Edelbrock 600 cfm carbs.

Dave · April 23, 2004, 07:35:09 PM

Im thinking mine is mucked up. It doesnt adjust right for the idle and if I go around a corner at about 25 mph and lift off the gas then back on its got a hiccup..I talked to edelbrock tech what a joke... He told me to just get used to a rough idle.? I dont think so...He also told me the hiccup was due to the float level being wrong. I checked it 3 times and its ok. Ive got another carb comming to to try next week just to verify if its he carb.
Anyone else have this problem...Oh ya i took the dam thing apart and cleaned it good but its brand new and shouldnt have any problem..
Dave :?:

Sean · April 23, 2004, 10:07:26 PM

Quote from: "N8DC"
Anyone else have this problem...

I was not impressed with mine either. Messed with the idle mixture several times and its either Rich, or idles rough, no in between.

Worked with the float level twice because I keep smelling Gas. I can pull in the driveway, pull off the air cleaner and find the entire secondary area wet with gas. Never have got it to stop, and as soon as I figure out what I did with the bolts for my Qjet, the Edelbrock is going elsewhere.

HOTRODSRJ · April 24, 2004, 04:48:30 AM

Sorry you guys are having such problems with the old AFBs. These usually are plug and play units only needing occasional spring changes.

But, the around the corner and on the gas problem can cause hiccups with engines/intakes that are outside the spec of the carb. This is either because the engine is tilted too far front or back or the intake is raked oddly?

The remedy nevertheless is upping the level of the float to allow slightly more fuel in the bowls. This should keep the primaries covered with fuel when you whip around those corners. And, I would make sure your "transition or crossover" springs are correct. This can be a problem. If you have a 16" vacuum reading on the engine and haven't moved up to a silver spring I think you are too lean in the throttle crossover circuit. This can mimic your problem around corner symptom. Try that first.

Mikej · April 24, 2004, 08:57:52 AM

Quote from: "Sean"
Quote from: "N8DC"
Anyone else have this problem...

I was not impressed with mine either. Messed with the idle mixture several times and its either Rich, or idles rough, no in between.

Worked with the float level twice because I keep smelling Gas. I can pull in the driveway, pull off the air cleaner and find the entire secondary area wet with gas. Never have got it to stop, and as soon as I figure out what I did with the bolts for my Qjet, the Edelbrock is going elsewhere.

Dave · April 24, 2004, 05:05:44 PM

Ok i changed the step up springs today and went to the silver or natural ones. Ive got 20 inches of vacum so it must be good and tight..I also played with the timing a bit and im no at 4 degrees btdc and il try that a while.Im hoping that i can fix it and not have to use the louvered side panels for the hood ive got comming as far as the high speed vapor lock goes but we will see. The paper with the crate motor said start at 10 degrees for the timing. Seems like a bit much to me its only a stock 350 about 250 hp with a 4 bbl. The idle still sucks but it acted better as far as the stumble that it had...
Dave

47convert · April 24, 2004, 05:29:48 PM

Steve, mine works good, but there's a bit of a flat spot sometimes when I let out the clutch. It wants to do a little nose dive if the RPMs aren't up a bit higher than I would normally take off. I'm kinda used to it now and it's not too much of a problem. If it was a Holley, I'd say the accelerator pump was a bit big - What do you think?

Mikej · April 24, 2004, 05:45:52 PM

I have a 750 Edelbrock and the throttle plates were out of adjustment causing a overly rich idle and no effective adjustment with the idle screws. It was idleing on the primary circuit.I closed the throttle plates up, messed with the timing alittle and got the idle ajusted. ( lean drop method) No more gasing me out of the garage. The dead spot you are having could be tip in hesitation caused by the improper adustment of the throttle plates.
I'm not a big fan of these carbs but they are fun to play with.

Dirk35 · April 25, 2004, 01:57:56 PM

Sorry to hear of the trouble. FWIW, I put a 750(700?) Eldebrock on my 390 FE quite a few years back. Oh my goodness did it work GREAT! It litteraly was a pull out of the box and bolt it on. I didnt even have to adjust the idle screw. It idled about 700rpm out of the box. A the same time, my brother put the Holley 650 on his Chevy 350 and he has had to fiddle with that thing every time he drives it just to get it to start, and after it warms up , he has to adjust it again! We had the same trouble with the Holley on our puller tractor.

They both are pretty warmed up engines with street/strip cams and bored 30 over and heads that are ported and polished and port matched.

htrdsx · April 26, 2004, 10:10:14 PM

Quote from: "Sean"
Quote from: "N8DC"
Anyone else have this problem...

