BA: no idle, dies after ½min
Hi all,
You might remember Finn Flatty and his '29 with BA. The same that had exhaust water leak some weeks ago.
Now we'd be almost ready to hit the road, however we have a major tuning issue with the engine.
The original carb, Holley 2100, was running bad and super rich. I rebuilt it with a carb-kit. Next the engine would not run below approx 2000rpm. By ear it runs good above 2000. Then dies suddenly after 15-60 secs. Needs some cranking to fire up again.
We considered the carb was still bad, so Finn Flatty brought in a brand new Holley 94. Still the same problem with the new carb: no idle, runs pretty well above 2000 and then dies suddenly. The nose indicator says the mixture is pretty good.
So, we have here a fresh rebuild BA, new carb, new Bubba Chevy distributor, new Blaster2 coil, new spark wires, champion #H10 plugs.
My best guesses
1) fuel pressure. universal electric pump puts out too much pressure the needle can't hold -> floods. We tried with another el pump and also with a regulator found at the garage shelf, but no change in engine behaviour (however i am not sure about the condition of the regulator)... two pumps and one regulator did not solve it. Yet i might need to check the pressure with a gauge. what fuel pressure would you run?
2) vacuum leak. low vacuum pulls open the carb power valve -> stumbles to rich mix. The missing idle speaks to vacuum leak too. But there is no visible vacuum openings intake nor carb. Is there some Flathead common vacuum leak points? At intake?
3) coil. maybe the new coil is bad. the coil does not heat up though. The connected timing strobe blinks all the way until engine dies.
4) distributor? simple mechanic device, hard to believe.
5) Cam dialed incorrectly
This drives me nuts, since it is hard to find a simpler engine than this, and i can't get it rock
Ideas and help are greatly appreciated.
Thanks.
Hi all,
You might remember Finn Flatty and his '29 with BA. The same that had exhaust water leak some weeks ago.
Now we'd be almost ready to hit the road, however we have a major tuning issue with the engine.
The original carb, Holley 2100, was running bad and super rich. I rebuilt it with a carb-kit. Next the engine would not run below approx 2000rpm. By ear it runs good above 2000. Then dies suddenly after 15-60 secs. Needs some cranking to fire up again.
We considered the carb was still bad, so Finn Flatty brought in a brand new Holley 94. Still the same problem with the new carb: no idle, runs pretty well above 2000 and then dies suddenly. The nose indicator says the mixture is pretty good.
So, we have here a fresh rebuild BA, new carb, new Bubba Chevy distributor, new Blaster2 coil, new spark wires, champion #H10 plugs.
My best guesses
1) fuel pressure. universal electric pump puts out too much pressure the needle can't hold -> floods. We tried with another el pump and also with a regulator found at the garage shelf, but no change in engine behaviour (however i am not sure about the condition of the regulator)... two pumps and one regulator did not solve it. Yet i might need to check the pressure with a gauge. what fuel pressure would you run?
2) vacuum leak. low vacuum pulls open the carb power valve -> stumbles to rich mix. The missing idle speaks to vacuum leak too. But there is no visible vacuum openings intake nor carb. Is there some Flathead common vacuum leak points? At intake?
3) coil. maybe the new coil is bad. the coil does not heat up though. The connected timing strobe blinks all the way until engine dies.
4) distributor? simple mechanic device, hard to believe.
5) Cam dialed incorrectly
This drives me nuts, since it is hard to find a simpler engine than this, and i can't get it rock
Thanks.
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