Ok so a quick run down on what im working with, my car originally was a auto. One of the PO's swapped in a T5 that is mech. speedo trans. 91 as we all know uses electronic speedo. So when i got the car it had two different codes showing up, one being a code 24(vss open/no circuit) and the other being if i remember correctly a 42(Ignition bypass circuit error). After some research to fix the vss i purchased http://tpiparts.net/inc/sdetail/10956/7587 to get the signal to my vss. After installing this i was able to clear the code 24, and to clear the code 42 i just connected the ect wire that had been previously spliced and left loose. Its worth mentioning that when I purchased the car, there was no vss and the ect cable was unplugged as it would not run very long/well with it connected, but was able to drive the car 200 miles with little issue other than bad gas mileage and only being able to get the rpms so high before it hit a wall and fell flat on its face. So when i got the car put back together and connected the vss and the ect wires the car idle great and revved up like it should. so the car set like that for the night and the next day i installed a new trans crossmember/torque arm from umi(i doubt all this has anything to do but just providind details). When we got the car back on the ground she was still running great. i take the car down the street and up the road maybe a 1/4 mile and all the sudden it started running just like it did before with the ect wire connected with no vss, im kinda at a lost as to what i am looking for here. Ive read a few post about fuel injectors shorting out and knocking out the other injectors on that rail. I also let the car sit with the battery disconnected in hopes of me coming home from work the next day and it atleast running smoothly till it warmed up. Sorry for the wall of text but i am just trying to get down all the details as to what ive done and maybe should try next.

 

Go back to the basics. Check base timing. Check fuel pressure. Ohm check injectors. Previous problems may have nothing to do with the current ones.

 

Your ECT is a high priority sensor. Your ECM relies on this heavily in order to adjust fuel trim. That being said, make sure that it is giving an accurate reading to your ECM with a scan tool. Operating temp should be around 200 degrees Fahrenheit. At what temp does this problem occur?

Second, I believe the manual and auto trans vehicles use separate ECM's. I remember seeing somewhere on this board that fuel and spark tables are different from one ECM to the other.

 

Same ECM ;
just a different tune programmed on the removable memcal ( chip ) inside

 

Ah. I wasn't 100% sure.

Do some research. Find the correct PROM for your vehicle. Verify that your current PROM is correct.

 

Well guys after looking into it some and ohming my injectors it looks like I had 4 bad injectors. So I will be replacing the injectors and will report back with what happens next