My 1970 Duster with a 318 has an Edelbrock 1407 carb. It idles well, cruises well, and runs great at full throttle. But, at light application of the throttle, it stumbles pretty bad. what would be your recommendations to correct this?
Edelbrock 1407 issue
- Thread starter jacko241
- Start date
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Basics, basics.
- Did it ever run well?
- New?
- Check float level, should be 7/16"
- check for acc pump shot: engine off but carb full of fuel; operate the linkage while looking for a fuel squirt into each pri bore
- check that met rod pistons & rods are in place. When re-fitting pistons, tighten covers so that pistons are captured, but you can see them. Run engine, in gear idling, if auto. Pistons should stay DOWN. If they move, you need a softer step up spring. Move to neutral & blip the throttle, pistons should pop up & hit the covers.
- does the engine have a 'hot' cam? This could expose too much transfer slot. Refer to the Edel handbook for fixes.
- Did it ever run well?
- New?
- Check float level, should be 7/16"
- check for acc pump shot: engine off but carb full of fuel; operate the linkage while looking for a fuel squirt into each pri bore
- check that met rod pistons & rods are in place. When re-fitting pistons, tighten covers so that pistons are captured, but you can see them. Run engine, in gear idling, if auto. Pistons should stay DOWN. If they move, you need a softer step up spring. Move to neutral & blip the throttle, pistons should pop up & hit the covers.
- does the engine have a 'hot' cam? This could expose too much transfer slot. Refer to the Edel handbook for fixes.
Thanks for the info. Car has been dormant for over 10 years. I rebuilt the carb, float level is spot on.
Ok so first question still unanswered. DID IT ever run good?
I fixed the part throttle on my boys 340 Duster that
had that issue buy putting in a set of faster (lighter) springs
in the distributor to give it more timing at lower RPMs.
Available on Summit etc and not expensive 10 to 15 bucks.
had that issue buy putting in a set of faster (lighter) springs
in the distributor to give it more timing at lower RPMs.
Available on Summit etc and not expensive 10 to 15 bucks.
One easy adjustment you can try is moving the accelerater pump to the hole closest to the carb body. That gives a richer pump quicker. Worked for me in the past when I had an off idle stumble.
I rebuilt it with new accelerator pump, floats, needles, seats, and gaskets. It is more of a stumble than a bog, like it is lean in transition. I am more familiar with Holleys.
Still do the checks I outlined. New means nothing. I fitted a new pump plunger to a TQ. Within a few weeks, the rubber cup rolled up & no pump shot!
That was because of the soft type of rubber used to make them E fuel compatible.
That was because of the soft type of rubber used to make them E fuel compatible.
I checked the fuel pump shot, and I think you are right. Something is wrong with it. On light application there is almost no shot.
If the rubber plunger is good, making a seal, start with the pump shots rod in the closest hole for a maximum shot. Adjust the height of the top of the plunger correctly as to make sure the plunger is in the right spot of filling up the well and delivering a maximum amount of fuel into the carb.
You can try to work your way back on the attaching point of less shot if the closest hood is delivering to much.
Do you have extra/spare pump shot clusters?
You can try to work your way back on the attaching point of less shot if the closest hood is delivering to much.
Do you have extra/spare pump shot clusters?
Good gawd.
I don't have anymore spare parts. How do you adjust the height of the plunger?
The pen points to the rod to be bent.
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The area to measure is pointed at by the pen. Adjust the the height to spec here….
Adjust IF need be.
Adjust IF need be.
Freakin fat finger Thursday!!!!
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When you don’t, it looks like the above quoted message.
As it appears, it seems like I said thank you, which I did not, the reply including your “Thank You” (In which you are welcome!) would seem to be seen as if I included the thank you and IMO, looks like I’m being sarcastic or an *** towards you.
Remove the carb top & you can check the plunger cup. Unlike brand H, you do not need gaskets if you are careful.
If the cup is damaged & needs replacing, the original leather ones are best if you can find one. There were two sizes, 3/4" & 13/16"; pretty sure the E carb uses the 13/16".
If the cup is damaged & needs replacing, the original leather ones are best if you can find one. There were two sizes, 3/4" & 13/16"; pretty sure the E carb uses the 13/16".
Thanks, I wonder if the Chinese amazon kit I got had the wrong size cup?
Johnny Dart
Well-Known Member
Another good tip would be to take off the pump nozzle, or squirter, and blow compressed air through it. Sometimes it gets clogged, or blocked from sitting. I've seen 1 or both sides completely clogged. Gives you a nice clean pump shot of gas when done.
Garbage bag of parts. The plunger may be OK.
Don’t cheap out of parts for you good carb. It’s not worth the PIA of working on the carb only to do it twice.
Check this out….
Rat Bastid
Dunamis Metron
Don’t know what junk you buy, but I have gaskets that are 6-7 years old that have been apart so many times I can’t count.
You seem to be married to Holley junk. I stay away from anything with Holley on it.
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