fj60 Carburator Issues (1 Viewer)

[ACPIT]

Hi all - had carburator rebuilt and installed 2 weeks ago, was working beautifully until last night. Hit 4th gear and was going 60mph when the engine started bucking and it felt like loss of gas to the engine. Drove it in third for a while w no problems then the same started happening. Noticed a line was unplugged so I reconnected it and now when I try starting it idles low then turns off... I'm thinking maybe I marked or installed the lines incorrectly but then how could it drive like a dream for 2 weeks????

Any help is appreciated!

 

[ACPIT]

Just tried running it again and noticed there's a lot of wetness on the exterior of the carb around where the throttle connector meets the carb... there's a lever that moves up and down near the base of the carb - not sure if I'm making much sense here.

 

[klinetime574]

Photos always help.

Sounds like something is getting clogged though.

 

[Slow Left]

Noticed a line was unplugged so I reconnected it

Which line are you referring to here. Can you post up a picture identifying the line and the component(s) it runs between?

Also, have you checked the ICS (Idle Control Solenoid) to see if it is working correctly?

Short version of testing the ICS:
1) Engine off
2) Unplug the green connector of the ICS at the carb
3) Turn ignition to 'On' but not 'Start'
4) Reconnect the green connector on the ICS at the carb

If you hear a 'click' when you reconnect the connector, ICS is actuating properly. If you don't hear a click, it is most likely due to a bad ground (it grounds through the Emissions Computer). The mod is to reground the ICS permanently.

 

[ACPIT]

That's where I noticed the wetness yesterday. So I removed the air filter and checked all the bolts on the base - of course the hardest to reach (front-right) was loose so I tightened it down but same issue. Now I'm noticing a ton of black smoke coming out the rear... read another thread where it was a possible fuel filter issue? Will check the ICS next and work from there. Thanks for the help guys - I need her running ASAP as she's my daily.

 

[Slow Left]

The wetness is most likely a result from the Secondary Slow Cut Valve assembly (see image below). It is a non-serviceable part (can't get new OEM anymore, and can't be rebuilt because the valve itself, overtime, wears down and the tolerance between the valve and the housing wears, causing a gap and allowing gasoline to leak out). But you can pluck the valve from the housing, tap the hole in the housing and then thread in a bolt with some JB Weld on the threads to permanently hold the bolt in place. see this thread for more information or search 'Secondary Slow Cut Valve' in the 60's section for more specifics on the modification:

https://forum.ih8mud.com/threads/newly-built-carb-fuel-leak.850428/#post-9694055

Also, does the pipe that the blue arrow in the image twist/move? I've never seen that pipe outlet pointing to the side like that...I've only ever seen it curve and point upwards....

 

[Slow Left]

On second look, that Secondary Slow Cut valve assembly looks rather newish (at least the screw do...). Have you contacted the folks who rebuilt the carb and tried to do any troubleshooting directly with them? Might be a good idea, too...

 

[ACPIT]

Spoke with the guy who rebuilt the carb and he stated the bucking would be caused by something entering/blocking the carb and not the carb itself. He said I needed to buy additive cause I used costco gas and it's the worst for carb engines (wasn't aware) - added the additive and took for a drive. Still bucking around 2k rpm. Next on the list was fuel filter and pump.

Side note - no more wetness noted anywhere on carb after I tightened it down yesterday...

 

[ACPIT]

Also - I clicked the link and didnt notice a blue arrow anywhere on the image....

 

[Slow Left]

Also - I clicked the link and didnt notice a blue arrow anywhere on the image....

Ooops...forgot to upload the image...it should be there in post #6 above.

 

[3_puppies]

Side note - no more wetness noted anywhere on carb after I tightened it down yesterday...[/QUOTE]

Spoke with the guy who rebuilt the carb and he stated the bucking would be caused by something entering/blocking the carb and not the carb itself. He said I needed to buy additive cause I used costco gas and it's the worst for carb engines (wasn't aware) -

I call BS on this, no need to buy an additive for Costco gas. sounds like the guy is passing the blame.

I would check and change the fuel filter, also check the entire fuel line to make sure someone else didn't install another filter underneath.