I was not impressed with mine either. Messed with the idle mixture several times and its either Rich, or idles rough, no in between.

Worked with the float level twice because I keep smelling Gas. I can pull in the driveway, pull off the air cleaner and find the entire secondary area wet with gas. Never have got it to stop, and as soon as I figure out what I did with the bolts for my Qjet, the Edelbrock is going elsewhere.

I have the same problem with my Edelbrock 600 cfm. When I shut the engine off there's a strong smell of raw gas. I pulled the airfilter off and the secondary area was wet with gas. Anyone have any idea what is causing this? I guess I need to check the throttle plates also, because it's idling rich and won't adjust out.

GaryB :cry:
//www.nucwa.com/page2.html

Dave · April 28, 2004, 07:06:34 PM

Quote from: "htrdsx"
Quote from: "Sean"
Quote from: "N8DC"
Anyone else have this problem...

I was not impressed with mine either. Messed with the idle mixture several times and its either Rich, or idles rough, no in between.

Worked with the float level twice because I keep smelling Gas. I can pull in the driveway, pull off the air cleaner and find the entire secondary area wet with gas. Never have got it to stop, and as soon as I figure out what I did with the bolts for my Qjet, the Edelbrock is going elsewhere.

I have the same problem with my Edelbrock 600 cfm. When I shut the engine off there's a strong smell of raw gas. I pulled the airfilter off and the secondary area was wet with gas. Anyone have any idea what is causing this? I guess I need to check the throttle plates also, because it's idling rich and won't adjust out.

GaryB :cry:
//www.nucwa.com/page2.html

Is the fuel boiling maybe and over flowing and thats why you smell gas?
I havent checked my throttle plates yet cause ive been changing other things. I did go with a carter 6 psi 120gph fuel pump hoping that more presure and flow will over come the vapor lock problem. I went for a ride tonite cause its about 70 here and it ran ok. I may go out tomorrow too cause it may be near 80 and thats when it really acts up. If all else fails my 4 row louvered side panels came yesterday an I can fit and install them after paint. Im thinking about just going ahead and fitting them then id have 2 versions to use..
Dave

purplepickup · April 28, 2004, 08:12:42 PM

Dave, when you get tired of dinking with that junk edelbrock and decide to go back to a Holley, let me know. I'll give you $50 for that piece of crap.

buffalo bob · April 28, 2004, 08:30:48 PM

I don't know about the new Eldelbrock carbs, but the early ones required less than 5psi to unset the needle which let fuel into the float bowl. At idle stock Chevy fuel pumps put out 5.5psi which is more than enough to unseat the needle. Without a fuel pressure regulator the carb tends to flood while idleing around, like sitting at a traffic light. I had a Cagle fuel pressure regulator before my Edlebrock carb and didn't have any idle problems. Kinda dead on top, but idled fine.

htrdsx · April 28, 2004, 08:51:31 PM

I really don't have any overheating problems and I'm using the stock mechanical fuel pump. This morning before I started it I took off the filter and looked down into the secondaries. I noticed that inside the void where the counterweights run on the outside of the bore, gas was puddled on both sides. I dried it up with a rag and took it out for about a three hour cruise. I checked it when I got back and it was still dry and there wasn't the usual smell of gas after I shut it down. It's got me stumped. I guess I'll just keep and eye on it and see how long it takes it to accumulate again.
Oh yeah, I did snug down all the screws on the carb top before I left this morning. Maybe that was my problem, although they only tightened about a quarter turn.

Gary

HOTRODSRJ · May 01, 2004, 08:20:51 AM

These carbs like regulators that keep things under 7psi. Any more and who knows. I always use the Carter fuel pumps with the built in regs.

If you are having "tip-in" problems such as hesitation when letting the clutch out, this is a transition spring problem usually. The engine RPMs are pulled down and vacuum drops therefore dropping the rods. I would install a stronger spring. If that doesn't do it, go to a richer transition rod and leave the cruising step alone. Basically, it's leaning out.

One poster makes a very good point about throttle involvement at idle. If you can turn your idle screws in or out and not affect the idle quality of the engine then the mechanical idle screw is set too high. Back it off and get it to idle on the idle circuit. Usually a 2 turns out from bottom will at least get an idle with the right amount of timing.

And another thing.......USE FULL TIME VACUUM ADVANCE. This helps idle quality and stability as well as cooling.