Webber 36/38 or some odd, issue. (1 Viewer)

[FJ-40Original]

I just put a Webber 36/38 I think, on a 2F in this 75 FJ40, the car will start and run excellently but will not idle, it drops to damn near 100 RPM's and just dies.

Now I read the FAQ and all the posts on these Webbers and how to tune them but this damn thing run's so friggin good, there's no load up of fuel, there's a TON of power top end so I am nearly positive that it's not lean.

The suggestions are: If the motor will not run with 1.5 or so turns in on the Idle set screw (Throttle opening not AF screw) then the jet's are too small.

But that does not seem to be the issue, I don't undersand how a larger jet will act like the main venturi is providing more air...

Anyhow, I don't have a darn Jet kit to play with this thing.

Is it unadviseable to just crank the idle set screw up until it no longer dies, even though the screw has already compressed the anti vibration spring...

 

[Richard R]

Webers are different. The fixed size idle jet controls the mixture well above the idle, almost up to mid range.
Try larger fixed size idle jets.
Look in the Redline web suite for exploded drawings and other information.

 

[FJ-40Original]

Damn! So I gotta get a friggin Idle Jet kit right?

What do they cost and how long do you think it will take to get a package.. I only have a few more day's with this FJ, before I move out of state and give it back to my FJ man.

 

[Pin_Head]

There are a number of things that need to be right for it to idle properly:
1. manifold vacuum
2. idle mixture setting
3. idle speed setting

Make sure that there is no manifold vacuum problem first.

 

[FJ-40Original]

There are NO vacuum issues that I'm aware of. the intake seals up to the head, and the carb seals up to the intake...
The only vacuum port is for the vac, adv. and that's plugged off.

I've already taken off the carb but I'll put it back on this afternoon with the exact same settings, and take a vacuum rading. But I am 100% positive that there's no vacuum loss.

I'll post my results as soon as I get them. For now I gotta go make a 33K lb flatbed trailer out of an old 40' boat trailer today... miracles are needed... my landlord is delusional...

 

[Pin_Head]

There are NO vacuum issues that I'm aware of....

"Aware of" is the key issue.

The way to be aware is to put a vacuum gauge on it. Adjust the idle speed screw until it will run at about 625 RPM and see what the vacuum is.
You would expect to find > 19 inches of H2O. If so, then adjust the idle speed and mix to give 625 RPM at the lowest mixture setting. As long as it isn't pulling fuel out of the main nozzles, then it is running fine.

I think the chances of a carb leaving the factory in a condition where it would not be able to deliver enough idle fuel is slim to none.

 

[FJ-40Original]

Now that's impossible.. In order to get the thing to idle at 625, OR ANY speed for that matter, is to remove the spring on the idle set screw and crank it in even more than it's fully adjusted state already.

The Good Book say's 1.5 to 2.5 turns, I'm something like 5 turns in to get it to idle, but it idles sooooooooo smoothly right at about 400 RPM's then when it get's up to temp then idles to zero then dies...

vacuum leak = faster idle in almost every application I can think of.

Lean = Popping out carb in almost every application I can think of...

Anyone havea jet UP kit handy they wanna sell, just in case today's tricks don't work?

 

[Pin_Head]

vacuum leak = faster idle in almost every application I can think of.

That's not my experience. Vacuum leaks lead to rough idling and misfiring at idle.

 

[FJ-40Original]

I can see that happening also Pinhead, you're correct, but this carb does NONE of those things. It simply run's EXCELLENT except that the idle speed is in the 0 to 200 rpm range when fully warmed up... Even with that damn idle screw in fully.

Anyone have a jet kit they're not using handy??? I got $$

 

[76FJ40]

As long as it isn't pulling fuel out of the main nozzles, then it is running fine.

Not to hijack, but what does it mean if fuel is coming out of the main nozzles? This seems to be my problem. Now back to your regularly scheduled program ...

