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Posted By: JAGI410 305 runs great, then won't restart (easily) - February 21st 2018 5:49 pm
My 1984 G20 with LE9 305 4bbl (electric choke) is having a hard time adjusting to winter. In the 6 months I've owned it, this phenomenon has happened 4 times, all inconvenient times of course. I'm new to carburetors and engines measured in cubic inches.

My normal cold start process is this: Key on, pump gas 3 times, turn key. Fires up quickly. Hold down pedal slightly for several seconds until it idles steady (but low), then wait for fast idle to kick in. Once it's fast idling, shift into gear, idle drops to normal and I'm on my way.

The problem happens when I get somewhere. Usually on drives under 10 minutes. I put it in park, let it idle for 5 seconds, then turn key off. No "dieseling" effect usually, but that has happened before. When I go to restart it 10 minutes later, it cranks and cranks and cranks and never starts. The battery usually dies and I have to jump it. After jumping it, it still cranks for a bit before it roars to life. Then it idles and drives like nothing happened. Days or weeks can go by without this problem happening again. On a normal day, it restarts without touching the gas.

What should I be looking at? Fuel filter? Carb rebuild? Sniper EFI conversion devil? I love this van dearly and would love for it to be as reliable as possible. We have lots more adventuring to do!
Posted By: Hasan Ben Sobar Re: 305 runs great, then won't restart (easily) - February 22nd 2018 3:45 am
You shouldn't have to wait for "fast idle". If the choke is set properly , it should go right to high idle immediately. THe other issue sounds like vapor lock.

Simple crap first:

Fuel filter. After , cut the old one open and check for debris.
Next, Replace all rubber fuel lines. Today's garbage that comes out of the pumps kills rubber quickly. Screw hose clamps as well. If there are return or vapor lines , ensure they are functioning as intended.

Now-if that doesn't do it , remember that electrical issues can sometimes masquerade as a fuel problem. Carry a can of starter fluid with you. When it won't start give it a shot of it. It if momentarily starts and then dies-it's fuel. But before you do this , stick your shnoz in the carb. do you smell fuel or do you SMELL FUEL? Your not starting when warm COULD be a flooding condition. Have a flashlight handy. Look down the carb throat is it dry or soaked?

FI is a great thing. But you could do a TPI conversion with junkyard parts. TBI systems are nothing but really expensive carbs.
Posted By: JAGI410 Re: 305 runs great, then won't restart (easily) - February 22nd 2018 2:42 pm
Thanks for the input! I'll take care of the fuel filter and lines this weekend and look into choke adjustment. I've seen one fix for vapor lock being adding a carb spacer, that seems like a cheap solution I'm willing to try while I'm in there.

Junkyards around here are pretty scarce, I'd be better off going with a nice new carb or Sniper system than piecing something together.
Posted By: Hasan Ben Sobar Re: 305 runs great, then won't restart (easily) - February 22nd 2018 6:27 pm
Chase those other possible fixes first. Vapor lock in MN in the winter is highly un-likely. Look at Mega squirt before you spend 1200.00 on a computer controlled carb.
Posted By: JAGI410 Re: 305 runs great, then won't restart (easily) - February 22nd 2018 7:22 pm
I agree vapor lock seems unlikely when it's been below freezing for months, especially since she runs a little cold blooded anyway. The more I think about it, everything points to a improperly adjusted choke. When it first starts in the morning it does blow black smoke out of the exhaust for a minute, clearly running too rich. Perhaps the choke is sticking and causing a flooded condition on the warm restarts. A little youtubin' this morning makes it look pretty simple. I'll tackle that on Saturday after the fuel filter stuff and see how she does. I appreciate the advice!

If this works, I'll owe ya a beer or high five when I make it down to Tucson again. I miss the Sonoran dogs from El Guero Canelo!
Posted By: jcd74 Re: 305 runs great, then won't restart (easily) - February 22nd 2018 11:05 pm
There is a fuel filter inside the carb where the fuel comes in. If you take the line off, you can unscrew the filter housing and take a look at it. This assumes you have a factory carb, and all of the silliest things make sure you have a good gas cap. Your tank may not be getting fresh air.
Posted By: JAGI410 Re: 305 runs great, then won't restart (easily) - February 23rd 2018 2:01 am
Factory carb, and likely factory gas cap!
Posted By: Hasan Ben Sobar Re: 305 runs great, then won't restart (easily) - February 23rd 2018 5:27 pm
Originally Posted by JAGI410
I agree vapor lock seems unlikely when it's been below freezing for months, especially since she runs a little cold blooded anyway. The more I think about it, everything points to a improperly adjusted choke. When it first starts in the morning it does blow black smoke out of the exhaust for a minute, clearly running too rich. Perhaps the choke is sticking and causing a flooded condition on the warm restarts. A little youtubin' this morning makes it look pretty simple. I'll tackle that on Saturday after the fuel filter stuff and see how she does. I appreciate the advice!

If this works, I'll owe ya a beer or high five when I make it down to Tucson again. I miss the Sonoran dogs from El Guero Canelo!




Keep us in formed. Also check the rubber lines. If there are old , two things could be happening. they are cracked and the pump is sucking air or they are too soft and are collapsing from the suction.

Posted By: JAGI410 Re: 305 runs great, then won't restart (easily) - February 25th 2018 7:15 pm
I pulled the doghouse and inspected things last night. Nice to work from inside the van while 4” of snow dumped outside! All of the fuel lines look fairly new, I’m guessing the previous owner replaced them. This van sat unused for 6 years, previous owner had a lot of work done to make it live again. The Quadrajet carb looked nice and shiny without much discoloration or buildup. The choke was set really tight. I adjusted the electric choke to match what I’ve seen in YouTube videos. I checked the linkage while I was in there and everything looked good. The heat stove pipe wasn’t connected properly, so I fixed that too. A quick turn of the key and she roared to life, straight into fast idle. I let it run for 5 minutes and shut it down for the night.

This morning I went out, turned the key, pumped gas once, and it fired right up into fast idle, then lowered down into regular idle on its own. No black smoke either! This appears to have made a huge difference, we’ll see how she does after a couple weeks of driving.
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