Jeep TPS Issue?

[Aaron]

Hey all,

I'm no mechanic but I think I have a Throttle Position Sensor issue in my 97 TJ 4.0. Actually, I know I do. I when out wheeling yesterday (see Yankee Hill May 3 Report) and there was lots of water an mud. On the way home, the check engine light came on but there really wasn't any symptoms.

Today, I started it up and it idled pretty rough and when I blip the throttle, it acts like ti wants to cut off. If I get it past the "cut off" RPM range, it sounds better (not perfect) but then when it returns to idle it tries to die.

The code says that the TPS is not sending the correct voltage. So, I assume the TPS is not working. I disconnected the TPS and the symptoms did not change (get worse or have new ones). I'm hoping its the TPS and not wiring or the PCM so my thought is to just go get one of those and change it out, unless you guys have a better idea :)

Aaron

[Funrover]

If you went and played in mud I would check connections first. chances could be water or such go in there. clean off connections and see what happens first

[Aaron]

I disconnected the sensor and it looked clean and dry but I'll leave it disconnected to let it dry out.

[WINKY]

your engine wont run well with the tps disconnected , also what might help is get it started and run it till it get nice and warm (normal running temp) and just let it run for a while to assist in drying out all the intake and such.

[Aaron]

I just disconnected to diagnose. I wanted to see if it ran any different while it was off than when it was on. It didn't which leads me to believe that it is not doing anything (i.e. broke).

I will give the letting it run for a while idea a go and see what happens. Hopefully that fixes it.

Thanks Randy

[WINKY]

i had the same thing happen to my 1500 when i went through a puddle 5.5ft deep after a hurricane... check engine came on etc.. ran a touch rough at lower engine speed but after a while of driving down the road it cleared and never came back. sometimes too when you go through water it steams off the engine and get sucked into the intake and condenses on stuff, sensors are extremely sensitive and if they get coated in any moisture they freak out. the point of running the engine stationary is to get hot dry air through the intake to dry out the internals the easy and safe way. once it dries you will know it.

[Pathrat]

I have to ask, because I would rather ask and look stupid than electrocute myself and look dead. When you remove sensors/MAF is there any electrical thing I should be aware of? I don't need to disconnect the battery do I?

[WINKY]

most times not. but i do recomend it when taking the connections off the computer.. just to be safe. bottom line if you dont feel comfy bout it disco the batt first.

but there is no way in heck that you could kill yourself off a 12v battery on your fj cruiser...its not ac. if anything doing the wrong thing will cause them to blow up, but keep the negatives on the negative and positives on the positive.

[Pathrat]

most times not. but i do recomend it when taking the connections off the computer.. just to be safe. bottom line if you dont feel comfy bout it disco the batt first.

but there is no way in heck that you could kill yourself off a 12v battery on your fj cruiser...its not ac. if anything doing the wrong thing will cause them to blow up, but keep the negatives on the negative and positives on the positive.

Thanks Randy. Electricity is not generally my friend. I have been zapped before and like to check first now. Of course, I don't want a blown-up battery either :D

[WINKY]

for dc to kill you one must be between the poles of current and its got to be very high amperage, there was a guy i heard about who was working in the dc powerplant in a telecom office and it was live, he was sweating profusely and stuck his head between the buss bars inside the rectifier bay on the dc output side and literally cooked his brain.. he was dead instantly. i think it was upwards of around 1200amps dc @54v


see ac stops the heart and locks your body up even at small amounts.... blah blah blah...

dc fries your ass like a baked potato at very high amounts.

[Brody]

for dc to kill you one must be between the poles of current and its got to be very high amperage, there was a guy i heard about who was working in the dc powerplant in a telecom office and it was live, he was sweating profusely and stuck his head between the buss bars inside the rectifier bay on the dc output side and literally cooked his brain.. he was dead instantly. i think it was upwards of around 1200amps dc @54v

Hell, Randy, I have done that at least 6 times and I haven't noticed anything different. Come to think of it, neither have any of my friends.

