Topic: Low Range Off Road 22R Reproduction/Replacement Carb

[fireitup]

Intro

Last year I pulled my Aisin 22R Carb off and rebuilt/refurbed it.  My truck has not run right since.  Writeup surrounding that can be found o'er yonder here http://board.marlincrawler.com/index.php?topic=102038.0 . I still hope to figure out what is going on there with that setup at some point...

Recently, over in H8PVMNT's Aisin 22R Tech/Study thread (http://board.marlincrawler.com/index.php?topic=100917.120) Helipilot77 mentioned that he saw Low Range Off-Road was selling a 22R Reproduction/Replacement Carb!  I jumped on this as it could give me a chance to have a working truck while i figure out the issues with the other carb.

The New Guy

Listing: http://www.lowrangeoffroad.com/toyota-22r-new-reproduction-replacement-carburetor.html

Listing Image:



Quote from Listing: "These are a work of art.  They are exactly as the factory units were back in the day."

Me: "Yeah gimme one of those!"

Pics Upon Arrival:







The first things I noticed:
1) Shiny
2) No Outer Vent Control Valve (There is one in the listing picture)
3) No HAC Hookup (Cant really tell from the listing picture)
4) No rectangle shaped idler valve emissions i think thingy (There is not one in the listing picture, however the gasket sealing surface for it is cast into the carb just above the PCV hose hookup)

My initial impression based on the items above (Aside from #1), is that this is NOT "exactly as the factory units were back in the day." as the listing proclaims. However I will do my research and make sure there is not some variation of this carb that was missing the items noted.

Bottom line, the carb I was sent is not the one in the picture listed on Low Range.  However it is already bolted down under the hood, so we will see what we can get done with this thing.

[:)bestgen4runner]

[ryantowry_81]

I am curious how well this one runs. I have a 86 2wd that needs a carb and this sounds like a good price for a new carb vs a reman.

[fireitup [OP]]

Install went well, no issues with alignment or anything.  Carb Dropped right in.

I fired it up with no air filter on and zooooommm! this thing revved real high like (3,000 RPM+) and then abruptly died.

Float level was a little high, but not worth messing with.  I noticed that the choke was not fully closed. 

I set the fast idle cam to keep the choke closed per FSM: "While holding the throttle valve slightly open, push the choke valve closed and hold it closed as you release the throttle valve."

Still revving really high (~3,000 RPM), just not dying now.

Pulled vac-advance hoses off, set timing to 0 deg and backed out the fast idle screw as far as I could.  Fast idling now ~2,600 RPM so that seems to be in order.

Next issue, after disengaging the fast idle cam the RPMs drop but only down to ~1,800.  Idle speed should be ~700.  Choke is barely open, and I can get the truck idling better if I cup my hand over the carb throttle intake to limit the airflow.  This tells me that the carb mixture is very lean.  Adjusting idle speed screw/idle mixture screw does not seem to have any effect.

My thought here is that, since I have EGR deleted on the truck that the primary jet must be limiting enough fuel flow into the throttle and keeping the Air/Fuel Ratio lean.

I popped out the Trail-Gear-Stock jet and found that it was a 116.  This is a bit richer than the 111 that I pulled out of the stock Aisin carb.



^Old/New



^Old/New



^Comparison of 1) Old/Stock 111 Jet 2) New Trail Gear 116 Jet 3) Hitachi Motorcycle 120 Jet

I swapped in the Hitachi 120 Jet and the idle speeds came down a bit. Added the air filter back on and they came down just a bit more. Still no significant behavior change by adjusting idle mixture/fast idle screw, and the idle speeds are still up in the 1500 RPM range. Is my motor really this fuel hungry after the EGR delete!? 

[gnob]

Are you sure there isn't a vacuum leak somewhere?

[fireitup [OP]]

Are you sure there isn't a vacuum leak somewhere?

Short answer, never... Good question though.

I was thinking along these lines this morning and trying to find all vacuum related idle assist mechanisms for this carb and eliminate them. Here's what I came up with:

1) Choke breaker: slightly opens choke when vacuum is applied.
2) Choke Opener: Moves link to open choke when vacuum is applied.  I do not think this affects idle much though, could be wrong.
3) Idle-Up Diaphragm: Moves link to when vacuum is applied.
4) Vacuum Advance:  Advances timing when vacuum is applied.
5) HAC? This is no longer connected as this carb does not have connections for it.

This evening I plan to play with the old carb to see what 2/3 really do for idle.  Very nice to have one carb off truck to help troubleshoot the one that is on!

