eledblrock

[monte70car]

I'm trying to get a small block to run with a edelbrock 750 carb. For some reason we can not get it to idle. The old car was a holley 600 which idle good. Is acts like it running out of gas but when it cuts off it will start back up then cuts off again. We did have it idle good enough to move the car in the yard. Any and all help is welcome I'm not sure which model # edelbrock it is but its not a factory built from edelbrock.

[Mike 57]

eledblrock? Sounds like a vacuum leak.

[monte70car]

So check all areas and go from there joy. Any ideas how far the mixture screws should be set?

[Sam (Bones)]

1 1/2 turns

 

[Winston Wolf]

Is this a new carb? Have you set the float levels?

[Sam (Bones)]

can you keep it running with the gas pedal? if not I would tear it down for inspection and as Winston Wolf said...check the float level

[monte70car]

I had it running long enough to pull my out of the garage and wash it even went around the block, came back went to back it up farther in the yard and it just die. From looking at the box it was a rebuilt until just hate to pull it apart for something was was supposed to bolt on and go oh well, one good thing is it's just a matter of pulling the top.

[MonteFox89]

hey, I actually had a similar issue about a week ago. I kicked off my edelbrock quadrajet and threw on a 650 holley. I know you're going higher than a 650 but this may also help. Basic rules of carb switching, Check all Vaccum lines, floats, and also check your power valves to make sure you're not flooding out your carb. I had a power valve that was to large and I had to drop it down just so I could stay running. also, Most of everyone here may know this and is well experienced with cars but, Those vaccum lines at the back of the carb running to the master cylinder.... yeah those are important too... ahaha... I didn't reconnect mine at first and tried to seal it off.... Don't try it... not worth it! besides all of this. if it's not a new carb, simply try rebuilding it *shrug* couldn't hurt anything more than your wallet, and the engine/carb if you rebuild it wrong O.o I trust you though, I mean hey, you were smart enough to ask these guys

[Winston Wolf]

Tell me the model number stamped on the fron of the carb and I'll tell you how to make it work.

 

And you need to install a fuel pressure gauge if you don't have one already.

[monte70car]

This is the first time I've messed with a Edelbrock carb a Holley is pretty easy to do. As for vacuum lines the only ones on the carb is for the dist. and the pcv brakes runs off the org. port in the intake. Whats funny is Monday after I got it we had it up and running with the rear port(for the booster) not plug. We did mover it over in the drive way yesterday and it ran fine but then again it didn't go more then 10' from point a to point b.

 

Wilson the only thing I see on the front is the Edeblrock name plate I will run out and double check though. It has 1411 8192 with a build date I'm guessing 04 09.

[Sam (Bones)]

ERT, pull the vacuum line off the booster and see if it runs with a massive vacuum leak like that then, you've just narrowed it down to float level or needle and seat, it's flooding

 

I would still pull the top off and double check everything

[monte70car]

Sounds like a project for tomorrow just got the front end put back together and some what close to what the book said.

[MonteFox89]

hey, I actually had a similar issue about a week ago. I kicked off my edelbrock quadrajet and threw on a 650 holley. I know you're going higher than a 650 but this may also help. Basic rules of carb switching, Check all Vaccum lines, floats, and also check your power valves to make sure you're not flooding out your carb. I had a power valve that was to large and I had to drop it down just so I could stay running. also, Most of everyone here may know this and is well experienced with cars but, Those vaccum lines at the back of the carb running to the master cylinder.... yeah those are important too... ahaha... I didn't reconnect mine at first and tried to seal it off.... Don't try it... not worth it! besides all of this. if it's not a new carb, simply try rebuilding it *shrug* couldn't hurt anything more than your wallet, and the engine/carb if you rebuild it wrong O.o I trust you though, I mean hey, you were smart enough to ask these guys

 

hmm, in hind sight, none of this may relate to you because the carb is from '76... and I still have the original engine in the '72... soo if you're running something newer, I'm sure it's different X.x

[Riznitch]

Is it possible it's to much carb? i had a 700cfm quad on mine and it ran super rich! I had the needles maxed out and still no luck. had my original rebuilt and there was no problem.

[monte70car]

It runs and sounds like it should no stumbling getting on it and seems to have a pretty crisp throttle and the top didn't come off. I turned the mixture screws out 1.5 turns had a puff out the carb so turned the dist a little to the passenger side until it started and was able to play with the throttle. now to adjust the alternator out so it keeps the belt in line with the rest of the pulleys.

[Riznitch]

I had to make alternator bracket adjustments as well. glad it's working out for you.

[Winston Wolf]

It runs and sounds like it should no stumbling getting on it and seems to have a pretty crisp throttle and the top didn't come off. I turned the mixture screws out 1.5 turns had a puff out the carb so turned the dist a little to the passenger side until it started and was able to play with the throttle. now to adjust the alternator out so it keeps the belt in line with the rest of the pulleys.

 

Sounds like it needs to be timed, along with adjusting the carb. Use a vacuum gauge to set the idle mixture. Download the manual from Edelbrock and do exactly what it says to do.

[monte70car]

Here is a short video if it running camera is sitting on the battery pointing at the motor so it does move. The - battery cable looks close but it's not.

[monte70car]

Well we changed the float level using a 7/16 drill bit and it still stumbles, would it be ok change the floats some more? The pump ARM rod is currently in the middle hole total timing is 32 degrees. As long as you easy into it its fine but to stand on it from a stand still is trys to cut off.

[Mike 57]

I would bump the total timing up to 36

[monte70car]

This dam carb is driving us nuts we did bump the timing up to 36° and it still cutting off when you get on it from a stand still. We followed the adjustment for the floats using a 7/16 drill bit and the fuel bowls are half full before they were a 1/4 full.

[Sam (Bones)]

accelerator pump

[monte70car]

accelerator pump any idea on which one? I don't see any where were it talks about changing the accelerator pump, just the metering rods. Today the game plan is to bolt my old(less then 100 miles) q-jet on just to see how the suspension and the alignment is. I just got to figure out how the spread bore to square bore plate bolts down as it has a place for nuts to sit in the plate.

[wallaby]

The accelerator pump is the squirter that shoots fuel into the carb throat when you open the throttle.

Does you squirt seem to be working ok? It should provide a solid stream right away as you quickly add throttle. If the squirt happens on a delay, or comes out sputtery, there is room for improvement.

Another question is whether the engine has this stumble when it's in neutral, or only when you are actually driving it?

[monte70car]

The stumble is there when in park and is only noticed when reving the motor and the car cuts off but then it starts right back up.It does squirt gas pretty good.