We used to joke about the fact (among my rock climbing skiing and boarding buddies) that if any of us ever got a serious head injury, it would probably be months down the road before anyone noticed that there really was something wrong. All of my buds and I have had the 'bleed from the ears, bleed from the tear ducts' head banging concussions from playing a bit hard. Usually we just wiped ourselves off and went back to playing hard......I am running on about 7 now....

LaDawn says that about me all the time. She says that I am so weird that it would take her a long before before she came to the conclusion that there was something wrong...

And yes....I realize that I have just left myself wide open for all sorts of comments....

[Aaron]

i had the same thing happen to my 1500 when i went through a puddle 5.5ft deep after a hurricane... check engine came on etc.. ran a touch rough at lower engine speed but after a while of driving down the road it cleared and never came back. sometimes too when you go through water it steams off the engine and get sucked into the intake and condenses on stuff, sensors are extremely sensitive and if they get coated in any moisture they freak out. the point of running the engine stationary is to get hot dry air through the intake to dry out the internals the easy and safe way. once it dries you will know it.

Absolute brilliance! I let it run for a half hour in the driveway yesterday. When I revved it, there was moisture coming from the exhaust which upon checking was water (glad it wasn't fuel). After a while it wasn't coming out anymore.

I drove my son to scouts in it last night and it was running slightly better but not perfect. By the time I came home it was near perfect. I started it this morning and all was well with the world. I reset the computer (disconnected the battery for a bit) and when I reconnected and started the Jeep, no light.

Thanks for saving me $50. Now I just need to figure out how to make it not happen again.

[Funrover]

Good to hear that there was no need for part replacement. To avoid you have to weather seal the hell out of it or not go through mud/ deep water at high speeds a bunch (which isn't gonna happen)...lol I have seen heat shrink used.

[Aaron]

Good to hear that there was no need for part replacement. To avoid you have to weather seal the hell out of it or not go through mud/ deep water at high speeds a bunch (which isn't gonna happen)...lol I have seen heat shrink used.

Mud and speed is a fact of life so I think some waterproofing is in order. I found a good set of instructions on how to do it with dielectric grease and liquid electrical tape.

http://home.att.net/~email.id/h2oproof.doc

However, given the water coming out of the exhaust pipe, I think that Randy might be right that the steam from the water hitting the engine got drawn into the intake. The only way I can think of fixing that is to have the intake from outside (i.e. snorkel.) or to have vents on the hood but that mught let more water in than out.

Thoughts?

[Funrover]

I have one of those... made from pvc pipe.. does pretty well, however I did it for the clean air.. not water LOL

[Aaron]

I have one of those... made from pvc pipe.. does pretty well, however I did it for the clean air.. not water LOL

Very cool. Do you have a writeup on how you built that? Where is the air cleaner in the mix?

[itsjustdan23]

I thought about putting a snorkle on my truck. But it still looks to stock to add anything like that. Plus, ITS BROKEN. But I have a friend down here who owns a shop said he'd fix it.

[Funrover]

Very cool. Do you have a writeup on how you built that? Where is the air cleaner in the mix?

I have a write up on another forum... It will take me awhile to find it... been a few years!

[WINKY]

Absolute brilliance! I let it run for a half hour in the driveway yesterday. When I revved it, there was moisture coming from the exhaust which upon checking was water (glad it wasn't fuel). After a while it wasn't coming out anymore.

I drove my son to scouts in it last night and it was running slightly better but not perfect. By the time I came home it was near perfect. I started it this morning and all was well with the world. I reset the computer (disconnected the battery for a bit) and when I reconnected and started the Jeep, no light.

Thanks for saving me $50. Now I just need to figure out how to make it not happen again.


that is normal part of combustion is water vapor. it isnt what was coming from the intake. all you did was dry out components on the intake. the combustion process creates water vapor which condenses in the exhaust.. when you rev the engine its just blowing out that water which has pooled up. but glad to be of assistance!!! moving the intake to a snorkel will eliminate steam condensing in the intake and any water intrusion from puddles. and waterproof your connections.