trousermonkey

My 93 Toyota pickup has 129k is excellent on gas and oil for the $187 I paid for it. The problem is that after it warms up it decides to loose all response on take off, it hesitates and sputters like there’s a fuel problem. When its cold it runs great, take off is exceptionally smooth and power is right there no hesitation or sputtering at all. I have ran injector cleaner and replaced the fuel filter but it seems to get worse at times only when warm, if I mat the accelerator it smoothes out and takes off like it should. I believe it has something to do with the Mass Airflow Sensor but I could be wrong.
Any suggestions on what or how I could figure this one out.

trousermonkey

Please any advice before i end up changing everything. I spent very little money on this truck and it is going to be a budget build, the truck is in pretty nice shape except for the box LH rear corner.
I work in a salvage yard but parts there are little to none for the Toyota pickup. I replaced the Mass Airflow Meter with one off an 89 same thing runs great cold but after warming up it hesitates and sputters. this leaves me to believe its the TPS or injectors but why would the TPS screw up after it is warm, I have heard of injectors spraying inproperly after engine has warmed up, anyone here ever have this problem?

Furthermore I have pulled the engine code for my truck in normal mode and test mode and the code comes up normal leaving me totally stumped, I asked a well know mechanic and he said it sounds like a sensor but he didn’t have time to get in to details for me, I kind of figured that much out for my self but without a code once again I’m in the dark.
Anyone with a clue please help

trousermonkey

For anyone who was following, I believe to have the problem at hand. After talking to several mechanics and listening to there advice I went a hunting. Checked for any imaginable vacuum leaks using carb cleaner, sprayed around all the lines and gasket while it was running at an idle and never once could I get it to stumble. So after doing that I cleaned the throttle valve just because, knowing that wouldn’t solve my problem it just looked like it needed to be done. Got a lot of useful information from postings here thanks everyone.
After all this I decided to read further into the TPS, I tried to set it with the Ohmmeter but one of the terminals would just not set to where it was suppose to be. I took it for a test run and it seemed worse. I read if it was advanced to far it would disable the vehicle, so I did and it had little to no affect on it. This makes me believe that the contacts in the TPS are worn. So I decide to get prices, the local parts store quoted me $179 WOW. Just for the hell of it I called the dealer to my surprise it was only $90. I talked to them for a bit and they said that sounds like what might be my problem and advised me to trouble shoot it farther. If I can find a good used one I will try that.
I apologize if this is way to long just thought I would post in case someone else has the same problem. I will leave further details when I replace the TPS.

I hope to start doing more to my truck soon beside trouble shooting, major make over all around mechanically and cosmetics.

trousermonkey

The other day I decided to pull the TPS off and clean it with WD-40. I sprayed inside where the armature and spring is and I also took off the metal plate on the outside and sprayed in there. After working it around for a while it seemed to move more freely like it should. I wiped out all excess penetrating oil I could, taped the cover on with electrical tape temporarily and placed it back on in its original position. Due to time I wasn’t able to test drive it then, figuring it probably didn’t solve the problem anyway I really didn’t care. The following day I decided to go to a U-pick and pull salvage yard to scavenge for parts. After driving down the road a couple of mile I noticed it didn’t start hesitating yet, reaching a stop light four miles from home I took off with no hesitation or sputtering at all I was actually able to take off with traffic. Further more highway driving was also much smother throttle response was right there in higher gears. So the bottom line is anyone who ever has this problem and has narrowed it down to the TPS first try cleaning it with some good old WD-40 and save yourself $90 to $179.
I hope all the above is help to someone.

Kas888

I seem to be having the same problem, I'm not a mechanic , I was just wondering what is a tps?

AgRunner06

Throttle Position Sensor

Here is a great site on it.

trousermonkey

After all my efforts to be a cheap A@# I ended up replacing it with a new one, but I was blessed with getting a discount were i work my final dealer price was around $72. Make sure you check all other possible causes for hesitation. The problem always appeared after the warm up period. I hope that this is of some help, if your not good with trouble shooting ask a friend who is or start doing some searches on line feel free to ask any more questions you have

trousermonkey

That is a good article on the Throttle Positioning Sensor, it seems to be used on many other sites as well very helpful.

Kas888

thanks for the quick response , i had a check engine light on and i brought it to the dealer because my 99 4runner was still under warranty. They said my airflow meter was dirty.They cleaned it out. But I'm wondering is this something that I should do periodically? Is it a simple task?Any help would be appreciated.

kwando

Sorry to bring this thread back to life.

I happen to have the same problem. It's almost like the engine is missing or timing is off.

In my case when I have the A/C running it doesn't happen as much.

I'm goign to have to give cleanin the TPS a try this weekend.

toddowaddo

I had the same problem, a used TPS solved it. I scored one on an ebay auction for $9.99, it was attached to a throttle body that was actually the item for sale. I think I made out pretty good on the deal.

22RE_yota

lol no too shabby-toddowaddo. I am having trouble adjusting the tps on my 22re, I have the 4 crawler link, but I cant seem to get many of the reading correct. Also can I just pop the Metal plate with the part number sticker on it to clean it. Is that how its done?
any help is much appreciated

eightnine

i have the same problem and have bought a new tps for it and it still hesitates...

Adam F

this thread is 5 years old

22RE_yota

lol well you know what they say...same sh#t different year!