Holley 600 carb help

[Popdart]

Help please . . . I've got a 600 Holley 1850-4 / 4160 on my 383. I have no history on this car or engine. I have been fortunate to have got it running without too much grief, it runs good, but continue to find issues that I am glad to have you guys for.

I had a gas leak at the accelerator pump. I pulled the pump and didn't see any damage to the diaphragm, so I cleaned it up and reassembled. It still leaked.

The engine also has a definite hesitation and falls on its face when you give her hell, which I am wondering is also accelerator pump related. If you baby the throttle, you can accelerate steadily and hear the secondaries kick in. The timing is around 10 (old school with a timing light), new plugs, new wires. It idles good, but even when you aggresively open the throttle at the carb, it definitely will hesitate.

After going to the Holley site, I purchased a replacement diaphragm 135-5, 30cc, which I believed to be the stock/standard diaphragm.
As you see in the pics, the diaphragm I purchased is not the same as the one that was originally on the carb. The one on the left is the one I found on the carb, the one on the right is the 135-5 I bought. So I am guessing my original one is not the stock/standard diaphragm. Which one is correct?

The accelerator pump cam is orange in color and is screwed in at the #1 position. The pump nozzle is #25. What's your guys opinion, should I change the cam and nozzle to help with the hesitation?

Any ideas / suggestions to help remedy my situation or improve it? I'm also thinking that if I just replace the diaphragm, I may stop the leak, but not do anything about the hesitation..

Thanks guys . . . . Rog

 

[crackedback]

If you need to buy another pump diaphram, get the green GFLT diaphram. It's not as prone to cracking from the ethanol in our fuel now. Cars that sit with those black diaphrams have them get hard, shrink and crack.

The one you bought is correct. The old one has shrunk.

The hesitation may be from the accel pump.

I don't run ANY mopar with only 10* initial timing. Where is your total number now and does it ping at all? Get that total number, dial in the initial to get that correct and fix the curve. It may require you limiting mechanical in the distributor to hit your total number. I'd pump the initial up, it will idle cleaner and may get rid of the hesitation. If it's got any kind of aftermarket cam, at least 16 initial would be my suggestion.

 

[Bad Sport]

I would reconsider your fuel filter choice too, put a metal one in there.

 

[Popdart]

If you need to buy another pump diaphram, get the green GFLT diaphram. It's not as prone to cracking from the ethanol in our fuel now. Cars that sit with those black diaphrams have them get hard, shrink and crack.

The one you bought is correct. The old one has shrunk.

The hesitation may be from the accel pump.

I don't run ANY mopar with only 10* initial timing. Where is your total number now and does it ping at all? Get that total number, dial in the initial to get that correct and fix the curve. It may require you limiting mechanical in the distributor to hit your total number. I'd pump the initial up, it will idle cleaner and may get rid of the hesitation. If it's got any kind of aftermarket cam, at least 16 initial would be my suggestion.

Thanks for your reply Cracked...
It supposedly had a "mild cam" according to PO, so I'll move it up to 16ish to see how it runs. The "bulge" on the diaphragm installs away from the carb, towards the cover, I assume. Thanks Rog

 

[Popdart]

I would reconsider your fuel filter choice too, put a metal one in there.

Thanks for the reply Badsport . . .
I agree and I will be changing it after all my tinkering, just figgered I'd leave it for now to assure I'm getting fuel to the carb . . . . Rog

 

[crackedback]

Thanks for your reply Cracked...
It supposedly had a "mild cam" according to PO, so I'll move it up to 16ish to see how it runs. The "bulge" on the diaphragm installs away from the carb, towards the cover, I assume. Thanks Rog

Correct. Spring goes in first on bowl, with bulge fitting down into the cover.

Check your total timing before bumping up the initial. You may get into an area where it will ping. Some big blocks can handle 40*, but that's not usually the norm.

If you have any questions ask...

 

[Popdart]

Correct. Spring goes in first on bowl, with bulge fitting down into the cover.

Check your total timing before bumping up the initial. You may get into an area where it will ping. Some big blocks can handle 40*, but that's not usually the norm.

If you have any questions ask...

