New carb, still stalling when hot. FJ60 rebuild fun! (1 Viewer)

[slingblade16]

Hello gents,
In resurrecting this FJ60 from storage of a friend in a barn for 11 years. Overall its great, but NOT definitely a daily driver yet.
Some background.
It drove great in the morning, it drove great in the afternoon. It did not drive great in the morning and the afternoon!
So I'm trying to figure out why when I drive it to work, then around work, and when driving home in the summer afternoon it stalls going up the mountain.
Yes, I'm in New Mexico. My work is at 4000MSL and I live at 6500MSL. Not that high, but it is still hot here.

They tuned up the engine and put a new carb on. I think it might be a choke issue.
It starts quickly and reliably without pulling out the choke. Does that mean the choke is permanently pulled out regardless of the choke knob position? It feels odd when pulled. I don't know if the choke cable is stock. It looks newer and maybe a lawnmower cable.

So I'd rather close the choke and pump the pedal if needed for a cold start. How do I do that?

Thoughts?
Thanks Guys.

2 inch Jack it lift kit success. I think 31 inch tires next...if I can get it to stop stalling!
-Matt

 

[Dodobo]

Stalling could be a lot of things - when my fuel pump started to fail it would be fine around town but stall up mountains. Recommend you replace with OEM as the aftermarket one I tried failed in a few months.

Re the choke - just follow the cable to where it connects to the carb and make sure the cable housing is clamped correctly. Without choke pulled the housing should connect with no slack in the cable and the valve should be about vertical, when pulled it should nearly close the valve. You can see this with the air filter box removed.

 

[CruiserTrash]

Did you look in the throat of the carb to see if the choke knob is actually moving the choke? You could find your answer there in under 5 minutes.

Stalling … lots of questions before anyone can help you there. When you say you got a new carb who is “they” and what is the carb? Original Aisin carb? Weber? Did you verify “they” hooked everything in correctly? Did they tune it? When did the fuel pump last get replaced? Does the truck have the original emissions equipment? What’s your idle vacuum and do you have any vacuum leaks? Does the exhaust smoke or smell funny at idle? Etc, etc, etc. All of the above can be figured out in about two hours, these are a good place to start in trying to figure out why you’re stalling.

6500 meters above sea level … do you mean FEET above sea level? i think you do. Idle vacuum should be 15-18inHg depending on the health of your motor. If you’re seeing below that you’ve got a definite vacuum leak which can cause stalling in some cases, especially at altitude.

 

[2mbb]

get a copy of the emissions manual (a PDF version available for download can be found under the resources tab, above). On the stock carb for the FJ60 there are two different systems that will open the choke plate (1) once the truck warms up and (2) once the truck starts. So it is not as simple as the choke knob being pulled out or not.

Also there is the high altitude compensation system (HAC) that is detailed in the emissions manual.

 

[OSS]

Just because a shop installed a new (Weber?) carburetor-doesn’t mean it’s set up right for engine.
4000 ft elevation is getting up there and 6K definitely is.
On the original Toyota carburetors, a high altitude compensation system kicks in at around 4000ft to lean out the mixture and advance the timing.
Since you can start a cold engine without a choke, that saying the mixture is too rich.
Normally you wouldn’t be able to without lots of struggle.

 

[Seth S]

Could very likely be riddled with intake and exhaust manifold leaks. This is a common problem as the trucks age and will lead to all sorts of hot and cold running issues. Expect a proper manifold service to run about $1000 if you do it yourself between parts and machine shop work.

 

[Spike Strip]

Pictures at this point might help.

 

[slingblade16]

Update. Gentlemen thank you for your input and help.

I do think the mixture is too rich. I can start the truck easily without the choke.
Also the chole cable does not move the choke at all. Here is a picture of the carb when the choke knob is pulled or not.

The carb I believe to be a OEM Weber Carb, new. The people who installed it and did the engine work so far are 1 Stop Automotive in Alamogordo NM. 4100 FT MSL(Mean Sea Level). Sorry about the elevation confusion. I'm a pilot. Eleveation kinda a big thing for me.

So I will be ordering a new choke cable, the knob has always felt funny to me.
Next I would like to lean the mixture.
I am also looking into the HAC that you speak of.

More to follow!

 

[CruiserTrash]

Update. Gentlemen thank you for your input and help.

I do think the mixture is too rich. I can start the truck easily without the choke.
Also the chole cable does not move the choke at all. Here is a picture of the carb when the choke knob is pulled or not.

