Topic: Throttle pos sensor going bad??

[Jhcujo]

Are there any symptoms of one going bad? I have been having a problem with valve chatter it seems to happen when I shift gears manly. But if I either press the gas pedal a little more or let off a little it goes away. The thing that I can not figure out is it is not all of the time. It may run fine for a day no chatter then it is so bad I can not even stand it. I put in new plugs,wires,cap, used Seafoam a number of times. Nothing seems to get rid of it for good. So I wonder could it be the TPS. Any help or thoughts would be great.

Thanks Joe

[/dev/null]

I've found that TPS sensor issues usually appear around idle. Now, if the problem area you mention is at the same place in the gas pedal travel, it could be the TPS. It won't be RPM related, just where the pedal is. If it acts like the engine is getting too much or not enough fuel at those places, it could be TPS. Outside of that, I'd look elsewhere.
Anyone else?

Peter M

[canadian_woody]

the tps problem usually shows up at idle and at around 2k RPM.

[Jhcujo]

Okay so buy idel what do you mean? Sometimes the jeep seems okay at ide. Others it is kind of ruff. But as I said above there is no real pattern to it all. And  responding to the other person who commented I can not say for certain it is in the same throttle posistion. I am just at a loss as to what to do. I can but a new TPS but not want to flus another 40 bucks down the drain and have the same problem. PLease keep the suggestions coming. I thankyou two who have responded.

Joe

[/dev/null]

The TPS is basically just a variable resistor. If you have a multimeter, hook it up to the TPS and move the throttle, if you see unusal jumps either to open or a dead short, the TPS is faulty. It should show increasing and decreasing resistance through the full range of motion.

Peter

[Jhcujo]

Thank you again. At least now I have something to check

[Guardian7]

Valve chatter is really considered a mechanical issue and may mean your hydraulic lifter valving is beginning to clog up. Also lifters get a ridge worn in the area of travel and later in life they will not adjust past that ridge when more valve train slop requires more travel. I would change the oil and filter asap in hope this helps it by cleaning the lifter valving. When the TPS is worn it just effects the fuel metering to your throttle body injector and the engine runs rough. Is the engine mileage 100K or more? If so the lifters most likely have a ridge worn in them and will need replacing soon and is a common jeep issue, I have read this can be done without pulling the head by using a special tool which looks like a long rod with a suction cup on the end.

[Shrek]

If the sound you think is valve clatter goes away or gets worse with minor throttle changes it's probably detonation or "pinging". Loading or unloading the engine will not have any effect on valve train clearances. Try running a tank of higher octane fuel just to see if it goes away. That way you can rule that out.

[Guardian7]

It does sound like you are hearing detonation, have a mechanic take a ride with you or someone who knows engines and they will know if it is detonation really easy. What kind of miles are on the engine?

[Jhcujo]

As for miles on the motor I have 200,000. I have only owned it for just over a year. But i did a compression test before I bought it and it tested well acrossed all 4 clyinders. I have some more info if it well help you guys help me. Last weekend I ported out the manifold to 62MM and put on a 62MM throttle body. Plus I reset the computer. I can say that she runs a lot better. The ping or chatter is not as bad as before. I still got some but not nearly as bad. Now today I put in Mustang fuel injectors. I did some reading and found out that Ford V-8 injectors plug right in 2.5 jeep motors. Now it runs REAL WELL but I stll get just a little bit of pinging.But  the injectors made a big differecne in porformance. If it is lifters can I change them now? I was hoping to just get a new head and out that on over the winter. Doing the port and polish with new lifters, cam.Any other advice you guys have I would really like.

 Thanks Joe

[Jesse-James]

Sorry to stray from topic a little, but what year Rustang? Are they from the 5.0 or the 4.6?

[Jhcujo]

There are a number of years and makes that will fit from what I understand. The 4.6 motor Mustangs 96-04,92-98 Crown Vic, 95-96 Tbird, 97-01 F- Series truck. There maybe more that is just a few that I found. Really you are looking for a 19lb yellow top injector. The jeep runs a whole lot better. I do not have to be going down hill to hit 75 MPH anymore!!I do not know what effect it has on my gas mileage yet but from the looks of the gauge it does not seem that I have lost any at all but time will tell

[jwrape]

I have a similar sound that happens at the same time you are talking. When I let off the gas a little or glide to a stop without the tranny in gear. But mine is my tranny gears chattering. It is common in the AX5 and AX15. Could you possibly be mistaking gear chatter for valve train chatter?

[jwrape]

Where did you read this bit of interesting info? Got a link