Thanks for hanging in there with me PA. And thanks for jumping in Poorman.

Today I cleaned the throttle body out, disconnected and sanded clean all ground wires I could find. I tried finding the specific ground in the picture but on my engine it is not there.

I tried to listen for the fuel pump but couldn't hear it. I tried from the back seat and from the filler neck with the cap off. I don't think it's the pump because you can even smell it running rich.

I'm definitly getting spark at all the plugs and I didn't change the cap and rotor cause it had been done within the last year and looked clean with no corrosion.

I tried to get the engine to stall by jiggling the key in all directions and it would not.

The only lights I remember coming on were the oil and battery. I've only gotten 1 CEL and it was a code 1 for o2 sensor. Ever since resetting it hasn't come back.

Two things I noticed today was a hiss or hum from above the intake plenum. And it would stall almost immediately if I turned the ac on.

I purchased a multi meter today so if there is any test I should perform let me know. Tomorrow I will start withe testing the ignition switch and ingniter as those and the icm are the only things left in the ignition system.

Thanks again. Let me know what you think.

 

You should hear the fuel pump turn on for only about 2 seconds when you first turn the key to the II position and do not try to start the car. It turns on while the check engine light turns on. Once you hear that sound, then you can listen for that sound to determine if that sound is there or missing when the car is not starting.

When you changed the spark plugs, how did the old ones look?

Also, when the car stalls out and will not start, unplug the electrical connector to the distributor. With the key in the II position, the blk/yel wire going to the distributor should have 12V to body ground. I always use the valve cover bolt for body ground.

Another test you can try is when you turn off the car, pull the vacuum hose to the fuel pressure regulator. If you notice a strong smell of gasoline, then you have a problem with the fuel pressure regulator.

 

Ok I will check for the pump again and more carefully. The plugs, wires and cap were all replaced under a year ago. The plugs were NGK V groove, they looked clean and had a light brown color to them. The wires were cheap no-name so that why I went ahead and replaced them with the quality NGK wire set, and I thought new plugs couldn't hurt either.

I want to quickly go over the symptoms again.

Starts fast and smooth everytime (except 2 times it stalled in traffic)
Fast idle is smooth during warm up.
After about 2-5 minutes it starts to miss at idle once the rpm have come down.
After warmed idle bounces between 900rpm to under 500rpm.
Idle stays iradic and sometimes stalls.
AC turned on almost always stalls it.
Turning the wheel left and right causes rpm to drop.
Engine sounds and feels smooth revving it past 1500-2000rpm

I will follow up with the results of the further testing you have suggested.

 

Ok the last desciption of the issue helps a lot,

I see you cleaned the TB. Have you clean the IAC or the FITV? I did a quick re-read and didn't see that in there.....If I could only do one, the IAC. This allows more air and that into the engine to help it with loads, ike when you turn on the AC.

 

After a few more tries I'm pretty sure I can hear the fuel pump kick on. Very hard with the chiming from the ignition.

Yes i cleaned the TB, IACV, and the FITV. I also tested the IACV today as the Haynes manual suggests. These were the results.

- 11.3 volts to the plug. Manual says battery voltage.
- 11.8 ohm resistance on the valve. Manual says between 8-15.
- IACV continuity was 0. Manual says 0.

So as I understand besides a small difference in voltage the valve checks out electrically. It could still have a mechanical failure inside right? When the engine stalls the IACV humms unroll you unplug it.

Another thing I noticed is when I had my meter hooked up to the battery voltage was 12.8v with the car off and 14.55v when on. As I watched it there would be major spikes in voltage as the car would stall. It would be idling fine with a steady voltage and all of a sudden the voltage would drop and the engine would drop rpm and start to stall. The meter would bounce from 1v to a high of 18.6v. If this fluctuation was transfered to the distributor it could cause the stumble??

I'll get to the fuel regulator next.

Let me know what you think. Thanks again.

 

SOLVED!

I want to thank everyone who helped on this. I'm a complete NOOB and I'm red in the face for the fact I have to admit I overlooked the most basic part.

When I did my initial inspection of the cap and rotor I did not look close enough. There was line of corrosion on the bottom edge of the rotor lip. When looking from the top you could not see it but when looked at from upside down it was visible. Also after comparing a new cap to the old I was able to see that the tips inside of the old one were about half the size.

So now after cleaning the TB, IACV, FITV, and replacing the plugs, wire, cap, rotor, and coil it fired up right away. Idle went to 1600 for a couple minutes and then slowly dropped to 800 with no hesitation. Car idled and never dropped rpm. The true test for me was turning on the AC, it blipped less than 100rpm and went right back. Test drive showed night and day improvement with no hint of bucking at high speeds.

Only time will tell but in my mind it wasn't drivable yesterday and today I hit highway speeds so thanks again everyone. Now time to spend the $75 credit at the junk yard for the IACV I bought today.

 

Glad you got it! Hope the two cents helped......