Unexpected engine stall problem, any ideas?

MikeM_66_Stang

New member
Hey y'all, haven't posted much on here yet but I've been reading a lot, and I definitely think you guys may be able to help me. I have a minor problem that I'd like some opinions on. Here's what happened:

Yesterday I finally fired up the 'Stang after it had been sitting about two months. I try to start it once a month or so in the winter, but it had been longer than normal. It started right up after only a few cranks, like it always does when it sits. I ran it for about a half hour in the driveway and circled the block a couple of times. No problems, ran like a champ.

Today a buddy came over and we changed the tranny oil. After we did that, we took it into town and filled it with gas, then put about twenty miles on it, just cruising at moderate speed. It ran perfectly until about 3 miles from home, then all of a sudden it started missing a lot and stalled every time I pressed the clutch. It would pop-start if I let the clutch out at speed, but stall again as soon as there was no load. We pulled over and started it several times. It always started and would run as long as I gave it gas, but stall every time as soon as I let it idle. We managed to get home by staying in gear the whole way and re-starting it every time we had to stop at a light. There are no loose plug wires, vacuum hoses, or fuel lines that I could find. The fuel pump is one of the few new things in the engine bay (less than 2 years old.)

One more item of relevance: I drove it less than 20 miles in the last year and I haven't put any fresh gas in since last April. It was down to about a quarter tank, and we filled it with 93 octane this morning.

My theory is that because of the old gas and the low level in the tank, maybe there might have been sediment or possibly water in the gas. I think this is a clogged fuel filter issue, and that's the first thing I plan to change. I will also add some fuel dryer additive to the gas to get rid of any water. But is there anything else this could possibly be? And if it's what I think it is, what else should I do? Any help would be appreciated, thanks.
 
I had similar problem with a car that sat for a long time. It started acting up on the way from Tidewater, VA to Nebraska. I bought the biggest inline gas filter I could, and periodically backflushed for 1300 miles. Made it OK. That puny filter in the carb clogs easily. I like the see-through type.
HW5200_EMPIAirCleaner.jpg
It's just left of the alarm, right near the pump's outlet. :wink:
 
Gas that has sat for that long could cause a problem. I would also check the choke and what the idle speed is.

Also check for vacuum leaks, and check timing.
 
I'd suggest checking the points. My money is on the gap wearing too close. Set them with a dwell meter if at all possible - it's the most accurate way.
 
Bad gas is always a good possibility, even the 'new' stuff you just bought could be the problem. With the prices these days I bet they are selling a lot less premium than they used to so it may not even be that fresh. If you have a way to do it maybe rig up a different gas source, like a portable marine tank?


And like addo said, check the points (if you still have them). My car did some strange stalling things turned out to be the points would stick open sometimes. While you are in there looking look close at the wires in the dizzy, maybe as the advance moves a loose or broken wire is causing your drops.
 
Thanks guys! We took the distributor cap off and looked at the points & wires yesterday, everything looked fine. If the new filter + fuel dryer doesn't fix it, though, I'll def. work on that next.[/quote]
 
Just for a little background, last Monday a guy complained to me about his Typ 3 VW - "It needs a carb rebuild". Down on power, would barely hold an idle, sucking fuel at a great rate.

I convinced him to check the operating gap of his points - they were nearly shut! Regapped to 24 thou with a handy guitar string (he's a musician) the motor ran like a champ. End of "carb problem", and a cheaper, faster fix than putting a kit through it.
 
The theory in big trucking is to not let it set for very long unless the tanks are full or condensation will develope...and that is with diesel.

It seems like contemporary gas formulations don't have the shelf life of the older stuff so if it is going to set for an extended period you might try leaving the tank full IF you can get someone to start and run it about once per week. That's the way I do with my F150. Since I am on the road for months at a time I have my son-in-law start and run it or drive it to work once per week.
 
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