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Original Aisin carb choke froze along with other age related issues. Decided to swap with cheap Chinese carb getting 4 star reviews on Amazon. Installed it, turned the key, fired right up but couldn't get it dialed in. In that process, I found there was no power to the electric choke. Round, green carb plug has power to three of the four connections but, again, no power to the electric choke. The Aisin has an electric choke or, at least, a wire to the choke but it wasn't getting power either. Wondering if there ever was power there and, if there was, how to restore that power? If there was never power to the choke, can I assume that a carb with an electric choke will not work on this engine?
The wire in question should be to the heater in the carb. Or the fuel cut solenoid? a picture of the connector would help.
Hope you haven't tossed your old carb. It might be useable with some work. Those Aisin carbs were fairly bullet-proof.
I'm back. I've spent several hours trying to figure out the "embedding photos" process. Not so easy. The thread in tips didn't work out for me. May be me - may be the link. Admin could check it and let me know if it was me.
Robert m - I watched the thread you linked me to called Choke Opener but it never addressed the electrical issue.
Jimkola - I still have the Aisin. I haven't searched for the Aisin carb rebuild thread yet but, I will get around to it eventually.
Finally, I am going to repost this in Electrical since this is about power to the choke more than a carb issue.
My 1987 EWD manual shows the round green connector, but only three of the four slots have wires. It's the factory EWD, so it only covers that one specific year
Here's a picture of the loom side of the "C" connector (female). The positions are numbered as if you were holding the connector and looking inside.
The upper left (#1) is empty
The upper right(#2 slot) is color Black-yellow stripe(B-Y) and is for the fuel cut solenoid. it's running to the 7.5 ignition fuse.
The lower left (#3 slot) is color Back with white stripe (B-W) and is also fuel cut solenoid. this runs to the emissions ecu
The lower right (#4 slot) is Yellow (Y) and is for the choke heater. it runs to the 7.5 charge fuse.
I'm not sure what's in the top left slot(#1) on yours, but 1986 to 1987 had some design changes. What color wire, including stripe?
Sorry in advance for the size of the pics here. None of the tutorials are lining up with what I experience in Photobucket.
Someone advise me, please, regarding leaving this thread here and admin moving it to "Electrical" or should I start a new thread and post in "Electrical"?
A couple pics below of the plug where power should be supplied to the yellow wire that ultimately goes to the back of the choke.
Critical question: Does the electric choke summon power when needed?
I saw in another thread that someone had issues with power supplied to the choke all the time and choke remaining HOT. Yellow wire on left send power to choke but no power to yellow while key is on but engine not running. Top arrow shows where the yellow wire is in the plug. Bottom arrow shows what it plugs into. With key on, no power to that yellow wire.
Electric chokes I am familiar with get continuous 12 volt current whenever the ignition key is on 'run'.
There is a bimetallic spring coil that holds the choke plate closed when cold,
and a resistance heater that is supplied with voltage whenever the key is on.
As the bimetallic coil is warmed by the electric heater, the choke gradually opens up.
Voltage to the choke heater should remain on so long as the key is in 'run'.
Any source of key switched current should enable correct electric choke operation.
I don't have a schematic handy of this Toyota setup, but I'd be surprised if it's operation is different than others I have seen and worked on.
"Key in Run position". Is it possible, I haven't checked is why I'm asking, that the engine needs to be running for the power to be supplied to the plug and then to the choke?
All of this started because the stock Aisin carb had a seized choke requiring starter fluid for every start. I had already ordered a Chinese carb for replacement. After installing the China carb, it started right up but there were vacuum leaks (my fault) and the engine would die after warming up because, finally determining, there was no power to the choke. Thankfully, the manufacturer sent a replacement carb. While waiting for number two China carb, I picked up the Aisin and, examining the choke, discovered the choke linkage was stuck. Freeing that linkage meant it was worth putting it back on to see if it would work properly. Aside from the vacuum leaks, it was working quite well and getting power to the choke when the engine was running. If not for the vacuum leaks, this story would be over.
millball responded to the "power to the choke" question and I found that power is supplied to the choke when the engine is running. No power to choke with JUST the key in run position. So, got that problem figured out. Thank you millball! Two out of two Chinese carbs meant to replace the Aisin had no power to the choke with the engine running or the key in any other set position. I continued using one in the R&R rotation trying to figure out the vacuum leak issue finally resolving the vacuum leak around the base of the carb by being a lot more diligent about cleaning all four mounting surfaces.
Now, the Aisin carb, which fires right up and choke is working properly, is experiencing a vacuum leak just above the four vacuum lines on the passenger side of the body. Is it time to rebuild it?
I haven't yet looked through the forum regarding rebuilding Aisin carbs but, in the meantime, if someone chimes in here leading me to a solution this side of rebuilding, I will be very grateful.
I'll also be looking for recommendations on rebuild kits and the best forum link to help with the rebuild process.
I just discovered a NEW Aisin carb for sale. Buy new or rebuild what I have?
