Its not for a turbo application, but I know there are people on here who can help. I have done a search but didnt find anything in the nine pages that was what I was looking for.

The problem is that when I step on the throttle it stumbles a bit. It does not appear to be getting enough fuel from the accelerator pump. I got a new one but have not put it in yet. I even stepped down on the rods to fatten it up one step so it would not suck so bad on the street. When I took off the top of the carb, the accelerator pump well has scores on the inside of it, the strange part is, they are all running paralell to the base (the walls are not smooth). Any of you guys run into this before? My neighbor had the exact same problem with his after a while and he just bought a new one and stuck it on his engine to fix the problem. I have even tried to bend the pump rod to get it lower in the well so it would move more fuel. I will be rebuilding it pretty soon again, but I want this to work.

Chris

 

The best fix for it is in the garbage can, and then buy a holley, but beside that, when you look down the carb do you see it squirt fuel at all? have you tried moving the accelerator rod to a different hole that will give it a higher ratio of squirt, to fix the scores just sand it or buff it with a dremel but don't think that would be enough to stop the fuel from flowing tho, maybe the plunger is shot, or the hole is plugged. there's not much to really rebuild in those carbs, usually the only thing they need is the plunger which can be bought separetly and all the holes to be blown through with high pressure air.

 

Sounds to me like you need a larger accellator pump nozzle, they make them and summit sells them. Also you can drill a hole below the lowest hole on the accel nozzle level for more pump shot.

 

Thanks guys. I have tried to make it push more fuel with the different hole and even by bending the rod to have it pump sooner. It just seems like there is no fuel at "tip in" when I tried to drive it. I pulled it apart last night and the hole is not clogged. I sprayed through it with brake kleen and then used the old plunger and it pushed a little. I used the newer plunger and it pushed like a champ. I think that should fix it. Thanks again.

Chris

 

i have had two edelbrock carbs on different vehicles sometimes if your engine is pulling alot of vaccum you can go to a heavier metering rod spring to help bring in extra fuel on tip in. you might be running into a problem where when you step on it the vacumm is strong enough to not let the metering rods come up any at all causing a lean stumble.might try that if you havent.

 

[ guess everybody has their opinion, but I've been throwing away holley's and replacing them with afb's for years, from before borg warner and edelbrock caught on and screwed them up. Have never yet had anybdoy that didn't appreciate the improvement. An afb woujdn't fit in my garbage can, it's too full of holleys. I've seen brand new holleys have a bunch of machining debris in the metering block. They didn't work good on trucks, cars, or anything else that wasn't messed with constantly. They're good for racing, and maybe turbo apps, but little else from my point of view. When my turbo makes eec4 useless it's megasquirt, period, no holley for me. I've run quadrajets, 4150 fords, and holleys in heavy haulers, and the quadrajet had best mileage and performance. Spent to much time working in a dyno tune up shop to have much sympathy.
(I do know where to find it however, in the dictionary, between shit and syphlus"

 

holy shit, you finally said something that i agree with i've drilled the squirters out to increase the amount of fuel at the inital hit, i feel like holleys are awesome for wot only applications but if you want to drive one around get a good qjet (the key word here is good) or if you can't find one buy an afb/edelbrock and get somebody that knows what the fuck they're doing to tune it and you'll never love a carb more. $.02

 

That's right and there have been tests proving that. Holleys will beat most any other wo, and arent worth crap anywhere else.

 

I have tried to explain that to people for years about the tempernmenatal carbs such as the Q jet and AFB. I think it is because people do not understand the principals of all of the circuits that are involved with them since they are more complex. On the up side, the more adjustments you have, the better all around performance you get during ALL OTHER driving. A Holly is good for dumping fuel AND can be made to run. BUT since there is only a mixture for the jet, and it does not change with throttle placement, it is just a fuel dump that sits between the fuel pump and the engine.

On a different note, I have had to put the project on stand by for a few days, The airhorn has a stripped out hole for the spring, cup, metering rod, cover on one of the sides. I have some Epoxy in it now and am going to try to tap it later after it sits for a few days. I hope it works, but if it does not, does anyone know if they make a helicoil that small? Talk about pissed off, that was the LAST bolt to put in to finish the carb...............................................................................and it was stripped.

