Bad TPS?

[RatedR]

I've been working on my friend's SR and we've got it from a no-start, to a no-idle, to a rough idle w/ no rev past 2000. I BELIEVE that the rev problem is because of the MAF, but I also pulled a 24 code from the ECU (Ignition signal). I looked around and saw someone say that the ignitor chip can throw a code of the TPS is off. I tried checking the TPS sensor, while running and w/ the engine off Key ON, the sensor read 5V. Is this a bad sensor?

-R

[vutony]

tps suppose to be .45v

[RatedR]

I know its supposed to be .45V. We even opened up the throttle to see if the voltage would change, it stayed the same. Would the TPS going bad throw a code 21?

[S13FASTBACKSR]

21 is ignition signal 24 is throttle valve switch 43 is tps (assuming you have a redtop) i dont know if the blacktop ecus are different...the tps voltage definately sounds suspicious? did you adjust the tps all the way down to see if that made a difference? also check your mafs voltage.

[RatedR]

I believe the MAF is bad, the owner bought it from a known ripoff salvage yard owner. It is a redtop, but I'm not sure what you mean about adjusting the TPS all the way down, do you mean closed? If so, yes, we tried it closed and WOT. No change though. As for the ignitor chip, I'm not sure why it would still throw a code, a simple part swap ruled it out from being faulty....or is it possible to swap it out to another SR and still have that SR run well?

[S13FASTBACKSR]

you can put a known good ignitor into your harness and see if it fixes it or put yours in another friends and see if his starts to run bad..but you did that test already you said...test the voltage of the maf..you can also unplug it with the engine running and try to rev over 2000 rpm or 2500 rpm or so..sometimes 3500..if it doesnt surpass that then your maf is good..if it does then your maf is bad...try 4500 also...also by adjusting the tps i mean loosening the screws and turning the actual tps all the way down not just the lever.

[RatedR]

What other parts could be causing the car to stumble so early in the rev meter? I know its definitely an electrical sensor, but what should I look for?

[S13FASTBACKSR]

have you tested the maf voltage yet? and did you adjust the tps with the 2 little screws like i said? if your tps sensor isnt reading the correct voltage at idle (which yours isnt..yours is so far off then it sounds like the problem..also check your maf voltage and how is your maf wired?)

[RatedR]

The maf is wired w/ the ground in the middle I believe, then the white and white/black wires across. I'm not sure, didn't check...but I checked the ECU and it threw a code. After I cleared the MAF code, it didn't come back. The only ones that came back were the knock sensor and the ignitor chip. I had the owner check w/ a timing light, and #2 isn't giving off any spark. Everything else is shooting off, 1,3 and 4 all have spark. That sounds bad to me....

[S13FASTBACKSR]

have you checked continuity of your ignitor? and check the voltage at your ecu as well...also check the voltage of all your coilpacks...swap # 2 with #1 coilpack and see if you get spark to cylinder #2 now

[RatedR]

He tried that, no spark on #2 still, so the coil packs are not a problem. The ignitor chip he's planning on using is the one for a 92 Q45. I dont know if that will work....

[S13FASTBACKSR]

Q45 ignitors will work but im not sure of exactly what years or if they are just plug and play or different wiring technique etc. etc. but thats what the search button is for..but you can also check with a voltmeter to see if your ignitor is bad or not

[RatedR]

Alright, I just got back from helping my friend and I got some more info. I checked all the coil packs, they're good. The Q45 was wired up using a wiring diagram from Heavy Throttle. Also, I've tried switching the Q45 and the SR ignitor chips, both only fire off #1,3 and 4. I've checked out the wiring from the Ignitor chip to the ECU and the wiring to the coil packs. The only thing I can think of is the wiring for the coil packs is wrong. Anyone know where to get the wiring harness diagram for that part?