Fuel Injector ?

[scott.lingerfel]

OK Here Goes:

1974 914 2.0L All stock Fuel pressure 29#

I have noticed lately that the engine seems to be missing. Thought it might be the trigger points. Remove distributor to check and they look good. A little wear on the tabs that come in contact with the shaft.

So with the engine running I tried at cylinder 1 and removed the injector plug and the engine rpm dropped and sounds like it might shutoff. Replaced the plug and the engine smoothed back out.

The big question would be that cylinder 2 had no affect on the engine when I removed the injector plug. I continued to cylinder 3 & 4 and the same affect happened at cylinder 1.

Injectors 1 & 2 removed from the manifold with injector 1 plug removed and the coil wire removed from the distributor I turned the motor over and injector 2 would spray into a glass.

Could there be an issue that when the engine is running that cylinder 2 injector may be having an issue?

Any thoughts and/or things to check.

Thanks,

Scott

[bowlsby]

Is the 'missing' problem intermittent or constant? Seems odd the #2 injector has no effect on idle when unplugged while idling, but fires into a jar. If intermittent...it could be a wiring or electrical connection problem.

Maybe its not a fuel delivery issue, but a spark issue?

[scott.lingerfel]

Constant.

I have tried moving the harness while at idle but no change. I have brand new plug wires and plugs. Checked the gap and spot on. I will switch the plugs and injectors tomorrow to test.

Thanks for your reply

[John Rogers]

Trigger points! Well, if you search all the posts about missing and other "unusual" forms of bad engine performance, you'll note that I generally say to replace the trigger points. Since they are VERY expensive, most do not want to do this and generally replace everything else and also adjust the valves and eventually they replace the trigger points and the issue clears up.

Some things to note are: You can not tell if they are bad by looking at them as I have seen some that were oil covered work just fine. Cleaning or dressing them with a small file will not work. Trying to change tension will not work. Trying an old pair that someone says "are okay" will in all probability not work.

Unless a broken wire to an injector is found or a bad spark plug is found or bad plug wire, etc, etc, then replace the trigger points.

[Dave at Pelican Parts]

Try an extra spark plug on the #2 plug wire. Tape it with the ground part (the outer electrode or the threads) grounded, then look to see if there's a spark when the starter is cranked. New parts can fail; could be plug or wire or cap.

--DD

[scott.lingerfel]

Problem Solved

Swapped the spark plugs and all worked as expected. Bought a new set of plugs and no more issues.

Never thought a new plug could be bad.

Thanks to all that have replied!

Scott