96 xj intermittent fuel starvation

I was convinced that my intermittent stalling problem was the pickup coil in the distributor, and replacing it seemed to make the difference, but suddenly the same problem appears. This time, I have the Standard box sitting in the back, so when it started acting up, I swapped pickups, and the problem persisted.

This time, I can keep it going on the road, and it runs fine. Let it idle for a couple of minutes at operating temperature though, and it starts to starve. Sometimes it dies. Sometimes it won't start, or will start, run poorly, and die. All in the middle of a busy intersection if possible. Once I'm doing over 50, it acts like nothing ever happened. Get down around 40, and it'll stall while driving.

I pulled the crankcase vent tube from the valve cover and dumped carb cleaner on the air intake when it stumbled, and it went right back to normal. Stop the fuel flow, right back to crap. I can go back and forth like that and it'll keep running. Full blast is a little too much, but it's obvious the fuel delivery is intermittent, while the spray can is not.

No check engine light, new NTK O2 sensors, new cam position sensor, ignition tune up, and a low mileage, recently rebuilt engine dropped in two or three weeks ago. I'm considering swapping the fuel sending unit from my 96 2.5 to see if I get any difference, but thought I'd stop here if there's any better suggestions.

Just because it is too basic not to ask: How long since you changed the fuel filter?

Before you go swapping units which may not be compatible (I have no idea about interchangeability between 4cyl and 6cyl but I am betting they are different) I would first get a fuel pressure gauge on there and try to figure out what you get at idle and what happens when you open the throttle.

The fuel filter was replaced before it was parked. It started clattering on the way back from Arizona last summer, and was parked for almost a year. I'd start it and drive it around once or twice a month to avoid ruining the tires, and even added a bit of fuel from time to time.

When I replaced the pickup coil in the distributor, my problem disappeared. I was able to go out of town, idle for twenty minutes with the air on, and navigate stop and go traffic. Did fine for about a week. As previously noted, changing the pickup with a cold one made no difference.

Considering other than the difference in cylinder count that the injection systems are identical, I'm sure the assembly from the four will swap right over. It has the same integrated regulator in the tank and calls for the same amount of pressure.

I know my tank was sealed at the factory and is approaching 300k miles. The symptoms are not unlike what the 2.5 did before I replaced the fuel tank, it would run great until the screen loaded up, and then it would quit. Sometimes as long as half an hour.

I figure it's worth a shot. Faster and easier than finding a pressure gauge at present.

The swap went smoothly. Surprisingly, the rubber isolator under the pump was missing, but I couldn't seem to locate it in the tank. It's obvious to me that nobody has ever been in there, and I've been familiar with it since it was new. I didn't look hard, nor did I reach in and fish around for it. The locator was in place, so I stabbed the other assembly in and locked it down. Fired up the two door and parked it back where it was. Fired up the four door and observed no detriment. I'm about to take it across town, do some idling with the air on, and see what it does.

If I don't come back, it's because it died pulling out into traffic.

Overland said:

If I don't come back, it's because it died pulling out into traffic.

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That is a credible statement.

I have driven in Mexico.

Anak said:

That is a credible statement.

I have driven in Mexico.

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West Texas, but close enough.

My confidence is restored. It idled for a good half an hour with the air on, got plenty hot under the hood, and drove around town without a bit of hesitation. This is with the old pickup coil in place, even.

I was proud of my 300k mile pump, and I wonder what it would do with a new screen? Not worth dying over, that's for sure. I did run it near empty most of the time, and ran it out of gas a couple times at least. I'm sure a screen would solve the problem, but I have a new Carter on the shelf. It can go in the Carter box.

Hi , I believe we have finally found the culprit to my woe's . Bought an Alternator from the Auto Recyclers , 50$ a cheap way of getting mobile again !. Thanks to all who helped me , ive now learnt how to test a CAS,TPS and check the fuel system , so a few positives out of it all , thanks again