 

[Pin_Head]

what does it mean if fuel is coming out of the main nozzles? ...

It means that the idle circuit isn't working properly and you have increased the idle speed screw to compensate.

Either there is a manifold vacuum leak or the idle fuel circuit is plugged.

Some people call the main nozzles "venturis". Hopefully you don't have them confused with the bowl vents, which are small brass tubes cut at an angle.

 

[FJ-40Original]

I feel like such a retard...

I'm betting that if I rout the PCV valve to somewhere BELOW the carb where it's drawing vacuum, then I'd get my carb adjustments back where they should be... Ya think?

This setup has the friggin PCV hose coming out of the block adn routed into the air cleaner which gives it no vacuum at all...

I'm really feeling like a heel now....

 

[76FJ40]

It means that the idle circuit isn't working properly and you have increased the idle speed screw to compensate.

Either there is a manifold vacuum leak or the idle fuel circuit is plugged.

Some people call the main nozzles "venturis". Hopefully you don't have them confused with the bowl vents, which are small brass tubes cut at an angle.

Thanks Pinhead. I've checked repeatedly for a vacuum leak but haven't found anything. The fuel is coming from what I would describe as venturis, not the angle cut brass tubes. Looks like I need to check the idle circuit.

 

[Pin_Head]

I feel like such a retard...

I'm betting that if I route the PCV valve to somewhere BELOW the carb where it's drawing vacuum, then I'd get my carb adjustments back where they should be... Ya think?

This setup has the friggin PCV hose coming out of the block adn routed into the air cleaner which gives it no vacuum at all...

I'm really feeling like a heel now....

I doubt that this will matter, even though the PCV valve should see manifold vacuum.

Thanks Pinhead. I've checked repeatedly for a vacuum leak but haven't found anything. The fuel is coming from what I would describe as venturis, not the angle cut brass tubes. Looks like I need to check the idle circuit.

If it is a stock Aisan carb, the first place to start is the idle fuel cut off solenoid. Even if the solenoid works, sometimes the O ring degrades and cloggs the fuel passage.
Some vaccum leaks, like a cracked intake and a leaky brake booster are difficult to find from the outside using traditional spray type methods.

 

[FJ-40Original]

It's a Webber 36/38, as said in title.. But I think the extra air coming in below the base of the carb will make a big diffrence.

I'll know sometime tomorrow

 

[Pin_Head]

If the PCV connection to manifold vacuum isn't blocked off, that would create a large vacuum leak.

Are you sure it isn't a 38/38? I have never heard of a 36/38. They have gears connecting the two throttle plates. The 32/36 is a little small for a 2F as the stock carb is a 38/40 mm.

 

[FJ-40Original]

Oh heck maybe it is a 32/36 and I was just off in my #'s. I only know it's the doppleganger to every 1970's Ford Pinto 2.0 liter carburetor...

I bought it from a guy here on MUD, it took me 3 day's to get all the sand out of it He loved mud.

Now I'm not talking about a vacuum leak, the PVC connection was simply never there to begin with. Some retard had the PCV hose routed into the air cleaner lid...

I took the plug out of the base plate adaptor and bought a 5/16 ID nipple to place there and hook up the pcv hose.

On all my old fords the PCV goes to manifold vacuum under the carb, so that's where I'm putting this one.

THen I'll fire it up again and go for it again.

 

[FJ-40Original]

Well, It worked enough to get the thing to idle at about 500 then I upped it to 650 maybe 700, gettting tight on the set screw again, and pulling 18" lb of vacuum at idle through the vac adv, tube, as that is the ONLY point on this F2 in which I can place a vacuum gauge.....

Anyhow the vacuum wasn't the issue, the carb really is a tad small...

With the hedders adn cam this guy has in it it will empty the carb bowls about 3 seconds into second gear in a hard run, so I need to raise the float level about 1/4" and get a decent fuel pump, this one is old, but the alignment turned out fantastic and the rig run's excellent!

Thanks for all your help