Look in the porthole window and see for yourself...
some engines like more advanced timing, give that a try.
when did you last adjust the valves ?
What have you done to your Land Cruiser this week? (39 Viewers)
- Thread starter IH8MUD
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
some engines like more advanced timing, give that a try.
when did you last adjust the valves ?
Could be set wrong on the float. Easiest way for me to hunt vacuum leaks is with a can of WD 40 with a pee tube. Cold engine idling, spray lightly and quickly along the gasketed surfaces for vacuum - intake manifold and carb base and the carb sections if RPMs kick up there is your leak. Pays to have a fire extinguisher handy - thus lightly and quickly on cold engine.
Weak fuel pump? You could put a $10 electric fuel pump in line or bypass the mechanical one as a test.
Brake booster can leak - Put a big hemostat on the hose - see if that makes any difference - manual brakes take way more pedal pressure to work on your test drive.
Carb work isn't for everyone. I have bailed out several folks that got lost on their first attempts.
Did you look at the adjustment screws? Some gorilla's crank down on the screws damaging the smooth taper on the screws with a ring or the seats are damage - either make adjusting properly very difficult and flustering at best.
Weak fuel pump? You could put a $10 electric fuel pump in line or bypass the mechanical one as a test.
Brake booster can leak - Put a big hemostat on the hose - see if that makes any difference - manual brakes take way more pedal pressure to work on your test drive.
Carb work isn't for everyone. I have bailed out several folks that got lost on their first attempts.
Did you look at the adjustment screws? Some gorilla's crank down on the screws damaging the smooth taper on the screws with a ring or the seats are damage - either make adjusting properly very difficult and flustering at best.
Last edited:
6f40j9
SILVER Star
Valves about 2 years ago when I put the head on. I’ve been trying for over a year to get it into mudrack’s for a hot valve adjust and carb timing but he’s too busy.
6f40j9
SILVER Star
I’ll check again for vacuum leaks.
New oem pump when I put the head on, about 600 miles ago.
No brake booster present.
I just watched a tuning video that was pretty basic. I just need a tach and vacuum gauge.
You don't need Gary to adjust your valves or your carb. I bet there's videos for that too, and how-to posts in the FAQs...
6f40j9
SILVER Star
I’ve been playing with this pos carb for 2 years. I obviously don’t get it. This summer, out of the blue it decided to run just fine for 3-4 weeks until it didn’t. Then I found the bad plunger. Now the more I mess with it, it just gets worse. I can’t get it to idle and it’s backfiring out of the top of the carb. I’m not smart enough to figure it out and I lack probably some key tools.
I barely got the valves adjusted cold, there’s no way I have the patience, or skills to do them hot.
Honestly it’s a wonder this thing runs at all due to the fact I’m the only one that has touched it during my ownership and I’ve replaced the head, exhaust manifold, water pump, carburetor…
timing issues cause backfiring out of the carb a lot of the times
6f40j9
SILVER Star
Yep!
6f40j9
SILVER Star
I would try to adjust it but it won’t stay running long enough to.
pb4ugo
SILVER Star
A Backfire thru the carb could be a lean condition also, it could have a vacuum leak.
When I was running a Weber carb and DUI distributor, the 40 ran ok.. timing was set to the factory 7*… it usually started hard and coughed until it warmed up. I did advance it about 1/4” pass the mark ( turned out to be around 11*) and the truck ran much better and not nearly as sluggish.
Since all of the Sniper stuff was already on my shelf, I did convert it all to electronic but timing could be your next thing to rule out
Since all of the Sniper stuff was already on my shelf, I did convert it all to electronic but timing could be your next thing to rule out
Just because you bought and installed new parts don't mean they are still good. You can check the fuel pump, after engine is idling enough to run. Shut it off, disconnect the fuel hose at the carb and put it in a coffee can. Start engine and watch the fuel flow - smooth pulsing is fine; surges as in fuel flow then nothing then fuel flow again isn't good.
6f40j9
SILVER Star
One thing I have noticed is the idle mixture screw seems to have no effect (by ear anyway) on rpms.
According to the carb video above you back it out to raise the rpms, then turn the idle screw to bring them back down, and repeat.
I had it all the way in and several turns out with no change.
According to the carb video above you back it out to raise the rpms, then turn the idle screw to bring them back down, and repeat.
I had it all the way in and several turns out with no change.
so adjust them cold, or warm. You can check the gaps when hot and adjust them as they cool. Get them close anyway. For an hour of shop time at Mudrak's you can buy the key tools you need and you get to keep the tools. The more you practice adjusting the valves, the quicker and easier it gets.
Happened to me once, I put a gasket in backwards and partially blocked the air passage that goes to the mixture screw. Take it apart and follow that internal passage with little zip ties to see where it goes and is clear.I had it all the way in and several turns out with no change.
pb4ugo
SILVER Star
^^^^^^this is where I'd start:^^^
Your idle circuit could be blocked or clogged.
The carb is suppling fuel or air thru another circuit. Are the venturis leaking fuel at idle? Are the throttle plates closing? Make sure nothing is stopping them from closing. They could be hanging up on a gasket, linkage or dirt.
Your idle circuit could be blocked or clogged.
The carb is suppling fuel or air thru another circuit. Are the venturis leaking fuel at idle? Are the throttle plates closing? Make sure nothing is stopping them from closing. They could be hanging up on a gasket, linkage or dirt.
Ackcruisers
SILVER Star
You can always buy the aftermarket Chinacarb while you rebuild the carb. I’ve run this one for the past few years. It works. Carburetor Carb For 1969-1987 Toyota Land Cruiser 2F 4230CC FJ40 21100 - https://mostplusauto.com/products/1x-carburetor-carb-for-1969-1987-toyota-land-cruiser-2f-4230cc-fj40-2110061012?srsltid=AfmBOophHL0lSnvINPc84ZsB6E2WvFVVL0X356Wch1J0JvWXVkgQZGkJ
6f40j9
SILVER Star
I think I need a bunch of brackets, a different throttle cable and air cleaner top to run that one.
6f40j9
SILVER Star
I’m not sure what I did, but it’s running better now. Probably have the idle a tad high, but I tried driving it hard-ish, bogging it, decelerating, fast stopping, etc and it didn’t die on me, so…I’ll just accept it for now. 
