HELLLPPPP!
 

I have a stock '74 2.0L. I thought that I was having a fuel related problem that was causing a hard start problem. As it turns out, I have a cylinder not firing. I have pulled the plug, and it is firing. I switched the injectors. That was not the problem either. I have checked the compression with my thumb over the spark plug hole and the cylinder has compression. How much or is it enough I don't know yet.

I talked to a car buff friend and he said that it could be a burnt valve. I suddenly remembered several years ago that I had to advance the timing to compensate for what I know now were vacuum leaks. (If I only knew then what I know now!!) I was told that running the engine for way too long with the timing advanced too far can burn a valve.

If I have burned a vlave, what is involved in fixing the problem?

By the way, thanks to all those who have helped with advice and specifics to all my other posts!

Any words of wisdom will be appreciated.

PRITCHARD

PS- the 2.0L runs surprisingly well on three cylinders! But I hope that you don't have to experience this for yourself.

I would do a compression check to see what they are. If one has very little ## then the engine may poorly or may not run at all. Recently at a track event here in So Cal one of the 2.0 914s bent a couple of valves, just enough to keep them from seating and there was no power and the engine would just barely start. How much? only 0.003 inches was enough to do it. Engine drop and head work is required. When you swapped injectors did you check the flow into a vial? You might want to swap the injector electrical connectors on the bad side to see if the problem moves to the other cylinder? Good luck.

[This message has been edited by john rogers (edited 11-05-1999).]

[This message has been edited by john rogers (edited 11-05-1999).]

I forgot to mention that I had switched the FI wires and the problem still remained.

I recently had similar problems. I switched to pointless ignition and they went away, but.. they came back. After going through all sorts of things in the ignition and fuel injection I could still not find a problem. It turned out to be the fuel injection points were worn and made the engine run as if a cylinder was not firing. What happened is the stubs on the points that ride the cam lobe on the distributer shaft had worn so far that a pair of fuel injectors was stuck open flooding the cylinfders and causing them not to fire. For only about $70.00 you might as well try, my car has never ran as good as it does w/ the new points.
Good luck

After running a compression test, if all cylinders are within 10 lbs of each other, start the engine and spray carb cleaner around the injectors and vacuum lines to check for leaks. Old injector seals will become hard and cause leaks. Each injector has 2 seals. Also, squirt some atf in the cylinders for a wet compression test. If values go up, you may need new rings. Good luck. SBell

I flow tested the injectors, and all are delivering the same amount.

Next, I did a compression test on all 4 cyl. The three cyl. that are firing are all reading virtually identical. The one cyl. that isn't firing is reading at about 25psi.

I squirted a small amount of oil into the bad cyl. to check for leaking rings. The compression did not change. Still around 25psi. I rechecked my valves for proper adjustment, and unfortunately they are correctly adjusted.

My guess is a burnt valve. If y'all have some other ideas, I welcome them all.

Thanks,

PRITCHARD

PS-what is a typical compression reading on a 2.0L? Mine were right at 100 psi.

[This message has been edited by Pritchard (edited 11-08-1999).]

Coule be a burned valve, could be a damaged valve seat, could be something else--but it most likely *is* serious and internal to the engine.

This is a bit of a long shot, but have you adjusted the valves? If one is too tight, it may be letting the compression "leak" out past it. Odds are, unhappily, that you need to overhaul the motor.

100 PSI is pretty darned low. New motors are usually in the 150+ PSI range, and 100 is about the lower limit. I'd say that at least the top end of this motor is pretty tired. If you have an oil pressure gauge, you can guess as to the bottom end's condition. (<10 PSI per 1000 RPM is bad.) I would think that you'll want to do a complete rebuild.

Sorry for the bad news.

--DD