So I replaced the massively oversized holley 800 on the maverick with a holley 650 mechanical secondary. I'm getting a hesistation / stumble in low throttle conditions like right after the clutch is released or under load when realeasing the clutch. Mid throttle seems very responsive and pulling ok. Wide open throttle also feels extremely flat and boggy. No leaks from carb and the car idles fine. 3 speed manual 4.10 gears Car weight under 2900 lbs Anyone got any advice? Is a 650 to big? Mild erson cam Stock mid 80s heads ( don't laugh ) Long tube headers Torker 1 intake Mallory hyfire ignition Thanks
http://mmb.maverick.to/showthread.php?t=98392&highlight=holley+carb+issues Sounds a lot like the problems scoop had. Also, I highly suggest this: http://www.youtube.com/user/HolleyPerformance
Is the 650 Holley a new or used piece? If used, I would double check the size of the acc pump squirters as well as the acc pump adjustment.
Adjustments seem fine. 28 primary 37 secondary White cam ( I think ) #1 position 6.5 pv primary with 67h jets No pv secondary with 73h jets
Not sure if this will help, but this wiki entry for the pump cams has their profile curves and stuff. http://www.crankshaftcoalition.com/wiki/Holley_accelerator_pump The white is like one of the least aggressive. It was suggested to me to use over the red while I was tuning for minimum fuel consumption on the 350cfm Holley. The jets seem fine, a 28 seems a bit smallish to me. Maybe the previous carb owner was into maxing his MPG. White is a 17cc shot cam according to the chart. Yea you might be stumbling a bit after letting off the clutch.
Hey Nut...Put on a more aggressive cam. I did, as per instructions from groberts, and my carb WOKE UP!!! I have the most aggressive on the secondaries, and the next most aggressive on the primaries, and it doesn't stumble at all, and goes from idle to primary to secondary smoothly and fluidly.
And NO, 650 is not too big. I ran 2 different 600 cfm carbs, and everyone said they were more than big enough. I put a 750 on, and everyone (on here) said it was too big. Took it to the dyno and Richard Lelsz at Strictly Performance dyno (look him up on google or http://strictlypro.com/index.php ...knows his stuff on ford engines) told me, "yeah, a little big for just cruising, but it will work and it will work GREAT at higher speeds". I just needed to tune it UP from stock configuration to make it work.
Ok thanks. Any idea on the jet sizes I listed. I reset the idle screws to 1 1/2 turns out and I will bust out the timing light and vac gauge and see if I can get it right. A local shop sells tons of holley parts so I can pick up squirters and cams. What cams / squirters / jets should I have? Any idea on what position the cam should be in. Mine is on 1.
I bought the cam kit, used the biggest ones, and put them on #1. Made a world of difference. Also put on a larger secondary squirter, but don't go there unless you have to.
And another question. I have a 800 holley center squirter that works great except.its fouling plugs and obviously too big. Could I just the jets etc etc from my 650 and throw them in the 800 and be done?
The link that I put up earlier has the cam specs for how much they squirt. And you could put the jets and stuff from the 650 into the 800, but it would have a really air heavy AFR, and I wouldn't want to tune that without an Air/Fuel Ratio Gauge installed. What is the accelerator pump size on your carb? You need to know that really to make sure you have the right pump cam. The 650s if I recall usually have a 20-30cc pump, so you need the 20-30cc pump cams. It would help a lot if you have the model # for the carb so we can figure out how much it's been modified. I would guess if it has the smaller pump cam, someone might have put on the smaller pump to try and get their mileage down. Or maybe they just put the smaller pump cam on. In any case I'm positive someone tried to make a hyper-miler and couldn't figure out the tuning.
