1992 318iC with around 170k on it.
The engine seems to only run on 3cyl at times. It dosen't matter if it is cold or warm. Low, mid or high RPM, part throttle or wide open. It seems to do it more so when accelerating, even just a little vs steady cruise.
I've taken the car on a couple long trips for the first time. On the left side of the back of the car, there is a light coating of black stuff, almost like a soot on the car, I've seem this on alot of older Honda's, which owners said was from the Vtec system.
The car does not blow visable smoke. The engine is consuming oil, I'd say maybe a quart every 1,000 miles? I just fixed an oil leak from stripped out lower oil pan bolts, and there dosen't appear to be any more oil drips under the car.
The idle also surges at times, it is hardly ever smooth, usually wanders a bit, sometimes between 500 & 1000RPM. This may be from running on 3cyl, when I tap the gas it stumbles, so I have to bring the RPM up to 1500-2000 enable to get moving.
I can tell from the vibration and loss in power it is dropping a cylinder. But for it to do that it would have to loose fuel, ignition or compression. It is a very quick "on/off" problem, sometimes by feathering the gas pedal I can get it to clear up. Because of this, I can eliminate a loss of compression such as any problem with the piston rings or valves/head.
I have addressed the under intake manifold issue, changed fuel filter, air filter and spark plugs. Wires appear to be original. I am thinking it may be a faulty wire or coil pack? I am waiting to just do a COP swap. I was also thinking it may be a faulty fuel injector? But every now and then I can smell a fuel smell, like the engine is running rich.
When the engine is firing on all 4cyl, it is strong. It runs to 7000RPM with no problem and pulls very well, is smooth and fun to drive. But lately it seems like this problem is happening more often. I don't have any CEL codes either.
Topic: Engine appears to intermittently drop a cylinder. (Read 1928 times)