I have a stock '99 XJ Classic at 120,000 miles, I got it around 75,000 miles. I have been good about changing fluids and basic tune ups. My issue is strange and I have no idea what it could be so here I go.
- went to start up on a cold and wet Saturday morning and it would crank and crank and crank but no start. would start to fire and then quit and just kick out a cloud of black smoke. I thought it was CPS, so I changed it, and nothing. My brother (who is a Jeep guy too) said to take off the air intake off the throttle body and jam something under the throttle to keep the butterfly valve open and try to start it. That worked and the Jeep kicked out a lot of crap and it ran fine. I changed out the spark plugs with Champion RC12ECC
- I had an issue with the engine feeling like it would suddenly drop RPM's and seem like it was being choaked when I pushed further on the accelerator pedal. Took the Jeep home and changed out the MAP sensor and TPS. Put in a lot of HEET and Lucas Fuel Treatment to help with extra cleaning. Put a fuel pressure tester on it and saw 45-49 PSI when starting and running.
- I was driving on the interstate christmas eve with my daughter in the back and when I got down to about 1/4 tank I got poor performance, almost no zip and very delayed response. It seemed like the engine kept wanting to go lower and lower RPM's until it would just die. I was able to start right up and when I put it in drive it would die under a load by pressing down on the accelerator pedal. I finally got a code, OBD2 p0171, system too lean. So basically it's like I have low fuel.
- I have put in a lot of SeaFoam and it's running fine now, I notice the problem come back when I get low on fuel.
- Now I'm having LONG cranking times in order to get started, 5-6 cranks, but use to be 1-2 cranks.
BUT WHY? I am keeping a lot of fuel in the tank for now but want to try to figure out why this is happening.
Is it a bad pump? Fuel Regulator? Check valve?
EGR Valve?
Somewhere else I found talk about the IAC (Idle Air Control) on the throttle body.
Can somebody give me some advice here, I'm going bananas.
- went to start up on a cold and wet Saturday morning and it would crank and crank and crank but no start. would start to fire and then quit and just kick out a cloud of black smoke. I thought it was CPS, so I changed it, and nothing. My brother (who is a Jeep guy too) said to take off the air intake off the throttle body and jam something under the throttle to keep the butterfly valve open and try to start it. That worked and the Jeep kicked out a lot of crap and it ran fine. I changed out the spark plugs with Champion RC12ECC
- I had an issue with the engine feeling like it would suddenly drop RPM's and seem like it was being choaked when I pushed further on the accelerator pedal. Took the Jeep home and changed out the MAP sensor and TPS. Put in a lot of HEET and Lucas Fuel Treatment to help with extra cleaning. Put a fuel pressure tester on it and saw 45-49 PSI when starting and running.
- I was driving on the interstate christmas eve with my daughter in the back and when I got down to about 1/4 tank I got poor performance, almost no zip and very delayed response. It seemed like the engine kept wanting to go lower and lower RPM's until it would just die. I was able to start right up and when I put it in drive it would die under a load by pressing down on the accelerator pedal. I finally got a code, OBD2 p0171, system too lean. So basically it's like I have low fuel.
- I have put in a lot of SeaFoam and it's running fine now, I notice the problem come back when I get low on fuel.
- Now I'm having LONG cranking times in order to get started, 5-6 cranks, but use to be 1-2 cranks.
BUT WHY? I am keeping a lot of fuel in the tank for now but want to try to figure out why this is happening.
Is it a bad pump? Fuel Regulator? Check valve?
EGR Valve?
Somewhere else I found talk about the IAC (Idle Air Control) on the throttle body.
Can somebody give me some advice here, I'm going bananas.