[GeneralGuy]

Hello All,

Got a bit of an issue with my 1989 GT here that just popped up. Basically, the car runs pretty nice when cold, but once it's had a chance to warm up, I get a constant check engine light with a wicked fume (smells alot like gas) smell from the exhaust. Here's the background:

I was getting code 66 a little while ago for my KOEO tests, which is a low voltage readout on the MAF, so I went out and bought some MAF cleaner, which would clear it up for a bit, and the car would drive all nice, and then the CEL would show up again. I believe I can litterally feel the car get weaker at higher throttles with it on, and the only other codes where emmisions related.

Long story short, I bought a new MAF from NAPA. When I say new, I mean it was a remanufactured part. It looks exactly like the MAF I had in the car previously, same sampling tube and all.

So I pop this sucker in, runs rich as hell. Run it a bit, turn the car off and on, and it seems pretty good. Runs fine for a bit, then gets nastly again, runs worse, etc.

Ive cleaned this new sensor already, threw some dielectic greese on the plug, checked to make sure all the intake tubing was fastened well, etc, and it still does it. I ran codes, here is what I have for KOEO:

67 - Park Neutral Position Switch Circuit Open; A/C On -Manual (O), Manual Lever Position Sensor Out Of Range/A/C On (M,O), Clutch Switch Circuit Failure (M)
81 - Secondary Air Diverter Circuit Failure (O)
82 - Secondary Air Bypass Circuit Failure (O)

And for memory codes, I only have:

31 - EGR Valve Position/Pressure Feedback EGR Circuit Below Minimum Voltage. 0.24 volts (O,M,R)

My mods are listed in the signiture, but basicly it includes a bunch of bolt on intake and exaust stuff to the best of my knowledge (I didn't actually do those mods), nothing too fancy. Emmisions equipment has been more or less disconnected. I can deal with some smell on the exaust but this is seriously aweful smelling and it seems to be effecting driveability, cause again it drives fine when cold, and it has never smelt or ran this poorly, even when it limp home mode.

The only other thing I can think to try is to disconnect the battery for a while to drain everything it the system. Is this a must do?

Anyways, thanks for any help!

 

[89coupe]

You need to run the KOER test, but code 67 will not let the test start. Did you even try to run the KOER?

 

[GeneralGuy]

I've tried running KOER tests but as you suggested it does not run it. The car is in neutral and the AC is off when I ran the KOEO test, and I'd love to check if the neutral switch is even in the car but I haven't the slightest where it is. That said, I haven't tried running it today as its 11:30 at night, lol. I'm sure the neighbors would not appreciate it.

That said, the car USED to be able to run them, but that was over half a year ago. I haven't tried to run it in quite some time, and plenty of work has been done durring that time. You'd imagine that any engine running issues would be stored in memory, but maybe not. I'll try running one towmarrow and report back.

In the meantime, any ideas?

 

[89coupe]

There is a white plug on the Clutch pedal switch, it has two terminals in it. Just use a jumper and connect the two. This will cause a permanent In Neutral Condition, and the Codes should flash. Or you could try and hold the clutch down while you run the KOER test, but if you let off of the clutch, the test will abort, so it has to be held down till the codes are done flashing.

Code 67 can cause idle issues, as the ECM changes the idle strategy for when the ECM thinks it in gear. Ive attached a picture of the Plug your looking for if the Hold Clutch down method doesnt work.

 

[GeneralGuy]

The idle does change when the clutch is released and depressed. Idle is usually a bit higher and "stronger" i would say when the clutch pedal is pushed down. Releasing it makes it got down a bit. Dunno if this helps really, just thought I would mention it.

I will be trying to run the KOER test later today.

 

[GeneralGuy]

Okay, KOER time!

So as guessed I had to keep the clutch floored the whole time, and when I say floored, I mean it. Anything more than a slight movement off the floor would cause the test to abort. Either way, I tried to run the KOER a few times when the engine was cold, and it would start and then stall shortly after. After about 5 tires, it caught itself and ran the test.

So, cold engine KOER gave me (in this order):

21 - Engine Coolant Temperature, ECT Sensor Out Of Self Test Range. 0.3 to 3.7 volts(O,R)
94 - Secondary Air Injection Inoperative. bank two, driver side (R), Torque Converter Clutch Solenoid Circuit Failure (O)
44 - Secondary Air System Inoperative. bank one, passenger side (R)

Interesting, nothing too major, cold engine is probably why I got the code 21. I put some dielectric grease on that sensor, reseated it, and went for a drive. Car acted the same way, crap just after getting started, fine when driving around a bit. Let it idle a bit, did fine for about 2-5 minutes until the idle drops like 250rpm (so from about 750rpm to about 500rpm) and it runs like crap again.

So I killed the engine, let it sit a bit (like 10 minutes), then did another KOER. That time, I got code 11, which means it all passes.

Here are a couple other things I did and noticed:

When my idle was really low after the first KOER, I pushed down on the salt and pepper shakers, and the idle picked up nicely for a bit. Not sure if it was coincidence or because I had a bad connection. I also put some dielectric grease on the TFI (the plug just below the distributer cap, I think thats the TFI?) before reseating it. I couldn't get a check engine light to show after all that. Still kind of smells though, still a bit choppy on off throttle when moving.

