The Ford Barn

the99car · 09-09-2016, 07:18 PM

my resent purchase , a 1946 sedan, runs and sounds great til about 1/2 throttle . had dist. out 3 times all set to spec and looks good even cleaned the vac. line coming from intake. all exhaust is clear ,carb is clean. starts at first bump on the starter button. goes flat and chokes & back fires at 1/2 throttle and above. what am I over looking??????????
Kenny Zhills FL

39portlander · 09-09-2016, 07:27 PM

Kenny, Take the distributor out again, send it out to Bubba and then let us know

Binx · 09-09-2016, 07:57 PM

"Backfire" can be ambiguous. Is it through the carb or the pipe?

Lonnie

Kruzn40 · 09-09-2016, 08:44 PM

If it's backfiring thru the carb that sounds like the fuel delivery is not keeping up with the demand (A/F ratio going lean) at half throttle and above.
Check the fuel pressure at the carb and verify that it remains steady. You may have a partial obstruction somewhere between the gas tank and the carb like a clogged fuel filter or even in the tank at the pickup, insufficient tank vent, crud in the fuel line, or it might be the fuel pump laying down on the job at higher speed. Vacuum leak is another possibility.

Mart · 09-10-2016, 03:39 AM

If this is something that gets worse after it has run for a while, then recovers when running from cold again, it may be the HT side of the distributor. I have had rotor arm problems and distributor cap problems that gave similar symptoms. I've had this in helmet, crab and Lucas distributors.

Mart.

the99car · 09-10-2016, 08:16 AM

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will check fuel delivery. thans kruzn40

09-09-2016, 07:18 PM	#1
the99car Junior Member Join Date: Jun 2010 Location: Zephyrhills , FLA Posts: 18	what the ???? my resent purchase , a 1946 sedan, runs and sounds great til about 1/2 throttle . had dist. out 3 times all set to spec and looks good even cleaned the vac. line coming from intake. all exhaust is clear ,carb is clean. starts at first bump on the starter button. goes flat and chokes & back fires at 1/2 throttle and above. what am I over looking?????????? Kenny Zhills FL

09-09-2016, 07:27 PM	#2
39portlander Senior Member Join Date: May 2010 Location: Suth'N Maine Posts: 1,996	Re: what the ???? Kenny, Take the distributor out again, send it out to Bubba and then let us know

09-09-2016, 07:57 PM	#3
Binx Senior Member Join Date: Oct 2011 Location: Gloucester VA Posts: 1,042	Re: what the ???? "Backfire" can be ambiguous. Is it through the carb or the pipe? Lonnie

09-09-2016, 08:44 PM	#4
Kruzn40 Member Join Date: Sep 2010 Location: Menifee, CA Posts: 61	Re: what the ???? If it's backfiring thru the carb that sounds like the fuel delivery is not keeping up with the demand (A/F ratio going lean) at half throttle and above. Check the fuel pressure at the carb and verify that it remains steady. You may have a partial obstruction somewhere between the gas tank and the carb like a clogged fuel filter or even in the tank at the pickup, insufficient tank vent, crud in the fuel line, or it might be the fuel pump laying down on the job at higher speed. Vacuum leak is another possibility.

09-10-2016, 03:39 AM	#5
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,754	Re: what the ???? If this is something that gets worse after it has run for a while, then recovers when running from cold again, it may be the HT side of the distributor. I have had rotor arm problems and distributor cap problems that gave similar symptoms. I've had this in helmet, crab and Lucas distributors. Mart.

09-10-2016, 08:16 AM	#6
the99car Junior Member Join Date: Jun 2010 Location: Zephyrhills , FLA Posts: 18	Re: what the ???? Sponsored Links (Register now to hide all advertisements) will check fuel delivery. thans kruzn40