New Purchase stalls and found oil spray

[fred_e81]

Hello everyone,

Im back with a new purchase. A 1981 GMC Sierra with a 350 and automatic trsnsmission and a propane kit on it. I test drove prior to purchasing and it ran well. On the way home on the freeway, she coasted great. Suddenly I smelled oil or ATF not sure which one. I pulled off the freeway and took the back roads home. While at stop lights she began to stall. I'm going to start with the free stuff, vacum leaks, plugs wires, cap and rotor. Where else should I look? Also, where do you think this oil is coming from? It splattered all over the carb, only the carb. Any ideas. It was dark when I checked it and I took a pic as well.Thanks in advance for any and all help.

[rainamy]

Describe the stall...

Around corners? At a stop sign or light? Does it not happen if you two foot it - ie one foot gas, one lightly on brake, to keep rpms up? Does it buck or chug under acceleration uphill or under heavier load?

[fred_e81]

Thanks for the quick reply. It only stalls when at a stop sign or stop light. When I two foot I, it stays running. No bucking or chugging when going up hill or on a load.

[rainamy]

Definitely is a low idle issue, and I'd expect the sort plugs/wires/cap/rotor won't touch.

Its been sitting a while... could be a needle sticking on the carb. Gently (GENTLY) tap the carb housing a few times and see if it still does it. If that helped, running a bunch of strong carb cleaner through may help.

Vacuum lines are the first "repair" to do. That could help the idle issue as well.

Do not try to adjust / tune the carb before checking out the vacuum lines though.

I had a 79 I bought about 20 years ago, had a 327 with a 4bbl holley on it. Had sat some. Behaved like you describe at first, but after running a few bottles of strong carb cleaner with the gas through it it cleared back up. If that's your issue beware running at high throttle or stoming the pedal down... that helps it stick again.

[rainamy]

As far as the oil goes...

I'm on a cell so I cant see the picture well. Is it possible the pcv or breather disconnected and blew oil out due to some bad blowby?

[Dead Parrot]

Were you running on propane or gas for the trip?

Based on the pic, check for a gas leak at the carb filter housing. How long had it sat before you bought it? Well aged gas can have weird smells.

Maybe some oil escaped from the AC compressor.

Think I would start with a can of carb cleaner and a spray nozzle on a garden hose.

[fred_e81]

The pcv might be it the source of the oil. Should I replace it?

I was running unleaded gas during the ride home. I plan to remove the propane system.

The truck was being used but, I did get a hint of the old gas smell. Probably a good idea to clean the area good to get a better idea of where the leak is coming from. Thx guys. I'll start when I get off work.