I went ahead and disconnected all vacuum hoses from the carb and found that it behaves exactly the same as when they are on. So either they don't do anything relevant to this, OR there is a leak somewhere making it seem that way.

Hard to say at this point.

[fireitup [OP]]

Quick vid of what I’m dealing with because why not.

*Edited to embed youtube link*

[fireitup [OP]]

 

Possible solution for the dying after fast idle cam issue.  This carb comes with a different connector for the fuel cut solenoid/choke heater hookup.  I had to rig it up with some fly wires and possibly did something wrong there.  Also possible that the fuel cut solenoid is just bad and that would immediately kill it when transitioning to idle/explain why the mixture screw adjustment did not make a difference.

Logically makes sense from this diagram that emsvitil posted over in H8PVMNT's Tech Thread.



I will run through the fuel cut solenoid troubleshooting as soon as I get a chance.

[fireitup [OP]]

So here is a picture of the connector on this new carb (sorry it’s pathetic).



Only two connectors so I assume it’s 12V across the terminals.



No clicking when I hook up 12v across the connector.

Either the connector is not 12V and I fried the solenoid or the connector is bunk.

I’ll rig up the spare off the old Aisin carb tomorrow and see if we can get this thing cooking.




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[pleasetellmeno]

I've ran 2 of these aftermarket "reproduction" units from National carbs. (Chinese casting with rubber to handle ethanol fuel) I've had both of the fuel cut solenoids crap out on me, even when hot wired on 12v, the solenoids refuse to click, or only work once or twice out of 10 tries

Engine would start and immediately die unless i held my foot on the throttle or turned the idle way up. if i removed the fuel cut solenoid and plugged the hole the engine would run fine but diesel for a few seconds after being shut off. i ended up buying a factory Aisin carb off ebay and cleaning it out.

I would try just using the fuel cut solenoid from your old carb, the aisin ones don't seem to have an issue.

[fireitup [OP]]

Aisin fuel cut solenoid swapped in and works great.  Carb no longer dies when trying to idle.  Will move on to idle mixture/speed adjusting later this week and see if we can get a drive test in the works.

This Chinese fuel cut solenoid had me curious though.  It only has one wire connected to the back where the Aisin solenoid has 2.  Due to the way the spinny invisible wheels and well thought out stacks of rocks work inside these things, we certainly must have two things: POWER AND GROUND.  Most likely this solenoid is relying on the conductive housing for ground. So i connected 12.5V to the one wire from my bench supply aaaand...

Click!

So the Aisin one is relying on a direct connection to harness ground and the Chinese one is relying on the Carb casting itself to be grounded.  So it looks like mine is not. Interesting.

[fireitup [OP]]

A better shot of the connector that came with the Low Range Carb. Red wire went to the choke heater, which is currently disconnected.





Glamour shout.

[emsvitil]

So if you add a ground wire (hose clamp and wire should do it) to the new solenoid it should work correctly............

[helipilot77]

Thanks for biting the bullet for us all and trying this thing out. Looks like it’s not everything they promised.

[300k]

Thanks for biting the bullet for us all and trying this thing out. Looks like it’s not everything they promised.

It's seemingly a trail gear product, which explains everything. Probably put together in China by Hmong slaves chained to a table. For 185 dollars, I'd much rather H8PVMNT the carb. Get a rebuild kit, some carb cleaner, and get a much better end product. Or buck up 65 more dollars and get you-self a Weber.

[Gnarly4X]

In the past 10 to 15 years, it seems that the quality and performance of the aftermarket parts I’ve purchased have been defective, does not fit, will not work according to supplier, or very poor quality.  For me, sadly this includes parts like motor mounts, electric window motors, radiator hoses, gaskets, transmission input shaft seals, steam irons, coffee makers, and tools.

The marketing, sometimes false advertising, and mass sales of very poor quality imitations coming from foreign exporters into the USA consumer is staggering.  I don’t think you can be overly cautious now when buying ANYTHING!!

Gnarls.

[H8PVMNT]

Good job sorting out the fuel cut.  Also thanks for trying this carb.  We need everybody to try everything and post the results so we know things 

[fireitup [OP]]

Flange nuts that hold the carb down to the intake manifold studs are M8-1.25 in case anyone was wondering.

[fireitup [OP]]

Thanks for biting the bullet for us all and trying this thing out. Looks like it’s not everything they promised.

Good job sorting out the fuel cut.  Also thanks for trying this carb.  We need everybody to try everything and post the results so we know things 

No problemo.  At some point I will review this carb on Low Range Off-Road's website. Currently trending towards not so great review but we will see once this is all said and done.

