Hey guys. I need help with my cousin's '98 Z28.

When it gets cold here (a few deg. below zero), her car starts, but revs upto 3000-4000 RPM, then down, then up again, then down to ROUGH idle (too low), then dies.

It sets no codes. When its warm, it runs OK, but, she says the milage is down.

I am thinking possibly TPS sensor. What do you guys think? Any way for me to check it (like unplugging it)?..

Thanks.

 

Perhaps there is a vaccuum leak or air leak somewhere ?


Have you looked at that little hole that is in the butterfly in the throttle body ?

Sometimes that will get plugged up and cause weird troubles.


I have no clue how to test a TPS, but would assume that if it was bad there would be a code somewhere .


Good Luck !


Britt

 

At least in regards to the start up, then die.


This was on a '99 (?) Ford 1/2 ton - we tapped on the IAC/TPS ( gently ) while the owner held the gas to keep it running. he said as I tapped on it, he could feel something come loose , and now it acts fine.

Probably a little pice of trash on the IAC.

Here's a pic of what I am referring to :





Entire article is here:

http://www.installuniversity.com/ins...ar/tb_swap.htm

May be of some help.

Britt

 

Get some electric parts cleaner and spray the MAF and the IAC. Make sure it's just the cleaner and not a lube too. You want something that doesn't leave any residue. You can find it at just about any auto parts store.