Engine hesitation and Stall on acceleration

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C2ndLTpigeon

Mopar or no Car!
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Ive been driving the Valiant for a bit now. It has a 318, with an edelbrock AVS 600 CFM, hughes wiplash cam, RPM air gap, pertronics flamethrower III dist.

Today it started to act up. When I left my parents house as soon as I made it down the street it would jerk under acceleration and then die. I though maybe the coil wire or wires at the dist were loose as I just changed them. I messed with them but no it still wanted to die after 30-50 feet of acceleration. Finally got the car home and reverted to the old plug wires and still does it so its not that. I let it cool off for a bit then started it again in park it would have a hesitation still and if I let it idle after about 30 sec to a min it would go from smooth idle to rough an then die. Im thinking fuel or carb contamination?

Im running 2 filters, a see through which looks good near the pump and a small edelbrock filter at the carb. But nothings fool proof. Carb, dist, plugs wires etc all have less than 500 miles since my build was complete.

Wanted to see if anyone could chime in on what it might be.

Thanks.
 
I'm leaning towards a fuel issue here.
What's the history of the carb ?
Is the carb box stock, (springs,jets,rods) ?
Having a baseline of the carb is a good place to start.
I have had good results with an out of the box stock Ede 600 on a mild 318.
Have you gone through it ?
Blowing compressed air through the ports works to get rid of any foreign matter, and works wonders. Make sure both sides of the squirter is working. I have had it get clogged after sitting with today's fuel. Make sure it is getting a good clean shot on both sides.
Why the double filter ?
Is your fuel system (tank,fuel lines) suspect with dirt ?
If the fuel system is clean, a single Wix filter is sufficient.
 
if it coughs and dies after a few minutes of idling, its running out of fuel or air (flooding). Id suspect crap in the seats. let it die and check your pump shot. If its there for 2-3 cycles your flooded, if its not your empty. Carefully watch the boosters while running and it chokes itself (be very careful of a backfire or fuel blowback) I bet there is fuel visibly pulling out the boosters. IIRC if it runs out of fuel, it will chug and recover, pick up to a high idle for about 2-3 seconds then die. If it is flooding it will just die with nothing on the tail end. Accelerator pump is not in play when its just idling and dying and a low fuel level will make the pump shot small to none. Vegas long shot on ignition issues.
 
Carb is stock out of the box, no adjustments made other than AF mixture and idle.
Looks like both of the squirters were ok
Double filter is because Im still running the stock line that had the filter at the near the pump. This is a temp setup until I get a cleaner permanent fuel line set up.

I think the simplest thing to do is pull the carb and double check cleanliness and and go from there, I figured it may be fuel Carb related and I will update if I find anything out.

Thanks for the suggestions.
 
just pull the top off. No need to remove the carb to get to inlet seats. Just pull the top after it chokes and dies. you wont find fuel level issues if you remove the carb from the motor easily. 8 screws, fuel line and 2 linkage clips.
 
Sounds like fuel is dumping down the boosters, floats settings or needle n seat thing.

Was it setup and working fine before this?
 
I put an Edelbrock performer 650 carb on my 340 Challenger and it would drop on its nose while accelerating especially on cold mornings. I got a metering rod kit and played with them until it performed perfectly except when I was at a light at times it would studder and stall. Foot to the floor was the only way to get it to restart (flooding). Thats when I learned that to much fuel pressure to an Edelbrock carb will push past the floats and flood. I put a pressure regulator in line and tweeked it down from 8 psi to the recommended 5.5 psi of pressure and never had another problem again.
Hope it helps.
 
Ok, so after spending all day on the car I still have an issue but have ruled out alot of possibilities.

Its is not the carb, I took it off completely dismantled it and its good I did as there was a small amount of debris, also found some slop flaws in casting of the secondary rods, made sure everything was in spec with the floats, reassembled and still had the problem.

Next I ran an external pump from a mason jar full of gas to the inlet line to the carb, bypassing the tank, pump, and bottom filter. The external pump kept the car running for a little under 10 min and I turned it off. Which means not a carb or ignition related issue.

So it must be something from the fuel pump back. So I changed the fuel pump with a precision pump from Oreilly, $20 stock mechanical pump. Still has the problem.

So I figure ok maybe metal fuel line, pickup or crap in the tank. Dropped the tank, pickup and strainer were fine. The tank needed a good cleaning as there was alot of loose crud. Used the compressor to blow out the metal line, some rust color crud came out eventually all the crud came out. Changed the rubber fuel line at the pick up as well, installed tank and Still a problem!

Ive tried 3 different fuel filters, the original was a clear wix filter. the 2nd was the clear filter the edelbrock carb came with, and the 3rd is a metal wix filter. Same issue.

