Stomp test no work...what gives?

[paanta]

I used to be able to do the stomp test, though it was always sort of hit or miss. It doesn't work at all anymore. CEL works, comes on if I disconnect a major component, etc. The TPS doesn't seem to be the problem...it doesn't work even if I jumper the WOT and ground terminals on the connector and the switch tests fine anyway.

Is it possible my ECU itself is bad?

[Ross]

I also have a rough time getting cars to respond to the stomping. Sometimes I must get the cadence correct and it works fine, others I can't make it work.
Don't you have a suspect TPS?

[Jeff N.]

What Ross said. You have to do it just right to trigger. Check your TPS to make sure the WOT signal is actually triggering. They get flaky when the get old.

Not hard to recondition a TPS is you're careful. Cheaper than buying a new one.

[paanta]

Yeah, I checked the TPS and it is reading a little high in terms of resistance. ~25 ohms measured from the DME end of the run. I don't know what it's supposed to be, but I thought it might be bad because the idle switch was showing more like 4 ohm.

So what I did was attach a pair of leads to the TPS connector and try to make the stomp test work by shorting them together (ie, just taking the tps switch out of the loop entirely). That didn't work either. So either the DME has a problem seeing the WOT switch internally, has an internal problem that makes code reading no longer possible, or I've lost the coordination to make it give me codes. :)

What needs to be done to recondition a TPS? I tried prying a spare one open and had no luck whatsoever. That thing was sealed up TIGHT.

[Jeff N.]

So you have a Bentley's right and are sure you've followed the instructions?

Is this a manual or auto, can't remember.

For a manual - you have two options on the TPS. First one is pry it open and clean the contact on the WOT trigger. The second is a bit more risky but can work as well. Blast a bunch of carb cleaner into the unit around the throttle plate connection and shake it around. The WOT signal fails when the unit ingests oil and not longer makes a good contact.

Here's the guts of one from a manual tranny unit. I recall the autos are different.

http://home.comcast.net/~jsnord/pics/tps.jpg

[paanta]

Yep, have the Bentley and followed the instructions. MT car. Excellent picture. Now if I can pry it open without trashing it. :)