What are the syptoms of a TPS sensor going bad, Because my car has been acting up latley stalling and stumbling from idle.

I have run the car in Speed Density mode for a few days now, I haven't had the stalling but a couple of times I have had the revs stay up at 2,000 rpm when I am coming to a halt. I blip the throttle (in neutral) & it returns to tickover revs again?

 

You need a data log, or at least some scan data of the car sitting at idle, both with the correct idle speed, and with the elevated idle speed before you "blip" the throttle. That way we can see the TPS closed throttle voltage, actual idle speed, prgrammed target idle speed, IAC counts, etc. There are just too many possible causes of your problem to pin it down with limited info.

If you can't scan it, you might want to check the TPS voltage at idle. Should be in the range of 0.20-0.90V, with most stockers coming in around 0.65V. You could also use the voltmeter to check the readings when the idle is too high.

Just a suggetion - don't take it the wrong way. Don't list specific people in your topic. It results in the many other people who might be able to help you ignoring your posts, and may create bad feelings.

Just a pet peeve of mine... hope you understand.

 

No problem sorry Injuneer but I have tried two posts already trying to get any reponse to my problem. 1 in LT1 engine tech them in computer section and now one has replied in 5 days except me!

The only reason I used your name was because I need someone with your techinacal expertese to give me some guidence sorry I didn't mean to offend you.

Thanks for the quick responce least I'm not talking to myself anymore.
I am in the UK and nobody over here knows Jack about these cars.

Most of what I know about my car has come from this board either directly or it has led me to pages like yours, Brent's and Shoebox's and it's a brilliant way to find out everything about your car.

I have done a scan with Datamaster and the tps was sitting at 0.53v at Idle and 4.53v at wot. I must admit that looks ok to me. The car was acting up running rough and it seems to only happen in closed loop. I have a Freescan log aswell, but this was sitting on the drive I don't have any of the surging and when I have had to push it in to neutral and blip the throttle to get the revs back down.

I am trying to work out why my stalling and serging are worse when the cars in MAF mode yet when I run in speed density it runs much better.

There is a lot more detail in this thread of what I have done so far

http://web.camaross.com/forums/showthread.php?t=375894

You will see why I think I'm talking to myself I kept adding more detail and hoping someone would jump in.

I was thinking what used in both of these modes and would affect cause stalling and serging.

I have managed to buy some used sensors on Ebay which will be here in about a week I have a TPS,IAC & MAP all for $35 all working

 

What is your vacuum at idle?

Normally if I see a sd=fine/ maf!= fine I think leak in the intake tract or line PCM is seeing a bad MAF signal.

So check idle quality and log MAF

 

Have you cleaned the IAC motor yet?

 

I have just checked the vacuum is 15 at tickover!
That's a bit low shouldn't it be 18?

I have a datamaster scan but in MAF mode when the car was running kinda rough there were no DTC codes

What would I use to clean the IAC motor would fuel injector cleaner be OK?

Thanks for chipping in you guys the car is running pretty good in SD mode but as soon as I switch it back to MAF mode it starts the stalling and bogging down again.

I have a some second hand sensors on the way to me from the USA, TPS, IAC and MAP they should be here with in a week so I could try swaping IAC then TPS to see if it cures it.

 

It gets prety exspensive replacing parts some one stated cleaning you iac which is a good idea you can you carb and choke cleaner to do that also might think about cleaning your throttle body with it also vacume is also something you want to look for sounds like you might also have a vaccume leak

 

Stock cam at idle should produce 20-21"Hg vacuum (or 9-10"Hg MAP). You have a vacuum leak if you are only seeing 15"Hg (not sure what you mean by "tickover".... is that Brit for "idle"? ).

And when you clean anything associated with the throttle body (here's a radical idea) use ONLY "throttle body" cleaner. There are anti-carbon coatings on the TB blades that can be destroyed by other solvents, like "carb cleaner".

 

Yes that's Idle (everything is goes by a diifferent name over here)
No one sells throttle body cleaner over here I will have to send of to the States for that.

Anyway I ran in SD mode for 2 weeks and then my used sensors arrived from the USA I fitted the MAP. I then switched back to maf mode and it has run fine for 2 weeks now including a long run to the track. So what ever it was has cleared it self must have been dirt in somewhere.

The car has never run so good since I installed Mad Wolf's tuning the 3.73's and the headers. I can't wait to spray the Nos at the track cause the serge of power is wicked! or Sick as you guys say!

 

im gonna be spraying nitrous with ya soon andy

im looking for that skyline that beat me!!........

well done for getting your car sorted out,its not easy to do over here is it?!

the 12s 1/4s are coming!!!!!

 

Yes Thanks Andy, I will see you at the Mopar Nationals at Santa Pod on the 30th or 31st of July, I will be there for both days. All I need to do before then is get the Nos refilled 12's are there to be had.