Is my TPS broken/wrongly adjusted/wrong for my car?

[DaJackal]

Hello folks.

The guys at the DSMClubFinland couldn't help me this fast so I decided to come here with my problem.

The problem is that my Eclipse (1995, 420a n/t) has a bit bad idle... or the idle sounds almost ok (850-900 revs), but when the engine hasn't warmed up (during startup and next ~10 kilometers) the car has a bad habit to just "die" when I have to stop in a crossroads. The car just goes off like I would have turned the key. Sometimes the car also tugs and possibly flashes the CEL when driving (luckily this is rare).

A diagnostic program (not sure what was it) showed that the TPS gives a value 15% when the throttle is closed (idle) and value ~70% when the throttle is full open (pedal is pushed to the floor). This can't be ok, right?

We measured the TPS with my friend and it gives the following resistances:

Pins 1 and 3: 4.5 kohm (constant)

Pins 2 and 3: 0.65 kohm (throttle closed) -> changes linearly to 3.4 kohm (throttle full open).


Shouldn't the value from pins 2 and 3 be the same 4.5 kohm as in pins 1 and 3, when the throttle is open? I thought that my TPS could be adjusted wrong... but then I found out, that I have this TH-188 TPS http://i15.ebayimg.com/05/i/001/42/92/a239_1.JPG
and this is not adjustable.
Then again, DSMGraveyard says that a 420a TPS looks different (couldn't reach their website now, but the part I mean is TH-142).

Now I am confused. The TPS has been replaced once by the previous owner, is it possible that I have the wrong part? I checked the number from CAPS and it gives me a code that translates to the upper, non-adjustable TPS... but I'm not sure which CAPS I have, it might be European spec CAPS.


Could some 420a owner check which TPS he/she has under the hood and possibly measure the resistances?

I wouldn't want to order the wrong one.

Thanks already in advance,

Olli-Pekka, Finland

P.S. Sorry for grammar mistakes

 

[rush2252]

According to CAPS this is what I came up with.



M04762716

TPS 95-96 GR,RS Eclipse M/T or A/T


M04874430
Should be the 97-99 GS,RS A/T Im not used to CAPS but its similar to some other systems Ive used and I think im about 90% correct


Cheers!
Kolby


EDIT** If you input the VIN it shouldnt matter which version of CAPS you're using.

 

[rstare]

The TPS outputs ~.4v at minimum throttle (idle) and 3.8v at WOT.

 

[Locke]

Flashing CEL indicates severe misfire, I'd work on the ignition system. I ran my car without the TPS plugged in once to prove a point, and it never died.

It is odd that you have a 420a motor in Europe; EDM 2gnt DSM's had a naturally aspirated 4g63. You're sure you have the 420a and not the 4g63, yeah?

 

[DaJackal]

Flashing CEL indicates severe misfire, I'd work on the ignition system. I ran my car without the TPS plugged in once to prove a point, and it never died.

It is odd that you have a 420a motor in Europe; EDM 2gnt DSM's had a naturally aspirated 4g63. You're sure you have the 420a and not the 4g63, yeah?

Yes, I do have a 420a. It has been imported to Europe from USA in 2006. And it is not that odd, I'd say at least 20-30% of the 2g non-turbo DSMs in Finland are with 420a. They have been quite popular imports from USA, because rust-free EDMs that are for sale are hard to find.

I'll change the spark plugs next. I just thought that the wrong TPS might give extra trouble to the plugs, because the TPS seems to give disinformation... and because of this the plugs might be worn and cause the misfires and therefore the CEL. This doesn't solve the TPS problem, though.

When/how should I measure those voltages? With keys in my pocket? Or power turned on, or the engine running?

 

[DaJackal]

Locke, you do have a 420a too, right?

Could you tell me which TPS do you have in your car?

This DSM Graveyard - Your #1 Source for Used DSM Parts!
or this http://i15.ebayimg.com/05/i/001/42/92/a239_1.JPG

And if you have the latter one, could you be so kind to measure the resistances from the pins? I would appreciate it a lot, I would know then if my TPS really needs to be replaced. The summer is already here and I would like to get the car running on full performance asap, the local Ford Escort boys need to learn some respect.

