Contour Enthusiasts Group Archives Forums General Troubleshooting Funky OBD-II readings...bad TPS?

Am I missing something? Did you check if the fuel pressure is high?

It varies between 30 and 40psi. It is usually about 35 when idling but never goes under 30psi.



BP

You have not taken it anywhere yet???

Did you replace the tensioner with the timing belt? You really should verify static timing.

Unless the IAC is not getting a signal from the computer, don't know what else to do. But the rich thing does not really go with that. Shouldn't run rich just cause the IAC does not open enough. The timing could, but manifold vacuum should be low - maybe only 15 in.

ButtonPuncher: I have the reference values chart from the Ford DVD. I can email it to you. It lists several items and what their values should be at KOEO (Key On Engine Off), Hot Idle, 30 MPH and 55 MPH.

Listen to Rogerm60, too. My problem turned out to be mostly incorrect static timing. Even though I was already checking it when he posted the idea, he was the only one that ever recommended looking into it.

EDIT: Nevermind, finally got the FTP client to upload it. Right click - Save me... It's for a '98 w/ MTX, but it should be able to give you the big picture.

  My Zetec shows a minimum TPS of 17.6% and a minimum MAF of 0.177 #/minute when the engine is not running.  A Duratec that I recently examined showed a minimum TPS of about 18%.  I think this must be normal.

  Perhaps the scaling of the TPS range supposes that 0% would be completely closed, so that no air at all can go through â?? a position which, for obvious reasons, should not occur.

WOW! Thanks for the input everyone. Here I go...

Rogerm60,
No, I still haven't takin it in yet. I just got promoted last week and have been working my A$$ off. I just haven't had time. Anyway... I had my timing belt replaced just after I bought the car (at 87k, now I have 100k). I doubt that they replaced the tensioner. How can I verify if it is working properly? What do you mean by static timing?

The one piece of test equipment that I don't have is a vacuum guage. If I buy one, what should my readings be at idle?

D Davis,
Thank you, thank you, thank you, thank you, thank you for the OBD readings! This is what I've been dying for. Finally something to compare to. Did you actually fork over the cash for the diagnostic DVD?!? You are HARDCORE!! ...either that or you work at a dealership... Thanks again!

Bob,
Those readings are EXACTLY the same as mine. I feel much better now.

Thanks again everyone!

Now please tell me about static timing and vacuum levels. I wanna fix my baby!!

You're welcome I bought the DVD from Bill Jenkins last year. I think it was about $25 through him.

Static timing is the physical alignment of the cams and crank. I just redid mine this weekend. The car runs better, but I have a CEL (P1383 - VCT OverRetarded) and what feels like a loss in power below 3k rpms. You can read the progression of my issue here.

D Davis,
Just got finished reading your thread. The static timing problem sounds VERY interesting. But I doubt that that's it because it was an intermittent problem that turned into a constant one. I should check it out tho. I'll have to bust out the service manual to see where the timing marks should be. Thanks.

Now about the vacuum levels. Anyone? Pretty please with sugar on top?

BP

You've got to be kidding me! I have to take the freakin valve cover off to see it the cams are aligned!?! Why didn't Ford put some kind of marking on the cam gears?

Will a local dealership have that alignment tool? How much is it?

Questions, questions, questions...

BTW, just got a big-a$$ vacuum guage from Sears.

BP