Builds Bringing back my 74 FJ40 (1 Viewer)

[DustyFJ]

Cleaned all the plugs and confirmed spark. Also asked the gf to tighten the carb down. She said one of the bolts she got several turns on. Had her tighten all of them and went for a test ride. Everything seems back to normal now.

Maybe the carb vibrated a bit loose causing cylinder 2? To run lean and foul? And causing 4,5 to run rich?? Mysterious...

 

[Dizzy]

During assembly, you can't get good torque if the threads are a bit dirty, or not lightly lubricated. I wouldn't expect the carb to jump ship on its own just from vibration. It is good that she noted that.

Plugs look like gas was 'pumped' to start a cold motor? I'm not overwhelmed by their consistency. But on an cast iron head engine, I totally appreciate the practice of taking them out to read performance of the motor.

 

[DustyFJ]

good time last weekend with the CLCC guys

 

[mrboatman]

Very cool video and looks like a fun time
JP

 

[DustyFJ]

Finally pulled the carb to try and seal up the vacuum leak I suspected was coming from the base of the carb. (Pics attached) All kinda suit on the intake below the heat shield where I suspect the leak had developed

Not sure if I screwed something up reassembling but now the truck idles crazy crazy high. I tried messing with the fuel mix screw and the two idle speed screws on the firewall side. But I can’t get it to slow down.

I’m wondering if fuel is leaking past the accelerator pump. The rubber around it seems to have aged prematurely and is already failing at 5 years old

 

[Stumpalama]

something up reassembling but now the truck idles crazy crazy high. I tried messing with the fuel mix screw and the two idle speed screws on the firewall side. But I can’t get it to slow down.

Lots of soot on that intake... While you're there, you may want to replace that intake exhaust manifold to eliminate any possible leaks from the manifold.

It sound like you have a massive vacuum leak. Also, check you linkages and confirm they didn't get mixed up.

 

[Dizzy]

Finally pulled the carb to try and seal up the vacuum leak I suspected was coming from the base of the carb. (Pics attached) All kinda suit on the intake below the heat shield where I suspect the leak had developed

Not sure if I screwed something up reassembling but now the truck idles crazy crazy high. I tried messing with the fuel mix screw and the two idle speed screws on the firewall side. But I can’t get it to slow down.

I’m wondering if fuel is leaking past the accelerator pump. The rubber around it seems to have aged prematurely and is already failing at 5 years old

View attachment 1989330

View attachment 1989331

Suit originating from the PCV is a bit out of the normal. Is the EGR hooked up?

Also, check the throttle linkage adjustment. If you can pull the throttle pedal back a bit and the idle drops, then you might want to adjust the length of the adjustable section a bit.

 

[Stumpalama]

Is the soot on the valve cover too? Is it dry/chalky or is it kind of sticky/oily? The pattern is interesting... the rear center intake retaining nut is very sooty! While the front one is fairly clean.
I’m going to go out on a limb and say you have an exhaust leak and you have been running extremely rich and that soot is the result. It’s getting blown around a bit and settles under the heat shield where there isn’t a lot of airflow.

 

[DustyFJ]

Is the soot on the valve cover too? Is it dry/chalky or is it kind of sticky/oily? The pattern is interesting... the rear center intake retaining nut is very sooty! While the front one is fairly clean.
I’m going to go out on a limb and say you have an exhaust leak and you have been running extremely rich and that soot is the result. It’s getting blown around a bit and settles under the heat shield where there isn’t a lot of airflow.

No soot on the valve cover really. I possibly had already wiped that bolt off before I thought to take a picture. I put a wench on all the intake bolts and they are pft. I’m pretty sure the leak was from the uneven jacked up surface of my heat shield/riser between the carb and intake. I’ll have to look at the linkages again but they seemed correct.

I don’t think I’m even running an egr valve right now

Looking down in the primary and secondary it looks like the gasket I cut maaaaay be holding the secondary open ever so slightly. Or possibly the primary??? Could that be the issue? I thought I cut it tight but some blue permashield gasket dressing is visible looking down in there

Pic didn’t come out but possibly the secondary can’t close completely

 

[Dizzy]

I didn't see it on the exterior of the top of the intake manifold because of my phone. I thought that you were discussing the interior of the manifold. That down-pipe flange looks different from the OEM pattern?

 

[Stumpalama]

Take a coat hanger with a rag on the end and stick it into that center cylinder intake hole of the manifold and see if it comes out sooty.
Also, those bolts may be tight, but that won't matter if the gasket is hooped and leaking from the #4 & 5 exhaust ports. Also pull your plugs, say #'s 3, 4 & 5 and see if they are black and or fouled. I am still going to bet you are running very rich with a leak at the exhaust gasket.
Your carb gasket should match the shape of the carb holes, even a hair smaller.

