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Jeep dies when driving

xjon

NAXJA Forum User
Location
So.Cal. MV
Battery good. Fuel pump changed last weekend. Still with the same symptoms. Starts and runs fine. Then when coasting the engine just dies. It cranks fine but just wont fire. After awhile when it does start I can smell gas for a little bit.

So my guess is that it is not getting spark. 6 months ago I had the plugs, wires, cap changed. At least it looks like the wires and cap was new. (dont trust anyone doing any work, but had no time). So what should I check now?

thanks.
99 xj 4.0 with 115k miles.

BTW, it runs smooth when it runs and check engine light is not on.
 
Last edited:
Check to see if you have spark. If you do not it very well could be your CPS.
 
X2 on the CPS. Some people notice just before their jeep dies the tach shoots up then flatlines at zero then it dies. My jeep used to die out of the blue, I would wait about 15 min then it would run for another ten miles then die again. Pretty easy to change but you'll need about 12-14 inches of extensions and universal swivel joints and go up over the top of the bell housing of your tranny. Thats the easiest way to get at it. Once you figure that out it only takes like 15 min to change out. I think mine was about 80 bucks from autozone. Good luck. -Shaun
 
RPM doesn't shoot up. It just dies. Sometimes I don't even know it died, it would just coast.

I briefly checked my haynes manual and couldn't find CPS on it. I'll do a search later.

Thanks for the replies.
 
crank shaft position sensor. thats sounds like what happened to my when it died. If you wait long enough it would start but eventually one day it wouldn't.
 
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