Engine trouble
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Freshman User
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You mention pump twice and it starts. It's using the fuel from the accelerator pump. Have you had any fuel quality issues while running the current carburetor? It's possible the carburetor jets are plugged. Have you rejetted and reset your H and L mix screws?
Try this. Once started try lightly tapping the accelerator to continuously deliver fuel through the accelerator pump. Try to keep it running without flooding it. If it stays running like that but dies when you quit perhaps the jets are plugged.
Try this. Once started try lightly tapping the accelerator to continuously deliver fuel through the accelerator pump. Try to keep it running without flooding it. If it stays running like that but dies when you quit perhaps the jets are plugged.
Lead Driver
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no fuel quality issues I have been able to detect have not re-jetted the carb, or played with the idle mix screws since bolting it on as I use a vacuum gauge to set it to proper tune and it’s not running long enough to do that. Did try playing with the set screws on the previous carb and it did not seem to alter anything.
The second thing to try short of gaining access to the float and valve to make sure it's not stuck is to tap on the float chamber with a screw driver especially in the area of the valve.
With those items out of the way you can move to the ignition system. Because it behaves like a fuel issue I'm still thinking it's fuel related.
Also did you perform a compression test? What do the plugs look like?
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Two things to try. First close off the idle set screws all the way in. Do not torque the screws in, gently finger tight. Count the number of turns to close them then reset to spec or to the same number of turns as it took to close them. This will clear the jet orafices. Then reset them to your spec or in your case to where you started using the vacuum guage.
The second thing to try short of gaining access to the float and valve to make sure it's not stuck is to tap on the float chamber with a screw driver especially in the area of the valve.
With those items out of the way you can move to the ignition system. Because it behaves like a fuel issue I'm still thinking it's fuel related.
Also did you perform a compression test? What do the plugs look like?
The second thing to try short of gaining access to the float and valve to make sure it's not stuck is to tap on the float chamber with a screw driver especially in the area of the valve.
With those items out of the way you can move to the ignition system. Because it behaves like a fuel issue I'm still thinking it's fuel related.
Also did you perform a compression test? What do the plugs look like?
The plugs are essentially new, just a bare bit of run on them maybe two minutes at this point, had a minor bit of lean run appearance on them prior to the new carb.
Old plugs had a rich wear to them prior to being replaced. Honestly needed to rejet the Holley as the initial jets were just to large for my application.
Lead Driver
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*sighs* at times the engine fires right up no issues then at other times it’s just playing crank around the rosie please start please start… that is to say sometimes it fires up as soon as you pump twice and turn the key, other times you’ll crank and crank and nothing.
It’s the same way with restarting. Sometimes it’s a simple turn key or one pump turn key and it restarts briefly (run maybe 5 sec) other times it’s the initial start then won’t restart.
It’s the same way with restarting. Sometimes it’s a simple turn key or one pump turn key and it restarts briefly (run maybe 5 sec) other times it’s the initial start then won’t restart.
Do you ever get instances where it starts but dies seconds later? That would point to an intermittent fuel delivery issue, where the carb float chamber had at least some fuel in it at the last shutdown, but now isn't getting properly replenished. That could be a sticking float valve, bad fuel pump, pinched fuel line, clogged pickup tube, etc.
Reviewing this long and sordid thread, I still see no mention of having checked for spark when the engine won't start. My hunch, offered for free and worth every penny, is your ignition is fine. Go back to post #6 and try the starting fluid trick next time the engine won't start. If the engine runs okay briefly until this alternate fuel supply is consumed, then you know the ignition system is okay. I can't stress strongly enough how much time and aggravation this 30 second trick will save you when trying to diagnose a no-start condition.
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Freshman User
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How consistently does the engine fail to start? And once it does fail, what does it take to start again? Letting the engine sit for at least X hours? Taunting it with Yiddish curses or threats of violence?
Do you ever get instances where it starts but dies seconds later? That would point to an intermittent fuel delivery issue, where the carb float chamber had at least some fuel in it at the last shutdown, but now isn't getting properly replenished. That could be a sticking float valve, bad fuel pump, pinched fuel line, clogged pickup tube, etc.
Reviewing this long and sordid thread, I still see no mention of having checked for spark when the engine won't start. My hunch, offered for free and worth every penny, is your ignition is fine. Go back to post #6 and try the starting fluid trick next time the engine won't start. If the engine runs okay briefly until this alternate fuel supply is consumed, then you know the ignition system is okay. I can't stress strongly enough how much time and aggravation this 30 second trick will save you when trying to diagnose a no-start condition.
Do you ever get instances where it starts but dies seconds later? That would point to an intermittent fuel delivery issue, where the carb float chamber had at least some fuel in it at the last shutdown, but now isn't getting properly replenished. That could be a sticking float valve, bad fuel pump, pinched fuel line, clogged pickup tube, etc.
Reviewing this long and sordid thread, I still see no mention of having checked for spark when the engine won't start. My hunch, offered for free and worth every penny, is your ignition is fine. Go back to post #6 and try the starting fluid trick next time the engine won't start. If the engine runs okay briefly until this alternate fuel supply is consumed, then you know the ignition system is okay. I can't stress strongly enough how much time and aggravation this 30 second trick will save you when trying to diagnose a no-start condition.
the rubber fuel lines have been replaced had several small sections that were old and brittle one had cracked and was actually open to air, had several broken hose clamps that have been replaced and all the hose lines and even the tank selector have been blown out with a compressor. Then tried to start it then ran the fuel volume test, with the tank selector bypassed and it just picking up fuel from the front tank both with the initial test start post hose replacement and verified good pump, and fuel volume test right after the failed start.
in regards to spark, again it has new plugs which were ohmed out to verify they were good prior to install, wires ohm out, cap and rotor are good, coil is ohmed out and boy did I watch it arc before reconnecting the coil wire so it’s got good strong voltage from the coil to the dizz.
Lead Driver
Joined: Nov 2013
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Does your distributor have vacuum advance? (It will have a small external actuator looks like a flying saucer on its side.) If so, remove the distributor cap and inspect the wires from the pickup coil. These wires can rub against the housing and short to ground, killing the spark. The gotcha is when the advance mechanism rotates, the wires don't always land in the same spot. The ignition may be fine one moment, dead the next, and then fine again.
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Well so every knows, I found and fixed the problem!!! Sorry it took so long but it was a busy holiday season. Anywho, the issue was the old smog computer, it was tied into the coil wires and as killing it’s ability(reducing the voltage to the coil) to spark on run, unplugged it, started up and idled. I checked and adjusted timing, put the vacuum gauge on it and set the carb(pulls a good 20” of vacuum) and now she runs like never before. Until the next thing breaks lol thanks for all your help guys!
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Lead Driver
Joined: Apr 2002
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Well so every knows, I found and fixed the problem!!! Sorry it took so long but it was a busy holiday season. Anywho, the issue was the old smog computer, it was tied into the coil wires and as killing it’s ability(reducing the voltage to the coil) to spark on run, unplugged it, started up and idled. I checked and adjusted timing, put the vacuum gauge on it and set the carb(pulls a good 20” of vacuum) and now she runs like never before. Until the next thing breaks lol thanks for all your help guys!
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