CRXtoRX7

OK, first of all, I have searched, and tried about everything. Myself, and two other rotorheads can't figure it out. My car is possessed.

Story:
My car has 260 miles on rebuild, succeeding a previously 1000 mile rebuild (first time, come on..). Throughout both rebuilds, my car could never pas 3800 rpm, because the secondary injectors would not come on. We troubleshooted that for a long time, until we figured out that the previous owner had the FPR and FPD switched so that the regulator was on the primary rail and the dampener was on the secondary rail...dumbass... SO...I put the FPR on the secondary rail, and decide to eliminate the FPD with a Banjo bolt. We find a bolt that fits (about a CM too long, but it screws all the way in..) and drill it out so it functions as a banjo bolt (I have a real one to model from). So I go to put the rails back in, and drop a rail bolt into the LIM. OOPS. Take off the turbo and mani and get the bolt out. Put everything back together. And now comes the problem. I start it up and immediatly it dies. I can get it to run for about 5 seconds but it sounds really choppy and when i give it more gas it cuts out and i have to keep tapping gas to make it to the 5 seconds. Then its flooded. I have a cut switch and every time i try to start it takes about 15 seconds of burning off fuel, which is a lot longer than most i have seen. after some different stuff, i could nurse it around till it would idle really choppy at 750...(it used to idle at 1400) but now i cant get it to idle.

What I've tried:
-different fuel rails, but not new FPD, just the banjo bolt on both.
-4 different fuel injectors (had 4 720cc's and now have two 460's and two 550's)
-unplugging (independently) afm, tps, pressure sensor, S-afcII
-all brand new intake gaskets, everything tightened down.
-spraying with carb cleaner for intake leaks
-tried new fuel pump
-fuel filter blew clean and seems perfect(1000 miles old...)
-CAS is inserted properly, but timing is not set...we moved it around and no change in real problem.
-wiring at on position at injectors is ~12 and 0 per 2 wires an injector (which is right)
-fuel pump reads ~12 at on and ~11.8 while the car is at on or trying to rev.
-checked engine compression on cold engine(remember 260m on rebuild): F-80-80-80 R~65-70-70(battery was running lower)
-all vaccuum lines are connected, and everything else I could find.

All that I can think to check:
-TPS voltage
-remove banjo bolt and use FPD
-try different ECU or check individual pinout voltages
-pouring gasoline and throwing match and walking away.

PLEASE HELP ME...its been too long without my car running....

mods I think are in sig...

CRXtoRX7

sorry the thread is so long, but it should save some time asking questions and what not. Any experts out there have something else I can check?!

thanks,
Ben

WAYNE88N/A

Hook a meter to the AFM door input pin at the ECU, ground the other lead, turn the key on. What do you get? Should be about 4 volts. Now start the car, for whatever amount of time you can keep her running. What voltage do you get now? Should be about 3, depending on idle speed. If either of the above checks don't work, check the 5 vref output of the ECU. If it's good, start looking closer at the AFM. If there's no 5 vref where it's supposed to be, start looking at the ECU. Could be lots of things, but start here first...

This link may help...https://www.rx7club.com/2nd-generation-specific-1986-1992-17/troubleshooting-your-car-ecu-340578/

CRXtoRX7

well I borrowed an AFM that came off of a running car but had been sitting for a while, and the symptoms didn't change. I will still try checking the voltage though. How can I check on the ECU? Just turn the key to on and unplug the 3 connectors and check every pin, or do I need to check with them connected or what? And any links to see what I should be getting for each pinout. I am sure I could try a donor ECU from a friend in a few days. Anything else is greatly appreciated, and thanks Wayne..

Ben

CRXtoRX7

Ok found some interesting results.

Checked a couple ECU voltages.
(car was in on position, but I couldn't run the car since my fuel filter is off)

AFM = gave weird numbers. started at 2.5v and slowly dropped down while holding the two terminals in place. Every check after yeilded .1-.5v. I tried different grounds and no luck.

Vref = 5.1v
All injectors = 12.1v
02 sensor = like .2

Some notes:
When holding the leads to the afm wire and a ground, sometimes when i let go, a solonoid on the back of the UIM would click. I could do it pretty much on command...

The ECU (just in the on position) was getting pretty hot. Is there supposed to be an in-cabin ground? The only grounds i know of is the one from the wiring harness to the top of the engine (connected) and the one from the intake mani to the firewall(connected).

I checked my tps wire too, and I got like .2 or so. I set it to 1v at one point in time. Tomorrow I will try again after resetting it.

PLEASE MORE INPUT PLEASE!!

Thanks,
Ben

powrdby13B

i think ur sposed to check resistance on the AFM... there's a thread started by me from yesterday or two days ago that has some info on this...

