View Full Version : FJ40 Idle Solenoid Change Over

07-20-2009, 10:21 AM
I have an Aisin carb with a November 3, 1969 date code. I had been experienceing intermittent dieseling upon shut off. This weekend I checked the idle solenoid and it clicked, but it was a very week click. I removed the solenoid and found the arm was slightly bent.

I replaced the idle solenoid using one from from another Aisin carb, but could not find the date code on the other Aisin carb. I do know that it appears to be of the same vintage; 2 barrel, no ported vacuum, throttle cable. The idle solenoids appear to be the same. With the "new" idle solenoid the truck is turning off as soon as the key cuts power to the solenoid.

However, since installing the "new" idle solenoid the truck is very slow starting in the morning. The truck starts up fine during the day as I run around doing errands. In the morning I have to pump the gas while cranking to get it enough fuel to start running.

This got me to looking a bit closer at idle solenoids. On SOR, they show an idle solenoid for September of 69 through September of 72 and a different solenoid for September of 72 up until January of 75. I believe one of the reasons for the different parts has to do with the power connection for the idle solenoid on early trucks was the ignition coil and then it moved to the voltage regulator. Does anyone know if this is the only difference? At the shaft lengths of the idle solenoids also different? Are the diameter of the shafts different? I did not check these items before making the swap.

Not knowing the exact vintage of the "new" idle solenoid I am wondering if I have put one in that is not correct and is a contributing factor to my morning starting issue.

I've also posted up on MUD hoping that Mark A. or Jim C. might have more insight.