Idle solenoid 1981 FJ40 (1 Viewer)

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Hope you all can help me on this. Background: truck would not stay running- it would start but had to keep foot on gas to keep it running. Dealership fixed vacuum leaks, replaced fuel filter, and cleaned carb (carb was rebuilt less than 50 mi ago). Attempted to drive home after picking it up at dealership. After 15 -20 min it started stalling at red lights. Towed back to dealership. They have had it for 2 weeks ...cleaned carb again and said that the idle solenoid may be bad. Apparently it's running great now but they said it may stall again because of the possible faulty solenoid (I'm picking it up tomorrow).

Question: They said the solenoid can't be replaced and I would need to buy a new carb and solenoid.. Is this correct? I think I have seen them on-line for sale. I have read on the forum about cleaning the contacts and that they rarely go bad. I have little mechanical experience and have few tools but am always willing to learn. How difficult to access it and clean them or just replace myself? Thanks all in advance.
 
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Hope you all can help me on this. Background: truck would not stay running- it would start but had to keep foot on gas to keep it running. Dealership fixed vacuum leaks, replaced fuel filter, and cleaned carb (carb was rebuilt less than 50 mi ago). Attempted to drive home after picking it up at dealership. After 15 -20 min it started stalling at red lights. Towed back to dealership. They have had it for 2 weeks ...cleaned carb again and said that the idle solenoid may be bad. Apparently it's running great now but they said it may stall again because of the possible faulty solenoid (I'm picking it up tomorrow).

Question: They said the solenoid can't be replaced and I would need to buy a new carb and solenoid.. Is this correct? I think I have seen them on-line for sale. I have read on the forum about cleaning the contacts and that they rarely go bad. I have little mechanical experience and have few tools but am always willing to learn. How difficult to access it and clean them or just replace myself? Thanks all in advance.

You have a fairly common problem with the late model rigs.

See post #10. I would start with reflowing the solder on the "emissions computer".

If that doesn't do anything you might want to just get a new idle solenoid. Dealer is incorrect you can replace just the idol solenoid without having to remove the carb, or buying a new one for that matter.
 
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Thank you both for your quick responses...I didn't think the dealership was correct. And thank you oregon for that link..it was one that I had not found in my earlier research. I think I'll just replace it as it doesn't seem like an expensive part (<$20). Thanks again...always can count on you guys.

You have a fairly common problem with the late model rigs.

See post #10. I would start with reflowing the solder on the "emissions computer".

If that doesn't do anything you might want to just get a new idle solenoid. Dealer is incorrect you can replace just the idol solenoid without having to remove the carb, or buying a new one for that matter.
 
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Follow Mark's suggestion first and make sure that the solenoid is actually the problem. Give it a good ground before you bother spending any money or doing any work. I am not sure I have ever seen a solenoid go bad. I have seen more of the "computers" fail than I can keep track of.

Mark...
 

65swb45

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Follow Mark's suggestion first and make sure that the solenoid is actually the problem. Give it a good ground before you bother spending any money or doing any work. I am not sure I have ever seen a solenoid go bad. I have seen more of the "computers" fail than I can keep track of.

Mark...

I Always try to give credit where credit is due. 😉
 
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Great point...I'll test it first.

I have another related question...the carb blower fan never had ran for me but when I first got it back from the dealership it ran. However when the truck started stalling, the blower fan never went back on. Wonder if the two are on the same circuit or it's somehow related.???
 
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Florida
Follow Mark's suggestion first and make sure that the solenoid is actually the problem. Give it a good ground before you bother spending any money or doing any work. I am not sure I have ever seen a solenoid go bad. I have seen more of the "computers" fail
Related as in routed through the same erratic, 40 year old computer? :hmm:
Lol...you got me there
 
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Florida
Update:. Dealership tested the emissions module..it's getting power to the idle solenoid. The mechanic took off the solenoid and blew it out and reinstalled it. He believes the valve inside is getting stuck. I got home without stalling ;). Hopefully it was perhaps some kind of debris in the connection. Between replacing manifold gasket, vacuum tubing, fuel filter, soldering cracked manifold intake, cleaning carb several times...I think the stalling at idle may be fixed.... hopefully (can't afford anything else for awhile). Thanks again all for the advice!
 

Blue77FJ40

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I post I made recently:

I did manage to get my '40 running. It started ok, but wouldn't idle without the choke. First thing I checked was the idle solenoid, I never had a problem with it before, so I checked for 12v with key on. Power was there. The FSM said to check it by removing it, and testing it on the battery. Ground the body on the negative post and jump a power lead to the positive post. I got a muffled click. Queried mud and found one problem with the solenoids is they can get gunked up. Since the truck hadn't been run in a good while, that seemed to fit the situation. I dunked the carb end into brake cleaner, swished it good and blew out the cleaner with compressed air. Did that about 6-7 times and tested it again. CLICK! I didn't know what was supposed to move, apparently there is a thin brass needle that either extends or contracts in the middle of the brass end, not sure which, when power is applied, and it was sticking. Truck now idles fine.
 
Joined
Jan 20, 2009
Messages
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Location
Florida
I post I made recently:

I did manage to get my '40 running. It started ok, but wouldn't idle without the choke. First thing I checked was the idle solenoid, I never had a problem with it before, so I checked for 12v with key on. Power was there. The FSM said to check it by removing it, and testing it on the battery. Ground the body on the negative post and jump a power lead to the positive post. I got a muffled click. Queried mud and found one problem with the solenoids is they can get gunked up. Since the truck hadn't been run in a good while, that seemed to fit the situation. I dunked the carb end into brake cleaner, swished it good and blew out the cleaner with compressed air. Did that about 6-7 times and tested it again. CLICK! I didn't know what was supposed to move, apparently there is a thin brass needle that either extends or contracts in the middle of the brass end, not sure which, when power is applied, and it was sticking. Truck now idles fine.
Blue77fj40...glad to hear yours was a simple and inexpensive fix!
 

Landpimp

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the problem is....the computer grounds the solenoid not powers it.. its not the power that fails...its the ground, which is in the emission computer. willing to bet the dealership didn't test the emission module....unless the techs dad was once a Hi Fi repairman.....its vintage tech....

I bypassed the computer(as mark and mark did) on all my cruisers that have them, its just a matter of time before the computer fails. Never had an actually solenoid go bad

maybe it was just junk stuck in there . there is also a tiny O ring that goes on the needle of the solenoid, its probably been eaten away by now


Update:. Dealership tested the emissions module..it's getting power to the idle solenoid. The mechanic took off the solenoid and blew it out and reinstalled it. He believes the valve inside is getting stuck. I got home without stalling ;). Hopefully it was perhaps some kind of debris in the connection. Between replacing manifold gasket, vacuum tubing, fuel filter, soldering cracked manifold intake, cleaning carb several times...I think the stalling at idle may be fixed.... hopefully (can't afford anything else for awhile). Thanks again all for the advice!
 

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