914 strange running situation.

[fst951]

Hi Guys.

I hope that you can give me some ideas. I wrote Dave, the administrator direct with the following situation:

I have a bizarre situation here.

I have a 10 or 1971 so 1972 1.7 liter car that ran the other day and then just stopped after about 15 minutes.

It just simply stopped running on the highway.

It will now run again because i fixed the fuel line. It leaked out a ton of gas from the return line that broke.

O.K. seems like problem is fixed, but now it won't idle at all. It will rev up fine, but has a miss.

I found that the cylinder closest to the driver, I think Number 1 has spark and a noid light shows ignition, but it isn't firing. I can hold the header and all the others are hot, but not this one. It has a wet plug in the cylinder, and carbon on the electrode of the new spark plug.

I ran a compression and leakdown on all 4 cylinders and they all look really good.

Intake and exhaust valves and rings seem just fine. I changed the distributor cap and swapped wires, still no fire on that cylinder. I even put a inductive light and it shows that the wire is getting a pulse from the distributor.

Also, all the fuel lines seem to be blowing, like the pressure is way too high. I will check the return line tomorrow for a blockage and I will also check the fuel pressure at the rails.

Been on Pelican about since it started. I am a monthly lurker.

Thanks you all in advance.

[John Rogers]

New plugs all around. If you can, look inside the distributor cap to see if there is any arcing or burns. I would also check just to be safe what the plug wire resistance is on all 4 wires to make sure the misfiring cylinder is about the same as the others.

[Dave at Pelican Parts]

Get an extra spark plug and tape it with the threaded part or outer electrode touching the head. Plug it into the #1 plug wire, and look while someone cranks the starter to make sure it sparks.

Pull the #1 injector out of the intake (only 1 nut holds it in) and put it in a jar. It should squirt when the starter is cranking, and if the engine catches it should also squirt then. Make sure it does.

Chances are that one or the other of those things is not happeninng.

--DD

[fst951]

Hi guys. Thank you for the good info. I had already done all that. I started thinking, why would the hoses start leaking all of a sudden? Coupled with the fact that the spark plugs were very black I checked the fuel pressure. 90psi. Cut to the chase, kinked fuel return line under the tank from a prior mechanic. Lucky it stopped running, otherwise 1 more minute and it would have burned to the ground.

Still kind of strange #1 still wouldn't fire when all the others would. Crazy.

Thanks to all.