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98 Stalling Constantly.

B

bustedtrigger137

NAXJA Forum User
Location
Woodhaven, MI
98 XJ, 4.0L, AW4, NP231. Bone stock w/Up-Country Package.

It was stalling, mainly in reverse. Unless I give it more "gas", it will jerk and buck. It also will lose revs and stall out while taking hard right turns, as well as going over rough pieces of road (RR tracks, potholes, etc).

I replaced the NSS, thinking that was causing the reverse problem. The original one was cracked, and contacts were bad, but it made no difference in fixing the problem.

Replaced TPS, no difference, same with CPS.

Every time it stalls the Gas gauge goes down to "E" and slowly works it way back up. It seems like it is not getting fuel during this time.

I have searched and cannot find anything similar. I have even un-plugged the TPS, and jumped the pins on the NSS to try and eliminate problems. Any other ideas?

Thanks.
 
Is there any way to test for this before I go buying more parts that are not needed?

I assume the float must be messed up and would cause a bad gauge reading (this is the same with two Clusters, my original Idiot light one, and a new one I swapped in with full instrumentation).

What would be causing it do to this, particularly in reverse?
 
You should have fuel pressure of around 40lbs if I'm not mistaken, and it can be tested at the rail with a fuel pressure gauge. When you go to start it in the morning, does it crank a bit and then fire, or just fire right up? My Fuel pump is getting old and to build up enough pressure I have to turn my key of and on a couple times for it to start right up, otherwise it cranks forever. If it's your pump I would buy a gauge and see what you're reading before just installing a new (expensive!) fuel pump.

It really sounds like you may have a short somewhere. I had a Land Rover with a similar problem that a guy sold me for bones, and it just turned out to be the connection/wires to the fuel pump.

Good luck,
 
Sometimes it takes a few times to start. After stalling on select times it takes a few times to crank it and get it to fire. One time I was on lunch and left it at a gas station parking lot next door after it stalled. Went out after work and it fired right up.

The Pressure Guage should thread on the schrader valve on the Fuel Rail, no?
 
My jeep is doing the same thing. It will do it in reverse mostly, but it just started doing it recently in drive. I took a right turn going about 15 mph, and the rpm's dropped then it just shut off.

t starts up in the morning fine, maybe has a little trouble, because its like 10 degrees, but it starts and runs fine, just every now and then it will just drop rpms and stall, only when I'm going around 10-15 mph.

fuel rail is getting good pressure, could it be a sensor?
 
The 1997-2001 fuel pump pretty much works, or not, there isn't much else it can do.

1) Bad wire connections at the fuel pump, giving either a short circuit or an open circuit.

2) Damaged or loose wire/wire connectors in the engine bay, short or open. Movement of the engine during acceleration or sharp turns or vibrations from a bump cause the wires to momentarily disconnect or short circuit. The 4.0L doesn't tolerate voltage fluctuations very well so check your ground wires also.

Next time it stalls and the fuel gauge drops to E, check for fuel pressure at the fuel rail before you attempt to restart.
 
Last edited:
quick update: I was just driving it again around 25mph, and it was cruising foot of the gas, when I gave it gas, it felt like it died real quick and started back up after giving more gas. kind of like a bad spark plug, but it only did that once. wierd
 
Sensors won't make the gas guage go to E. Sounds like grounds. Engine moving a little in reverse or around turns????? Fuel guage and pump are on different power circuits but use the same ground.:sure:
 
actually i'm not sure if my gauge went to E. I didn't notice. It looked like all my lights on the dash stayed on like mileage and stuff. didn't notice the gauge though. I know how to test the cps, but how do you test the tps sensor, just to be sure?
 
man this has been happening more than usual today. while i was driving, rpm guage would jump from up to down and back up, which would cause me to lurch forward. jeep stayed on though and would keep going. the stalling hasn't happened again, just the rpms goin crazy
 
check the cable. mine fell out of the snap ring and my throttle got stuck. which only happen every once in a while. i was driving on the freeway and really noticed it because there was a auto cruise control. as i step on the pedal it stayed there and the srping was bad and wouldnt return. there for my throttle was sticking pretty bad and reves up on its own on occasion.
 
So, this morning, my check engine light came on. After multiple rpm jumps and stalls, I took it to get the codes checked, and it gave me P0138, P0135, and P0141. They all have to do with the o2 sensors. Thing is, I changed them under a year ago. So, I'm gonna go the warrantied and see if this continues..

I wonder if my bad gas mileage had something to do with the sensors if they're no good. Also on the last two codes, it says its the 02 heater circuit. My heater works fine though.??
 
well one of the problems was that the rear o2 sensor was rubbing on the driveline, which probably caused to to short out. Problem solved for that one, wonder which codes that takes care of.

I looked at the front one couldn't find anything visually wrong. I'll check the whole wire harness and post an update
 
So, I replaced both sensors, and reset the codes. like 6 hours later it started sputtering again while in park. i went out and checked the fuel pressure and it sprayed out pretty good.

What else could this be?
 
by checked the fuel pressure you "hooked up a gauge and measured the pressure" or "pushed on the valve and crap squirted out"? cuz there is a slight difference between the two. if ur fuel pump is legitimately good then maybe the "fuel filters" on the pump are clogged. i read a post awhile ago when another fellow had the same problems stalling when turning right bad idle etc. he replaced the filters and the pump anyways and problem solved.
 
My 97 was doing the same sputtering and finally would not start at all.... Check to make sure the rear of the fuel rail is not wearing through the wire harness. This wore through the wire that sends signal from CPS (that's CAM) to the PCM. Another person found the same condition in his but it had not worn all the way through yet..

l_b3bbd3a504534a1ebaa742f5c6286796.jpg
 
xj88superjeep said:
My 97 was doing the same sputtering and finally would not start at all.... Check to make sure the rear of the fuel rail is not wearing through the wire harness. This wore through the wire that sends signal from CPS (that's CAM) to the PCM. Another person found the same condition in his but it had not worn all the way through yet..
Click to expand...
Want to send thanks for this valuable post.
I was experiencing the intermittent stalling that seemed to be pointing to the fuel pump and found the wires worn through at the end of the fuel rail as in the picture.
Thanks!!!
 
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