N1XRR

Let me explain the whole problem.

I first noticed a problem when I picked my little brother up from school, if I went above 3500rpms the car would hesitate REALLY bad. I figured it was the injectors malfunctioning. It was so bad that it almost game my little brother whiplash. I drove home below 3500rpms that night and have been running that way since(about a week ago).

I've been having problems with what I hope is my TPS. I have a very very bad idle, it drops down to 300-400 rpms and then surges to 800-900 rpms, this past weekend I had it stall on me. Then the car wouldn't start again. I pulled off the intercooler and re-adjusted the TPS. I also took the plugs out(leading) and cleaned them off, there was a lot of carbon built up on the plug and it was very dark(read black), not the usual tan.

At this point I turned the car over(with the EGI fuse out) to make sure everything sounds good...everything seems to be fine there(uniform sound coming out of the plug holes usually means good compression all around.

This morning, I got the car running again. Rough idle, but if I keep it in neutral and floor it the engine will go up to 4k, and then it acts like the fuel is cut and goes down to 3500rpms, and then back up to 4k, and back down to 3500rpms, like a rev limiter would.

HELP PLEASE!!!! Any idea's guys? I made an appointment w/the local rotary mechanic(Greg Burns), but he can't take me till Wed.

Thanks in advance, Michael

Josepi

Check the tps to see if it's working right? Erik and myself had similar problems that went away when we replaced our TPS outright.

Erik

i had the same kind of problem. the TPS in my T2 turned to **** on a long drive, and yeah, after a few hours i couldn't go above 2500 rpm's or the car would buck so bad the rear tires would chirp. although it always had a perfect idle during this time. i didn't adjust mine (supposedly the S5 ones are self adjusting), i just threw in a newer one and it runs great again. i ran the codes before i did this and sure enough i got both for the mid and full ranges of the TPS (codes 16-18 or something like that).

what year is your T2? you might wanna see if you can get another TPS or a new one...it might be at the point where adjusting won't work anymore...good luck dooood

also, the low idle may be from a bad crank angle sensor possible causing your timing to be off and therefore dip to 300...

Erik

lol...the two TPS boys reply simultaneously

N1XRR

Well, I guess I forgot a few things...

First, I've never checked the TPS before this happened, so I had no idea what its suposed to do. I made myself the little checking device out of a couple of LED's. I also took a multitester to the TPS. Here's what I found: At 'idle' position it reads 1.6, then will go up as I pull the throttle cable. When I get to one point the reading will go up to 8 or 9, then back to 5.5-6(where it should be). This is my first indicator that its bad, correct? Also, when I get to able 1/3 throttle the TPS will read the full 5.x ohms all the way up, indicating(to me) that the TPS is saying WOT at 1/3 throttle.

Next, incase anyone really needs to know, I have an '88 FC(10th Anniversary Ed.), just incase there is a diffrence between the 89+ FC's.

N1XRR

Thanks to both of you guys. I'm going to call Mazda right now and see if they have one in stock(yeah right) and how much it costs(THAT much?).

I never had ANY problems with my idle until this happened.(besides the fact that it idles at 500-600rpms and I don't know where the damn idle screw is on the turbo cars)

Josepi

LOL yea we both jumped on that one.

The 86-88(NA or TII, they are the same) TPS is cheaper so congrats! www.mazdatrix.com has them for $163.27 plus shipping.

N1XRR

YES! That was the question I was going to ask! I have a friend about 30 minutes away who has 3 or 4 not-running FC's(86-88 models). I'll go down there tonight!

Michael