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Discussion Starter · #1 ·
Hi everyone, first post on here-
I have a 289 with a recently rebuilt top-end (edelbrock e-street package - new heads, cam, timing chain, intake, carb). It was running great for about 3 months or so, then all the sudden started having issues- trouble starting, mainly just not running smooth- jerking, rough idle, occasional backfire, then sputtering and dying. I thought I had it figured out the other day when I pulled off the fuel filter and noticed it had a bunch of junk in it (rust from bad gas tank). So I replaced the filter and disconnected the hose from the bad tank and ran it into a red gas can with fresh gas. Took awhile to get started but once it did, it ran great! Kept it going for about 15 minutes then shut it off thinking I'd isolated the problem to bad gas. Later that day wanted to test again-it fired up on the first turn, ran great for about 5-10 minutes, then starting running rough again and sputtered and died! So far I have adjusted the timing, made sure the coil was getting good voltage, made sure gas in the tank (lol), new spark plugs and wires. I'm trying to isolate if it's a fuel or ignition issue. I sprayed some starter fluid in the carb and it did not seem to light right off, making me think it's ignition. A couple mechanics I had look at it recommended electronic ignition- currently has a cheap points distributor on there. But would that cause the intermittent issues? Or could it be some clogged jets from the rusty gas tank in my new carb :( Trying to figure this out the past few months has been a headache, any help is much appreciated!
Pat
 

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I’d be wondering about the coil myself. Ignition condenser. Grounded plate that the points are attached to. Stuff like that......
 

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Discussion Starter · #4 ·
Ok so I think I may have it figured out...I disconnected the fuel line at the carb last night to make sure the fuel pump was giving good pressure. It was pumping fine BUT I noticed a bunch of rust particles in the cup after! I cleaned out the cup really well and tried again and sure enough, more rust pieces!The only thing after the filter is the fuel pump (original) and rubber lines I just replaced. So I’m thinking the rust has got into the carb and clogged some of the jets. Sound plausible?

I’m thinking my next obvious step is to replace the fuel pump...but I’m also thinking I may need to clean out the carb if it’s clogged. I have partially rebuilt a Holley 4bbl a looooong time ago, but never an edelbrock, so any advice or tips are much appreciated!
 

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The Edelbrock carb has small filter screens at the inlet to each fuel bowl. I’m sure they have trapped most of the crud.

Edelbrock carbs are pretty easy.
Carefully unclip each linkage from the top of the carb. Those tiny clips are easy to loose.
Open the two little doors on the top and remove the metering rods and springs. Don’t loose the springs.
Undo all the screws on top of the carb and carefully lift off the top.
Remove the floats then remove the needles from the seats. Then unscrew the seats and you will find the inlet screens.
 

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Discussion Starter · #6 ·
So this weekend I took apart and cleaned out the carb. There was a LOT of rust/gunk in there- especially in the passageway between the two fuel bowls. (Like you said probably caught by the filters) Cleaned everything out and blasted dry with compressor. Installed a new fuel pump (oe style 6.5 psi makes 25gph). And just to be safe, ran 3/8 rubber fuel hose from plastic gas can, to filter, to pump, to carb (to be sure no possibility of rust) until new fuel line comes. Cranked it a few times into cup before re-connecting to carb- gas looked good not rust or particles. Re-connected to carb and tried to start and....nothing. Sounded like it wanted to kick over several times but would not. Tried some starter fluid and adjusting the fuel/air mixture screws (since I took them out to clean) and seemed to make no difference. At least before it would kick over, and then run rough...but now I get nothing. Thoroughly confused. I pulled off one of the plugs and it looked pretty black, so thinking maybe try cleaning those up (even though replaced not long ago). Any other ideas of something I’m missing? Any adjustments I’m not thinking about on the carb?


The Edelbrock carb has small filter screens at the inlet to each fuel bowl. I’m sure they have trapped most of the crud.

Edelbrock carbs are pretty easy.
Carefully unclip each linkage from the top of the carb. Those tiny clips are easy to loose.
Open the two little doors on the top and remove the metering rods and springs. Don’t loose the springs.
Undo all the screws on top of the carb and
carefully lift off the top.
Remove the floats then remove the needles from the seats. Then unscrew the seats and you will find the inlet screens.
 

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1965 C-code Coupe, Silver Metallic Blue, 3-speed toploader, 3.00 rear
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My intermittent stumbling issues I traced back to an ignition condenser in the distributor. An in line spark checker allowed me to see the spark disappear when the car started to stumble.

Really you have to isolate whether it's air, fuel, or spark that's causing the issue before you proceed. All the voltage and resistance tests in the world couldn't tell me what a plug wire attached to a light bulb could. :) https://www.harborfreight.com/In-Line-Spark-Checker-63590.html
 

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Always a good idea to start with spark, when you have no idea why it's not running, because that's easiest to troubleshoot. Then move to fuel. =)
 

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When I was in school before getting my ASE master one of the things they will drill into you is that 90% of carb and transmission(auto) issues are ignition problems. Always start with ignition and then go from there. An ignition scope is one of the handiest tools when it comes to diagnosis. I wish I had bought that old Allen scope when a shop was selling their old one for $300...

Personally I would throw that points distributor into the nearest aluminum scrap bin. I have no use for them in anything unless there is an EMP that takes out all the electronic modules in the world...

As for the rust in the carb it sounds like it's time for a new fuel tank and fuel line to me.
 

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A couple suggestions...

1. Get a post-pump filter. Edelbrock makes a nice filter and inlet line kit for the banjo-bolt inlet.
2. Get rid of the pre-pump filter. Diaphragm fuel pumps suck (literally) at PULLING fuel and don't need any extra interference.
3. Pre-fill the float bowls with clean, fresh fuel prior to trying to start.

FWIW, one thing we learned many eons ago was to NEVER use Ether "Starting Fluids" in any engine with spark or glow plugs. Besides being a "spark plug killer", either can easily break a piston ring or bend a rod if you use a little "too much". Stick with old-school carburetor cleaner or gasoline in a "mister".
 
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