C3larke

My car runs poorly under 3000 rpm. The problem has been going on for quite some time, and seems to be slowly getting worse. During acceleration the car jerks back and forth, though just barely, until I reach 3000 rpm. Once I pass 3000, everything smooths out and I can feel a sudden increase in power. At idle, the engine speed fluctuates slightly. I've tried setting the idle speed to 680 according to the workshop manual, but when I remove the jumper from the idle stabilizer the idle becomes too fast.

I noticed during the recent rainstorms that when I drove through a puddle the problem became signifigantly worse. A deluge of water from below seemed to increase the roughness and jerking. Once I got it running over 3000 it still seemed to clear up and after driving for a minute or two it was back to normal. Does that point to an electrical problem?

I will have some time to work on the car next weekend and I would appreciate any suggestions. What might cause these symptoms, and what can I check for? I have recently replaced the spark plugs, idle stabilizer, Temp II sensor, and rubber boots on the intake manifold.

Thanks for your help, I really appreciate your advice.

Chris Clarke
85 US 5-speed

WallyP

Get the car in a dark place and carefully look for any stray sparks on the coil wires, distributor caps, plug wires, etc.

Keep your fingers away!!

dr bob

... And hunt down some cracked vacuum hoses.

This isn't something that should be done in the same dark place as the wire demonstration...

C3larke

I started it up and looked under the hood in the dark. Sure enough, there were sparks all over the plug wires. I ordered up a new set of wires and will install them this weekend. Should be a big improvment.

Thanks for your input.

Chris