WAYNE88N/A

All right, where to start...

Yes, you can check AFM resistances, particularly the pot, while the door is being moved, and compare to the FSM specs. Much like testing the TPS while moving it, same scenario- you're looking for dead spots or bad initial readings...

All right, Ben, it appears as if you don't quite understand voltage checks at the ECU. No big deal, I wrote that thread from the standpoint of someone who has at least a little understanding of basic electrical troubleshooting, and I realize a lot of you guys don't, but it would have taken me another two pages to get you up to speed, lol...

So, here are the basics. You don't have to remove ANY plugs from the ECU to perform voltage checks. And the little studs sticking up from the chassis near the ECU are electrically the same as that ground on the rear rotor housing. In this case, a ground is a ground is a ground...

Your first AFM reading sounds like you were reading a capacitive circuit, I don't know what the heck you could have been reading, though. Back through the ECU, maybe, or you were on the wrong pin/wire???

Your vref is good, your injector power circuits are good, and your O2 sensor won't read much until she's hot, so .2 is good...Looks like your taking the meter readings right, just can't figure out what's up with that AFM reading...

I've never noticed the ECU getting hot before, but it wouldn't surprise me, there are a lot of power transistors in that baby. Never put my tongue on it to check though, lol...

Don't mess with your TPS voltage or attempt adjusting it unless she's running at idle, and very warmed up...

Now, what was this clicking thing on the UIM? BAC, maybe? That wouldn't make much sense either, because she's not running. Could it have been one of the little colored-plug solenoids on the left side of the engine? If the meter's on voltage, you shouldn't be completing any circuits through the meter leads to make things click. Red lead on the ECU pin, black lead to ground, right? I can't think of any scenario where you would have both meter leads at two different pins on the ECU, unless you're using the black lead in one of the ECU's ground circuit pins (and there's no need to do that since you have a perfect chassis ground right beside the ECU)...

Do that AFM input again, and make sure you're on the right pin (leave the plugs on, and "backprobe"- use a paper clip or something if you can't get the meter probe into the pin). Meter to DC voltage, red lead at the pin, black lead on a ground. Key on voltage should be about 4v. If you have a buddy helping you he/she can push the AFM door slowly as you're looking at the meter- the voltage should fall gracefully from that 4v

CRXtoRX7

I actually do understand the testing process. I left all of the plugs connected to the ECU. For the AFM I inserted the positive lead into pin E2 and the negative to a bare metal area on the chassis. The same one I used to test the others. Everything gave a standard reading except the AFM. For the clicking, I know it was that solonoid on the back of the UIM(I think it was the BAC). I heard it while first testing, then I had my dad test while I listened. I located the sound, then put my hand on it and could feel it clicking, and it was hot(i hadn't started the car the whole day). I don't understand what was going on, but I was for sure testing E2(G/R I think) and all of that was right. I'll go try it again, and see with the door being moved.

About the TPS, isn't it supposed to be at 1v regardless of being "on" or actually running?
Ill check that voltage at the actual sensor.

Thanks,
Ben

CRXtoRX7

well I tested again...this time with a friend.

AFM = this time is hit 3.5v and then fell to a stop at .16v.
The clicking still occurs on that solonoid(little cylinder on the firewall side of the UIM, has an electrical plug that connects to the harness under the manifold).

Next, we did a resistance check on the wire. We unplugged the ecu clip, and pulled back the boot on the afm plug to see which wire it was. I touch one lead to the green w/blue stripe at the afm, and the other to the plug end at the ecu. No resistance. We tried a couple times, then tested the multimeter and it worked when touching the two leads together, so it isn't the mm. So maybe I have a damaged wire? Can I just run a new one through the fire wall and solder in before each plug?

Next, I tested the TPS again(at ecu) and this time it was at a steady 3.96v. My friend moved the throttle, and it would go from 3.96v to 4.7v and back smoothly. Once the car is running, I will reset it to 1v. I don't know how it got so out of whack.

Thats all for the testing today.
If anyone else has any ideas or help, please chime in!

Thanks,
Ben

CRXtoRX7

anyone, anyone?

CRXtoRX7

Ttt

WAYNE88N/A

The TPS, if you were reading the narrow band one, is so far off that it in itself would explain the 3800 thing, I would think. You must remember also that the engine must be warm (the fast idle cam linkage must NOT be interfering with the throttle linkage)...

AFM readings are definetly screwy. The numbers you gave would mean that the ECU is seeing something close to idle, then all of a sudden seeing something beyond WOT. The funny thing is, if you're getting voltage (ANY voltage) at the ECU pin with the plug hooked up, the wiring must be good. If you had an open between the AFM and ECU, you should see 0 volts. If your fingers were touching the meter leads, that might explain the .16v instead of 0. Go ahead and run the new wire, after first making sure that the connection inside the AFM plug is good...How's your 5 volt ref going to the sensors? You can check that at the ECU also (plug on).

