Hey guys. First time poster and first jeep every owned.

I recently purchased a 96 xj 2.5 5 speed manual. When I bought it, It ran fine but ran a little rich at idle. Since then, it has started an issue which I believe to be the fuel pump, but I want your input on this.

The guy I bought it from, claimed he recently replaced the fuel sending unit, and even gave me the spare. He also gave me 3 fuel pressure regulators, weird right?

So here's what it's doing. When idling at a warm temperature (does not do it until it warms), it starts jerking around. Almost sounds like a slight backfire. When accelerating its gone, but when keeping a steady constant speed, it's there. I've had it die on me when turning twice (ironically at the same intersection both times, and it's not an intersection I normally use).

I've been doing research, but everyone seems to say it's something else. So what's your input? What is the first thing I should replace?

Here's what I've checked:

Spark plugs - look fine - will replace if suggested
Air filter - cleaned and oiled
Vacuum hoses - checked because I though maybe one would go to a fuel pressure regulator (before I read that it's all built into the pump).




I have not checked the fuel pressure as I don't currently have a gauge.

So what's your thoughts?

 

Temp sensor in the thermostat housing........replace it with Echlin or Standard Products.

 

My Renix 87 2.5L did similar problems as you described. My IAT was open, meaning infinite resistance, and the computer responds with a rich command thinking I am driving in the temp of space. Check both the Intake Air Temp sensor and coolant sensor, and see from there.

 

Is this where the intake air flow sensor is supposed to be? The previous owner put the K&N, but there's no sensor here.

 

The IAT would be mounted on the intake manifold, right behind the throttle body. That connector in photo is unknown to me at this time.

Edited due to further research on the location of sensor.

 

That connector is for the idle up on the power steering pump pressure hose.....unneeded.


Do what I suggested.

 

The only two gray connectors on the 2.5L are the intake air temp sensor (on top of the manifold near the throttle body), and the power steering pressure switch (on the pump).

Based on your symptoms it's likely either the IAT sensor (just unplugged?), or a clogged fuel pump pickup