Well, after sitting for a week in 20-some inches of snow, I finally got it back on the road yesterday. Drove it for about 20 mins with no major problems (very little bucking and whatnot, but I figured that was my driving cause I hadn't driven stick for a while), and then all hell broke loose.

When I tried to accellerate onto this highway in 4th gear, the car started to buck really bad, and I could hear a popping sound at the same time. I pulled over and popped the hood. When I revved the car I could hear it Pop back up through the throttle body.

The car runs perfectly fine (had it up to 70 while doing this) under very gradual accelleration. If you try drive it any harder, however, it bucks and pops pretty badly. Its worse in 3rd, 4th, and 5th gears when there is more power needed to accellerate.

It was raining when all this started, so I immediately thought of a cracked distributer cap, however the car runs perfectly while driving cautiously. So I am consulting the boards for help.

Any comments welcomed.

KZad

 

Did you check to see if your distributor is loose

 

I think its just wet wires or cap. Electrical probs are allways worsened under a load (higher cylinder pressure). It takes more volts to jump the gap and somtimes its just easier for the wires to arc instead of the plugs to fire. especially if the wires are damp. maybe some snow blew up under the hood while it was parked.

 

That's a lean condition. Fix your fuel pressure problem. You said it works fine under light throttle which says to me that the o2 sensor is fine and timing is fine. It's gotta be a clogged fuel filter, a pump going bad, or a pressure regulator issue. I'll put my money on either the filter or the pump. As my fuel pump got worse this was exactly what was happening. No problems light throttle but when you need the fuel the pump just can't keep up with the demand.

 

Thanks for the ideas guys, I will look into all of them.

I have also heard that it might be a worn lobe on the cam. This makes a lot of sense, considering that it is always the same cylinder, for which I can feel a definate 'bang' under the gas pedal coming through the firewall.

I've dealt with arcing wires, burnt wires, and one car with wires completely crossed up. This is different. Theres no way that the car can run as smoothe as mine does on less than 8 cylinders.

When I rev'd the motor from under the hood, it was perfectly fine until real high RPM's then it would pop.

Prevost - it has a brand new fuel pump, just about a year or two ago. Fuel pump should be changed.

 

My car also just turned 155,555 miles too.

 

I agree with JPrevost...sounds like it's heinous lean to me.

 

A worn down cam lobe and your car would NOT run smooth. Trust me, it just wouldn't. Mess with the timing all you want but I'm sticking to my guns with the fuel starved reasoning.

 

jon is right check fuel filter, had this prob last year, light acceleration was fine but at 55 i would try to drop down and hit fourth, for get it it would start missing and backfiring through tb, i replaced filter and everthing was great again 5 months later i ended up putting a fuel pump in. check filter.

 

ALL FIXED! I came home to fix it today, and everything is fine! Runs like a champ! Should I still change the filter, because it will probably be back next week, or think I'm fine?

Wires looked fine, didnt check for them arcing.

Thanks for the help.

Kzad

 

so what was wrong with the car ???
i had a similar problem a while back,now my car is out of comission(int he process of being fixed)...
dont leave us hanging like that..

 

Your guess is as good as mine, bigRED.

When I drove it last weekend and it acted up, I parked it. Midweek my dad drove my car to work and around town that night for about a half hour, with no problems whatsoever. He put it in the garage for me so I could look it this past friday anyway. I could find nothing wrong but a small burn mark on one of the wires.

My guess is that when it rained, the dampness allowed the spark to arc through the wires easier? Is this possible? I drove it in the rain today, with no problems at all.

Another possiblity is that when checking the wires, my dad twisted the burnt wire 180* and now the spot that was sitting on the exhaust manifold is now facing outward. And now an unburnt section of the wire is sitting on the manifold, and not allowing it to arc?

ANY OTHER IDEAS? How could my car mysteriously fix itself?

 

I'd agree with JP.
The bucking and cutting out is exactly what happened on my 91RS when my fuel filter was plugged.

Maybe a bit of water condensed in the filter and froze, allowing it to run, but not keep up with near full throttle demands.

If you haven't changed the fuel filter since you bought the car, I'd plan to do that. It ceratinly won't hurt anything.

I changed mine at about 95,000 miles and cut it open. It looked like it was full of roofing tar. Changed it and the car ran perfect.

Best-
S-D

 

i think that might be it too.. i had to have my fuel pump changed but didnt have much time since my camaro was a daily driver took it to a shop and i dont think the changed my fuel filter...
since i am taking it apart alreayd might as well do that too

 

Could a clogged fuel filter be attributing to my recent poor fuel economy? I seem to only be able to get around 160-180 mi. per tank lately. Usually its well up over 200's. This has been for the last month or two.

Kurt