Help with intermittent stalling.

[nitro66669]

I have a 92 GT that I had to have towed today. Died after running for 20 min or so, killed the battery trying to refire it.

I've replaced all components of the ignition system and tested all wiring to clear a code 18. I even replaced the 22k ohm resistor. The stalling issue went away for a little while.

I'm still getting that code and now today I also got a code 96. Haven't started troubleshooting that yet. Strange thing is I can read the codes using the CEL, but it's not coming on even though its storing an 18 and 96 in memory. Also the radio frequently resets when I crank it. Any ideas? This car is killing me.

Everything seems to be related to serious wiring issues, but I just can't find any.

 

[nitro66669]

Update: Car fired right up this morning. Let it warm up, no problems. Checked TFI wiring to pins 4, 36 & 56. All good. Ran the codes a couple of times, 11 on KOEO, codes 12, 44, 94 & 18 on KOER. Smog pump is gone, so 44 & 94 are OK. Pretty sure 12 is a bad IAC (already cleaned it), and 18 on a brand new coil, TFI, & dizzy with good wiring. No sign of code 96 yet, but it hasn't stalled out either. Runs great, but kinda scared I'll get stuck if i test drive it. I'm totally lost.

 

[txstang84]

The radio resets while you're trying to start? Almost sounds like you have an intermittent power supply issue..like a corroded fuse link or bad ground...?

 

[txstang84]

If I read it correctly, 18 says SPOUT signal open, or spark angle word failure...dumb question maybe, but is your spout connector in? have you shot the wires for continuity? I think you may be correct on code 12, but if you've already cleaned it and there's no fix, maybe the iac solenoid itself is bad? If 96 is stored, then you might wanna check voltage at pin 19 engine running for 12v. If it's flaky, you might have dirty connectors, or a glitching fuel pump relay.

 

[nitro66669]

SPOUT is in, checked for continuity this morning and slobbered it with dielectric grease. Not so concerned with the code 12, at least not until I get it to stop stalling. It hasn't stalled since I reset the computer this morning, so the 96 is unconfirmed at this point. I'm going to replace the negative battery cable, engine strap and clean up the grounds first, then go from there.

My 5" autometer tach also reads the wrong RPM. I'm wondering if that's related to the code 18. It's about twice what it should be, but every now and then it will read the right RPM.

 

[txstang84]

You said you have a new ignition parts installed correct? It would make sense for the tach and rpm disagree to be related to code 18, but sometimes I've seen tachs go nutz from poor connections-do you happen to have an MSD, or just stock ignition?

 

[nitro66669]

Stock ignition. For the first 2 years I had the tach, I screwed up and ran the 12+ power feed off the hazard switch. I was turning the tach on and off with the blinker and didn't realize it, so I might have messed up the tach. Pretty sure it likes a constant 12 volts...

 

[jrichker]

Code 12 -Idle Air Bypass motor not controlling idle properly (generally idle too low) - IAB dirty or not working. Clean the electrical contacts with non flammable brake parts cleaner at the same time.

Recommended procedure for cleaning the IAC/IAB:
Conventional cleaning methods like throttle body cleaner aren’t very effective. The best method is a soak type cleaner used for carburetors. If you are into fixing motorcycles, jet skis, snowmobiles or anything else with a small carburetor, you probably have used the one gallon soak cleaners like Gunk or Berryman. One of the two should be available at your local auto parts store for $22-$29. Take the solenoid off the body and set it aside: the carb cleaner will damages some types of plastic parts. Soak the metal body in the carb cleaner overnight. There is a basket to set the parts in while they are soaking. When you finish soaking overnight, twist the stem of the IAB/IAC that sticks out while the blocker valve is seated. This removes any leftover deposits from the blocker valve seat. Rinse the part off with water and blow it dry with compressed air. The IAC/IAB should seal up nicely now. Once it has dried, try blowing through the bottom hole and it should block the air flow. Reassemble and reinstall to check it out.

Gunk Dip type carb & parts soaker:

The code 12 could be the source of your stalling problem


Code 18 - SPOUT out or wiring fault - look for short to ground in SPOUT wiring going
back to the computer. Possible bad TFI.

This code can disable spark advance and reduce power and fuel economy.