 

[DustyFJ]

I didn't see it on the exterior of the top of the intake manifold because of my phone. I thought that you were discussing the interior of the manifold. That down-pipe flange looks different from the OEM pattern?

It’s a cheap advanced auto air cleaner if that’s the downpipe you’re looking at

Take a coat hanger with a rag on the end and stick it into that center cylinder intake hole of the manifold and see if it comes out sooty.
Also, those bolts may be tight, but that won't matter if the gasket is hooped and leaking from the #4 & 5 exhaust ports. Also pull your plugs, say #'s 3, 4 & 5 and see if they are black and or fouled. I am still going to bet you are running very rich with a leak at the exhaust gasket.
Your carb gasket should match the shape of the carb holes, even a hair smaller.

The gasket was just a hair too big causing the butterfly to not shut completely. Fixed, runs nice and tight now. I had pulled the plugs previously and could see fuel wasn’t being evenly distributed. Probably due to the vacuum leak. I completely forgot you suggested checking the inside of the intake. I’ll check next time the carb is off.

Looks like the banjo bolt or more likely accelerator pump is leaking fuel on top of the carb. Kinda scary, afraid of starting a fire if it drips down to exhaust manifold. I guess I have to order another carb rebuilt kit. Sucks that rubber only lasted 5-6 years

Cheers! Happy Friday everyone!

 

[Stumpalama]

It’s a cheap advanced auto air cleaner if that’s the downpipe you’re looking at




The gasket was just a hair too big causing the butterfly to not shut completely. Fixed, runs nice and tight now. I had pulled the plugs previously and could see fuel wasn’t being evenly distributed. Probably due to the vacuum leak. I completely forgot you suggested checking the inside of the intake. I’ll check next time the carb is off.

Looks like the banjo bolt or more likely accelerator pump is leaking fuel on top of the carb. Kinda scary, afraid of starting a fire if it drips down to exhaust manifold. I guess I have to order another carb rebuilt kit. Sucks that rubber only lasted 5-6 years

Cheers! Happy Friday everyone!

View attachment 1996934

Hmmm, make sure you have good copper washers on both sides of that banjo fitting.
I don't know that the source of your leak is the rubber.
I may have a good used Accel pump rubber you can have. I can drop it in an envelope.

 

[JohnnyC]

The banjo dose not look to have one on the bottom ... that will be your leak

Need a copper washer there as stated above

Nice cruiser!!

 

[DustyFJ]

Hmmm, make sure you have good copper washers on both sides of that banjo fitting.
I don't know that the source of your leak is the rubber.
I may have a good used Accel pump rubber you can have. I can drop it in an envelope.

Maybe if you clcc guys want to come tour the shed, I can show you where the cliff and cool rocks just off the trails are. I can get that pump rubber at that time.

 

[Dizzy]

The exhaust downpipe, actually. It kinda looks like you are running the '74 exhaust pipe with the 2F manifold from this angle. Do I also see suit on your steering box?

 

[DustyFJ]

The exhaust downpipe, actually. It kinda looks like you are running the '74 exhaust pipe with the 2F manifold from this angle. Do I also see suit on your steering box?

Yeah most everything is 74 but the motor was installed in 79. I’ve got 85 mini brakes on it and a 4 speed. Kind of a mish mash happening.

Just took the top off for summer! (Need to clean all that orange rust residue off)

 

[DustyFJ]

Sent my brake booster to rocauto for rebuild. Just got it back together this weekend. Nice to be driving again. Brake pedal is still hard. Maybe I need to bleed the brakes or look at the rear drums.

Still issues getting the truck to run smooth. Probably need to address that exhaust leak.

 

[Stumpalama]

View attachment 2067768

Sent my brake booster to rocauto for rebuild. Just got it back together this weekend. Nice to be driving again. Brake pedal is still hard. Maybe I need to bleed the brakes or look at the rear drums.

Still issues getting the truck to run smooth. Probably need to address that exhaust leak.

Check your pedal and MC rod length adjustments
And you'll never be able to properly tune with vacuum leaks

 

[DustyFJ]

Check your pedal and MC rod length adjustments
And you'll never be able to properly tune with vacuum leaks

Will do, initially when I went to the mini truck master cylinder the rod was too long causing the brakes to drag. I shortened it by maybe 2mm? Think maybe it’s too long still?