Thanks again . . . well, I have to admit I'm very old school, never did anything other than initial timing. I will have to "school up" to do anything more. Any threads or sites I can use? Rog

 

[Bad Sport]

Thanks for the reply Badsport . . .
I agree and I will be changing it after all my tinkering, just figgered I'd leave it for now to assure I'm getting fuel to the carb . . . . Rog

I wasn't trying to be smart, just so you know, but those plastic filters have been known to cause fires.

 

[Popdart]

I wasn't trying to be smart, just so you know, but those plastic filters have been known to cause fires.

lol I know you weren't and I agree . . . I heard the horror stories on here. I appreciate you and anyone, bringing to my attention, anything I need to address. Thanks again. Rog

 

[Bulldozer]

i dont think Bruce and i ever disagree.

I have a clear plastic fram on my duster, been there almost 2 years. no worries LOL

:hello2:

 

[Bad Sport]

I have a clear plastic fram on my duster, been there almost 2 years. no worries LOL

:hello2:

Pah! I used to run them when I was younger and I never had an issue either. Then I saw some pictures of a car that caught fire from the filter end snapping off. That was enough for me.

 

[Bulldozer]

Pah! I used to run them when I was younger and I never had an issue either. Then I saw some pictures of a car that caught fire from the filter end snapping off. That was enough for me.

i wonder if it was user error. at any rate, when it comes time to replace it i will use a metal one. i really like the idea of being able to see the fuel . every fuel pressure gauge i have used has been a piece of crap and never lasted for any length of time. to be honest, i have used them for 20+ years and never had an incident, not to say it doesnt or wont happen

 

[Bad Sport]

i wonder if it was user error.

Probably user neglect, when they get old the plastic starts to yellow and the get what looks like cracks in them. Brittle too. Probably never changed it would be my guess.

 

[Snake]

Looks to me that your pump arm is adjusted to tight also, what secondary spring are you using? they could be coming on too soon.

 

[dennday67]

I used the same filter when I got my valiant to check for rust and saw none so a year late I changed it for a metal one and inspected the filter. I found the metal ring that seats the filter flaired out so it wasn't doing much filtering.

 

[Popdart]

Thanks for all the help.

Update . . . check new pics on carb. It looks to me the adjustment screw that activates the accelerator pump is not in alignment with the pump arm. Is it supposed to be on that angle or is it bent?? Also, I pulled the secondaries vacuum diaphragm (??); it was all distorted and torn. I'm going to get a new one. Also took a pic of the spring, I don't believe thats the spring you are referring to is it Snake?

Cracked, my damper has several white marks on it equally spaced. I am guessing this has to do with reading the total timing?? I'll get that area turned to where I can see it and to verify that.

Thanks again . . . keep the input coming . . . it helps and I appreciate it. Rog

 

[crackedback]

It may be hillbilly timing taped.

Check the marks against your timing cover. Roll the tdc mark to 10 BTDC and see where those marks line up. Note the increments. I mark mine at 15 and 30 so I can get any reading up to 40 degrees BTDC.

 

[Popdart]

Sounds good . . . I will check, thanks Bud

 

[crackedback]

That secondary diaphram is toast.

Look on the holley site on how to adjust the accel pump arm. There are some youtube videos out there too. At full stroke the lever going to the diaphram needs about .015 free play. Otherwise you run the risk of tearing the diaphram by pinching it solid.

A secondary spring kit is a good investment too...

 

[Bulldozer]

accelerator pump adjustment

[ame="http://youtu.be/w3F3ssOb8lg"]302 Found[/ame]

 

[crackedback]

Thank you Lance...

 

[Bulldozer]

Thank you Lance...

my pleasure Rob !

i have a 600 as well that i was having pump shot problems with until i watched this video. problem solved

 

[Popdart]

my pleasure Rob !

i have a 600 as well that i was having pump shot problems with until i watched this video. problem solved

I will watch the video .. please look at the pics of my accelerator pump adjustment screw arm . . . I believe its bent . . . the video pic above looks alot straighter than mine. I believe I will straighten mine like the pics then adjust per the video. After I get some parts and get 'er back together, I update here. Thanks guys, Rog

 

[tekslk]

Try a 31 squirter but pull your throttle and make sure that the pump squirts instanly There should be no delay in fuel when you move linkage.

 

[Snake]

Yep thats the spring in ya pic I was talking about.