The carb I believe to be a OEM Weber Carb, new. The people who installed it and did the engine work so far are 1 Stop Automotive in Alamogordo NM. 4100 FT MSL(Mean Sea Level). Sorry about the elevation confusion. I'm a pilot. Eleveation kinda a big thing for me.

So I will be ordering a new choke cable, the knob has always felt funny to me.
Next I would like to lean the mixture.
I am also looking into the HAC that you speak of.

More to follow!

View attachment 3415115

View attachment 3415119

Weber is a carb company from Italy that now makes their stuff in China. It is not and never was an "original equipment manufacturer" (IOEM) supplier for Toyota. The original manufacturer, or OEM, for carbs on these trucks has always been a company called Aisin ... and it appears from the partial carb photo that you have an Aisin on there. That's a very good thing. If you're bored some time search for "Weber carb" here in the 60 Series section of the ofurm and enjoy reading all the issues folks have with getting them to work on a 2F motor. There are rare exceptions where somebody gets a Weber running right and they're happy with it, but that seems to be far and few between.

Likely you can reconnect the original choke cable and get it working. Is the boss end of the cable securely attached to the carb? And is the end of the cable housing pinched down by the screw on the carb? Is the cable routed so that it has a sharp bend?

In the Resources section of ih8mud you will find the 2F Engine factory service manual. Download that. This will tell you how to perform the "lean drop" carb tuning method. Do that. Some people take the air cleaner off to access the mixture screw on the back of the carb but I found just the right screwdriver to reach the screw with the air cleaner in place. Do NOT overtighten the mixture screw, only tighten until you feel the faintest hint of resistance as it bottoms out or else you can deform the needle or carb or both - and it will never work right after that.

 

[Ian Crawford]

That looks to be one of the remake, desmogged carbs that is a copy of the Aisin 2F carburetor.

Are you still running the original large cap distributor and ignitor? If you're running a non-factory distributor/coil this symptom can be caused by internal and external ballast resistors on the coil.

While you're in there, make sure fuel lines are away from heat sources, there is a damper in the exhaust manifold that should actuate and close as the engine gets warmer. Make sure that is still functional. If the heat riser is staying open it can cause the fuel to heat up and vaporize.

Reference 17231B; 17203, and 17231

 

[Ian Crawford]

Another thing to check would be whether or not you're running the stock cam driven fuel pump or if it's been bypassed or replaced by an electric fuel pump. A poorly wired fuel pump could be failing after running for some time. As electronics heat up resistance increases.

Also, in the photo you posted with the air cleaner lifted up, the choke is OPEN.

 

[Otose]

Update. Gentlemen thank you for your input and help.

I do think the mixture is too rich. I can start the truck easily without the choke.
Also the chole cable does not move the choke at all. Here is a picture of the carb when the choke knob is pulled or not.

The carb I believe to be a OEM Weber Carb, new. The people who installed it and did the engine work so far are 1 Stop Automotive in Alamogordo NM. 4100 FT MSL(Mean Sea Level). Sorry about the elevation confusion. I'm a pilot. Eleveation kinda a big thing for me.

So I will be ordering a new choke cable, the knob has always felt funny to me.
Next I would like to lean the mixture.
I am also looking into the HAC that you speak of.

More to follow!

View attachment 3415115

View attachment 3415119

Looking to see how you made out and if any updates. Been battling similar issues with my 86 fj60 for quite awhile. Thought that electronic ignition was going to be the solution but ran into problems again after the install. Runs well for the first hour or so, then stalls out horrendously. Also at 4500 ft altitude, with 7000 ft just an hour away, so would like some more reliability! thanks

 

[mattressking]

1. Check your vacuum at cold then at hot.
2. Check fuel level in sight glass when running and then when it stalls. Must be centered or within range of center.
3. Your truck has electronic ignition already, not points. Don't dump it for MSD, OEM is far superior.

 

[Otose]

1. Check your vacuum at cold then at hot.
2. Check fuel level in sight glass when running and then when it stalls. Must be centered or within range of center.
3. Your truck has electronic ignition already, not points. Don't dump it for MSD, OEM is far superior.

1. Vacuum is steady but low at 11.5 when cold - only slight movement up to 12.5 when warmed up. Measuring off the intake with a tee off of one of the multiple lines due to Cal emissions, with an external gage. Looking to fit an internal one as well.
2. Fuel level is always good in the sight glass - have not seen it out of center.
3. Should have been more specific on the ignition - switched to the Davis Unified Ignition. Much more power, truck runs great until it gets heated up ( ~ 1 hour of driving, which around here means you are normally changing altitude from ~4500' to 7000' and back again -- for some context).

