Stumbles on take off

  • Thread starter Thread starter Anonymous
  • Start date Start date
A

Anonymous

Guest
My 69 Falcon with 200 cu. in. developed a slight stumble on acceleration. Sounds like accelerator pump. I check it out and sure enough, shredded pump plunger. "Rebuild" the carb, problem solved. But not. It still stumbles. I am going to go over tune up and timing, the parts aren't worn enough to warrant replacement, just rechecking adjustments. Any suggestions as to where to look more closely. I used to be able to diagnose this kind of stuff in my sleep, but it's been awhile and electronic ignition and computer power makes one lazy or stupid. Anyway, it's kinda buggin' me. Thanks. .......Johnny
 
Too little ignition advance can cause sluggish throttle response as well. Check your timing and advance it to see if it clears up.
 
Thanks, I plan to check timing etc today. I know I got all the pieces out of the carb. This car was hastily timed by ear with the points set a little wide. I did recently find my dwell meter and rest my points, now within proper specs. Timing is a good place to start. Thanks, keep those cards an letters coming ..........Johnny
 
I don't thnk so, but I plan to check closer. Timing was way off, retarded. I have not road tested yet. Plugs were clean.
 
Aftre a road test yesterday, it still hesitates on take off. Accelerating just off idle or punching it seems to be ok(?). Also, going up a steep driveway or stopping, the engine falters and almost dies. I'm thinking floats stuck in the closed position. I checked them when I had the carb apart and they seemed ok, but I will check them again. I'm taking today off, my brain needs a break. Does any body make throttle body injection for a 1 barrel? Throttle body and and 2 barrel adapter? New carb, as in brand new? I'm checking on that one as soon as my headache goes away, Thanks
 
Had the same problem myself recently.
Moved my timing back from 26 degrees initial advance to 14 degrees in an attempt to gain some MPG.
Car runs better at highway speeds but I had the off-idle stumble when stopped or accelerating in traffic after taking my foot off the gas.
Changed from ported vacuum to full vacuum this morning and not a single problem (yet).

Now lets see if I can get some mileage outta this heap!! :lol:

82 Futura with a 200-6,C5 auto and Holly 1946 carb
 
You may be on to something. But, it was fine up until just now. Between down pours and naps today, I got the carb apart. The fuel in the bowl was very low, so I will check the floats. The new accelerator pump plunger was just as ripped as the old one(?). That $27 rebuild kit is going back to the parts store. I'm ready to buy another rebuilt just to have a spare for the shelf. I'll be at again tomorrow. A new kia is starting to look good. ......Johnny
 
It is kinda weird, it starts out ok, then as the engine warms up, it gets worse. If it's idling in gear, you can hear it getting worse until it stalls. Is it flooding from too much fuel or starving from not enough? Compression test, vacuum guage tests and dead on timing makes me sure it's fuel. There are only two components. My thoughts are either the fuel pump is no longer keeping up with demand or the carb has gotten dirt someplace it does not need to be. Before I order a new rebuilt, I will try the old electric fuel pump trick. I still have the one I had on my 390 F-100. It kept two fuel bowls filled on a much bigger Holley. I'm out of places to look, and I refuse to take a car this basicly simple to mechanic and pay for diagnosis. I'll just pay $120 for a carb I may not need. Did I mention that the 1 yr warrenty on the fuel pump and carb just expired? ............
 
I would also check (test) the condenser, coil and coil lead. Once you've written them out the picture, it definitely comes down to fuelling.

Regards, Adam.
 
You must log in or register to reply here.

Similar threads

M
FAST EFI Installation on 200 Inline 6
Replies
11
Views
22K
thesameguy
T
Back
Top