CRXtoRX7

alright, well it is pouring out today. Ill recheck the afm wire and make sure i dont touch the leads, but i doubt that is it, since none of the others did it, and the afm tested like that 2 separate occasions. I think what I am going to do is just test every wire with the car on, then test the important ones with the car running. Too bad its raining today, ill check on it tomorrow.

Ben

HAILERS

Is this a turbo motor in a non turbo car??????

If so, just which EM (emissions) harness are you using?

The solenoid on the back of the throttle body is for power steering. It;s called a air supply valve, I think. Disconnect its plug is my recommendation right now for that item.

The tps should read approx 1 volt when the engine is HOT./warmed up completely.

Do what you said.....ohm out each one of the afm's wires from point to point with the ECU connector off and the afm connector off.

Again, what harness'es are you using? All turbo? All non turbo? Half and half?

What series afm and what is the ECU number?

CRXtoRX7

yeah it is an s4 turbo engine in an s5 gtu chassis. About the solonoid, I had been wondering what it was, I disabled the power steering so I will just disconnect that. Tps hasnt been checked with the car warm, but I will do that soon enough. The wiring harness and ecu is all 332 s4 TII. Ill check on the AFM tomorrow. Thanks for the response HAILERS.

CRXtoRX7

Ok I checked some things and pinned out the whole ecu (only with car to ON position)

AFM says H010-1 on it

ECU pinouts:
(i tested in order of connector 3, 2, 1)

pin ||| (v)olts
-------------
1a .03-.08bouncy
1b .02
1c .02
1d .06
1e 11.9
1f .65
1g .09
1h 11.6
1i 11.8
1j 5.32
1k 11.8
1l .02
1m 1.14
1n .64
1o 11.6
1p .64
1q .64
1r 4.02
1s .02
1t .64
1u 4.34
1v 0
1w 11.9
1x .19
------------
2a 5.01
2b 2.26
2c .02
2d .03
2e high then falls to .16 while jumping around
2f .04
2g 3.96
2h 3.84
2i .02
2j 2.55
2k .6
2l 4.26
2m .76
2n .01
2o 0
2p 0
2q .18
2r .02
----------
3a .02
3b 0
3c 11.95
3d 11.96
3e 11.96
3f 11.95
3g .02
3h 11.96
3i 11.9

I haven't compared them to what they should be yet...but i think some still seemed a little whack. Let me know what you think

Ben

CRXtoRX7

oops left off 3j - 11.96

CRXtoRX7

and i didn't follow any of the directions for warmed up, self diagnosis turnon or anything. Car was just in "on" position.

CRXtoRX7

I have the afm problem figured out. I had my SAFCII tuned to 720cc injectors all the way around, so when i put in the 460's and 550's to test, I unplugged it so the 460's wouldn't be seeing -20 percent. When I plugged it back in, the AFM read 3.96v solid. So I put back on the fuel filter and made sure there were no leaks, and then tuned the safc to stock. I tried to start the car and pretty much same symptoms. Turn it over with pump shut off...it stutters and tries to start for a long time, then I turn on the pump and it catches and i can rev to about 1.5k rpms then it completely cuts out and dies. I do it again, and again, and one time i rev it to 3000 for like 2 seconds before it dies. I look out behind my car and behind each N1 is fuel/black gunk splatters for about 3 feet by 1 foot wide. My car is running deathly rich on 460cc primary injectors...HOW IS THIS POSSIBLE!!! I think my next plan of action is to switch back to my old FPR with the presumption that the fpr is stuck closed and creating really high fuel pressure?? Then im going to try putting my FPD back in instead of the bolt. and if neither work, try switching the FPD and FPR to the wrong rails again, since atleast it ran that way perfectly (minus the no secondary injectors working).
Any other ideas...? anyone?

Ben

CRXtoRX7

oops...double.

CRXtoRX7

news:
finally after some revving and holding it at 3k after a couple tries, I got it to idle at like 500 but it was going up and down really randomly...500 choppy, 1100solid, 500,900, 500........then i checked the tps. Still 3.96. I lowered it until the spring was loose which brought it to 1.5v and it now idles at 2000 fairly steady. I checked my afm voltage here, and it is at 1.5v at 2k. I am going to mess with the idle set screw and then try to readjust the tps, and see where that gets me. One of you 40000 board members can feel free to chime in!

Ben

CRXtoRX7

I just drove it
it is fixed.

The TPS was the problem all along.

Thanks for the couple who helped.

YAYYYYYYYYYYYYYYYY

-Ben.