Throttle position TPS replaced and nothing!

[maddog_187]

Ok sense replacing the ecu with a used one I had laying around I have had a cel 14 (Throttle Position sensor). I finally broke down and ordered one and replaced it and still have the same problem I've checked volts at the ecu and set it to .49, I checked resistance between pin 4 and 1 and am getting 6.03 ohms. I even checked my last sensor I was replacing and it too checks out good (should have done it first ) When I use datalogger I show .3% and does not move when you give it throttle. Where else should I start looking?

Thanks

 

[GsxEcutioner]

.63v Is what the tps is supposed to set at.

 

[maddog_187]

Everything I have read says .48v-.52v That's what it states in the 1g service manual. Is it wrong and should be .63v

 

[vandenberg33]

It sounds like the problem is the ecu. Make sure it is the right one for that car.
The pin out could be different and the ecu may not be receiving the signal from the tps. I beleive automatics and manual trans cars have different tps.
I would swap the old ecu back in just to check if you recieve a tps signal that moves.

 

[maddog_187]

I would love to swap out the ecu but the one I pulled from it is in very bad shape I couldn't even rev the car past 3500 rpms. So I had 90 ecu from a 5spd that I swapped in I did swap the pins on the ecu (6 & 14). Since then I have had a problem with the tps. I have one more computer I will try to swap in if I could ever find the stock chip. Is there anything else besides the computer that would cause this?

I forgot to mention this is for a 91 talon not the one in my profile (too many projects) It is stock other then k&n filter. Will be turning up the boost how ever after I figure out this tps problem

 

[vandenberg33]

My freind borrowed my 90 computer for his 91 laser and had a similar problem but If you swapped the pins and it started doing this check the diagram again and recheck the pins swapped because something had to go wrong their not sure if the diagram you used was correct or not.

 

[maddog_187]

Will do some more checking. The diagram I used was off VFAQ Site - Visual Frequently Answered Questions for swapping pins on the ecu from 90 - 91. 1G ECU Pinouts

Has anyone else had this problem and is there a fix if there is?

 

[vandenberg33]

Do you have the part numbers for the old and new ecu's?

 

[maddog_187]

The 91 ecu out of the car is:

MD166262
E2T36578

90 ecu is:

MD128623
E2T34473

Here is the link for checking the ecu's: http://simon.chi.il.us/ECU/ECUID.html

one is for federal one is for California both are for 5sp one is awd and the other fwd

 

[vandenberg33]

md 166262 is a federal AWD ecu and the md 128623 is for a CA emissions FWD. The California emissions one is quite a bit different. Your best bet is to find another federal one since the california one had an engine with more emissions equipment on it and may have adverse effects on performance if it cant find the emissions equipment. If you cant get another ecu now then you will need bot pin outs for the fedral ecu and the California one.

 

[maddog_187]

Here is a link let me know if I'm reading it wrong but it was saying that you can swap a 90 ecu in with no problems no matter the emissions as long as the transmissions are the same

http://www.dsmtuners.com/forums/newbie-forum/264341-what-ecu-will-work-92-tsi.html

 

[vandenberg33]

It looks like steves post says a Federal can't be swapped for the California ecu. Im sure that that is correct even if you swap pins 6 and 14. Pins 6 and 14 are for Federal 91 through 93 in a 90 Federal.

I havn't been able to find a California emissions diagram yet but If someone out their has one we could still get it to work but you may have an egr cel.

 

[maddog_187]

I could handle an egr cel I just hate when the car dies at lights after it warms up. Still in the process of finding my other chip I have.

Sorry read steve's post a little slower this time and I think you are right.

I finally found my stock chip for my other 90 ecu and still have the same problem. The ecu is a MD145903 and is a Federal

I am also getting a code 25 barometric sensor that I forgot about.

 

[92AWDHX40]

whats your problem with the car?

 

[maddog_187]

The problem I am having is I have a cel 14 (tps), and 25 (barometric sensor).

When the car gets warm it does not idle right. It drops rpms and will die sometimes but not always. My main concern is to get the car to stop dying at lights.

I've tried adjusting the tps according to the haynes manual.
I thought my code 25 was gone after swapping the maf but seems it is back.

 

[Colt4G63 also]

Do you have a known good TPS? When My TPS crapped out, I tested it with an ossciliscope and watched the graph on DSMlink. It looked perfect with the "key on engine off", but as soon as it was running I got little dropouts in the signal voltage. It made my car cut and hiccup while driving.

If you haven't tested the TPS with the engine running, and on equipment with a high sampling rate, don't rule it out.

As for the BARO code, it's probably going to turn out to be a bad MAF, assuming your wiring checks out ok. That would probably be partially to blame for the poor idle and driveability too.

 

[maddog_187]

I would assume it is a good tps I bought it from on green performance off ebay but that's not saying much. I will see if they can send me another.

 

[Colt4G63 also]

I would assume it is a good tps I bought it from on green performance off ebay but that's not saying much. I will see if they can send me another.

Doh! I completely missed the part in post #1 where you said you replaced the TPS after the problem started.

 

[maddog_187]

That's fine is there any other tests I could check? Can I check continuity between the three wires on the tps plug, to see if they are not fully connected? If so where would I find the other ends of the wires? I have the wires on the ecu out from behind the console to where I can easily check them should I see what the voltage is at full throttle?

 

[92AWDHX40]

did you look on here for idle surge there is a lot more too it than that once sensor, vacuum leak test? isc, throttlebody im having issues too.

 

[maddog_187]

I have. i've done boost leak test. I was just assuming that it was the tps since I was getting a cel also I would like to be able to turn up the boost, but won't do it till the computer is seeing 100% throttle just to make sure it can calculate for it.

 

[92AWDHX40]

do you have a wideband, a datalogger some sort of tuning device to monitor knock and air fuel rations before you go turning up the boost?

 

[maddog_187]

No wideband but yes on the datalogger. I would assume the default setting the computer goes to would be able to handle it I would just feel safer if everything was working good. I'm only turning up to 16psi.

 

[jrbach]

Sounds like it could be a combination of problems...perhaps even some build-up in the throttle body.
It'll definitely help when you know you have an appropriate and fully-functioning ecu.
I've never seen the TPS testing method using volts (only ohms), does someone have a link to that?

My manual says normal resistance across pins 1 and 4 is 3.5-6.5 Kohms
and that resistance across 2 and 4 should change evenly and approrpriately from idle throttle to wide open throttle.
Another way of testing the TPS (might help):
http://www.plymouthlaser.com/tps.htm

You probably will also have to set the Base Idle Speed Scew:
1G BISS Adjustment

or (and this includes a cheap part number for the o-ring)
http://www.plymouthlaser.com/biss.htm

 

[vandenberg33]

Their is no point in trouble shooting sensors when you have the wrong ecu since you may find issues with signal voltage not being their or power where ground should be. Who knows what the difference in pinouts is and what it is sending to where. Without the proper diagram for the California emissions ecu in your car your federal wiring is different and will cause all kinds of problems. You need either a diagram of the ecu pinout or the right ecu.