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By cbass139 - 14 Years Ago
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So I had a previous thread about a hard start problem I was having and we fixed but I have a new/old problem. I set everything, on the 292 f100 with 2 barrel holley and electronic/vacuum mallory dizzy, to the normal settings. that is I have the initial timing at 10, the idle screws 1 1/2 out, and the idle speed screw so that the transfer slot had just the square showing to try to eliminate a bog I got whenever the accelerator was initially hit. The problem is that with the idle speed screw set for the transfer slot it has the engine absolutely running away from itself at like 3000 rpms. So I crank it back to 800rpms and it runs nice except for the bog is there when i first step on the accelerator and if I dont let up it will die. So off the line or when turning corners I have to really ease the gas or get on and off and then back on again. What am I doing wrong that the transfer slot setting has this affect? and or what can I do to fix the bog? Thanks for the help, I hope to get the same result as the hard start, that is fixed thanks to you guys, and the FTE siters.
Cbass
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By rick55 - 14 Years Ago
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Thinking logically with this extremely fast idle, it would suggest that the carb is too big for the engine or you still have the engine too far advanced. What number Holley is it? Have you checked for vacuum leaks. With the engine idling spray wd40 around the intake legs on the manifold and around the carb base. If the engine stalls or flares when you do this you have an engine vacuum leak. Don't spray it down the barrels.
Are you sure of the timing mark on your crank pulley - has the balance ring slipped? Connect a vacuum gauge and time the engine with the gauge, advance timing til you get the highest steady reading and then back off timing to drop reading by 1" of vacuum. This may leave the engine slightly advanced but it should still start OK.
From there you will then need to check the carb. What main jets are you using? Is the power valve functioning correctly - what number are you using?
Bog issues are usually caused by a lean mixture or weak spark. Logically thinking, the engine reacts poorly to change of load till it steadies out.
Hope this gives you some thoughts on what next to try.
Regards
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By cbass139 - 14 Years Ago
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Ok, thanks for the ideas. I dont think the carb is too big because it is the original 2 barrel that came with the truck. As far as the engine being to advanced, I am at the fire house again so dont have stuff to check that but it was set at 10 and starting and running fine (except the bog). Will the timing change when I set the transfer slot? I did try to tune the carb using the vacuum method and with the highest vacuum I still had this problem. I think I would have to take the carb off the engine again to find out what size jets and stuff are on it. May have some time tomorrow when my son is taking his nap but other than that not sure my wife will be cool with me playing with my toys on xmas. 
Thanks again
Cbass
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By RB - 14 Years Ago
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What model Holley is it.. One of the old 3 bolt flange or a newer 4 bolt conventional 2150? There should be some numbers on the choke horn. You never know what might have been installed over the years. It sounds like the accelerator pump/ linkage is wrong or not working. A bog off idle like that usually means the carb goes extremly lean when you give it pedal.. Main jetting will not come into play until you get some rpms up. Off idle mixture is the idle and accelerator pump circuit's job
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By cbass139 - 14 Years Ago
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It is the 4 bolt 2300. Accelerator pump and linkage seem to be working just fine, have the lash set to holley's specs on idle and WOT. I hate chasing this but would love to get it right, it is not as fun to drive when you cant just accelerate without worrying about it dieing.
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By speedpro56 - 14 Years Ago
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It sounds like you're running out of fuel. When you look down into the carb and just start to open the the throttle does the accelerator start spraying immediately and if not then adjust it to come in quicker. While idleing with the sight plug out does gas trickel out alittle down the side, if not then the float needs to come up a little. There are 4 small air holes in the top front under the choke flap that may need to be blown out and cleared which can cause erratic behavior.
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By cbass139 - 14 Years Ago
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Gary, the spray is right away but I am not sure if it is the correct size. Might try to see what size it is tomorrow and then go to the store on Monday (as I am sure they will not be open tomorrow). I also will double check the float level but I am pretty sure that is good or was last time I checked (recent). I will look into this and if that is all good I might check the jet sizes. After that I am at a loss.
Thanks
Cbass
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By miker - 14 Years Ago
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Back around 1968, I had a very similar problem with a new 4160 Holley. It had been shipped with 55 jets, and finally someone at the speed shop looked in the Holley book and said "should have been 65". Free jets. Problem solved. Never had that happen again, and my memory about sizes 40 years later is not to be trusted. Check the book or the net, and see what it says before your pull it down, and see what jets you have. That was on an 11:1 312, jeez, I wish we could buy White Pump Chevron gas today.
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By Hoosier Hurricane - 14 Years Ago
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Has it been this way as long a you've had the truck, or is this something that came up suddenly?
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By cbass139 - 14 Years Ago
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pretty much as long as I have had it. I can advance the timing a bit to get it better but that led to the previous post where I was having really hard starts.
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By pegleg - 14 Years Ago
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[quote]cbass139 (12/24/2011)
So I had a previous thread about a hard start the accelerator and if I dont let up it will die. So off the line or when turning corners I have to really ease the gas or get on and off and then back on again. What am I doing wrong that the transfer slot setting has this affect? and or what can I do to fix the bog? First thing I'd do is check the float level. That's exactly what this sounds like to me.
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By cbass139 - 14 Years Ago
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Ok, here we go. I went to the parts store and ordered the stuff I thought I might need to get this all done and fixed for good. Of course the parts are not in stock but they would have them tomorrow, so I went home to double check everything I could so that I would have a starting point. In doing so I got the timing dialed in perfect and the idle where I want it and gave it a shot with the accelerator pump and noticed it shot right away but did not look like it was getting full travel. I went to adjust the screw and check the gap at WOT and the screw was completely loose. I tightened it down and checked the gap, started the truck back up and sure enough with full travel that girl runs like a dream. I thank everybody that gave advice and say to you all to double and trip check everything even stuff you are sure you had working great a few months or weeks ago.
Thanks a ton and have a great New Year.
Cbass
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