So last test I did which I should of done earlier, was the external pump from the metal fuel at the engine bay that goes to the tank, and ran it to the carb. So now Im pulling fuel directly from the tank to the carb. Car runs! and for 10 min again.

So its not the tank, fuel line from tank, sender, carb, ignition, only thing is the fuel pump.

Odd that a new Carter pump I only had on there for less than 500 miles would just crap out, and then I changed to another brand new one today and same issue. 2 pumps as its not impossible is just odd.

The only other thing besides the pump is the cam lobe that drives the pump. But if it was loose im sure it would be making some noise, Im going to remove the pump and check its position with a bore scope but id don't think this is the issue as I remember torquing it to spec.

Again car has been running great for about 4 weeks, and this just started to happen last night. quite odd.
 
I put an Edelbrock performer 650 carb on my 340 Challenger and it would drop on its nose while accelerating especially on cold mornings. I got a metering rod kit and played with them until it performed perfectly except when I was at a light at times it would studder and stall. Foot to the floor was the only way to get it to restart (flooding). Thats when I learned that to much fuel pressure to an Edelbrock carb will push past the floats and flood. I put a pressure regulator in line and tweeked it down from 8 psi to the recommended 5.5 psi of pressure and never had another problem again.
Hope it helps.

This may be a possibility, going to find out how much PSI these pumps are putting out. Just odd how this was working just fine yesterday.
 
This may be a possibility, going to find out how much PSI these pumps are putting out. Just odd how this was working just fine yesterday.
Lil hose between tank sender and hard line cracks over decades. Did you try another coil? We could toss everything in the book but that could send you on a goose chase.
 
Lil hose between tank sender and hard line cracks over decades. Did you try another coil? We could toss everything in the book but that could send you on a goose chase.

All fuel line hoses have been replaced. Coil would not be the issue if the car ran from another source of gasoline. Car ran both times i tried it with an external pump once pulling gas from a jar and the second time pulling gas directly from the line to the tank. Hook the line back to the cars fuel pump issues again. This has to be a fuel delivery issue. Only issue is both pumps were brand new.
 
Is your fuel cap a breathable type ? Possible breather pipe blocked with debris causing a vacuum in the tank and not allowing fuel to flow or slowing fuel delivery down.
 
Just check the curve in the distributor. Some of those have a really fast curve that will give you issues like your describing on acceleration. FYI
 
So it ran fine with the mason jar and an electric external fuel pump ?
 
Just check the curve in the distributor. Some of those have a really fast curve that will give you issues like your describing on acceleration. FYI

Distributor is cured to the camshaft I purchase. Why would the distributor be the problem if it runs fine from gas from an external pump and not from the cars fuel pump. Not and ignition issue.
 
Is your fuel cap a breathable type ? Possible breather pipe blocked with debris causing a vacuum in the tank and not allowing fuel to flow or slowing fuel delivery down.

Breather is blocked off sine I am no longer running a charcoal canister. I am using a vented gas cap. Ive been using the same setup for the past 4 weeks. If anything tank, lines etc are all better than they were and still the issue.
 
I have seen the pump eccentrics wear out. When you built it, did you look at it closely? Here is something you can try, but be VERY careful. Run the car on the electric and the mason jar. Leave the mechanical hooked up but the output into a gas can. See what level of fuel it is putting out over time.
 
Oh, try and run it with the gas cap off. That eliminates the vent issue if it still does it.
 
This may be a possibility, going to find out how much PSI these pumps are putting out. Just odd how this was working just fine yesterday.

I still think it is too much fuel pressure and its flooding. I drove my Challenger for several weeks before my flooding problem started to happen. I put an inline gauge, fuel filter and the pressure regulator so I could monitor the pressure and once I set it at 5.5 psi I never had the problem again. The fuel pressure should be addressed in the manual you got with the new carb. Here is a pic of my set up, regulator is mounted on the passenger fender well.
engine2 (2).jpg
 
Found it on page 3 of the manual that covers most edelbrock carbs.

6. Do not use more than 6.5 PSI fuel pressure. Excessive fuel pressure may cause flooding. If your fuel pressure is too high, install an adjustable pressure regulator, such as Edelbrock #8190.
 
Well I found out what the problem was when I took the fuel pump off I use the screwdriver and could feel that the pump Drive lobe was loose. Took everything apart and I was expecting the bolt to be loose but the bolt was actually tight. it looks like the Woodruff key was getting ground down where the cam Drive lobe attaches not sure how this happened but it looks like all I have to do his replace the key has anybody ever had this happened before? Could the key of been installed incorrectly? Here's some pictures of the key
1019201402.jpg
1019201405.jpg
 
Not really surprised, it should be pretty easy to remove the key and reinstall a new one. I would replace the eccentric also. The slot might be opened up. The single attachment bolt is not the greatest design. They make a nice thick washer to go behind the bolt.
 
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