Fuel Tank Crud? Redoing Fuel Lines, Etc. Options

[silverteener]

my tank was way worse than that. You never know that sock could be plugged. I guess if all else fails replace it. It takes a bit of labor but is a cheap fix. The socks are only around 8 dollars. good luck!

[kenshapiro2002]

Idle jet is a 50.

I'll check the idle jets in awhile and post it. How do I check the float level (11mm) without redoing the gasket, etc.? Can the low float level be because of the sock being blocked or not. What did you think about the photo of the sock and surrounding area? Normal stuff?

Transition issues. What size idle jet? Check your float level and bump up your mains.

You are getting a lean transition when you go from idle jet to main jet. You need to make sure your float level isn't low. After that try bumping up your main jet to 125 or 130.

Having a low float level delays when you come on the main jets. Then you pop at @ 3K. If your float level is good bump up your main jets. I personally think they are too small. I'd go with 130's and then go smaller from there. It'll run ok if they're a bit too big. It pops and stutters or you burn up stuff if they're a bit too small.

[kenshapiro2002]

I accept that the larger jet would be a good move, but keep going back to the fact that the car ran fine from CT to NJ. Then I filled her up with 93 and she started having rpoblems within 20-30 miles. It could be coincidental, but I have to assume that jet size, valve adjustment, etc. had nothing to do with what went sour at that point. I;ve had experiences in the past where the circumstances and evidence were simply wrong, but logic tells me it is a fuel problem...bad fuel (not likely, especially since the problem is RPM specific), or a fuel starvation problem within a specific RPM range. If it runs well at higher RPM than its probably not even the sock. Can it be electrical?

Changing the sock and fuel line is a good idea. I'd even change out your fuel pump. Unfortunately, thats not your problem. You can't adjust float level without cracking the carb open. You can assume it's fine and go with larger mains and see what happens. You'll be out the cost of the jets if that wasn't your problem. You will have gotten away with not cracking open the carb if it was. I do have to say a lot of guys with lean transition issues seem to be running a 115 main and a F11 ET. Thats what comes in the 40 when they come from Weber. I always wondered why when IMHO the 125 was the more suitable jet. I guess it's so they can sell you more jets.

[kenshapiro2002]

Is it sufficient information to order "125 main jets for an IDF 40", or do I need any more specific information like the full carb ID number?

Changing the sock and fuel line is a good idea. I'd even change out your fuel pump. Unfortunately, thats not your problem. You can't adjust float level without cracking the carb open. You can assume it's fine and go with larger mains and see what happens. You'll be out the cost of the jets if that wasn't your problem. You will have gotten away with not cracking open the carb if it was. I do have to say a lot of guys with lean transition issues seem to be running a 115 main and a F11 ET. Thats what comes in the 40 when they come from Weber. I always wondered why when IMHO the 125 was the more suitable jet. I guess it's so they can sell you more jets.

[jmill]

I accept that the larger jet would be a good move, but keep going back to the fact that the car ran fine from CT to NJ. Then I filled her up with 93 and she started having rpoblems within 20-30 miles. It could be coincidental, but I have to assume that jet size, valve adjustment, etc. had nothing to do with what went sour at that point. I;ve had experiences in the past where the circumstances and evidence were simply wrong, but logic tells me it is a fuel problem...bad fuel (not likely, especially since the problem is RPM specific), or a fuel starvation problem within a specific RPM range. If it runs well at higher RPM than its probably not even the sock. Can it be electrical?

I agree with you here. This one has me scratching my head. It sounds like a lean transition issue but you would have had it from the start if it was jet sizing. Does it only pop from one carb or a specific barrel? Check the accelerator pump discharge. Are the streams equal and even?

If you want to buy new jets you don't have to get that specific. Just tell them you want jets for an IDF Weber. If your sure it ran great before you might want to hold off spending money on jets and crack those carbs open. You have the parts and the book. If it's worth chancing $30 not to then try the bigger jets.

[kenshapiro2002]

I'll have to listen to those pops and crackles form the engine compartment instead of the drivers seat and let you know. How do I check the accelerator pump discharges?

I agree with you here. This one has me scratching my head. It sounds like a lean transition issue but you would have had it from the start if it was jet sizing. Does it only pop from one carb or a specific barrel? Check the accelerator pump discharge. Are the streams equal and even?

