Topic: 22R Aisan Carb Refurb

[fireitup]

Washed the outside and got all the muck/dirt/grime off.  Looks like it could use a strip/paint job, but I am dying to get this baby running right so its going back on like this. Ive seen worse...



Inside of the tank was very clean, so I just did a rinse out with some gas that I had drained previously.  Some gunk collected in one corner, along with some water from washing the outside of the tank.  I was able to get all this out by using a hand vacuum pump with that little attachment used typically for bleeding brakes. Here is why you don't want to get water in your gas tank!



That will never be able to evaporate, and no bueno if that pocket of water gets sucked into your engine...

Stay vigilant.



I decided this ^^ was clean enough to go back on the fuel pickup line so it did.



And here are the sweet new socket cap screws installed.

I also installed the Mr. Gasket inline fuel filter in place of the stock filter.  It is really nice to be able to see in there.  I'll post up a video of it as soon as I can get it on YouTube.

Hopefully get a drive test in tomorrow to see if all of this fiddle farting around did any good.

 

[fireitup [OP]]

Here's what the fuel filter looks like.

https://youtu.be/wqkzD0qgjEw

I'll be orienting it permanently so that air bubble is always on the filter intake side.

[fireitup [OP]]

No dice.

 

Back to debugging vacuum, or maybe something didn't get put back together correctly on the carb.

I just want to drive this thing!!!!!

[Gnarly4X]

No dice.

 

Back to debugging vacuum, or maybe something didn't get put back together correctly on the carb.

I just want to drive this thing!!!!!

Oh crapity!!   

Gnarls.

[H8PVMNT]

If you tow it up here I'll help you figure it out .

[Gnarly4X]

If you tow it up here I'll help you figure it out .

Hey H8PVMNT.... If I DRIVE mine there, will you help me figure out my issues??? 

I'm only about 1300 miles south and 20 hours drive time with 4 potty stops and 4 fuel-ups!! 

By the time I get there my rebuild should be broken in very well. 

Gnarls. 

[H8PVMNT]

I am a little rusty on EFI but I will try.  At the very least we can scratch our heads at it under a shady tree by the creek.   

[fireitup [OP]]

If you tow it up here I'll help you figure it out .

Thanks for the offer! I might do it just for the shade tree head scratching by a creek in Montana part... 

[fireitup [OP]]

So in all of these trials I believe I have basically run through every test in the carb section of the FSM, but in order to prove my self wrong I have printed it all out and will be walking through it again.  Will take good notes this time just to be sure I'm not missing a step!

Good thing is that the truck runs just not well enough to drive.  I am sure it is something simple (and likely related to the EGR delete) just need to find it.

 

[fireitup [OP]]

Got a chance to work on this today and have a few updates.

1) I removed this vacuum switch that (I think) used to run to the Hot Air gate on the old airbox. Plugged everything up and didnt notice any difference in performance.



2) Tested the main Accel Pump and it seems to be working fine. I manually actuated the pump at idle and the RPMs dropped immediately due to the rich mixture.

3) Tested the Auxillary Accel Pump and it seems to be working fine. I applied/released vacuum with the BVSB line and the RPMs dropped immediately due to the rich mixture.

Here are the two interesting items:

4) Float Level:

At idle the float level looks to be dead in the center of the sight glass. However, after driving around for a minute and having the engine bog down, the float bowl seems to be completely full of gas. Not sure if that is to be expected but it stuck out to me...

5) Secondary Choke

During operation the secondary choke flap/carb metering needle do not seem to be moving. I was able to get a video of the carb with the air cleaner off while driving around. I got the engine up to about 2k RPM in second before I ran out of power.

Video to prove it here:

https://www.youtube.com/watch?v=zlmM1pzkZJI&feature=youtu.be

Should this flap be actuating when I get into the secondary? Wondering if something got mixed up in the choke linkage when I put it all back together.

Hoping that I am on to something

 

[H8PVMNT]

Dude that is some outstanding footage!

Yes that flap is called something like the "secondary air valve", and it should be opening when you are into the secondary.  It lifts the needle out of the jet for your secondary fuel.  When the choke linkage is in a certain position it is disconnected and won't open.  I would take the carb off and play with things until you see what makes it operate or not.

Probably has to do with the fast idle cam stuff.  FYI you can take all that off if it's not going to work properly due to wear or damage and it will do just fine.

[fireitup [OP]]

Dude that is some outstanding footage!

I zip tied a cheapo GoPro knock off to one of the heater hoses.  That thing comes in handy for drive tests!  The battery only lasts about 20min nowadays...

[brainlessfool]

good video. ? did you get onto the secondaries? the sound is not great, butt it does sound like it starving out. can you put the gopro pointing at the front of the carb. so you can see the float bowl level?

[emsvitil]

Where are the flames?

 

[fireitup [OP]]

Taking brainlessfool's comment into consideration I decided I really dont know whether or not I was getting into the secondaries in the last vid.  I actually don't understand at all what causes the carb to get into the secondaries... Air flow? Throttle Position? Some combo of all these things controlled by carb vacuum internals?

I have a little more research to do before I fully understand that.

Also, I took another video of the camera facing the float bowl window.  The quality is not great, but from what I can gather it looks like the bowl is way overfull for the entire drive test.  Towards the end when I am hammering it in second you can finally see the fuel level most likely due to slosh...

I'll post the link when it is done uploading to youtube.

If that is the case then I need to adjust the float to sit further down in the float bowl right? That would cause the float to lift the float needle sooner => decreasing fuel flow => not flooding the bowl?

[brainlessfool]

yes, if it's flooding that will help. if it's starving will make it worse.

[fireitup [OP]]

yes, if it's flooding that will help. if it's starving will make it worse.

Read a bunch of other posts on tuning the float level this weekend. Made one adjustment and will iterate until I get it right.

 I took off the carb to mess with the choke linkages and can't find anything wrong there. From what I can tell, the secondary choke flap on the intake manifold side of the carb is linked to the throttle position /primary choke. The flap on the air filter side of the carb is likely opened by airflow alone, as I can't find any obvious mechanical linkage between the two.

Thanks for listening!

Sent from my D5803 using Tapatalk

[brainlessfool]

not sure which ones you are referring to, but the choke is on the primary and the "air flap"? is on the secondary. the choke is opened by the choke spring and the vac. pull off.

[emsvitil]

There's usually an interlock so the secondary won't work if the choke is closed..........

Prevents WOT until you're warmed up.

[H8PVMNT]

The choke is the one on the passenger side.  The drivers side "flap" is not a choke at all.  It is called the "secondary air valve".  This lifts the needle out of the secondary jet to give you the fuel for the secondary.

When the choke is set the fast idle cam junk unhooks the secondary and it won't open at all.  The purpose of this is to keep your mixture richer and to not allow much action until the engine is nice and warm.  If your secondary air valve doesn't open when you get it on then there is something wrong there.  Could be the fast idle cam or the choke breaker not working.

You can take all that fast idle cam stuff off however and the secondary will still work.