 

[Fotowntalon]

exaclty what code is your CEL giving you? Dying in intsersections and rough idle could be related to many things. I had a simular problem once, stalled a lot till it warmed up, ended up needing to change my fuel filter, just an example.

The code can help narrow it down a lot so we can help you better.

 

[DaJackal]

I don't have a diagnostic program (nor obd2-cable) myself yet, so I can't check the code.

I know that idle problems can have a hundred different reasons, especially when it comes to DSMs. I just want to eliminate this TSP question first, because the diagnostics showed that it gives clearly wrong values (we checked this with the seller before I bought the car) and the resistances from pins 2 and 3 are weird too.

If changing the TPS and spark plugs won't solve all the problems, then I'll move on to replacing the wires (looked fine to me when I checked, but...) or the fuel filter (thanks for the tip!).

 

[Fotowntalon]

if ya have an ohms checker you can also check your coil pack which can be a another great reason for misfires. If ya don't have a obdII checker, most autozones will check yuor codes for free.

While most your stuff (plugs filter etc.) should more than likly be replaced due to simple maintenance ( i beleive fuel filter is ever 60k miles and most people dont do that) I reccomend taking it to autozone to try and save ya the most money, don't want you to replace parts you don't need to.

 

[DaJackal]

I'm living in Finland so the nearest Autozone is a little far away. But I could of course ask some repair shops, if it's not expensive I might try to let them check the codes.

The coil pack would be a good thing to check, gotta remember that. I just have concentrated on the TPS because, as mentioned above, it gives false readings and everything else seemed to be fine.

All filters, belts, plugs and wires have been replaced during the last 2 years by previous owner. I know, he might have lied to me, but I haven't had a single reason to doubt his words this far.

 

[96TurboGS]

I ran my car without the TPS plugged in once to prove a point, and it never died.

. Out of curiosity, since i cant try this anymore, was there a difference in acceleration when you did this?

I'm living in Finland so the nearest Autozone is a little far away. But I could of course ask some repair shops, if it's not expensive I might try to let them check the codes.

The coil pack would be a good thing to check, gotta remember that. I just have concentrated on the TPS because, as mentioned above, it gives false readings and everything else seemed to be fine.

All filters, belts, plugs and wires have been replaced during the last 2 years by previous owner. I know, he might have lied to me, but I haven't had a single reason to doubt his words this far.

Depending on what scanner you used (standard) it's quite normal to see those kinds of readings depending on what scanner you used. From the reading you gave it seems like its using a 0-5v ADC scale. I was seeing something like 8% = ~.4v and 70% = ~3.70v, witch was close to factory standards (using standard data logger). Find a good shop that caries a snap on tool for better results if your still worried about it. I would look at things like the IAC, Intermittent wire loom around EGR tube / CPS harness, possibly a bad PCM. Good luck.

 

[DaJackal]

Depending on what scanner you used (standard) it’s quite normal to see those kinds of readings depending on what scanner you used. From the reading you gave it seems like its using a 0-5v ADC scale. I was seeing something like 8% = ~.4v and 70% = ~3.70v, witch was close to factory standards (using standard data logger). Find a good shop that caries a snap on tool for better results if your still worried about it. I would look at things like the IAC, Intermittent wire loom around EGR tube / CPS harness, possibly a bad PCM. Good luck.

Is this true that the TPS should give this kind of readings? 8% on idle and only 70% WOT? The 8% on idle I can understand, but how coome it would never go to 100%? I got to make these voltage measurements asap.

Also, I would like to get an answer for my question about the TPS type: Is the correct TPS for 420a this TH-188 or TH-142?

The ISCM has been tested, it functions correctly. I bought new plugs (NGK BKR6ES) 2 days ago, gotta try to find time to install them asap. Maybe I should also try to add some engine/injector cleaner to fuel tank? I've had the car only a month now, so I don't know has the previous owner ever done this.