[jmac80]

You can get around a broken fuel cut solenoid by having the fuel cut solenoid housing crimped to the point that the solenoid is stuck in the open position.  Not the cleanest thing, but it works.  New ones / new old ones ain't cheap neither.

[fireitup [OP]]

So I was fiddling with everything and found that, with vac advance cut, I could not get the rpms below 1700 while timing was at 5DBTDC. No matter what I did to the idle mixture/speed screws.

Thought that maybe the distributor was not lined up correctly or something so I took that apart and off the engine. Ended up doing a complete R&R and reinstalled per FSM. Not much difference.

Adjusted timing to 0DBTDC, 1500RPM

Adjusted to the max retarded timing allowed by the distributor bolt and it dropped to 1200.

Next I started fiddling with the throttle and found that if I pushed it more in the closed position that the rpms dropped. Hmmm...

I poked around some more and apparently adjusted where the throttle position was bottoming out and the rpms plummeted and the engine died!

Was able to adjust idle speed with the idle mixture/speed screws.

I guess something in the throttle linkage/mess of cams in the back of the carb was sticky and causing it to be constantly revving? 

I’ll soak it with lube once the thing cools off and hope that all is well next time I start it up.

I went ahead and pulled a H8PVMNT and ripped all that junk off my Aisin carb.



Might end up doing the same to this one if it keeps giving me trouble!



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[fireitup [OP]]

Discovered something new that may have been contributing to my woes.

The stock connector for E-Choke/Float Bowl Vent/Fuel Cut Solenoid is only putting out ~3V to the E-Choke on the Aisin carb.  I hooked this new E-Choke up to that same line.  Due to the behavior of the new fuel cut solenoid, I am certain that the new E-Choke runs off of 12V.  I hooked the new E-Choke up to a 12V line and everything seems to be much happier.

Either:
1) Aisin E-Choke takes 3V and new E-Choke takes 12V
OR
2) Aisin E-Choke takes 12V and that line is jacked up somewhere and only putting out 3V.

All that said, this carb is now officially up and running! 

Did a drive test today to Lowes/Gas Station and man does the butt dyno on this thing feel nice!  I may be oversensitive, as my truck has had absolutely no noticeable acceleration for almost a year... We'll try and be methodical about this though so here's the starting setup.

1) Carb: Low Range Reproduction
2) Primary Jet: 120
3) Air: Stock Air Box/Filter
4) Tires: 235x75xR15 Treadwright ATG (Finally getting some miles on these!)
5) 23.5 PSI All Around
6) Timing @ 5 Deg with Vac Advance Cut.

Chime in if there are any obvious variables that I am missing here.  Will report back once I get through this tank.

[Gillesdetrail]

Where did you end up setting the timing at?

[helipilot77]

So in conclusion would it be true that the real reason that the carb wouldn't work as a bolt on and go unit is because the linkage was bound up and the choke uses a different voltage? let's get a comprehensive list of necessary modification to get this carb working. 

[fireitup [OP]]

Where did you end up setting the timing at?

Pretty sure I settled at 5deg BTDC with all vac advance lines connected per FSM.  Will double check that and add it to previous post. 

[fireitup [OP]]

Reasons Why this Carb Is Not a Plug and Chug Replacement

1) In general, E-Choke/Fuel Cut Solenoid connector does not fit my stock connector.
2) Fuel Cut Solenoid on stock carb has a wired ground and new solenoid relies on housing to be grounded. Either ground the housing with modification, or ground ensure carb housing is grounded.
3) E-Choke on Stock carb was connected to 3V. E-Choke on new carb needs 12V.
4) *Possibly* cam linkage on back of carb was bound up and needed lubrication or fiddling.  This could also have been due to E-Choke being connected at 3V instead of 12V.
5) No Outer Vent Control Valve (does not affect ability to function)
6) No HAC Hookup (does not affect ability to function)
7) No rectangle shaped idler valve emissions thingy (does not affect ability to function)

I think that's everything that I learned while getting it up and running.

 

[H8PVMNT]

I am not 100% but I think you get the three volts to the plug when the key is in the on position, motor not running and 12V to the plug when it is running.  At least I think that is how it's supposed to act based on what mine did.

[emsvitil]

Look at a wiring diagram.    You should be able to figure out the 3v vs 12v

[Gillesdetrail]

Pretty sure I settled at 5deg BTDC with all vac advance lines connected per FSM.  Will double check that and add it to previous post. 

Should be 5btdc with all lines disconected, not connected. I'm at 12-14btdc and run on premium.

[H8PVMNT]

Look at a wiring diagram.    You should be able to figure out the 3v vs 12v

I seem to remember something about the alt turning to get the 12V to that wire.