it up, drove it home, cranked it up & took it to the dealer. They are charging me 85 bucks to check it. It happened to them twice so far & they are saying it's electrical. They can't fully find the problem yet & said when it happens they don't get spark. They think it's from computer to coil, some where in there. Any thoughts? RollBar

youdidwhat

I would say O2 sensors but for good reason. Two of us had this issue last year with XJ's here is the break down of what all we tryed. two different answers to the same issue. sorry the thread is sooooo long but there is alot in there that could help.

Hope this helps.

http://www.kcjeepclub.org/forum/viewtopic.php?t=2609&start=0&postdays=0&postorder=asc&highlight=&sid=3b68b041a27d0795fef313cf1127fd0c

rollbar

Thanks, RollBar

rollbar

It was a bad coil, runs great. Thanks, ROllBar