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What carb for 454

77snowwheeler

77snowwheeler

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I’m really getting frustrated. Having all kinds of trouble with my truck. Backfire, almost stalling, and even the front butterfly valve on the carb locking shut.
I’m going to start over. Replace my manual fuel pump, for an electronic? My Avenger carb for maybe a double pumper, or classic, 750/850cfm? New AC Delco distributor, for the MSD? And possibly have to start over with a new set of wires to replace my very expensive ceramic end wires? Going to leave the performer rpm intake because it matches my large oval port heads. I don’t know what cam I have but I know my 454 does have a very mild performance. Any ideas out there? Thanks in advance.
 
I ran Holley carbs forever (vac sec and dbl pumpers, even a Dominator) but for a non racing motor I absolutely love the user friendly-ness of my electric choke qjet. It runs great but it’s not spicey like double pumper Holleys which is ok for me now.

My smelly opinion, get a pro built electric choke qjet, stick with a good HEI and mechanical fuel pump - these pieces are dead azz reliable.

I wouldn’t consider replacing your existing fuel pump unless a test gauge shows inadequate pressure or it’s leaking from the weep hole.

Throw in a good tune up also (probably FIRST).
 
83ChevyK5Blazer said:
Contact sean murphey induction (SMI) and have them build you a qjet. Nothing will run better on or off road.
Click to expand...
They built mine over a decade ago and it was a huge improvement. I did make the mistake of NOT using a spacer and cooked the epoxy off of the well plugs. I wish that there was a better solution.

Do you have any recent experience with them?

My next choice of a carb for a truck would be an Edelbrock, just because I have never had any luck at all with a Holley.

Is there a way to confirm that the MSD is not having problems and contributing to issues?
 
nvrenuf said:
I ran Holley carbs forever (vac sec and dbl pumpers, even a Dominator) but for a non racing motor I absolutely love the user friendly-ness of my electric choke qjet. It runs great but it’s not spicey like double pumper Holleys which is ok for me now.

My smelly opinion, get a pro built electric choke qjet, stick with a good HEI and mechanical fuel pump - these pieces are dead azz reliable.

I wouldn’t consider replacing your existing fuel pump unless a test gauge shows inadequate pressure or it’s leaking from the weep hole.

Throw in a good tune up also (probably FIRST).
Click to expand...
I really like your idea of the qjet. If they’re tuned right they are really nice. Maybe an 850cfm. I really didn’t want to change the manual, but still need to get rid of the problems
nvrenuf said:
I ran Holley carbs forever (vac sec and dbl pumpers, even a Dominator) but for a non racing motor I absolutely love the user friendly-ness of my electric choke qjet. It runs great but it’s not spicey like double pumper Holleys which is ok for me now.

My smelly opinion, get a pro built electric choke qjet, stick with a good HEI and mechanical fuel pump - these pieces are dead azz reliable.

I wouldn’t consider replacing your existing fuel pump unless a test gauge shows inadequate pressure or it’s leaking from the weep hole.

Throw in a good tune up also (probably FIRST).
Click to expand...
 
6872xtc said:
They built mine over a decade ago and it was a huge improvement. I did make the mistake of NOT using a spacer and cooked the epoxy off of the well plugs. I wish that there was a better solution.

Do you have any recent experience with them?

My next choice of a carb for a truck would be an Edelbrock, just because I have never had any luck at all with a Holley.

Is there a way to confirm that the MSD is not having problems and contributing to issues?
Click to expand...
 
My intake is dual plane. Do you recommend a spacer? I’m thinking about an open spacer for qjet if I go that route? I had a Edelbrock 750, and it ran great until I started hill climbing, then it ran out of gas.
 
nvrenuf said:
I ran Holley carbs forever (vac sec and dbl pumpers, even a Dominator) but for a non racing motor I absolutely love the user friendly-ness of my electric choke qjet. It runs great but it’s not spicey like double pumper Holleys which is ok for me now.

My smelly opinion, get a pro built electric choke qjet, stick with a good HEI and mechanical fuel pump - these pieces are dead azz reliable.

