Weber 38/38 and 1F (1 Viewer)

[greytandy]

I have a Weber 38/38 installed on a '74 F engine (from an FJ55) in my '70 FJ40. Despite setting and resetting the timing, adjusting the carb mixture, and the idle speed, I still get some mild dieseling. The engine runs great, idles smoothly, and provides plenty of power otherwise. It was suggested that I may need to get headers as there may be excess fuel in the cylinders after cutoff (working hypothesis). Anybody have any ideas? Thanks.

 

[honk]

How low can you get the idle?

If you can get it to idle at around 500 rpm it should solve or cut down the dieseling.

You already know the answer is to run an Aisen carb with an idle stop solenoid, right?

I don't think headers will help.

 

[grant5127]

Check for vacuum leaks at base mounting and
manifold to head areas..excess fuel lingering in the manifold can be sucked in after cutoff .. set RPMs of descent to 500/550 revs...use a pressure regulator, set @ 3, regulators are necessary not so much for pressure control but to maintain low turbulence in the float bowl... check for proper float bowl fuel level.. keep the throttle plates as near to closed as possible.. use the adjusting mixture screws to obtain the best lean idle.. read your plugs.. a complete tune-up w/valve adjustment may be needed.. run a tank of better quality gas through it and a dose of Seafoam to help eliminate any carbon deposits.....

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[greytandy]

Thanks guys - advice appreciated. Yes, I wish I had an Aisin carb. The Weber came with the engine and I can't afford to buy another carb right now.

 

[hatchman]

Wanna Tade?

I just pulled an Aisin carb from a 1978 2f was runnin good. Let's trade! I'll ship to you and you ship to me.....Let me know if nterested

Hatch

 

[greytandy]

I just pulled an Aisin carb from a 1978 2f was runnin good. Let's trade! I'll ship to you and you ship to me.....Let me know if nterested

Hatch

Maybe I should rethink. You sound a bit too anxious. Upon the advice of my trusted mechanic, I'm going to keep the Weber.

 

[hatchman]

What ever!...no sweat off my ballls.just trying to help a fellow mudder

 

[greytandy]

just trying to help a fellow mudder

Thanks. It is appreciated.

 

[Herb]

Greytandy
I've got a 1F, Headers and a weber 38...I get deiseling too. I've been meaning to look at the carb base but haven't gotten around to it. Maybe someone at the meeting can help us out.

 

[Felix]

[hijack]

Herb, you coming, too? Damn, this should be a good meeting

[/hijack]

 

[greytandy]

Greytandy
I've got a 1F, Headers and a weber 38...I get deiseling too. I've been meaning to look at the carb base but haven't gotten around to it. Maybe someone at the meeting can help us out.

What brand of headers do you have?

 

[greytandy]

[hijack]

Herb, you coming, too? Damn, this should be a good meeting

[/hijack]

[subhijack]

I take that as a compliment.

[/subhijack]

 

[Herb]

That's RIGHT! Finally getting my act together....I may even drive the beast there...maybe.

Looking forward to it.

 

[Herb]

I'm not sure which brand headers I have.....is there a RUSTY brand?

PO installed them.

 

[greytandy]

I'm not sure which brand headers I have.....is there a RUSTY brand?

PO installed them.

Likely these?

 

[Herb]

Yep, thats the ones. Minus the nice black paint...because mine are now rusty.

 

[Otterav]

Hello,
I also have a '74 with the 1F, running headers, and a 38/38. I am using a non usa distributor w/pertronics. No dieseling issues, idle is set at 600 RPMs. Check the base plate for vacuum leaks. Get a can of starting fluid and the small tube from a WD-40 can and spray small amounts around the mounting base. If the idle increases there is your leak. What jets are installed? I don't have my jet numbers handy, but will get them out of my shop later if you need them.
eric

 

[ranger]

Hello,
I also have a '74 with the 1F, running headers, and a 38/38. I am using a non usa distributor w/pertronics. No dieseling issues, idle is set at 600 RPMs. Check the base plate for vacuum leaks. Get a can of starting fluid and the small tube from a WD-40 can and spray small amounts around the mounting base. If the idle increases there is your leak. What jets are installed? I don't have my jet numbers handy, but will get them out of my shop later if you need them.
eric

I wouldn't spray starting fluid around a hot manifold..............
I use a small propane bottle ( like the hand torch bottles) the valve, minus the torch end, and put about a 18" section of rubber hose on it. Crack oepon the valve and dirrect the gas around areas of suspected vacuum leaks. When the engine speeds up, you found the leak.

 

[mikeymouse]

I eliminated the dieseling on my 38/38 by installing the fuel cut solenoid. It was instant and never came back. It's easy just run a 12v ignition-on power source to the solenoid and poof it's gone. It's a racing carb, not a gentile well behaved beast. It's basic and stable. The fuel cut solenoid will fix the issue.

 

[mikeymouse]

I wouldn't spray starting fluid around a hot manifold..............
I use a small propane bottle ( like the hand torch bottles) the valve, minus the torch end, and put about a 18" section of rubber hose on it. Crack oepon the valve and dirrect the gas around areas of suspected vacuum leaks. When the engine speeds up, you found the leak.

I have always used WD-40. It's not as flammable as starting fluid it makes the RPM go down and you don't have an insanely flammable gas cloud around the engine. Just my $.02