So, since I have no faults now for some weird reason, despite the fact it still smells, here is my last question I guess. Should I or shouldn't I put some dielectric grease on my salt and pepper shaker connectors? I know there is alot of pins in those and not sure if I should be concerned with shorting them or something weird by using too much grease.

Thanks for any help!

 

[89coupe]

Di-electric grease, and use a small mechanics pick to spread the male terminals just a tad. Usually when no codes are present, and symptoms like you get are present, the Salt and Pepper connectors are a good place to start.

 

[89coupe]

Di-electric grease, and use a small mechanics pick to spread the male terminals just a tad. Usually when no codes are present, and symptoms like you get are present, the Salt and Pepper connectors are a good place to start.

 

[89coupe]

Di-electric grease, and use a small mechanics pick to spread the male terminals just a tad. Usually when no codes are present, and symptoms like you get are present, the Salt and Pepper connectors are a good place to start.

 

[GeneralGuy]

Alrighty, did a bunch of stuff! And no real change.

Opened the salt and pepper shakers, used some dielectric grease, put them back together (did not see your post until after all this, so didn't spread the connectors).

Hook it back up, start it up, no real change. Go for a drive, car got really bad running for a bout a second, got CEL, then went back to being decent. Grabbed KOEO codes, looks like it ended up shorting a few circuts for a moment. Cleared codes, tried KOEO again, 67, 81, 82, so nothing besides emmisions issues and my clutch sensor.

KOER is aces, gets an 11.

Still same symptoms. Periodic CEL when driving, surges after the "let down" after you let off the throttle. Like you accelerate, you let off the throttle, it does its thing where it brings the RPM down gentely, then it sort of surges, where it has even power then the power cuts and then comes back, giving it a herky jerky feel. Also at really low revs in 5th gear (like 750 or so RPM, around where idle would be), the car gets bad, and I hear some mechanical noises, almost sounds like a knocking.

I've dumped some high grade gas in it (usually I run regular), and drove around a bit. Unable to grab codes at this time again but Ill try to do so. Still get CEL, but maybe its just emmisions stuff kicking in and relizing it has nothing to do.

Btw, I perodicly get a loud ticking noise from the car at autocrosses if I run it hard in first gear, sounds like it might be valvetrain noise. Seeing as how I'm running out of codes to chase, might a bad valve or valve spring cause a bit of a bad smell/bad off throttle behavior?

 

[89coupe]

Are you running the Smog pump?

 

[GeneralGuy]

Yup, the smog pump is installed. However, there is no space in the exhaust for it, so it just kind of... runs. There is a metal pipe with a fitting on the end of it that comes from behind the intake that is not hooked up either, but it sits there blowing hot air into the engine bay. Might be related, not sure.

 

[89coupe]

Sounds to me like you talking about the crossover tube on the back of the heads. Am I correct?

 

[GeneralGuy]

Honesty I have no idea if it is. Ill try to describe it better:

It is a metal tube that runs from somewhere behind the intake drivers side, no idea from where exactly. It comes over to the passenger side, where it bends towards the front of the car. It is well underneath the intake rubber tubing that runs to the TB from the MAF. It stops shortly after that, and has some kind of fitting on the end of it. The fitting looks like it is designed to have another tube hooked up to it, as it has a lip on it like some kind of rubber line was supposed to be on it. The hole in it is about and inch or so in diameter. Hot air blows out of it when the car is running, but I use hot relitive to the outside air. Its probably about as hot as the rest of the air in then engine bay. Makes a good amount of noise too, sounds like something "chugging" or ticking almost.

 

[89coupe]

Plug it up and see how it runs. If its what I thinks it is, when its working correctly with the Smog pump, the pump is injecting air into the Cylinder head. Which kinda means you have an exhaust leak.

 

[GeneralGuy]

Awesome, I'll give that a try! Just wondering, any suggested method of plugging that guy up?

 

[89coupe]

Its metal so one way is to have it welded up, the other is just to fit some high temp rubber hose on it, with some kind of plug in the end, or take the crossover tube off, and find some 5/8 11 thread plugs to go in the back of the heads.

 

[GeneralGuy]

I tried a temporary block on that pipe, few things I've noticed:

One, it sucks in air rather than blows it, so thats my bad.
Two, blocking it seems to do pretty much nothing. Gunna try it again in a bit to see if I can get a batter seal though.

Question, is there any downside to running the car with a jumper on the ECU clutch sensor to see what it happens? And no, I would not jump the ignition connector, just the ECU one.

 

[Bullitt95]

Hello All,

Got a bit of an issue with my 1989 GT here that just popped up. Basically, the car runs pretty nice when cold, but once it's had a chance to warm up, I get a constant check engine light with a wicked fume (smells alot like gas) smell from the exhaust.

That sounds like you have at least one bad O2 sensor.

 

[89coupe]

I tried a temporary block on that pipe, few things I've noticed:

One, it sucks in air rather than blows it, so thats my bad.
Two, blocking it seems to do pretty much nothing. Gunna try it again in a bit to see if I can get a batter seal though.

Question, is there any downside to running the car with a jumper on the ECU clutch sensor to see what it happens? And no, I would not jump the ignition connector, just the ECU one.

No downfall for jumping the Clutch connector. Once you block everything off, clear codes and go for a test drive, your probably still gonna have a CEL since the smog system is not working propery, but should cause no drivability problems