Running hot after long trip CEL Code 124 TPS?

[///Manuel]

Sometimes after a couple of hours of driving 75mph+, the CEL comes on and off (roughly after 2 hours) but it's not systematic. The temp gauge can fluctuate a bit and go to R-M. Now, if I come to a stop and idle, the idle stays around 1500rpm like the computer is confused or something. I tried to shut the car off and when I immediately restart the idle becomes normal again.

Scanned for codes and got 124 as the throttle sensor voltage is too high or something. Any way to clean that baby up or should I replace it. Does it look like it's the problem?

 

[Maniak]

You can't clean the TPS. Its a sealed unit. You can see if the TPS is the problem by backprobing the TPS and watching the voltage move. It should be around .96v (I think) when closed and should go upwards slowly as you open the throttle.

there is a thread on here about getting free hp by adjusting the tps and it shows where to backprobe and what voltages you should see.

~Mark

 

[///Manuel]

Thanks for the answer. I have seen that before but could it cause the engine to run hot though at high RPM's? Water pump is new, hoses are new and not soft, stat seems to open fine, no fumes, cools off just fine idling.

 

[ma96782]

Sometimes after a couple of hours of driving 75mph+, the CEL comes on and off (roughly after 2 hours) but it's not systematic. The temp gauge can fluctuate a bit and go to R-M. Now, if I come to a stop and idle, the idle stays around 1500rpm like the computer is confused or something. I tried to shut the car off and when I immediately restart the idle becomes normal again.

I don't KNOW codes or have a code reader................so, I'm guessing here.

*********I COULD/CAN BE WRONG********************

If it were my vehicle........I'd be thinking O2 sensor or A/F mixture issue.

Reason:

If I were going 75mph+ for long periods of time, the cats really heat up (if A/F mixtures are wrong-lean)............plus, your engine temp it up there (as opposed to normal temps)..........CEL comes on.............so, computer tries to adjust to the rich side or you slow down cause the CEL scares you............CEL may go out..........you come to a stop and the A/F mixture is still rich, so high idle speeds. You shut it down...........the computer re-sets the A/F mix and lowers the idle speed.

Of course O2 sensors aren't cheap.................though, IF THEY HAVEN'T BEEN CHANGED................might be worth a try.

I have seen that before but could it cause the engine to run hot though at high RPM's? Water pump is new, hoses are new and not soft, stat seems to open fine, no fumes, cools off just fine idling.

Between R and M doesn't sound so hot.........N O R M A L.............hey, your'e going 75+ for long periods. Of course a real reading (in degrees) would be better than just reading the factory gauge (between R and M).

Aloha, Mark

 

[///Manuel]

Ok. Now we are talking. That was my first clue, but I was trying not to give any bias to my first post. However, I didn't get O2 codes? The car has 176k miles and so does the 02 sensor. I believe I have only one (92) and it's $47 at Autozone.

 

[ma96782]

Well......it could also be a COMBINATION of things.

Aloha, Mark

 

[///Manuel]

I reset all codes and will go on a long trip again (>200 miles). I adjusted the TPS which seems fine.

We'll see what happens. Prior gas mileage with big windsurfing boards on the roof rack, car packed with camping/windsurfing gear and 78mph cruising speed was 17.5mpg (Temp 90-100F).

 

[ma96782]

Speaking of TPS.........

http://www.explorerforum.com/forums/showthread.php?t=164529

Note: Some parts mfn are better than others?? At any rate, it's something to note.

Aloha, Mark

 

[///Manuel]

TPS might have improved throttle response some but gas mileage is the same. No Check Engine light, car ran cool. It's not easy to reproduce so it could definitetely be a sensor issue. I will check for codes.