Hello all, just did a NA to t2 swap (s4) in my 88 gtu.

Only issue right now is when it idles it bounces from 500 to 1500. up and down and up and down and up and down in rythem.

I unplugged the bac, nothing changed.

The tps is set for 1k ohm when warm.

and the bac screw has been adjusted from close to open with no change.

I need some help ASAP I need to get it running before school starts here in a few days.
Thanks.
Tweak.

 

OOOOOhhhh yesterday my car idled fine, till I had to remove the UIM and fix my PD and a leaky upper injector. I didnt think about this before, but the injectors go into the intake so they could be causing a vac leak?? If they arnt sitting perfectly correct?

 

can you manuallu crank the TPS up or down so that it does not surge?

and have you checked timing?

 

I dont have access to a timing light, so I will have to buy one later if my first plan doesnt work.

Last night, the first time I turned the car on after the swap the idle was PEFECT. I had a bad PD in so it was leaking, and also 1 of the secondary injectors was leaking also. So I had to take the UIM off and also take both the injector fuel rails off.

From what I have been reading recently, I might have just a TINY (or combination of tiny) fuel injector vacuum leaks. Im going to try that first seeing how everything WAS GREAT (othe then I had some BAD stumble when I tapped the gas (but I think that migh thave been cause I didnt have a good PD / had injecotor leaks)) before I took off the UIM and played with the injectors.

I have sprayed carb cleaner around to see if I can find a vacuum leak, but I havnt been able to find 1. I think its really hard 2 get the carb cleaner down to the primary fuel rail.

Anyways, how do I manually crank the TPS up and down when I have the intercooler on?

Other then using a timing light to check timing, is there any way just by looking at the red and yellow marks? I found them today but dont know how to read it.

Thanks.
~Tweak

 

I believe the timing light flashes at the same interval as the plug wire that it's hooked to. So 1 flash per turn of that wheel you were lookin' at. so when it flashes, you see the position of the wheel when that plug is firing. The marks are so you can adjust your timing and line up the corresponding marks (I think the haynes manual outlines the timing setting procedure) So unfortunately no, you need a timing light to set your timing.

 

ok, timing light is on its way. args I am getting sick and tired of this t2 rx7. I should be on my way to see my g/f by now.

I have no vac leaks, the TPS is set as good as I can seeing how its impossible to keep the car running long enough to get it warm. (BTW is it better to be over 1k ohm or under? From what I noticed is it drops down the warmer the car gets.) The bac is all the way open ( I dont know if that helps at all.)

So on my latest adventure I messed with the max idle screw and the other screw next to it that is close to the pot. I have messed with them so much I have no clue what is stock and I have searched with little success on what is the correct setting for both those screws.
If anybody knows how to set those two to stock specs, that would be AWESOME.