Rebuilding really would be cleaning in carb dip, replacing the needle and seat, new float, and assembling with new gaskets. Setting the float properly is key to a good outcome. If you limit your scope to that it should go fine
I'm back with another question or maybe two. I just refuse to give up on this Aisan carb. I've replaced a number of metal parts removed from one of the Chinese carbs and it runs great until it warms up. Then this vacuum advance type roughness sets in. The timing is correct. It will keep idleing but rough. But, here's something new...when I place my hand over the top of the carb, the rpm's increase and the engine smooths out to perfection. I don't cover the entire opening just a little more than half. So, thinking it's getting too much air, I started dialing down the idle mixture adjusting screw until, now, it is completely closed but it's still running.
Thoughts?????
Just so you have an idea what Toyota set the mixture at, screw the idle mixture all the way clock-wise till you feel it seat, then turn counter clock-wise 3 1/2 turns.
My thought would be to confirm all the vacuum lines are properly routed. Photos off the internet might be helpful, but use in conjunction with an actual schematic. I see photos all the time of 22RE's routed wrong, and it has a lot less to mess up than the carb version. I'd then check for any vacuum leaks by idling the vehicle and using something like brake cleaner or carb spray to see if the engine rpm changes. The carb base would be a good place to start. just make sure none of the spray mist goes down the carb throat, giving a false reaction.
Assuming it doesn't have any external vacuum leaks, the FSM gives about 7-8 things to check for warm drivability issues with the carb, and testing procedures for each.
First on the list is the automatic choke. i know you've overhauled the actual choke, but I wonder if the Thermal vacuum switching valve (TVSV) that controls it is out of spec.
89 22re automatic idle rough especially on hills??!!!
Don't understand this one, 1st time thought it was cold, that's what it sounded like, drove it home from top of MA to mid CT, didn't drive her much, then she sounded ok to and from gas station and what not, long story short and a ton of paying extremely close attention...it's mostly when I'm uphill?!!!??? At a light or driving, all fluids full, this is really the first problem I've had with her! She came from Guam few years ago with now has 134k nice and clean inside and out. Any guesses? could it be carb if only on hills? Timing? This is even when she is well warmed up
Last edited by 76-87-89yota; 01-02-2024 at 08:08 PM.
I'd check the float level.
A running Toyota engine can usually handle a rich condition without drivability issues. In fact, The ECM is designed to default to a rich condition if a sensor fails to give data, as a rich engine is safer to drive than one running lean. So you might look for a float that's sitting a bit low.
I'd check the float level.
A running Toyota engine can usually handle a rich condition without drivability issues. In fact, The ECM is designed to default to a rich condition if a sensor fails to give data, as a rich engine is safer to drive than one running lean. So you might look for a float that's sitting a bit low.
Makes sense!!! Hopefully not super complicated, I have the "yota bible" I'll check it out! Thank you for not blowing me off because I'm a girl 😁 I'm going to change the fuel filter also , I should do the fuel pump at the same time I think , -going on what the -how to fix your Toyota for dummies says (otherwise known as the Toyota Bible) what is your opinion on fuel additive for cleaner????
Last edited by 76-87-89yota; 01-09-2024 at 09:13 AM.
A carb vehicle needs very low fuel pressure compared to EFI, spec is 2-4 psi. Usually you'd see an external leak if the fuel pump a problem. If you do replace make sure to get that spacer between the head and pump, otherwise the actuating arm on the fuel pump will be destroyed in seconds.
Additives have merit. The process for refining gas is pretty universal. Everyone's barrel of oil comes out the same. It's the additives they add (or don't) that makes certain brands stand out, like Chevron. So if you fill up with a "top tier" super unleaded gas like Chevron. Mobil, or Shell, and a few others you'll probably get a decent mix of cleaning additives already.
The 22R# was pretty forgiving on gas quality, though, unlike some other high revving Toyotas. The 22R# could burn almost anything fairly well.
I'm not familiar with your "Bible", but it's hard to beat the FSM
A carb vehicle needs very low fuel pressure compared to EFI, spec is 2-4 psi. Usually you'd see an external leak if the fuel pump a problem. If you do replace make sure to get that spacer between the head and pump, otherwise the actuating arm on the fuel pump will be destroyed in seconds.
Additives have merit. The process for refining gas is pretty universal. Everyone's barrel of oil comes out the same. It's the additives they add (or don't) that makes certain brands stand out, like Chevron. So if you fill up with a "top tier" super unleaded gas like Chevron. Mobil, or Shell, and a few others you'll probably get a decent mix of cleaning additives already.
The 22R# was pretty forgiving on gas quality, though, unlike some other high revving Toyotas. The 22R# could burn almost anything fairly well.
I'm not familiar with your "Bible", but it's hard to beat the FSM
Hmmm, no.
The FSM is the Tome of Knowledge. I think that manual is the equivalent of the pamphlet you get handed as you enter the revival tent. It may be better than Chilton or Haynes, though. Bentley made a very good non-oem manual, if you can find one for your year.
But that's just my .02
09-23-2023, 12:32 PM
power to choke resolved