Remove the passenger side kick panel and disconnect the computer connector.
There is a 10 MM bolt that holds it in place. Disconnect the TFI module connector
from the TFI and the measure the resistance between the yellow/lt green wire and ground.
You should see greater than 100 K (100000) ohms.
Next measure the resistance between the yellow/lt green wire on the TFI module connector and
Pin 36 on the computer connector. With the SPOUT plug in place, you should see less than 2 ohms.

The following is a view from the computer side of the computer connector.

Diagram courtesy of Tmoss & Stang&2birds

 

[nitro66669]

I replaced the negative battery cable, added an extra 4 gauge to the block and replaced the ground strap. Checked all grounds in the EFI harness. Pulled the computer out to check the connector and the pins. Also ran the above tests again for the igniton.

No change, it almost seems like it runs worse. Not that I don't expect that with the code 12 flying around, I'm concentrating on the code 18 for now.

I don't know if I mentioned it earlier, but when the car stalls it fires back up and dies right away. Have to wait a little while before it'll run again.

 

[jrichker]

Check or recheck the ignition timing, be sure to remove the SPOUT when you do it. Your problem symptoms mimic what I saw when I wasn't careful about setting the timing and had too much initial advance. If you have one of the fancy timing lights with the dial on the back, be sure it is set correctly

 

[nitro66669]

First off, thanks for all the help so far. I feel like I'm making progress.

I replaced the IAC, code 12 is gone and it runs way better. I reset the timing to 10-12 degrees (it's hard to read the timing marks), still getting a code 18. I even swapped out a known good TFI module. I'm going to check tonight if it's even advancing the timing. What's the next step if everything checks out OK in the ignition system? Replace the computer?

 

[Blown88GT]

...I don't know if I mentioned it earlier, but when the car stalls it fires back up and dies right away. Have to wait a little while before it'll run again.

Any progress here? Mine is now doing the same thing. 1 day it works the next day it doesn't. Different codes all the time.We know it's not fuel, now, remote gauge shows all normal at startup, idle or under load.
Am looking for a chart of "salt & pepper" connectors pinout to EEC pinout to make ohming out easier. May have to generate my own. The TMoss wiring diagram doesn't show the two 10-pin connectors.

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif
http://oldfuelinjection.com/?p=6

 

[nitro66669]

My problem turned out to be a bad computer. I was getting no timing advance at all, plus the code 18. Well, I haven't really tested it yet to see if it still dies or not, but I'm definitely getting timing advance now.

I got a reman A9L from Autzone for like $90.

 

[Blown88GT]

Thanks for the reply. I'm 99% sure it's an electrical problem. I'm thinking it's the 60-pin connector; it's very similar to the notoriously unreliable "salt & pepper" connectors. Every time you unplug the old & insert the new, something changes (it shouldn't). EEC's just don't go bad for no reason. I've got a newly remain A9L & a spare on the way. I opened up the 10-pinners today & they look brand new inside, right down to the dielectric grease. Ford electrical is almost as bad as the older British cars, i.e. Jaguar XK series. All Ford connectors are junk. I used to have access to Bendix 38999 series Milspec circular connectors. They are 100% reliable, in fighter aircraft, spacecraft, etc. If it means anything, I'm an electrical engineer.

 

[jrichker]

Thanks for the reply. I'm 99% sure it's an electrical problem. I'm thinking it's the 60-pin connector; it's very similar to the notoriously unreliable "salt & pepper" connectors. Every time you unplug the old & insert the new, something changes (it shouldn't). EEC's just don't go bad for no reason. I've got a newly remain A9L & a spare on the way. I opened up the 10-pinners today & they look brand new inside, right down to the dielectric grease. Ford electrical is almost as bad as the older British cars, i.e. Jaguar XK series. All Ford connectors are junk. I used to have access to Bendix 38999 series Milspec circular connectors. They are 100% reliable, in fighter aircraft, spacecraft, etc. If it means anything, I'm an electrical engineer.

Nothing is as bad as Lucas electrical components. You would think that guys that were bright enough to invert radar could make a decent automotive electrical system, but they just couldn't seem to do it right.

 

[Blown88GT]

Nothing is as bad as Lucas electrical components. You would think that guys that were bright enough to invert radar could make a decent automotive electrical system, but they just couldn't seem to do it right.

Seen it countless times in my career. Research & Development, some can do one, some can do the other, but few can do both. One place I worked, we had more Dr's than a hospital, lots of really good ideas, but none of them knew how to implement any of them. That was my job, take the impossible idea & make it work. The only one that could afford these things is the US Government.