Just the ECM?

[six_wheeler]

OK, I'm about to order a remanned ECM from Alex, but first, I wanna ask this just to make sure I wouldn't need anything else.
It goes like this: The truck would be running fine, and then all of a sudden the check engine comes on and the trucks starts to sputter and misfire for about 15 to 30 seconds, and then everything goes back to normal. And the incidents seem to be few and far between. Is this only ECM-related?
New injectors, spark plugs and wires, fuel pump and filters are already on the truck (it's still in the shop.)
The datamaster tells only of a bad TPS, which I'm getting from Dubai. TB, MAP et al seem to be fine. What else is there?
(PS I know someone will tell me to pull the codes - with a paperclip. Can someone explain to me how to do that?)

TIA,
Shady

 

[vortecfiero]

Re: Just the ECM?

OK, I'm about to order a remanned ECM from Alex, but first, I wanna ask this just to make sure I wouldn't need anything else.
It goes like this: The truck would be running fine, and then all of a sudden the check engine comes on and the trucks starts to sputter and misfire for about 15 to 30 seconds, and then everything goes back to normal. And the incidents seem to be few and far between. Is this only ECM-related?
New injectors, spark plugs and wires, fuel pump and filters are already on the truck (it's still in the shop.)
The datamaster tells only of a bad TPS, which I'm getting from Dubai. TB, MAP et al seem to be fine. What else is there?
(PS I know someone will tell me to pull the codes - with a paperclip. Can someone explain to me how to do that?)

TIA,
Shady

data master has already pulled the codes... and showed you the TPS problem
Id start with checking the TPS wireing and plug at the sensor.. then try another working TPS sensor to see if that really is the problem
also... plug wire problems wont show up as an error code... id check them as well

hope that helps

 

[SBNova]

Re: Just the ECM?

A bad TPS sensor can make all kinds of problems. Why not start there? There are three wires on the TPS. With the key on, using a digital volt meter, probe the wires. One should have no voltage, one should have 5v (or very,very close to 5v) and one should have very little voltage (0.54 to be exact) and vary when you move the throttle, increasing voltage as throttle increases.

If you dont have 5v on one wire, the problem is wiring not the TPS itself.
If you dont have .54 on one wire, then your TPS is misadjusted.
If your voltage doesnt vary from .5 to 5v with throttle movement, your TPS is bad.
The wire with no voltage is a ground. Use an Ohmeter and verify continuity with that wire to a good ground.

This is an easy 5 minute procedure. You can check the TPS return voltage with TunerPro, I assume you could do the same with datamaster. Again, it should read .54v at key on not running or at idle running.

You said your problem is intermittant- and TPS problems can be intermittant as this sensor is like a potentiometer- it has moving parts that can fail and problems can fluctuate.

Start there- by having a code you know theres a problem. Fix it, clear the codes and continue to diagnose if problems persist.

 

[six_wheeler]

Re: Just the ECM?

But can it cause the behavior I just described?

 

[SBNova]

Re: Just the ECM?

It can cause all kind of havoc. Your ECM may think your car it idling, but may be showing near- and trying to increase fuel and timing when the engine obviously cant take it. My friends Vette had the TPS go bad, intermittantly, and would occasionaly not start. He brought it to a few shops that couldnt find a single problem. I drove it for a week or so before I found it- the TPS. When I finally got it to act up- the TPS return voltage was 5v. What this does is put the ECM into "clear flood" mode. It turns the fuel injectors off- and the engine wont start.

The TPS is an important sensor. You know theres a problem with it thats why you have a code. Even with a new ECM you will probably still get a TPS code, and you would still need to fix it. Diagnose it like I said above. Dont just go buy a new TPS sensor. Like I said it could be wiring, bad connections, or even a bad 5v output from the ECM to the TPS. Checking it is the only way you will know.