Which carburetors *actually work* for an FJ40?? (1 Viewer)

Joined
Oct 14, 2020
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2
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Troutman NC
1978 Aisin rebuilt by @FJ40Jim, for ‘78 FJ40, with factory electronic ignition, was night and day to what she was when I bought her.

Eventually, the oem dissy vac advance module developed a huge vacuum leak and I had an issue with the oem fuel pump diaphragm splitting and pumping fuel into the crankcase.

I bought a 2nd 1978 Aisin (from a MUD member) and sent it to @65swb45. Mark has come to Vegas for a wedding and we hiked and cruised together. He told me that he had learned some performance tricks that would make her run like an SBC.

I replaced the oem dissy, coil and igniter with a DUI and redesigned my fuel delivery system, eliminating the oem fuel pump and replacing it with two electric fuel pumps (One for each tank).

Once I installed the Aisin with Mark’s performance enhancements, she literally ran like she should have.

She started easily, easily cruised at 70... I passed at 75... once at 80. Once I found out all was good, I again kept my speed below 65.

I know nothing about other carbs... I do know Jim and Mark know their stuff.

I also know DUI, when installed as DUI recommends (timing @ ~12*BTDC, plugs gapped @ .050”-.055“ (I kept them at .050”), in concert with Mark’s performance enhancements gives more power and speed than a 40 rightfully needs.

Electric fuel pumps offer the security of never having fuel dumped in the crankcase and the inherent risks to engine intervals

Dual electric fuel pump provided me the security of knowing a pump failure would not shut me down... I just made sure I never kept less than 1/2 tank in each tank, minimum. I’ve been known to carry another 20gals on the roof rack.

So, this is my long winded way of saying there are experts on here that can make an Aisin carb hum. But, as @fireflyr inferred, above... you could be trying to fix an ignition issue, vacuum leakfuel delivery issue, etc., by tweaking your carb.

Good luck!!
Thank You Solace,
I am new to ih8mud and just purchased my first 78’ FJ43. Plagued with a variety of issues and Carb being the first to tackle. Fuel in the oil, fouled plugs, missing carb pieces, etc. not to mention multiple electrical ghost. The carb I have has been beaten and abused. Thanks for the direction.
 

Dizzy

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Santa Fe, New Mexico
Like what? Valves are tuned to spec, and I it should be timed right...
What is your spark dwell angle, or is it an original distributor, what is the points gap? Also, if you are dieseling at cutting the ignition switch, you probably have carbon build-up on the plugs or valves that are glowing hot. This is also a cause for pre-ignition, so spark timing may only be kinda correct. What do you spark plugs look like, up close, labeled 1-6? I'd bet that the engine isn't getting good spark on a cold start. Do you have to use choke or throttle at a cold start?

If you are running a 32/36, I'm pretty sure that your throttle plate is opened more than 1.5 turns in from touch-off, as an F or 2F needs more CFM. That makes your air fuel mix on the primary a bit arbitrary, and it makes the idle jet more critical.
 
Joined
Oct 7, 2011
Messages
1,007
Location
Austin TX
 
I've had a 350cfm Holley on a Downey adapter on my '79 2F for going on 9 years. It has never needed a rebuild and starts every time. I have had the truck up to 104 mph on the highway (GPS verified) and it purrs at idle. I have always had Holleys on all my cars and, to me, they are simple, cheaply rebuildable, and reliable. What more can you ask for? I have bought the 2300 series 350cfm's used off of Ebay for about $100, overhauled them, and put them on my son's truck and myd my spare 2F, and keep a few in reserve, but I have never needed to use the replacements. I adapted the original air cleaner to mount on the Holley air horn, so it still looks mostly original. I also converted the throttle linkage to a bicycle type cable which has proven to be reliable as well. If you go off-roading where you have to climb hills, Downey's adapter for the float bowl will solve that problem as well. If you want some photos, let me know.
Doug
 
Joined
Oct 27, 2019
Messages
27
Location
Texas
Thank You Solace,
I am new to ih8mud and just purchased my first 78’ FJ43. Plagued with a variety of issues and Carb being the first to tackle. Fuel in the oil, fouled plugs, missing carb pieces, etc. not to mention multiple electrical ghost. The carb I have has been beaten and abused. Thanks for the direction.
The 43s are fun. Did you import it yourself? Mine came up from Bogota and like yours, a variety of issues were including at no additional cost!
 