 

[ACPIT]

So I took the carb back to the guy who rebuilt it - he them proceeded to take it apart and said there was a bunch of crap inside the carb. I also took the fuel filter (as per his request) and he showed me that the gas had eaten away at the epoxy inside and caused the basket inside to come off completely. So the gas wasnt getting filtered and that caused the blockage in the carb. Aparently I also needed a new filter!

As I was placing the carb back on I noticed the "insulator plate" (as I was told it was called by Specter) where that BLUE arrow mentioned in a prior post was - had worn down completely where the metal pipe meets the plate. Luckily my local junk yard pulled an exact match from a similar model and I replaced it ($50).

Drove the truck most of last week and she is driving much better and I'm getting an extra 2-3 MPG. I will be taking her to the smog shop this week and hopefully she will now pass.

Thank you all for the help!!!

 

[Slow Left]

That was a good idea to take it back to the guy who rebuilt the carb...glad it worked out for you.

For fuel filter, I always go Toyota (OEM).

That pipe that curves up and out through the body of the insulator is a vac pipe. If there are cracks in the body of the insulator around that pipe, then it will be a significant source for a vac leak. If you wiggle that pipe a bit (don't put too much pressure on it) and it moves about within the insulator body, then you probably need a new insulator (also still available new from Toyota ~US$150).
When dettatching/attaching that hose that connects to that vac pipe, be mindful not to put too much pressure on the pipe, otherwise you might crack the insulator material around it (if the insulator is old and has seen a lot of heat).

Your US$50 used insulator should be good as long as the top and bottom surfaces are flat (not warped) and the pipe is still secure in the insulator body with no cracks.

When reinstalling the insulator onto the top of the intake manifold (and underneath the carb), dip your finger in some clean motor oil and spread it over the surfaces on the top and bottom of the insulator gasket where it makes contact with the intake manifold and bottom of carb. This will help it keep a seal, but also make it easier to remove next time. If you didn't do this on this last re-installation, don't worry about it too much...not too big of a deal...

If you still have issues passing smog, post back up on MUD and consider installing both a vac gauge (to read manifold vac) and AFR gauge (to measure air/fuel ratio in the exhaust stream)...search here in the '60s section' on MUD.

Here is a recent thread about the AFR gauge:
https://forum.ih8mud.com/threads/getting-my-butt-kicked-trying-to-ca-smog-my-60.788392/
https://forum.ih8mud.com/threads/air-fuel-mix-gauge-opinions.483391/
https://forum.ih8mud.com/threads/passing-kalif-smog-with-an-air-fuel-mix-meter.838628/#post-9591042

 

[Output Shaft]

There are different versions of the FST fuel filter. Models are linked below:

1. FST RPM500
2. FST RPM350
3. FST RPM300

 

[Spike Strip]

Output, that's a hellavalot of fuel filtration for a tractor. Is the filter element itself proprietary or can you use something else? How's it been so far ?

 

[Spike Strip]

HA! I got bit by the Pemex dirt bug many years ago in a VW Van. Bunch o' college idiots on the side of the Baja highway trying to clean a stinking Solex carb. Yeah, you're prolly right: Some things, too much is not possible.

 

[ACPIT]

So heres where I am at. The smog came within .25% of passing - much better since I was running close to 6% and now a bit over 2%. BUT - the carb guy said the issue is the solenoid won't close above 1500 rpm which is causing it to run rich over certain speeds. He says the solenoid itself is fine and most likely culprit is the computer. Anyone have an idea where I can get a new computer?

 

[ACPIT]

I left reports in the truck and its still at the smog shop. Will post when I get her back.

So.... I spoke with the carb guy and apparently there is "something" he can do with the Jets to get it to pass bUT it's temporary and would need to change back after the test. If it ain't the solenoid or the carb - what else could be the culprit???

Local dealer wants to charge me an arm and a leg to diagnose - but as per smog shop he spoke w a mechanic at the dealer who recently had a similar issue with another FJ. Looking at my options I am almost considering doing a diesel swap....

 

[Spike Strip]

Do a search on here for Alcohol and you'll find a way to pass smog, but it won't be a cure. The issue is probably not with your carb.

HEET is just denatured alcohol.

 

[Pin_Head]

X2 on the problem is not the idle fuel solenoid.

If the problem is 2% to 6% CO (carbon monoxide) then it is running rich. Maybe the carb guy put the main jet for the secondary in the primary side. The smaller jet goes in the primary.