C30 stalling Problem

[vlowe]

Engine runs for 30 minutes in gear then stalls, as if it is out of gas. The rpm's slowly drop then stalls but if I put it in neutral, it remains running. It always starts right up but the next cycle becomes shorter - i.e. 10-15 minutes, then 5-10 minutes. I have done all the things that Don Moyer has suggested as follows -

Fuel side - new carb, new fuel hoses and vent hose, Facet pump new end of last season, new Racor, arrestor cleaned, no dirt in carb. I have bypassed the pressure switch to run the pump and it will pump 1 litre in a minute or less into a container.
Question - when I changed the fuel hoses, I used 3/8" ID hose to replace the 5/16" ones. Anyone know what effect this may have on the fuel delivery. I have conflicting info in my manuals - one says 5/16 and the other says 3/8. The local A4 dealer says it should be 1/4" ID??!!

Electrics - new plugs, points, condenser, rotor, cap, wires, coil, pressure switch.

General - compression is 101-103 psi on all 4 cylinders and 35 psi oil pressure. Gas tank was emptied and fresh gas with enzyme additive for Ethanol added.
Yesterday, I checked the exhaust back pressure on the exhaust flange and it is 1.0 psi but periodically rises to 1.5 psi and when it stalls, will read 1.0-1.5 psi.

I am open to all thoughts and suggestions.

Vern

 

[Twice Around]

Vern,

Hopefully this question is getting answered over in the Moyer Forum.

Lots more Atomic 4 gear heads over there.
-Shawn

 

[Bob4203]

Vern, nothing beats messin about with engines, but I think with everything you did, I would contact a good Atomic four mechanic and let him troubleshoot and fix the problem.

Bob

 

[Team118]

I was going to say points and condenser. I haven't gone over to the Moyer sight, but this is a common issue.

It always seems to end with an electric issue even though it seems like a fuel problem.

What about a short at the starter? Or key/ignition point?

Be sure to post your solution when you find it.

Luck!
Chris

 

[pencema]

3/8 = 6/16. 1/4 = 4/16. Either way, you should have enough fuel. One thing you didn't mention checking was temperature. Is the engine fresh water cooled or raw? Is there enough raw water flow, either to the block or to the heat exchanger? An if applicable, is the heat exchanger big enough?