The 2F wants to stall

[fyton2v]

Now that the electrical system bugs are sorted out... I need to tackle the mechanical stuff.

The truck sat for pretty long time without running. Maybe 8 years. When it went into hibernation it didn't have this problem, since then it was mostly disassembled and reassembled and kept inside a garage for the whole time.

The first order of business is that the truck tries to stall when you floor it from an idle. It's idling nicely at about 650 rpm. Timing seems good at 7 degrees before TDC. Vacuum is pulling just above 15 PSI at idle and steady. I can see that the that the accelerator pump is supplying a squirt of fuel when i'm pulling up on the throttle with the engine off. Plenty of fuel in the bowl. I can't find any vacuum leaks, but that doesn't mean there aren't any. 15 PSI seems to be on the low side from what I've been reading, however I'm quickly running out of knowledge here.

What would you check first?

George

 

[Pin_Head]

1. Manifold vacuum leak.
2. Idle fuel cut off solenoid.

 

[thebigredrocker]

Glad to hear you got the electrical figured. Good feeling, ain't it. You're running the original Aisan correct? Rebuilt or just sprayed with carb cleaner? I have yet to use propane to check for leaks, I've read it works good.

 

[fyton2v]

It's the original Aisan, there's a decent chance it's never been rebuilt, ever. I've used carb cleaner with the engine off and running. This is going to sound dumb, but I was really under the impression that if I sprayed carb cleaner down the throat of the carb with the engine idling the RPMs would pick up. Instead, it tries hard to stall. Based on Pin Head's manifold leak suggestion, I started spraying carb cleaner around the intake manifold. So no obvious sign of a leak there, however, while spraying around the outside of the carb itself, the idle drops. It seems like there could be some sort of a leak there. Normal?

 

[78fj40mg]

Normal if a vacuum leak is present.
Check for dried out and compromised vacuum hoses.

 

[fyton2v]

Okie dokie. Fixed.

So when you guys see me write stuff like, my timing is this, my idle is that, you should probably respond... "Are you sure you know what you're talking about?"

I might not know what I'm talking about.

The hesitation was caused by a couple of things. I really do need to replace the small diameter emissions tubing. It's not firmly sealing on the VSV. Also, and it came this way from the PO, my vacuum advance and emissions tubing wasn't routed correctly. And some of the tube routing for the carburetor was funky. I have the emissions manual and FSM and access to Mud, so I was able to sort it out. Also, also, my timing wasn't accurate, which is likely the main problem. I redid my timing, and it's probably correct this time. Readjusted the idle-mix and idle and now i'm pulling 17psi at the brake booster. No stalling.

On to the next thing. Probably check valve clearances, but it's really hot out so maybe not.