Aaaaaaaah! it keeps stalling!

[shok]

I'm gonna try to give all the facts I have, it may be info overload but I don't want to leave anything out.
1966 250 inline 6.
I went out today for an errand and as I stopped to turn left it stalled, but since I was in gear I let the clutch back out and it restarted. This happened a bunch of times when I first bought the truck one day a couple of months ago and I thought it was fuel sloshing away from the pick up but to check I pressed the clutch in while driving and it dies instantly unless I give it gas. Its easier to restart if I give it some choke and throttle, I thought hey maybe my skull mask under the war helmet was a bad idea after all, (see pics) so I pull over and remove that and while I'm at it look for the idle speed screw and bump it up a bit.
Back on the road without the mask and all seems well, then its starts to stall while moving and then pick up again, off and on over and over again, I barely get to a parking lot and get it restarted, since I'm parked illegally I move to a new legal spot with a bit of choke in and pop the hood.
I had something like this happen years ago on a Mustang and it was a restriction in the fuel line and I only figured that out after adding a fuel pressure gauge to the system. To try and fix things I pulled the air cleaner and revved the motor and then smothered it dead with a rag, using the vacuum to hopefully pull any crud out of the way. It didn't give me any trouble after that on the drive home but I took it easy on her and was pretty cautious the whole way.
Other than the air filter set up and the cherry bomb muffler its stock. I've added some pics for carb identification and the air filter set up, I don't think any of this was caused by an air restriction issue but for the time being its using the cone only while I figure this out.
Ideas?

Current plan:

• Verify that the carb inlet filter is there and not all gunked up.
• Maybe pull the top of the carb and check overall condition, supposedly it was rebuilt not that long ago.

I already have a fuel cell with a rear facing sump and whether I go with a better I6 or a V8 there will be a 4 barrel under the hood one way or the other, so if anyone knows the AN fittings I would need to connect a steel braided line from the cell to the stock pump and from the pump to the current carb that would help me with some prep work for future mods while fixing the current issue. I'd also would want to plumb in a fuel pressure gauge on the cowl, overkill I know but I like engine communication.

[Gianyveedub]

Hey, I have had nothing but problems with my 1bbl during my current build. One of the things that stands out is that it does it while driving. You noted that when you give it some throttle and choke it starts easier. I would venture a guess and say maybe a vacuum leak. When you first start it in the morning, is it a bit of a pain or when you turn it off does it sound like it is dumping fuel?

The reason I ask is because recently my truck would be fine while driving one minute and then at the light, just stall. It turned out to be the leather in the accelerator pump was dried out and letting all the built up fuel in the bowl and empty it down the intake manifold and any orifice it could. Rebuilt the carb and not a problem since.

Even though the carb may been rebuilt not that long ago, it may have been stored in a crappy location or the seals could have dried up. If you wanted to test the fuel pump just to make sure, take off the inlet to the carb and place it in a bucket and start cranking.

I hope some of this helps. good luck

[joedoh]

why is there a vacuum line going from the intake to the valve cover? is there a PCV valve under there? because it may just be a big vacuum leak under that ziptied towel causing your problem.

[shok]

Originally Posted by Gianyveedub

Hey, I have had nothing but problems with my 1bbl during my current build. One of the things that stands out is that it does it while driving. You noted that when you give it some throttle and choke it starts easier. I would venture a guess and say maybe a vacuum leak. When you first start it in the morning, is it a bit of a pain or when you turn it off does it sound like it is dumping fuel?

The reason I ask is because recently my truck would be fine while driving one minute and then at the light, just stall. It turned out to be the leather in the accelerator pump was dried out and letting all the built up fuel in the bowl and empty it down the intake manifold and any orifice it could. Rebuilt the carb and not a problem since.

Even though the carb may been rebuilt not that long ago, it may have been stored in a crappy location or the seals could have dried up. If you wanted to test the fuel pump just to make sure, take off the inlet to the carb and place it in a bucket and start cranking.

I hope some of this helps. good luck

No problem on the first start or when shutting down. Since it drove home ok I'd say the fuel pump is working, but it could be on its way out and intermittently failing. It looks like the top comes off so I'll check it out Saturday.
I have the same worries about the carb you mention also.
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[shok]

Originally Posted by joedoh

why is there a vacuum line going from the intake to the valve cover? is there a PCV valve under there? because it may just be a big vacuum leak under that ziptied towel causing your problem.

It goes to a PVC valve, the motor has bad blowby from the oil fill and makes an oily mess so I put the rag there for now. Sad I know. Far as I can tell no vac leaks. Since it ran fine all the way home I now have to wonder if the trick with the rag helped or if it's just an annoying intermittent prob.
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[joedoh]

To test for vacuum leaks pull off a small vacuum hose. If the engine bogs down or speeds up, there isn't a vacuum leak. If the engine is unchanged, you have a vacuum leak.
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[shok]

Well at least in the case of the pcv hose I know it speeds up when I disconnect it, one of the first things I checked when I looked into the blowby issue, I'll check the vac advance line next. I think those are the only vac lines on the old beast.
Thanks for the ideas.

[shok]

One small little update: I had a few minutes to run outside and I removed the center bolt from the fuel pump hoping to see a screen, no screen but lots of what felt like chunks of rust laying in the standing fuel in one of the recesses.
I wanted to pull the carb inlet filter but discovered I need to get a set of tubing wrenches. IF there is a filter in the carb inlet, and thats a big IF, that would be the only filter in the whole fuel system.
I didn't start it up so I never did the check on the vac line to the distributor.

[theastronaut]

There is a filter in the fuel inlet on the carb, probably clogged if you found rust in the lines already.

[shok]

Originally Posted by theastronaut

There is a filter in the fuel inlet on the carb, probably clogged if you found rust in the lines already.

Well I know there should be, but considering some of the halfassed work done I dunno if there really is. Be nice to find a filter with an obvious problem and just know ok this was it, easy fix.
Either way I'm obsessive and will probably go overboard with a new fuel system

[shok]

So on Saturday I pulled the fuel fitting to the carb and the filter was there, here is a pic of some of what was piled in there. I circled it
Also the distributor advance vac fitting was loose at both ends so I took care of that. I didn't really drive it but I guess I need to to know if its really fixed.
The motor itself is getting much worse with blow by out of the oil filler hole so I'm bracing myself for the next inevitable step. Its a shame because other than the blow by it runs really great.

[geezer#99]

Try a different valve cover. One with the pcv at the back and the breather at the front. The way it is now it's short circulating and just pulling mostly straight air into the pcv.

[shok]

Interesting, I'll look for a stocker and try that.
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[shok]

I never did try a stock valve cover but I did a compression check today, I think I found the cause of my problems.
I didn't get exact numbers because I had to use the rubber kind that you push against the hole, which I did with one hand while using a screwdriver to jump the starter. Number 2 has less than 60 psi, goes up some if I add oil. All the others have over 150 psi easy.
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[Jim Boy]

When I bought my truck it ran like a dream. It came with about 1/2 tank of fuel. When I got gas the truck after a few miles wouldn't go above 60mph. When I got to searching I found the filter in the carb plugged which led me to the tank. I could see the rust line through the fresh gas. The truck had sat for a long time and the tank rusted. The fresh gas stirred the crap up on the bottom which then plugged the filter. No way to clean it so a new one was purchased and new filter. no problems since. Worth a look.