Within the past 2 weeks I've had a problem with my 99 JGCL. When driving down the road (70 mph), when the fuel guage gets to about 1/2 tank, the engine acts like it is fuel starved and RPMs drop from about 2600 to 600. The engine temp is good (just had radiator flushed, replaced thermostat), oil is ok and volt stays just below 14. If I work the accelerator pedal the engine will fluctuate up and down but never catch. I have to stop, turn off the engine for about 5 min and then restart. When I fill the gas tank, the problem disappears, at least so far, until the guage gets down to about 1/2 tank. This has happend to me 2 consecutive times.

I just had the accelerator sensor replaced (mech said it was out by 15-16 degrees) and the engine feels more responsive but I haven't used 1/2 tank of fuel yet to see if it will happen again. Mech also checked fuel pressure and said it was good and didn't drop when the engine was shut off.

Any suggestions are greatly appreciated!!!

Chuck

My 99 is doing the exact same thing? Did you try cleaning the Fuel Filter. I am about to try but need help on what works. Let me know if you find anything out.

I'm guessing that the baffle in the feul tank is no longer attached to the floor of the tank. remove the tank and check the line between the fuel pump and the fuel line. Don't smoke lol. spring steel nuts can be bought at the local auto parts store to hold down the plastic baffle in the tank. it sits on copper studs. check the size of the studs before going to the store.

Thanks for the info Leo...I'll give it a shot. I just got the tank down to 1/4 this morning and no problems so far but that doesn't mean anything yet. I want to see this happen about 4 times before I trust it again.

Bent, I had the fuel filter changed out by the dealership about 9 months ago but that is still a possibility. I'll just have to wait and see. I will keep you all informed. In the mean time Bent, you might have that accellerator sensor checked. The mechanic told me that the new one had a different OEM number on it indicating that there may have been a problem with the old design and it was replaced by a newer model. I'm not a mechanic so I can't validate this info but it sounds reasonable to me. Also, I have almost 156k miles on my Jeep if that helps anyone anywhere!

My 99 is doing the exact same thing? Did you try cleaning the Fuel Filter. I am about to try but need help on what works. Let me know if you find anything out.

Hey Bent! Since that problem with my JGC, I've had no other problems. It seems that the throttle sensor replacement fixed my problem...either that or something else got fixed without knowing about it. I've filled the tank about 6 times since my original post and I've had the fuel down to between 1/4 and 1/8 tank with no more problems.

I hope it helps your problem out!

Chuck

Hi,
1999 JGC exactly the same problem. Right down to the 1/2 tankof gas. Did either Bent or CharlesA have a "check engine" light? I've got 0 that is zero codes. Replaced fuel filter/pressure regulator, problem came back. So far have spent $220. I'm being advise locally now that it's probably the "crank sensor". Really curious about the check engine light.
I'm going to print all the messages and take them to my mechanic.
Thanks

Hi,
1999 JGC exactly the same problem. Right down to the 1/2 tankof gas. Did either Bent or CharlesA have a "check engine" light? I've got 0 that is zero codes. Replaced fuel filter/pressure regulator, problem came back. So far have spent $220. I'm being advise locally now that it's probably the "crank sensor". Really curious about the check engine light.
I'm going to print all the messages and take them to my mechanic.
Thanks
HI IT SOUNDS LIKE YOU HAVE THE SAME PROBLEM AS THE ABOVE POSTS THROTTLE POSITION SENSORS USUALLY DON'T TRIP A CODE IF THE CRANKSHAFT POSITION SENSOR GOES IT, CAUSES ENGINE TO QUIT RUNNING AT ANYTIME BUT USUALLY RESTARTS AFTER COOL DOWN, YOURS SOUNDS LIKE THROTTLE POSITION SENSOR. DALE
jeepman600@aol.com :smokin:

Hi,
1999 JGC exactly the same problem. Right down to the 1/2 tankof gas. Did either Bent or CharlesA have a "check engine" light? I've got 0 that is zero codes. Replaced fuel filter/pressure regulator, problem came back. So far have spent $220. I'm being advise locally now that it's probably the "crank sensor". Really curious about the check engine light.
I'm going to print all the messages and take them to my mechanic.
Thanks

Set:

When I took my Jeep into the mechanic (2nd mechanic), he told me that he got a code, but I don't believe that it came from the check engine light. I don't know anything about the computers that check engines, but if he polled the individual computers to find a problem, that is what he came up with. I had spent $450 a few days before and the solution was that the radiator may not have had enough water in it and the engine overheated. Well, at least I still needed a flush and new hoses.

This mechanic changed out the Throttle Sensor ($80) and also cleaned out the throttle body (?). He disconnected one of the vacuum hoses and attached a can of cleaner that was sucked into the engine while it was running. He said this wasn't a thorough cleaning but it would help (gas mileage has gone up about 1.5 mpg). This cost me $250. It's been running well since then! Hope this helps you some!

Chuck

What a bunch of numb nuts... if the problem is fuel related like you are suggesting and at 1/2 tank of fuel, dont you think the problem is in the fuel tank? what is in the tank?... the fuel pump, a fuel line, a float, a baffle, and a potentiometer to read the fuel level.

Get the tank down and do the dirty work, no sense in spending more money on what it can't be. if the fuel line or a seal is leaking in the tank it will cause the probem. if the electrical connector to the pump is bad it will cause the problem. Get off you laxzy butt and do the work that you need to do, there is no easy fix.

Hey Leo I'm just trying to research a problem. I've received three or four good ideas that I can take to my mechanic, your "inside the tank" idea among them. I appreciate all the help. What I don't appreciate is being called names (numb nuts???) and sarcasim (Get off you laxzy butt)("laxzy butt?????). Lighten up Dude, you have a good idea just not the only idea.

Lazy butt Lazy butt..lol