Chris

 

if it'll help i have the top from a 750 that the throttle shafts siezed up in.

 

Nah...Thanks for the offer though, I have another one here too. If worse comes to worse, I will just epoxy some studs in there and use some small nuts.

Chris

 

I'm gonna have to pick with that too, I believe that the old afb's worked much more reliably than their holley counterparts.
Qjets tend to wear throttle shaft bores more, but with proper return spring placement and throttle plate centering can be made to work pretty decent for the life of most cars. Between that and idiots cranking the front mounting bolts to tight and deflecting the airhorn. If those are eliminated I think qjets and afb's are the best carbs out there.


On your stripped screw there are aluminum repair epoxy's out there that machine just like aluminum.

 

I used cold steel and it seemed to work just fine. The funny thing is that on my spare carb, the bolts are twice as long. Wish I had known that earlier, but if it does not stay tight, I will just stick one of the longer ones in. Thanks for all the help and suggestions though guys. Im not sure when I will have time to put it back together, its raining and I have the starter, fuel, and all the ignition to hook up still. Hope it clears up in the next few days.

Chris

 

Update. I cant get this thing off of idle. I got a new fuel pump (mechanical) and it only spits fuel like a two year old. It will not keep the filter ball full so I think that is my problem. The pump will not push ANY fuel even if I do it manually. It feels very weak and this is starting to make me kind of mad. I am going to try to put one more pump on there before I step up to some more expensive one. I only need a few GPH so why is this so hard?

Chris

 

A properly modified AFB (like used on the Avanti Blower cars) will perform very well under boost. I believe there were a couple of guys with 650 cfm carbs (holleys) that ran well into the 9s under boost. AFMs at the same cfm should be able to do the same.

JMO

Tom V.

 

have you blown backwards through the fuel line to make sure that the sock in the tank isn't stopped up? just a thought

 

New tank, filter sock, and sending unit pipe. It had a new pump and line with filter to the carb. I have since taken off the pump and am ordering another one. I have blown through the line. I dont know if I got a bunch of curd out of it or not and I am going to try agin. Correct me if I am wrong, but should there be a constant squirt of fuel from the pump? This looks like you are spitting through your teeth. Just a tad larger than a mist.

Chris

 

LOL. you guys that speak that Holley's are good for WOT only, are you using box stock, home built carbs? I ask because for me, I've never used a home brewed Holley in the first place but have had excellent results with a new C&S carb that has 70/70 jets, gets excellent gas milage for the little street driving, cruises at 14.0 AF while driving but will dip to 11.2 to 11.5 under 32 psi of boost and stay there. Look at my jetting and WOT AFR, I can "STILL" take some more jet away to like maybe 68/68 squared. I mean the throttle response is absolutely rediculous and is crisp as I can ask. Now yes this is a professionally built carb but was wondering what/who's carbs are you using to say that they were only good for WOT?

I know absolutely nothing about the Carter, AFB, Edelbrock carbs and to be honest, I wouldn't have told the guy to throw his carb in the garbage since he evidentally wants to use what he has/owns. I do wonder how much boost can one of these handle though. I have seen as much as 38 psi out of my Holley and have heard of a guy (Heath) that uses 42 psi with his Pro built Holley.

Just wondering what you use Pro- built Holley or Home built.

 

You went to a C&S carb Brent? I figured you would stay with CSU.

 

I've always had a C&S on hand. I went with the CSU at the time because of the great customer service and great working carburetors too. With "MY" particular combo being that I have a small 302 inch motor with a 88mm turbo, I could not get the stumble to go away and I tried everything under the sun too. The CSU boosters work so well that I was getting un-needed fuel at the hit of the throttle and that was what was causing the bog issue for me. The LM-1 would go low 9's on the meter from 13.0 when I hit the throttle. I had all the fuel that I needed but not enuff airflow from my turbo to overcome that issue. If I had a F1R or F2, then I woulda been in a much better shape and the CSU carb would have worked perfectly for me then. It was when I sent the C&S back to them and had it gone through was when there was and is absolutely no bog issue at all and I was able to take jetting down to 70/70 squared on it. So far, so good and with a 162 MPH playing around on the track .