TPS codes

I took the advice of the people on here and replaced the IAC valve/motor. It seems to have helped the problem some, but there is still a problem. When I reset the CEL, everything runs fine until the CEL comes back on. It's throwing codes for both 02 sensors and the TPS but the TPS is called peddle position or something like that. The symptoms are when I gently press the gas it will not do anything but I can hear a noise coming from around the throttle body and eventually I will nail the gas o get going. If I hold my foot slightly on the gas, the Jeep will backfire and the engine will reb ocassionly. What gives?

97 I6
aw4

Vacuum leak? Check all the hoses and fittings and manifold gasket. Spraying something alike wd 40 or 5-56 around the intake manifold will detect leaks. I have used starting fluid, but obviously its dangerous as hell! There will be a noticeable difference in the engine sound.Be carefull doing this as you could have a fire if the exhaust is real hot. You DO have a fire extingushier handy while wrenching DONT you? If you find loose manifold bolts, it may not be a good idea to go cranking down on them too much. If there are chunks of gasket missing you will over compress thst area and distort the manifold or break the tabs. Just a few ideas? Not sure?

Since I have messed with this stuff for many years Im going to keep preaching on you newbies.
Get a fire extinguisher
Safety glasses
Move the vehicle away from the garage when you doing things that could catch fire. Why take the garage and house with the XJ
Dont breath the grinding and welding crap
Use jack stands
Keep your face away from the battery. They DO explode sometimes

I've checked all the vacum lines I could find. I noticed the part of the maniflod gasket that you cold see was a little messed up yesterday, but thought nothing of it. Also, when I get into the brakes pretty hard, I hear this clicking sound thats coming from uder the dash. Any ideas?:dunno:

bluedevils278 said:

I took the advice of the people on here and replaced the IAC valve/motor. It seems to have helped the problem some, but there is still a problem. When I reset the CEL, everything runs fine until the CEL comes back on. It's throwing codes for both 02 sensors and the TPS but the TPS is called peddle position or something like that. The symptoms are when I gently press the gas it will not do anything but I can hear a noise coming from around the throttle body and eventually I will nail the gas o get going. If I hold my foot slightly on the gas, the Jeep will backfire and the engine will reb ocassionly. What gives?

97 I6
aw4

Click to expand...

Sounds like you need to replace the TPS, Throttle Possition Sensor on the throttle body, they do wear out. Also check the vacuum line that runs from the throttle body (lower passenger side) to the MAP sensor on the firewall (Top center). If that vacuum line is loose it will cause your exact symptom, slow throttle response, back fire and sucking sound! Check out and follow that noise at that at the throttle body!!!!!!!

It is easy to knock loose from the throttle body. A bad, loose wiring connection at the O2 sensor, or if the O2 sensor wires have run up against the exhaust pipe it will short out, or loose conections will cause the O2 sensor readings to jump around and can cause the back fire, CEL engine codes, etc. You may have a bad O2 sensor, but I would check the wiring and the heater wire supply voltage to the O2 sensor before I write off the O2 sensor itself.

Get an FSM (Factory Service Manual) or Haynes manual to help you figure out where things are and what they are.

I've put like 3 TPS's on it in a week and I know what it feels like when they go out. Thats why I don't get why it's throwing a code. The only other vacum line I can seem to find besides the brake is the smaller one that is on the intake manifold. I'm not sure hoow it's supposed to look, but on mine this line runs to that weird black ball with a weird name. The black ball has a clip on it , but that clip is unused and mine sits right behind the fuse panel. Is that the vacum line your talking about? The MAP sensor is right across from the IAC right?

Then it is not the TPS, and its a sensor wire (O2, TPS or MAP) sensor wire or connector or ground wire problem, or the Vacuum line between the throttle body and the MAP sensor. See these for the MAP location and pictures.

http://www.lunghd.com/Tech_Articles/Electrical/Ground_straps.htm

http://www.lunghd.com/Tech_Articles/Engine/Vacuum_Leak_Diagnostics.ht

I'm pretty sure my MAP sensor has not vacum line to it. (97) The vacum line coming off of the intake manifold goes to the black ball thing which comes stock under the front bumper, but mine has been moved up near the firewall on the passenger's side. I figured I mine as well replace the top O2 sensor, but for the life of me cannot get the damn thing out. The other one came out with no problem. Do you have to use a special tool for it cause the 7/8 doesn't quite do it.

bluedevils278 said:

I'm pretty sure my MAP sensor has not vacum line to it. (97) The vacum line coming off of the intake manifold goes to the black ball thing which comes stock under the front bumper, but mine has been moved up near the firewall on the passenger's side. I figured I mine as well replace the top O2 sensor, but for the life of me cannot get the damn thing out. The other one came out with no problem. Do you have to use a special tool for it cause the 7/8 doesn't quite do it.

Click to expand...

The MAP sensor measures engine vacuum. It can't measure what it can't see.

Find the MAP sensor, find the loose Vacuum line and reattach it, or

If it is missing altogether, get a drawing of the correct OEM vacuum lineSSSS, that is plural with emphasis, and restore the OEM vacuum lines to their correct places.

At this point I would suggest you post some pictures of what you do have, as it sounds messed up.

http://www.napaonline.com/MasterPag...ption=Manifold+Absolute+Pressure+(MAP)+Sensor

That is the MAP sensor for mine. No vacum lines connect to it.