dcm01003

I am going to explain this as well as I can, keep in mind that the night before I drove it and everything was fine.
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Fiday afernoon I started my car and it started fine, no hesitation or anything and it was smooth.

Once I was on the move, i.e. throttle about a 1/4 down and at about 1500 RPM the entire car would shake, I mean shake, like the engine was going nuts or something. I also smelt a little gas.

At cruising speeds it's fine, but it's when I accelerate and reach the peak where I start to level off to cruise and then let the throttle back a little that the whole car starts to shake again, and then again if i have to accelerate a little, not like try to pass someone, but just if the people in front of me slow down and then speed up again, I have to floor it to get past the shaking and back to a decent cruising speed.

I made a usual trip up to massachusetts this weekend and use about a half a tank of gas going there and back, but this time i used about 3/4 of a tank. The only thing i can think of that I did the previous night was get gas at the local gas station. The car ran fine then and then acted all craazy the afternoon after.

Could it be an ignition problem(keep in mind just about everything related to ignition in my car has been replaced in the past 4 months) or a fuel delivery problem, potential water in gas or something like that?

Let me know if you have experienced this problem before, and what your solution was.

Thanks,

Dave

camaro_junkie

Does it always happen near a certain speed? This usually indicates a bearing or a u-joint or something in the rotating assembly is worn out.

dcm01003

no just at certain rpms, primarily when i attempt to accelerate gently, not floor it., but just regain speed.

also when the gas pedal is about 1/4 the way down

camaro_junkie

Did this happen right after you replaced some ignition stuff, or did it happen a while after you replaced it (i.e. was it fine for a while after you replaced stuff)? Is your distributor still clamped down properly?

Nixon1

You DID mention filling up.....maybe you got some bad gas...like contaminated with water. They make an additive to remove that if you feel like testing it..

How's the car run during acceleration? Does it feel weak? Misfiring under heavy load (aka top gear 1500 rpms tipping in on the throttle) could be an indication of a bad plugwire etc also..ignition problem. But you said you replaced ignition parts so I dunno....

dcm01003

im gonna throw some gas line antifreeze , about two bottles worth and let it run for about 15 minutes. If its water then that should fix it, but before that im gonna check all the wires again, it was wet today so looking around was kinda hard, hoepfully it will be nicer tomorrow. Im gonna check it out and then take it for a drive....ill post what i find out. Im also gonna se if I can't take it to a dealer and see if they'll plug their computer into it and see if i get any codes. Ofcourse this is if i have the time, but ill post an update later...

Dave

Nixon1

It's an 89. Not much for a dealer to see in terms of the computer...youre on the OBD-1 system. A little primitive in today's terms. Autozone can hook your thing up to a code-scanner for free and it'll pull up any check engine codes you've thrown. But most problems, in all honesty, OBD-1 doesn't pick up on.

CaliCamaroRS

More than likely a bad spark plug wire. And more than likely it's the number 3 cylinder next to the EGR valve.

EDIT: I had a brand new Delco plug wire get eaten in 2 months because of the EGR valve so don't rule anything out. It was arcing to ground and was very obvious, only acted up under load. Keep in mind that ignition problems typically act up under load.

camaro350man

PLUGS AND WIRES

dcm01003

Well it was just that, the plug wire near the egr. I had looked at it before and there was a little burn mark from the contact with the manifold, but when i looked at it it hadn't gone throught the outer shell so i assumed it was still good and zip-tied it away from the manifold. Well the car still didnt work, so i looked again, this time even harder. Well after about 20 minutes of nothing I pulled the other plug wire and since i had a spare(bought the accel 8.8mm set that comes with 8) i decided to be risky, so i bent the wire at the burn point, well, it snapped in two as if it were a tooth pick. Replaced the wire and runs fine now....feel kinda stupid, but now i know and im gonna get some shielding to put around that plug wire.

Thanks for the help....

Dave
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quote of the day "there is a reason why noobs are noobs, novices are novices, experts are experts, and vets are vets, and that reason is in the name" - Me

Nixon1

Heh good that it worked. It snapped in two because the silicone was overheated and destroyed. I had a spark plug wire's boot CRUMBLE on me before when I grabbed it. It gets dry and brittle with excess heat. KEEP THOSE WIRES AWAY FROM THE EGR!, exhaust manifolds, etc. Speed shops, Summit Racing, etc. sell plug boot shields to prevent heat damage. I have a set that I use RELIGIOUSLY. They cost me about $40, but I've been running the same MSD plugwires for over a year now and these headers are NOTORIOUS for eating wires. Ohm tested them just a few months ago and they were still between 80 and 120 ohms per wire. Not shabby at all.

EDIT: My bad, you already mentioned going to get some shielding. GOOD!