I wouldn’t consider replacing your existing fuel pump unless a test gauge shows inadequate pressure or it’s leaking from the weep hole.

Throw in a good tune up also (probably FIRST).
Click to expand...
As far as tune up, there’s Les than 500 miles on this brand new build. That’s what’s frustrating. And the two of the ceramic end plug wires started burning through because they’re almost touching the headers. Crazy. That is why I bought them.
 
What carb are running. I understand the primary throttle getting stuck is not related to the popping, but that does need addressing. Better closed than wide open.
Has a compression and leak down test. This will help eliminate anything mechanical.
Ie brunt bent valve. Also the valve springs should be checked.
All the basics have been done? Firing order double and triple checked? Timing chain checked against tdc?
Also another vote for properly prepared Qjets, and HEI.
 
Wes Harden said:
What carb are running. I understand the primary throttle getting stuck is not related to the popping, but that does need addressing. Better closed than wide open.
Has a compression and leak down test. This will help eliminate anything mechanical.
Ie brunt bent valve. Also the valve springs should be checked.
All the basics have been done? Firing order double and triple checked? Timing chain checked against tdc?
Also another vote for properly prepared Qjets, and HEI.
Click to expand...
Wes Harden said:
What carb are running. I understand the primary throttle getting stuck is not related to the popping, but that does need addressing. Better closed than wide open.
Has a compression and leak down test. This will help eliminate anything mechanical.
Ie brunt bent valve. Also the valve springs should be checked.
All the basics have been done? Firing order double and triple checked? Timing chain checked against tdc?
Also another vote for properly prepared Qjets, and HEI.
Click to expand...
I bought a used, 670cfm Avenger, but the guy said he never installed it on a vehicle. It looked brand new. I haven’t been able to get anything running as good as the other intake and Edelbrock. Performer 02. If I could have gotten it to hill climb, we wouldn’t be having these conversations. Lol
 
So the engine ran strong with afb clone? But the avenger has popping? That is the only difference?
 
77snowwheeler said:
I bought a used, 670cfm Avenger, but the guy said he never installed it on a vehicle. It looked brand new. I haven’t been able to get anything running as good as the other intake and Edelbrock. Performer 02. If I could have gotten it to hill climb, we wouldn’t be having these conversations. Lol
Click to expand...
Haven’t adjusted valves since initial adjustment. Maybe it’s time to put on the new distributor, take the valv covers off and readjust. Double check top dead center to confirm on the right lift for proper timing. Maybe I can find a way to repair the two ceramic ends on the burn spots? But I’m convinced the carb needs to be replaced, because no matter what I do, it never fills the clear fuel filter after warm up, like it won’t drink enough gas. And it only gets 6 miles to the galllon, and the Edelbrock was getting 8. My goal is ten, with the performance.
 
Ok so that glass filter is fire waiting to happen. I strongly recommend you remove it.
Since you have a mechanical pump use the steel line from pump to carb, with as little or no rubber hose as possible.
Put a metal 3/8 filter before the pump at the frame or back at the tank.
If you convert to electric pump, remove mechanical, block off pump boss and use quality braided hose and fittings.
That filter will never be totally full. The cleanable screen inside doesn't filter small enough, to keep debris out of the needle and seat or bowl
 
Wes Harden said:
Ok so that glass filter is fire waiting to happen. I strongly recommend you remove it.
Since you have a mechanical pump use the steel line from pump to carb, with as little or no rubber hose as possible.
Put a metal 3/8 filter before the pump at the frame or back at the tank.
If you convert to electric pump, remove mechanical, block off pump boss and use quality braided hose and fittings.
That filter will never be totally full. The cleanable screen inside doesn't filter small enough, to keep debris out of the needle and seat or bowl
Click to expand...
It’s just a clear plastic, but when hot it only trickles, like big drops, but it maintains 5-6 psi, on the gauge. When I replaced the new tank sending units they had filters on them, so wasn’t sure where to put the inline? If I go qjet, I’ll probably keep the manual pump.
 
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