It's my own stupidity.

1 and 2 side of motor ran way too hot. Cleaned out the mouse nest in the tin, sealed all holes in the tin, etc. Still hot. Injectors failed the flow test using the pill bottle method -- lean on that side.

Injectors on 3 and 4 are new. Didn't want to pay for two more. Here's the admission: I used carburetor cleaner. I know better. Wasn't thinking.

Installed the "cleaned" injectors. Car wouldn't start. I cranked, and cranked. After a while I realized I was out of gas. That's funny, I thought I had a gallon or so in the tank? When it started it was only running on one side. I shut her down when I saw raw gas coming out the tail pipe...

Changed the motor oil and filter. Surprise, what had been 4 quarts was now 7. Smelled funny too. Got some used 411 injectors and replaced 1 and 2. Retrieved a back-up fire extinguisher. The car started immediately. Maybe I had dodged the bullet? I thought.

20 seconds later I had a smoke bomb. White and grey plumes darkened the sky. The tail pipe spit black oil. Shut her down again. Dropped the exhaust, cleaned it as best I could of the gas and oil porridge that lined it. Changed the oil again -- only 4 quarts -- and waited till dark....

Last night I ran her till she smoked like a locomotive. Did that for 30 minutes then it started to clear. Finally, after an hour, no more smoke! Seemed OK.

I'd screwed up the injectors up so with carb cleaner that raw fuel entered the cylinders. This washed across the rings and combined with the crankcase oil to make it like a two-cycle motor. The engine would even run without the FI plugged in! The same thing had happened to me years ago with an old truck which had a massive single barrel carburetor. The float would stick open and allow gas to contaminate the crankcase.

I'm going to take the 914 for a spin and see how it runs. It's possible the rings or bearings are shot from the oil/gas mix, though I have oil pressure. The oil/gas mix freed up the oil-pressure sensor and I've got my green light again!

Next time, just use seafoam or Marvel Mystery Oil.

Post spin. Runs OK, fine actually. No new noises. Still an occasional waft of smoke. I'll check compression tonight.

Yeah, the MMO is on the shelf next to the carb cleaner. What a klutz I am.

BTW, the oil pressure switch that was freed up by the oil-gas mix, still works.

What does carb cleaner do to fuel injectors?

John

"Seal-be-gone," lots and lots of fuel.

Glad to hear im not the only one that uses Marvel Mystery Oil. I mix it with my gas for the valves. Did not consider that it will also clean the injectors.

Hopefully faithful use will keep me out of that injector failure trap!

You can use carb cleaner to CLEAN the injectors but you MUST:
1. remove the injector fuel filter that's made of plastic
2. flush them afterwards so no carb cleaner will remain inside.
3. in case you intend to store the injectors for a long time, oil them a bit.]

That Mystery Oil contains the same s**t as the carb cleaner but in lower concentration.

Valy, I would dearly like to know how to take an injector apart. Thanks.