The damper pointed out by Ian seems to be a potential as the springs are pretty dry with light corrosion - maybe a dumb question, but any idea on how to confirm that this is working?

thanks

 

[mattressking]

Whoa, vacuum is extremely low - you need to fix before you do any other attempts at repairs. Even at 4500-7000 you're missing around 5in of vacuum. Likely manifold gasket is toast unless pcv, booster or a variety of small vac lines are misrouted/broken/missing.

1. What is your base timing set at?
2. Since you have the non-usa replica carb, you do not have HAC as well so you will want to bump your base timing up if it is at 7-10* (see above question). Make sure to disconnect any vac lines to distributor if you have any connected. HAC isn't needed for you since stay above 4k feet, so you need to set base timing to 13* and up to 16* depending how well your engine runs and the associated carb tune. You don't want pinging so start at 13*.
3. Choke only affects cold start - not hot running unless it is staying shut. Please verify full open and full close with choke knob with air cleaner off. If it opens and closes with knob then it is fine, only replace if its sticking or causing issues with open/close.
4. Note you need to close choke manually after warmup, Non-USA carb does not have VTV/choke breaker to 'automatically' add air at cold start.

Key items here are to determine your base timing and vacuum. These are priority before any other diagnosis happens.

 

[Spike Strip]

12.5 is too low.

Is vacuum gauge needle steady at idle? Either condition of engine is very poor or you have a hella vacuum leak.

Mattressking beat me to it: you can't use HAC with that carb - it doesn't have the ports like the stock Aisan carb. If you want to use HAC for going above 4K feet, you'll need to go back to the stock carb.

 

[mattressking]

12.5 is too low.

Is vacuum gauge needle steady at idle? Either condition of engine is very poor or you have a hella vacuum leak.

Mattressking beat me to it: you can't use HAC with that carb - it doesn't have the ports like the stock Aisan carb. If you want to use HAC for going above 4K feet, you'll need to go back to the stock carb.

Correct - he can just bump base timing to 13* to start to skip HAC equipment.

 

[Spike Strip]

@mattressking

I just installed a fresh rebuild stock carb yesterday and was able to get the vacuum to 21 Hg with timing at 9* BTC. I don't usually go more advanced than that because I want to run 87 gas, and it sometimes pings without 91 on inclines with crappy Los Angeles AQMD gasoline.

btw, I remembered what you said about having the mix screw out 2.5 turns from the factory (measuring a still-capped mix screw), but it was way too lean (I have an A/F gauge) and had to back out the mix screw to about 3..25, then in a quarter or so, for lean drop to 650 rpm. Stock 1.47 primary Jet.

Runs great!

 

[mattressking]

@mattressking

I just installed a fresh rebuild stock carb yesterday and was able to get the vacuum to 21 Hg with timing at 9* BTC. I don't usually go more advanced than that because I want to run 87 gas, and it sometimes pings without 91 on inclines with crappy Los Angeles AQMD gasoline.

btw, I remembered what you said about having the mix screw out 2.5 turns from the factory (measuring a still-capped mix screw), but it was way too lean (I have an A/F gauge) and had to back out the mix screw to about 3..25, then in a quarter or so, for lean drop to 650 rpm. Stock 1.47 primary Jet.

Runs great!

Spot on! To run 87 that’s about as good as it will get! Nice job - the mixture screw definitely isn’t consistent but I start at 2.5 and go from there - usually 3. When I counted a capped mixture screw it was set at 2-3/4 turns CCW.

 

[CruiserTrash]

@mattressking Don't forget that in addition to the static timing bump the HAC also leans out the mixture under three different conditions. That isn't something that the idle mixture & speed screws can adjust for during actual driving. There is definitely a need for a little more air up here at elevation so I've kept my stock carb and HAC. Under about 80% throttle the HAC is kicking way to much air into the mixture though, so I have a 25cc VCV on that vac hose to kind of neck down the airflow a bit. At 80% throttle cruise the A:F was pegged lean before (18+) and is now about 16.

Fwiw My engine is pretty tight and the emissions systems have all been verified, and I sit at about 17inHg. They say there's appx 1inHg loss for every 1000' elevation, so I feel like I'm fairly on track that. Maybe that data point helps somebody.