crit111

It's a 1990, V6, 5 speed, ~140K, 2nd owner.

I've had issues with the car running fine and then whenever it decides it wants to, it starts to run bad.

The current symptoms are that it starts up and runs fine for a few miles. As the engine progressively gets hotter, it drops a cylinder (presumably #5, more on that in a bit). When it first starts, if you hold a gear to redline it clears up at about 3500RPM's to redline...once you shift and are below 3500RPM's, it starts skipping and stuttering again. Eventually it gets to the point where it's always stuttering, regardless of the RPM's. Once it cools down for 3 or 4 hours, runs great and starts the process over again.

Changed wires, plugs, rotor, cap, ohmed the injectors out, all seems to check out. When the car was hot and not running correctly, I pulled plug wires 1 by 1 until I pulled one that didn't make it run worse. Pulled #5, engine ran the same, hence why I think it's something do to with that cyl.

I need some direction, as I've tried everything I could think of.

Much appreciated.

maximo018

iTrader: (6)

Well it sounds like fuel, spark and air are what you need to check for on #5. Btw whats your temp gauge at when all this happens?

crit111

Temp gauge is running at normal temps/position on gauge. My apologies for not clarifying "when it gets hot", as the car isn't overheating during any of this. Basically the car only runs smooth when it's cold, just started up. As soon as the engine gets to normal operating temperature, the stuttering begins.

I definitely have spark at Cyl #5 and the plug appears wet when pulled after running. I believe I have fuel there based on that. Should I try ohming out that injector after driving it around for awhile, aka while it's "hot" or normal temp so to speak? When I previously ohmed it out, the car was cold.

Air filter is clean, however I'm not sure how to check if it's plugged beyond that into cyl #5.

As always, your help is appreciated.

maximo018

iTrader: (6)

Ah yes it was wet, but did you smell it to verify it was fuel. Sounds crazy but sometimes its oil. Probably fuel though. Not common for air not to get into the cyl. (Thats like saying the tires never touch the road when aired up) run a compression test and see what your results are.