If it aint broke, still fix it?

[fj user]

Should I replace the Weber carb with a rebuilt Aisan on my "desmogged" FJ60? (no emissions requirements, not my DD) The PO's mechanic did the desmog and I'm not sure it was done correctly. The air pump is still functional and blowing air into the engine compartment. Sometimes the engine chugs when the ignition is turned off, and it idles very low when it's hot and the AC is on. Aside from that, the truck starts and runs like a champ. Just completed a 200 mile highway trip in 100 degree weather no problem. Like many of you on this board, I like things to be just right, but I've also learned the hard way to not dick around if it ain't broke So, am I opening a can of worms? I know I'll spend around $400 buying a carb/air cleaner assembly and having the carb rebuilt by Jim C. I'm sure there will be other costs/gremlins I uncover. So, is it worth it?

 

[Michael Hanson]

Leave it alone till you have problems. 2 cents MIke

 

[slcfj62]

The fan that blows air into the engine compartment is not the air pump, but the carb fan, and you want that to still work whether desmogged or not. Could have carbon deposits in the cylinder heads that cause the chugging or dieseling after you turn the key off. And it sounds like your AC idle up function is not working which would cause your low idle with the AC on. So a new carb may not make any difference with those things.

 

[tclark]

It could actually be the air pump he's refering to; if the hose is disconnected it would just be blowing into the engine compartment.

 

[Southeast Overland]

If it works leave it like it is.

If you want a stock Aisin you'll pay $50-$75 for a core, plus $300 for a professional rebuild (get JimC or MarkA to do it) plus you'll need the air housing ($75?) - so plan on $450+.

You can get an aftermarket carb from Trollhole for somewheres around $225-250 but you will still need the air filter housing. You'll save about $100 total this way.

I'd try to fix your current issues without spending too much first.

 

[fj user]

It could actually be the air pump he's refering to; if the hose is disconnected it would just be blowing into the engine compartment.

I believe it is the air pump. It's belt driven and on the driver's side, right?

 

[lehiguy]

I believe it is the air pump. It's belt driven and on the driver's side, right?

That's it. You need it as a belt tesioner, but they can be disassembled and gutted so they don't pump air any more. Seal off the openings if you do that to prevent it from becoming a crud pump.

 

[fj user]

That's it. You need it as a belt tesioner, but they can be disassembled and gutted so they don't pump air any more. Seal off the openings if you do that to prevent it from becoming a crud pump.

Thanks. I thought that was it. Is it worth having Jim C. recurve the dizzy and get a pulley/egr plate/air rail plugs while I'm at it? I'd be willing to bet this mechanic just cut off the air pump hose and some wiring to make it work.

 

[lehiguy]

Thanks. I thought that was it. Is it worth having Jim C. recurve the dizzy and get a pulley/egr plate/air rail plugs while I'm at it? I'd be willing to bet this mechanic just cut off the air pump hose and some wiring to make it work.

Air rail plugs are a standard pipe thread, you can get plugs at Home Depot. The EGR hole in the intake can be coverd with anything really, I made one form scrap steel, another from aluminum. You will need to plug a hole in the exhaust manifold, I preferred to toss it in favor of a header, but you choose. A distributor recurve does wonders. For now, test your vacuum advance diaphrams to see if they hold vacuum. Check the mechanical advance by twisting the rotor. It should move freely and snap back into position fairly easily.

 

[tclark]

Are you sure it's a standard size? I searched everywhere locally for plugs for the air rail and never found the one's I really needed. Ended up using the closest I could find and I'm sure I jacked up the threads but they seem to be holding after a year or so.

My motto always seems to be if it ain't broke I'll fix it until it is...

 

[Heartworm]

You did not mention your mileage. That could give you some indication of how the current set up is doing. A properly tuned engine with a proper desmogging and a Jim C. Aisin carb has given me ~15mpg on three different rigs. Hope my math is right, but you save about $467 by going from 12 mpg to 15 mpg while driving 10K miles with $2.80 gas. And, I have AC idle up.

 

[fj user]

165k miles on the original engine. Only getting 10.5mpg. 15 sounds pretty good to me
OK, so the PO's mechanic didn't do as bad as I thought on the desmog, but there are definitely some fishy things going on.

Here's the EGR cover plate and air rail plugs. Seem to be working fine:


On the T-stat housing, I am missing all vacuum lines. Aren't the top two lines supposed to be connected to something?


No vacuum lines from the top of the dizzy. There are two lines coming out of the Vacuum Advance Assembly (at least this is what I think it is) on the side of the dizzy. These two lines T into one line and connect to the Weber carb. This is the only vacuum line attached to the carb:


This stuff is giving me a headache

 

[zebrabeefj40]

I don't think the PO's mechanic did you any favors with the bad desmog. Now you get to go through it and do it right. But you will know a little more about your truck for the future. IIRC there are a couple good desmog threads in the FJ60 section that can steer you in the right direction. I think you will find your efforts will be rewarded with a great running Cruiser that works better than designed. One you won't have to explain about chugging and dieseling.

Nick

 

[Southeast Overland]

My desmog has those two split nipples on the t-stat pulled out and capped - I think JimC has those plugs for sale.

 

[fj user]

According to this diagram, the one closest to the radiator (BVSV - whatever that means) should be connected to the VCV coming off the charcoal canister and the EGR R Port (have no idea where or what the heck that is ):

 

[zebrabeefj40]

The EGR R port is on the factory carb but not likely your Weber. Looks like you can install a tee fitting in the vacuum advance hose and run it to the BVSV on the t-stat housing (either one) and then on to the VCV for the canister.

I recommend reinstalling the distribtor venting system. It helps keep the inside of the distributor corrosion free.

Nick

 

[lehiguy]

Are you sure it's a standard size? I searched everywhere locally for plugs for the air rail and never found the one's I really needed. Ended up using the closest I could find and I'm sure I jacked up the threads but they seem to be holding after a year or so.

My motto always seems to be if it ain't broke I'll fix it until it is...

Yes, they are pipe thread, which is always tapered, so they get pretty tight after a few rotations.

 

[lehiguy]

You don't need any of the connections on the T-stat housing, don't worry about it. On the distributor, there are two vacuum advance diaphrams, one advances more than the other, but as I recall, they perform poorly when hooked up to the same line. As I said before, test them both to make sure they don't leak, they are pretty old. Try one vacuum line on them individually and see which gives you the best performance. Your air cleaner needs to be replaced with something larger. Those stupid little square things are fine for a 22R, but not for a 2F. Chances are good too that you could go down on the either the pilot jets, or main jets or both. Out of the box Webers (and all other after-market carbs) tend to be on the fat side. I see that you do have a header and the EGR port on the intake is already blocked, so no worries there. Your mileage should be better than what you're getting, start checking stuff.