KillerRS

I have a carb on my 305 that is a Edelbrock thunder AVS 650 cfm w/ electric choke. It is part # 1806. I have a problem that when i go WOT it hesitates. I adjusted the pump and that helped a bit, but im thinking it needs bigger jets, what do you guys think?

1985WS6transam

iTrader: (4)

I was wondering if you ever solved this problem i have the same carb and the same problem so maybe a TTT for this thread instead of making a new one.
edit only difference is that i have a 350...

camaronewbie

Kinda same issue here, only I have a 1406 Edelbrock - what happens when you make a circle - like driving into a cul-de-sac with foot on brake and at idle in gear? I've adjusted my floats per instructions, and no result. Are you guys running stock in-tank pumps?

1985WS6transam

iTrader: (4)

I have the same problem with the culdesac, i live on one and everyday my neibougers think that i speed around the block... at least now i know it is the carb.

camaronewbie

OK - I talked to the Edelbrock tech support again. Here's what they said:

1) Try adjusting the fuel pressure down - maybe fuel pressure is blowing past the needles/seats.

2) Try EDL-1465 - spring loaded needles - replace regular needles with these - $13.

3) Try dual feed line into carb, instead of single inlet - split fuel lines into 2 and use the Edelbrock dual feed line.

I'm trying #1 tomorrow - I'll post results.

What's everyone's fuel pressure set to? Everyone using the Mallory 4309 pressure reg?

1985WS6transam

iTrader: (4)

Mine is set to 4.5 but it dies, what is yours set to while it dies?

camaronewbie

Mine is set at 6psi. I'll try 4psi tomorrow. And I'm stopping by the pro shop for the spring loaded needle valves. I'll let ya know.

Please - anyone else with a possible fix chime in!

Sitting Bull

More often than people realise, the problem of your carb bogging at wide open throttle is the extra shot of gas not getting a strong enough spark. Check over your ignitions guys. How long since you replaced the plugs, wires, cap, rotor or coil?

Night rider327

iTrader: (13)

Ok guys... Heres yalls fix for the eddy carb probs.. I been useing them for 7 years and doing what others say they won't do (go fast, bog free)

The float level in the book is BS and wrong unless they changed it in the last year or so.

Adjust the floats at rest to 7/16", set the float drop to 15/16" to 1"

Put the pump arm in the very top hole. Not the middle or bottom

Make sure you have 5.0 to 5.5 psi max fuel pressure. I set mine to 5.25 psi.

Those things will pretty much stop your stalling on turns and braking, along with most of your bog if not all.

The spring loaded needles aint needed in 90% of the cases I seen.

Set the idle mixute screws using a vac. gauge. Put a vac gauge on full vac port (driver's side) and turn 1 screw at a time.. Your looking for the highest vac reading. When you get the highest reading go to the other screw.. Do the same thing.


The rest of the cal. is based on each engine combo. So hard to give you gen. info there.

Good gen thing to think about though. The elec. choke carbs are jetted leaner than the man choke ones from the factory.

The 600 cfm carbs in gen are too rich for stock-ish engines and too lean for more performance engines as they come out of the box.

The 750 and up shouldnt even be used on mild engines less than 350 cid and making under about 400-425 hp.. Then they will still be way too rich out of the box.


Most of the times the step up springs are too weak and need to go up 1 step on them (go from yellow 4" hg to orange 5" hg, or from orange 5" hg to pink 7" hg) , but check your vac at idle 1st. If you have a big cam, low vac you don't want a heavy spring that enriches while your just idling.

camaronewbie

OK guys - I tried what Nightrider327 said - I switched to the top notch on the accelerator pump, and things got better anyways. Mine still wants to die in the hard turn, but she's all power now at WOT. Maybe I need more float adjustment.

One thing I also tried - the vacuum line to the Mallory 4309 - and it was terrible - my pressure kept changing from one run to the next, and sometimes while driving. I'd stop, and it would be 0psi at idle, then I'd adjust up to 3psi, take another run, and look again to see it was now at 8psi at idle - it was really screwy! I scrapped the vacuum to the regulator, and just set it to 5psi, and it finally stayed put.

Oh, and Edelbrock instructions do now say 7/16ths and 15/16ths now.

Thanks! I'll keep at it til I get it - but at least it's driveable now!

Night rider327

iTrader: (13)

camaronewie... If it's stalling on hard breaking or turns then it's the float adjustment.

I ain't bought a new edelbrock in about 1.5 years (got 4 used ones still sitting on the shelf) but I'm glad they pulled thier heads out of thier butts and put the right float specs in the paper work.

use to say 11/32" at rest and 1" +/- 1/4" drop

The last one I bought new the floats wasnt even set to thier old spec right. Both sides was diff. from each other. Wonder if they are setting them better now.

I really like the carter AFB/Edelbrock carb design. Alot of people junk them or give them bad names just cause they don't understand the carbs and don't take the time to understand how to dail them in. Like I said I been running them for the last 7 years and you couldnt get me to switch to another carb.

These are probbly the easiest carbs to work on, tune and rebuild.

They are picky about the fuel pressure and float adjustments though

camaronewbie

Nightrider327:

Well, I haven't had time yet to recheck or do any further adjustments to the floats, but I'll check it this weekend again. If I now have the pump arm in top hole, and I'm set at spec (7/16 inch level and 15/16 inch drop), what direction on the floats would you suggest I make further adjustment? I don't mind trying different settings, but I don't have enough experience to know what direction to go from here.

Night rider327

iTrader: (13)

Check your float level now.. Then get back to me and I'll help you go from there on diff. settings.

I feel pretty safe to say if your fuel psi is 5.5 or under, and your still stalling in turns then floats will not be set right to the specs listed when you take it off and check.

here's you a tip.. Get you out a 7/16" drill bit (not one of the necked down types to fit in a 3/8" drill)

The 7/16" drill bit makes a great checking tool. Take air horn off, flip it over with gasket in place and slid the drill bit under the very front tip of float. You shouldnt see the float lift up any, but you also shouldnt see a gap bettwen float and drill bit.

On the float drop I use a steel rule (any type of ruler or tape will work), hold the air horn right side up, up in the air, hold gasket in place, now put your rule against the bottom of air horn gasket pushing up, and see where the very front tip of the upper part of the float comes too.

Any time you adjust one spec (rest or drop) be sure to check the other setting to make sure you didnt change it. Alot of times the specs will get out when you bend the tab to set one, now the other setting is off so you have to re do it.