If you want to buy new jets you don't have to get that specific. Just tell them you want jets for an IDF Weber. If your sure it ran great before you might want to hold off spending money on jets and crack those carbs open. You have the parts and the book. If it's worth chancing $30 not to then try the bigger jets.
[/quote]

[jmill]

Pull off the air cleaners, look down the carb and open the butterflies with the engine off. You should see a stream shoot down each venturi. Make sure they both look the same and are nice even streams.

[kenshapiro2002]

Tomorrow...thanks.

Pull off the air cleaners, look down the carb and open the butterflies with the engine off. You should see a stream shoot down each venturi. Make sure they both look the same and are nice even streams.

[ChrisFoley]

I personally think you have a combination of fuel delivery and carb issues.

(IMG:style_emoticons/default/agree.gif)
115 mains are too small even for a 1.7 IMO.
Get a new sock and get the bigger main jets. Do both at the same time!
That will more than likely make the engine run a whole lot better.
You can consider the rest of the suggested upgrades down the road.

[kenshapiro2002]

Just ordered the 125 mains. I'm going to do one thing at a time so I'll know better what the issue was (hopefully "was"). I'm pretty sure the problem won't be solved by the bigger mains, just because of the circumstances of how the problem showed up...unless the introduction of 2009 93 octane fuel to her old system really effed with her ability to drink. Now...gotta go out and check the pumps.

I personally think you have a combination of fuel delivery and carb issues.

(IMG:style_emoticons/default/agree.gif)
115 mains are too small even for a 1.7 IMO.
Get a new sock and get the bigger main jets. Do both at the same time!
That will more than likely make the engine run a whole lot better.
You can consider the rest of the suggested upgrades down the road.

[kenshapiro2002]

OK...checked the accelerator pumps and they are all nice and even. #3 might be a tad less, but even that looks close. So, I fire her up to see where the pops are coming from while watching the barrels. As I'm goosing the throttle, I'm getting gas on my finger from the barrel over piston #1. I tighten up the clamp and she stops leaking. As I'm revving her up, it's obvious that the left bank of cylinders (#1 & #2) are running rough, and the carb pops are coming from the same side. As I continue to rev her I notice what looks like a third emulsion tube emerging! It's the freaking stud that holds down the carb top !!! Guess that will cause some roughness, huh? Tighten down everything and put the air cleaners back on. She's MUCH better (not perfect), and I'm realizing that somebody was probably cleaned out the carbs after the long storage and did a half assed job. I've ordered the 125 mains too. I'll let ya'll know what happens from here. Guessing they need being broken down and put back together with some care.

I accept that the larger jet would be a good move, but keep going back to the fact that the car ran fine from CT to NJ. Then I filled her up with 93 and she started having rpoblems within 20-30 miles. It could be coincidental, but I have to assume that jet size, valve adjustment, etc. had nothing to do with what went sour at that point. I;ve had experiences in the past where the circumstances and evidence were simply wrong, but logic tells me it is a fuel problem...bad fuel (not likely, especially since the problem is RPM specific), or a fuel starvation problem within a specific RPM range. If it runs well at higher RPM than its probably not even the sock. Can it be electrical?

I agree with you here. This one has me scratching my head. It sounds like a lean transition issue but you would have had it from the start if it was jet sizing. Does it only pop from one carb or a specific barrel? Check the accelerator pump discharge. Are the streams equal and even?

If you want to buy new jets you don't have to get that specific. Just tell them you want jets for an IDF Weber. If your sure it ran great before you might want to hold off spending money on jets and crack those carbs open. You have the parts and the book. If it's worth chancing $30 not to then try the bigger jets.

[jmill]

I'm glad you got it figured out. With the addition of the larger jets and some tuning I bet you'll get them where they need to be. Read the section on adjusting the idle mixture screws and your linkage. Once you get those dialed in you'll be extremely happy with their performance.

Going through the carbs would be wise. Mainly because you'll have an intimate knowledge of the parts involved and how they work. You'll be able to tune and troubleshoot easily.

[kenshapiro2002]

I REALLY appreciate everybody's help, but especially yours. You've been there steadily...thanks.
Ken

I'm glad you got it figured out. With the addition of the larger jets and some tuning I bet you'll get them where they need to be. Read the section on adjusting the idle mixture screws and your linkage. Once you get those dialed in you'll be extremely happy with their performance.

