Engine cuts out after 3 to 4 seconds of medium acceration

[65Fury440]

So did you say you have a fuel pressure gauge at the carb? If it were me, I would want to see what the fuel pressure is when the problem is happening. I just went through this with the brand new electric fuel pump and regulator on my M37. Same symptoms, starving for fuel at RPM. It would run the primaries out of fuel, if you floor it, the secondaries would run for a short time, then run the fuel out.
What I did was properly hook up a go pro camera to my wheel well....no that is a lie.
What I did was duct tape my cell phone on video record to the wheel well and watched the fuel pressure gauge drop to zero as I drove down the road.
Turns out the cheapie regulator I bought would not flow the volume needed to support the engine. I put on a Holley regulator....done.
If you could run a pressure gauge with line up to maybe the cowl area, and watch it while you drive, you could know for sure if the carb is getting fuel or not.
It helps to eliminate so many maybes.

 

[Zymurgy]

Great idea I bet I can duct tape my phone next to my "Larry" light to luminate the gauge.

I was trying to think how to mount my small video recorder, the phone idea is great. I could probably buy some fuel line and get it up by my window too.

 

[65Fury440]

Great idea I bet I can duct tape my phone next to my "Larry" light to luminate the gauge.

I was trying to think how to mount my small video recorder, the phone idea is great. I could probably buy some fuel line and get it up by my window too.

I did it because I didn't have any tubing, but I did have duct tape and a phone. Yup, I'm a hack!
Too bad I destroyed the evidence, might be good for a chuckle.

I'm sure you will get it narrowed down and figured out. Just out of curiosity, what kind of pump and regulator are you running?

 

[cm23uoc]

But then they are not NOS anymore. Shame.....
Using NOS points while the whole world is looking for one to display in their trunk assortments at the car shows.

I got that many bunkered now to have a nice Display with my kid puppet Holding them in his Hands.:toothy6:

 

[commando1]

I got that many bunkered now to have a nice Display with my kid puppet Holding them in his Hands.:toothy6:

Jeez, at least put some clothes on him first.

 

[Zymurgy]

I did it because I didn't have any tubing, but I did have duct tape and a phone. Yup, I'm a hack!
Too bad I destroyed the evidence, might be good for a chuckle.

I'm sure you will get it narrowed down and figured out. Just out of curiosity, what kind of pump and regulator are you running?

It is a Jegs branded Edelbrock pump with built in regulator.

 

[Knebel]

Zymurgy, get a new condenser for the ignition if you havent already. I had something like this happening too before. On a different car, it was heat related and i could go about 2 miles and then the car would stall. Stop 5min open the hood, check here and therevand it would run again another 2miles. Fun to do for a 60mile trip on the german autobahn
Changed the condenser and it was fine!

 

[Zymurgy]

Update still having the same issues, I am at my wits end. Here is what I have done this weekend.

1. Reinstalled fuel pick-up
2. Checked timing OK
3. Installed new condenser
4. Checked points gap OK
5. Checked dwell angle, was 23 degrees should be 28-32

I could not adjust the dwell angle and ran out of time. I know this is off but I always thought the dwell angle was more of a fine tune item.

Here is a video. Sorry about the orientation, I recorded it in the wrong position to start with and my phone or YouTube won't allow me to change it.

The first cut out is medium to light acceleration. The second make a right hand turn and then I punch it. You can hear the 4 barrel kick in for 3-4 seconds and then it cuts out.

 

[68plymouth383]

A few years ago I'd be driving down the road just like you did and my engine would turn off completely for 20 seconds or so it was completely intermittent. It would come back on its own. I didn't find it fuel related. I contacted Richard erherberg he asked if the entire vehicle went dead or just the engine. I said just the engine. He instructed me to replace the ballast resistor. Sure enough that solved the problem.

 

[Zymurgy]

A few years ago I'd be driving down the road just like you did and my engine would turn off completely for 20 seconds or so it was completely intermittent. It would come back on its own. I didn't find it fuel related. I contacted Richard erherberg he asked if the entire vehicle went dead or just the engine. I said just the engine. He instructed me to replace the ballast resistor. Sure enough that solved the problem.

I will try that thanks

 

[Landyacht]

How thick of a carb gasket are you using. If you're using one of those thin gaskets that Mr Gasket makes you could be dealing with vapor lock. Had a similar problem with a performer series carb. Get the extra thick Edelbrock gasket if your not already using one.

 

[70bigblockdodge]

That seems like fuel the way it fades out, electrical usually abrupt.

 

[detmatt]

Interesting...how about the ground to the electric pump. If it's fuel related it would have to be that the pump is shutting down intermittently.

 

[Zymurgy]

How thick of a carb gasket are you using. If you're using one of those thin gaskets that Mr Gasket makes you could be dealing with vapor lock. Had a similar problem with a performer series carb. Get the extra thick Edelbrock gasket if your not already using one.

It is the one that came in the original kit when I did the rebuilt the first time 3 years ago. Thanks for the tip I am ready to try anything at this point.

 

[Zymurgy]

Interesting...how about the ground to the electric pump. If it's fuel related it would have to be that the pump is shutting down intermittently.

I can actually hear the fuel pump so I don't think that is it.

 

[Zymurgy]

That seems like fuel the way it fades out, electrical usually abrupt.

When It initially cuts out it is actually pretty abrupt, and I have nothing. When I let it coast for a few second then it kind of sputters back to life.

It is exactly the same every time. It never cuts out earlier or later unless I give it more or less gas. It really seem fuel related to me.

The vapor lock seems interesting to me, I have never experienced this before. I have had the carb off and on a I bet a dozen times.

It did occur initially when I removed the carb to check the pump discharge check needle. After I drove the car about 3 miles after the first time I removed the carburetor, it started doing this and has been doing it ever since. At the time I just presumed my short mechanic fuel pump push rod was the issue.

 

[Big_John]

Did you do a volume check on the fuel pump? Disconnect the fuel line and pump into a coffee can. Should fill the can quickly.

 

[Landyacht]

It is the one that came in the original kit when I did the rebuilt the first time 3 years ago. Thanks for the tip I am ready to try anything at this point.

It's a common problem with Edelbrock Performer series and Carter AFB carbs because of the location of the float bowls. They tend to soak up allot of heat from the intake manifold and cause the fuel to boil. Before I switched over to fuel injection I was running an Edebrock Performer series carb. I drove it all summer long using the thin gasket that came with the carb and had no problems at all. The very next summer when I took the car out the problem just seemed to pop up out of nowhere. It was frustrating. I ended up replacing my distributor thinking it was a spark issue ,rebuilt my carb , Installed a fuel regulator and a fuel pressure gauge and still couldn't find the problem . Finally just on a hunch I tried installing a thicker gasket and the problem went away instantly. Edelbrock sells a gasket that is about 3/8 thick for about 20 bucks. It comes with a set of studs but doesn't include the nuts for some reason. I can't guarantee it will solve your problem but its worth a try.

 

[Zymurgy]

I am working close to a Jegs this week I will look to grab the thicker gasket. Thanks for the tip.

Replaced the ballast resister no change.

 

[Wollfen]

Do you still have a fuel filter between the tank the electric pump?