ok, first off its a 91' base with 2.5 inch straight pipes, no emissions, unused plugs in engine harness have been removed, new intake gaskets, K&N cone filter, has other idle issues, new spark plugs, wires are unknown, coil packs are unknown, TB mod, and is stuck in limp mode.

So heres the problem, I finally got a somewhat decent idle at times (other times it just dies...) but when it does idle if you depress the clutch and put it in a gear the idle will change. Ive been searching for a while and i know my TPS is bad, but that will be replaced soon, im just not sure on where to even start.

I was thinking that maybe the ground was bad, because all my others are pretty crappy at this point, but i dont know where the ground is and electrical is not my strong point by far.

any ideas guys?

 

Why do you say the TPS is bad? Got a TPS code?

 

The online FSM shows that the NEUTRAL switch effects the BAC's operation

 

bad idle, 6500 RPM wall, and a few others related to it.

but i dont have the BAC anymore

 

High much higher we talking here?

 

all of my early 90's late 80's mazdas do that... like every single one.

 

about 500-1k more. I hooked up my safc II today and played with the tps and fuel settings and it stopped doing it... dont know if it was just those few stops or what, ill have to drive it more to confirm though.

 

I forget. Can you look at your TPS voltage on the SAFC? Or it's percent?

 

You might try the RELATIONSHIP CHART. Jpg of PART of it attached. You need to see the bottom of the page to make sense of it.

Even then it's not sure fire. Like it'll tell you the clutch switch effects AMOUNT OF FUEL INJECTED. Well that true but not true. It effects when and if you get fuel cut during deceleration, which indeed is AMOUNT OF FUEL INJECTED so to speak, but does it effect how much fuel is injected during idle?? Got me. Don't think so from what I've seen.

I'd go to the pages called CONTROL UNIT and get a meter out and check each pin on the ECU and compare it to the FSM. Like the CONTROL UNIT will tell you what the pins on the ECU should read for the NARROW and FULL range TPS. You get the engine hot and then check the pins and compare the results with the pages in CONTROL UNIT.

 

no its just the percent.

Im positive my TPS is fubared, in the sweep test it has bad spots. Im getting a new one but it wont be until after i get back from my vacation.

I got to playing with the fuel and TPS settings more and got it to stop. Not sure how, but it did. I still dont have a great idle due to a vacuum leak or 2 and the TPS is still crap. We'll see what happens with the new one though.

 

Well, I can disconnect the plug from my car which idles just fine, and after the disconnect it idles *funny* because it defaults to 100% TPS value which in turn fudges a number of things. I'll let it go at that.

 

Im also gonna call it tps until i fix it and it does it again... then ill call it something else! lol

 

I'm really stabbing in the dark here but maybe OMP? Again, I'm sure its totally wrong, but just figured I throw it out there.

 

Maybe the ecu then, cause i dont have an omp. The ecu has the car in limp mode because of the tps's top plunger not working correctly and screwing with the stepper motor which is then throwing a code. at least, I hope its just the tps thats making the omp throw the code, otherwise i have to buy the Rtek chip...