Going through the carbs would be wise. Mainly because you'll have an intimate knowledge of the parts involved and how they work. You'll be able to tune and troubleshoot easily.

[kenshapiro2002]

UPDATE...I just drove her for the first time since the tightening up. It's absolutley 80% better. She still seems to starve at certain points and a dose of full throttle punches through that. Also some decel pop that sounds more like exhaust pop than carb pop, though I still get a surprise carb pop every once in a while. The strongest evidence of an ongoing problem showed up when I returned to the garage. In neutral, sitting still, she'll rev all the way up to redline very smoothly as long as she has only been asked to do that infrequently, or after a rest. If I try that repeatedly without a "break", she does her starving act. After my education on here, I;m assuming that's pretty obviously the float chamber not having time to refill, right? If I;' correct, that could be the floats/chambers themselves, or some aspect of fuel deprivation (pump, sock, filter). Am I on target?

I'm glad you got it figured out. With the addition of the larger jets and some tuning I bet you'll get them where they need to be. Read the section on adjusting the idle mixture screws and your linkage. Once you get those dialed in you'll be extremely happy with their performance.

Going through the carbs would be wise. Mainly because you'll have an intimate knowledge of the parts involved and how they work. You'll be able to tune and troubleshoot easily.

[jmill]

Your on target. I would opt for inadequate fuel supply or old accelerator pump diaphrams not springing back quickly. Run the accelerator pump test but pump it a few times back to back. Does it spray nice and even through a few pumps? If no it's time to replace them. If yes then do a hard acceleration through the gears Does it go lean in the higher gears? If yes change the sock and that clicky pump. I'd still recommend bumping up the mains.

Decel pop through exhaust is most likely an exhaust leak.

[kenshapiro2002]

Thanks...got my list of work.

Your on target. I would opt for inadequate fuel supply or old accelerator pump diaphrams not springing back quickly. Run the accelerator pump test but pump it a few times back to back. Does it spray nice and even through a few pumps? If no it's time to replace them. If yes then do a hard acceleration through the gears Does it go lean in the higher gears? If yes change the sock and that clicky pump. I'd still recommend bumping up the mains.

Decel pop through exhaust is most likely an exhaust leak.

[kenshapiro2002]

So...the accelerator pump test went well. I changed the mains to the new 125s. Took her out and she was running so well I took her out on the highway. There were some rough moments but again I could "punch through" them with more throttle. On the way back I jumped off the highway and took a twistie back road route. All of a sudden she started to bog down / starve...couldn't even punch through. Eventually she totally quit on me. Acted as if she were out of gas. Had to get a flat bed ride home (Good old Haggerty insurance). She still has a good accelerator pump squirt, but will not start at all. She has a 1/4 tank of fuel (visually as well as gauge). I;m thinking fuel pump? She still has a click-click-click but it's much quieter and less rapid. CB rotary somebody said?

Your on target. I would opt for inadequate fuel supply or old accelerator pump diaphrams not springing back quickly. Run the accelerator pump test but pump it a few times back to back. Does it spray nice and even through a few pumps? If no it's time to replace them. If yes then do a hard acceleration through the gears Does it go lean in the higher gears? If yes change the sock and that clicky pump. I'd still recommend bumping up the mains.

Decel pop through exhaust is most likely an exhaust leak.

[jmill]

The clicky pumps slow down and get quiet when they reach pressure (float bowl is full) or have a plugged suction. Good squirt from your pumps means there is fuel in the float bowls. I'm thinking your current problem is ignition related. 12v to the coil? Good spark?

Can you get it to turn over and run a bit on the accelerator pumps or does it not even stumble over?

[kenshapiro2002]

No idea how to assess whether there's 12v to the coil or good spark.

The clicky pumps slow down and get quiet when they reach pressure (float bowl is full) or have a plugged suction. Good squirt from your pumps means there is fuel in the float bowls. I'm thinking your current problem is ignition related. 12v to the coil? Good spark?

[jmill]

Take a multimeter and check for 12V on the hot wire to the coil with the ignition in the on position. It'll be a spade type connector.

There are a couple of ways to check for spark. Some might have better ideas. I pull the plug and ground the threads and watch it jump the plug gap or just pull the wire and slide a small diameter phillips screwdriver in the connector and create a small gap between the metal shaft and a grounded part of the car and watch it arc. Either way be careful not to get zapped.

You'll need a partner to turn it over while you check for spark.