oldblue

i've been lurking for a while, and this site has a lot of great content. i did a search but didn't find exactly what i was looking for. i'm trying to check and adjust my timing on my '94 3.0. when i jump the terminals e1 and te1, the idle doesn't change and the timing pointer doesn't move. is this a problem with the tps? and if so, what do i do to check and diagnose the tps? also, dumb question, but when checking the timing, which side of the 0tdc mark is advanced and what is retard? is left side of mark advance and right side retard? i'm trying to learn!

bjslade0269

here is a FSM link for the throttle body that shows the TPS specs. As far as the timing marks go, you are correct. I have found that you can't set the timing until the TPS is set correctly. Also when I insert the jumper I do it when the ignition is off, then I turn it to on without starting it to make sure the check engine light is blinking. This tells you it is in the correct mode. Then I start it up and set the timing.

http://www.ncttora.com/fsm/1990-1995...e/throttle.pdf

TNRabbit

When the engine is warm & sitting at idle, the TPS should be set where it's at infinity until your JUST come off idle (the slightest fraction of an inch). As long as it doesn't hit that next bump in resistance while at idle, it will be fine. Fix that first then pin your e1/te1 terminals. Have you checked the FSM for TPS adjustment procedures?

oldblue

thanks for the good info guys. i have no clue if the check engine light was blinking, didn't know to look for that, but i will next time. and i don't know if the tps sensor needs adjustment, i'll have to look at that link and find out. thanks for pointing me in the right direction tho! but the timing marks, left of 0 is advanced and right of 0 is retard?

bjslade0269

thats correct, left of "0" is advance and right is retard

abecedarian

The proper setting would be where the IDL and E2 terminals are continuous (i.e.: less than 2300 ohm) when the throttle is closed. If they are not shorted when the throttle is closed (throttle stop less than .5mm-.75mm from the set-screw), the ECU will not think you're at idle regardless of what the VTA/E2 readings are and will not go into the proper mode to set the timing.
You could start the engine and insert the jumper then very carefully, and in very very small increments, rotate the TPS in the opposite direction of the throttle opening direction until you hear the engine idle speed change and can see the timing shift to the baseline reading. If that doesn't happen, the TPS is likely bad.

oldblue

ok, so with the .050 feeler gauge in place, i had an open circuit, so i adjusted the nut and screw, now all readings are ok. however, i didn't pull a vacuum on the throttle before doing this. so, does that mean these readings may be off? after i did this, the bucking i was experiencing from the 1-2 shift is gone, so i'm happy about that. but, there is still a slight miss that is only present at idle, and i think the idle is too low, but no tach to verify what actual rpm is. gotta figure out where this damn slight missfire is coming from at idle, and bump the idle up just a hair