Joined
Feb 22, 2017
Messages
274
Location
SW Washington
I've had a 350cfm Holley on a Downey adapter on my '79 2F for going on 9 years. It has never needed a rebuild and starts every time. I have had the truck up to 104 mph on the highway (GPS verified) and it purrs at idle. I have always had Holleys on all my cars and, to me, they are simple, cheaply rebuildable, and reliable. What more can you ask for? I have bought the 2300 series 350cfm's used off of Ebay for about $100, overhauled them, and put them on my son's truck and myd my spare 2F, and keep a few in reserve, but I have never needed to use the replacements. I adapted the original air cleaner to mount on the Holley air horn, so it still looks mostly original. I also converted the throttle linkage to a bicycle type cable which has proven to be reliable as well. If you go off-roading where you have to climb hills, Downey's adapter for the float bowl will solve that problem as well. If you want some photos, let me know.
Doug
Please send photos! What kinda revs were you doing at 104?! I didn't know these old 6's could spin that fast!!
 
Joined
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Troutman NC
The 43s are fun. Did you import it yourself? Mine came up from Bogota and like yours, a variety of issues were including at no additional cost!
Cartelcruiser! Great name. My 43 was a military import. Certain Service members can import a vahicle when they return to the US. Mine belonged to a navy officer. My 43 is a pig with a nice paint job. I have not been able to spend much time on my new ride. I have a full page of parts to repair/replace and will prioritize. I live near a state park and it runs well on short trips. Baby steps.
 
Joined
Oct 7, 2011
Messages
1,007
Location
Austin TX
 
Please send photos! What kinda revs were you doing at 104?! I didn't know these old 6's could spin that fast!!
My '79 FJ40 has 3.70 gears, an H55 5 speed, and runs on 31 inch tires. I took a photo of the tach and speedo as I was getting up to speed. I will post photos, they are on a different computer. I'm pretty sure I was under 4K rpm.
Doug
 
Joined
Oct 27, 2019
Messages
27
Location
Texas
104 is wild. I've topped out at 86mph using GPS, and it was a shaky ride. @WyattEarle that's cool! I found mine through online classifieds in Bogota and had an attorney down there (who knew nothing about cars) broker the deal and ship it to Houston. If it weren't for the transport fees, I'd say I got a pretty good deal for $6800. It needed about 8k worth of work once it got here though, and I'm still slowly doing repairs as I can budget them in
 
Joined
Feb 22, 2017
Messages
274
Location
SW Washington
Lots of good info, thanks!

What is your spark dwell angle, or is it an original distributor
Not sure. It's an electronic ignition system

spark timing may only be kinda correct. What do you spark plugs look like, up close, labeled 1-6? I'd bet that the engine isn't getting good spark on a cold start. Do you have to use choke or throttle at a cold start?
The spark plugs are what toyota specs and they're all gapped to spec as well... you think there's too much carbon buildup for them to work right? Also it'll fire without throttle if I have the choke on but I need choke and gas to get it running.

If you are running a 32/36, I'm pretty sure that your throttle plate is opened more than 1.5 turns in from touch-off, as an F or 2F needs more CFM. That makes your air fuel mix on the primary a bit arbitrary, and it makes the idle jet more critical.
The shop which I trusted to tune my carb told me that they'd probably have to re-jet it, but they ended up getting it to run without replacing any jets. Maybe I should? Also, how do I adjust my throttle plate?
 

Dizzy

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Messages
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Santa Fe, New Mexico
Electronic ignition has no dwell adjustment, IIRC.

Lets see the plugs, they might be fine.

Jetting the Weber might not be necessary. Until you identify lean or rich at a range of throttle. Jets can be drilled if a bigger one is necessary. Just a bit rich, or a bit lean is not evident without measuring the exhaust with an O2 sensor.
 
Joined
Oct 7, 2011
Messages
1,007
Location
Austin TX
 
@DougAustinTx did rising sun do the 5 speed conversion? I'm also in ATX
No, Wimberley Four Wheel Drive did the conversion to the 5 speed. They also switched out the rear end from an FJ60 so I had a real parking brake and single slave brake cylinders in the rear. I overhauled the split transfer case and used an FJ60 trans cross-member and modified it to fit and be removable.
 

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