skene

This morning when I started up my car it was running really roughly. It usualy is a bit bogged down when I first start it up and at low RPMs, but this time it got worse as it warmed up and as I reved the engine.

My first thought is it may be running on 3 cylenders? It idles at 900-1000, which is how it was before, but there is a whole lot of engine vibration that wasn't there before. The vibration gets worse up to around 2000rpm then seems to go away, but the car still runs in a rough, jerky manner.

Last weekend I did a good bit of work on the car:
Replaced all cooling hoses
flushed and refilled the cooling system
replaced all the vacume lines
deleted the venturi
put some marvel mystery oil in to try to solve noisy lifters

I'm 90% sure there is no vacume leak as I've replaced anything that can leak. I've probably put around 200 miles on it since doing all this and it's been running better then ever, until this morning.

Aside from checking the plugs and FPR, what else could cause this?

Burston

Engine mounts ?

testarossa_td

O2 Sensor?
TPS ?
Idle Stabilizer Valve hooked up after Venturi Delete?

skene

Possibly, but that doesn't explain the loss of power or surging acceleration.

skene

O2 sensor is new, maybe 500 miles on it so that's not it.

TPS. That's a definite posibility. I'm not sure why I didn't think of that as being a problem. I'll have to check that one when I get home.

skene

Update:
TPS is fine, but I'm definitly running on 3 cylinders.

The #4 plug was COVERED in oil. As in oil was on the outside and soaked the rubber housing around the plug wire. The plug itself was black and looked very rough. I'm not really sure what this means, but I fear the worst. It's time for a dinner break either way.