vbatla

Thanks! I will check that out as well.

oups59

I have about the same issue. I changed the O2 sensor (2 wires were cut)

I checked the temp II sensor and it was a bit out of range went hot. Changed it also.

The car runs a bit better but I still have the misses between 1500 -3000 RPM

The search continues.

vbatla

I cleaned the Hot Post along with the muitipin connector. The Temp ll appears to be OK. With the car hot, I've bridged the temp ll connectors as well as leaving them open. Still have the same issue. I also tried disconnecting the O2 sensor. Same result. One thing I've noticed is that when I push the accelerator down slowly about half way, there's no miss. It I press it down further, it starts. If I back off the accelerator a little it goes away. The car has 237,000 miles on it. Does that sound like bad injectors?

GlenL

Sounds like bad wires. At least a good try. Someone, somewhere, sells just the wires as the ends unscrew. I should know as I bought them. Much cheaper than full sets and made a sudden and noticible improvement on my 944. Had no reason to think that was a problem beforehand.

And having the injectors cleaned and tested isn't a bad idea. Had my 944's done recently by Witchhunter in Washington. Cheap and quick. New o-rings, repainted, etc.

How about changing the fuel filter? That may increase pressure which is a good thing.

GlenL

Sounds like bad wires. At least a good try. Someone, somewhere, sells just the wires as the ends unscrew. I should know as I bought them. Much cheaper than full sets and made a sudden and noticible improvement on my 944. Had no reason to think that was a problem beforehand.

And having the injectors cleaned and tested isn't a bad idea. Had my 944's done recently by Witchhunter in Washington. Cheap and quick. New o-rings, repainted, etc.

How about changing the fuel filter? That may increase pressure which is a good thing.

GlenL

Stupid Internets. Apparently it sounds like bad wires.

Rod Underwood

I just solved a very similar problem on my son's 89 corvette.

He had three subpar injectors and I thought that was the problem, but after going through injectors, rotor and distributor cap, wires, plugs, O2 sensor, it turned out to the the coil. Would run OK'ish when cold, but missed at a steady speed under no load.

I remembered in retrospect an old Chevy that did exactly the same thing, and it was also the coil. Might give it a try by switching out if you have a couple of known good coils in the area.

Good luck,
Rod

SteveG

Just came in at the end here: Along with Rod pointing to the coils, check for corrosion on coil wire connections, both ends. I had something similar at speed (I couldn't hear missing, but there was a "no-power/very slow accel condition") and cleaning the green corrosion on one wire, corrected it on the '85. Found some on the GTS too, which had been a CA car. Even though there are tight rubber sleeves, something about the coils generates this non conductor junk.

vbatla

Thanks for all of the posts. Had to replace the a-frame today. Very worn ball joint. Back to the ignition issue tomorrow.

vbatla

I noticed that once I drive the car for about 30 minutes, the condition begins. If I go from city to Highway driving, and the temperature of the engine comes down, the condition is still present. Smelling more and more like a coil....

vbatla

One last thing that I forgot to mention; I noticed that the intake tubes are full of cracks. Some are pretty large. I wonder if that could that be part of the problem? I'll look them over and try to seal them to see if that makes a difference.

SteveG

I had to go back to the beginning to see your MY, pls put that in your sig line. Cool air is denser and that is the purpose in the design, so I would tape or replace the tubes, but I don't think the intake cracks will cause this severe a result.

vbatla

I'm going to tape up the cracks and see what effect that has.

Lizard928

dont bother taping up the tubes,

go down to your local tuning shop and get some 2" silicone tubing and replace the old hoses with it. Just take an airbox to ensure fitment. You will need some larger sizes as well for the central tube.

As well with this issue, if you do now know when the O2 sensor was replaced, replace it. Same with the MAF, if you know the MAF has been replaced, do you know if the CO level was set either via Porken's method or via the factory manuals. If you replace the MAF ensure that the CO level is set after replacement.
Do these first and report if the problem still persists.

HTH

Rod Underwood

Well, what's the latest. Inquiring minds want to know? This will surely happen to me sometime.

Rod