[ScottK]

Hiya,
My 90 RS V6 began cutting out briefly (but not stalling) on acceleration, after idling (at a stop light), after 10-15 mile highway trips. The heavier I got on the gas, the more likely it would cut out. It would not necessarily repeat this behavior during the remainder of the trip. The radio would pop, the guages would dip, and the car would miss a few strokes. It slowly began doing this on shorter and shorter trips. I did a cap/rotor/wires/plugs tuneup and while the engine sounded better, it showed the symptoms after a short test drive. I sat in drive and while sitting at idle the car stalled completely. I got the car home and while shifting into reverse (from a stop) the car died again. I have a new fuel filter I intend to install, and I still need to set the timing, but while my gut feeling tells me its the fuel delivery system (maybe the pump?), I can't help but wonder why the problem got more severe after the tuneup. Any help would be greatly appreciated. Check engine light is NOT on, but does flash when the car cuts (as expected)
Thanks

[Tom Mobley]

I think you're right, put a pump on it. My wife's driver, an 88 Celeb was doing this same stuff except for the radio pop, I put a gauge on it it would only make 9 lbs fuel pressure and it took awhile to get up to 9. Fuel pump fixed it right away.

No fun pulling the tank in a Camaro.....

Tom

[ScottK]

Thanks Tom,

Appreciate your reply...
Last time I had to pull a tank was on my first rebuild disaster, a 65 Stang cvt w/a stock 4 barrelled 289. Had to refab every corner of that &*%%^#! unibody (rail rot at attach pts). It's a wonder the thing hadn't folded in half...
Something tells me that the Camaro tank pull isn't just 4 ez access nuts holding two straps eh? Done it yourself???? I'd owe ya for a quick list of tips, gotchas or lookout fors..

[Tom Mobley]

It's been awhile back, but the way I remember it you have to drop the exhaust to get the tank out, and drop the rear axle to get the exhaust out.

Like I said, it's been awhile (6-7 years) so it will be worth your while to look up in a service manual to make sure I'm not dreaming.

There may be a production code on a tag attached to the pump wiring harness, many GM's are like this. I did an 88 Celebrity the other day, had to have the code to get the right pump at the parts store. bummer, out in the parking lot, crawling around under a car I didn't want to work on anyway....

[ScottK]

Hiya,
Did a fuel filter xchg first before digging in to do the pump replacement just to check. After a 10 mile test drive I stalled the car by getting heavy on the gas. This time it wouldn't restart. It wouldn't even crank. I had trons at the guages, accessories & headlights. Left the car for 5 hours or so, came back & it fired up on the second stroke as usual. It obviously ain't the fuel pump. The only other thing I've had done to the car in the last year was a tranny mount. ANY help would be appreciated, I don't know where to start with the multimeter and I'm on a really tight budget..
Thanks.

[Robert B.]

Scott,
Did you ever get your problem solved?
I have an 89 Camaro that had an extremely similar problem. Turns out the answer was replacing the Mass Airflow Sensor.
I have a theory about why it fails in the first place. I'm very curious to talk to anyone who has this part fail.
My theory is that the part fails because of noise in the electrical system generated by bad spark plug wires that are arcing to the block.
I did not notice the connection between the two untill the second time it happened.
As I was driving one day last week, I noticed static in my FM radio that had never been there before. Within 2-3 days the car was chugging and stalling. My first thought was "bad spark plug wires". This would cause the radio static and engine trouble as well. I opened the hood at night and looked around the engine in the dark and sure enough I could see at least 3 plug wires arcing to the block. The next day I replaced all the wires, and while it did get rid of the static, the chugging and stalling remained.
At this point I immedieately went for the diagnostic link under the dash, shorted pins A and B and waited for the trouble code... yep 34... translates to (Mass Airflow Sensor). That fixed it. No more chugging or stalling. But I thought it was very strange that the MAS would fail right at the sametime my plug wires did. But if you look inside the MAS you'll see a small electronic circuit that makes up the sensor and it occurs to me that the high frequency- high voltage noise thats produced by arcing to the block may just knock out the small circuits in the MAS.
So I'm quite curious to know if the MAS was your problem?
Thanks,
R. Bobbio

[ScottK]

After the car sat for 2 weeks I drove it down to a garage to get it looked at. The problem has yet to reoccur. I think there may have been some schmudge in an injector.
Was check engine on? I'm assuming so. Mine never was.

[LAYDBAAK]

I HAD A SIMILAR PROBLEM WITH MY 90 RS. TURNED OUT THAT I HAD A BAD ELECTRICAL HARNESS. ONCE IT WAS REPLACED THE PROBLEM WENT AWAY. HAVE ALSO NOTICED THE CONNECTION BETWEEN BAD SPARK PLUG WIRES AND THE MASS AIRFLOW SENSOR. I ALSO CHECKED THE ERROR CODES AND GOT THE SAME RESULTS. REPLACEMENT OF WIRES AND MASS AIRFLOW SENSOR CORRECTED THE PROBLEM.

[ScottK]

In case it wasn't clear, the only repairs I made to my 90RS was the wires/plugs/cap/rotor tune up, after which the problem still existed. When I arrived at the garage I couldn't get the car to stall the way it had been. Funny how intermittents never EVER repeat in front of a shop mechanic. Car has been idling a little rough at times lately though.

I'm still not clear on one thing though; did either of your vehicles have the check engine light on while this problem existed?

[Robert B.]

Scott,
Yes my "Service Engine Soon" light was on.

Are you aware of the diagnostic connector under the dash and how easy and helpfull it is in finding car problems? I wasn't for many years.

Consult your car manual to verify this is the same for your model year, but if you look under the dash, to the right of the steering wheel there is a removable plastic cover. Pop it off and you'll find a multi-pin two row connector. If you get some clip leads or even a pair of needle nose pliers and short the top right two pins, then turn the key to the RUN position, the "Service Engine Soon" light will flash trouble codes at you if the on-board computer finds something wrong with the engine. Then get out your manual to find out what the trouble codes mean.

Also, the next time you find the car stalling on you, try this.

Pull the connector on the Mass Airflow Sensor. The on-board computer is programmed to run the engine at a normal setting if it loses the signal from this sensor. In my case this helped verify the problem. As soon as I pulled the connector off, the engine ran normally. The chugging and stalling stopped instantly!

I'm curious to know if this helps the next time it occurs.

Robert B.