Weird idle issue
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Weird idle issue
hello I am new to this forum I actually signed up to ask this question and hopefully get an answer. I have a 1989 ford 7.3 idi 89,000 original miles backed with a zf5 transmission. It idles around 900-1000 rpms no matter how warm or cold it is. I bought it with the timing advance and cold idle solenoid unplugged so I plugged them back in no difference. Still will sit at 1,000 rpms no matter the temp of the truck. I was just wondering if this is harmful for the truck or if there's anyway to fix it thanks.
Postmaster
Joined: Dec 2011
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First, the high idle solenoid will only engage if you pump the throttle after giving it power. It can't 'push' the throttle to high idle.
If it's still not doing anything(and you can see the rod on the solenoid moving when it's engaged), you can adjust it.
The 'low idle' position is adjusted with a flat blade screwdriver, there's a screw right on the throttle lever going into the IP, right next to the high idle solenoid. You should see where it hits when at the 'idle' position. Just back that screw back a little until you get it where you want it.
The 'high idle' position is adjusted by loosening the two 1/4-20 bolts holding the high idle solenoid bracket to the IP. Loosen them a little, and just physically move the whole solenoid where it needs to be; with no power to the solenoid, the throttle lever should /not/ be touching the solenoid rod(it should bottom out on the low idle screw), with power to the solenoid and the rod in the 'activated' position, it should be adjusted to whatever RPM you want.
As far as 'will 1000 rpm idle hurt the engine' goes? No. It shouldn't matter at all, but might use more fuel. If you are doing a lot of idling, it's actually a good thing - it charges the batteries better than at 700 rpm, there's more airflow if you're running the AC, and helps prevent 'wet stacking'.
If it's still not doing anything(and you can see the rod on the solenoid moving when it's engaged), you can adjust it.
The 'low idle' position is adjusted with a flat blade screwdriver, there's a screw right on the throttle lever going into the IP, right next to the high idle solenoid. You should see where it hits when at the 'idle' position. Just back that screw back a little until you get it where you want it.
The 'high idle' position is adjusted by loosening the two 1/4-20 bolts holding the high idle solenoid bracket to the IP. Loosen them a little, and just physically move the whole solenoid where it needs to be; with no power to the solenoid, the throttle lever should /not/ be touching the solenoid rod(it should bottom out on the low idle screw), with power to the solenoid and the rod in the 'activated' position, it should be adjusted to whatever RPM you want.
As far as 'will 1000 rpm idle hurt the engine' goes? No. It shouldn't matter at all, but might use more fuel. If you are doing a lot of idling, it's actually a good thing - it charges the batteries better than at 700 rpm, there's more airflow if you're running the AC, and helps prevent 'wet stacking'.
Lead Driver
Joined: Apr 2008
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Make sure its not hitting the solenoid arm when you turn the idle down like mac says. Also, the movement you will get from loosening the bolts is almost nothing. Better off adjusting the pushrod, its threaded, and can be turned out or in. 700-800 is where mine likes to idle, but 1000 wont hurt anything... annoying maybe lol
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Right sorry meant to put in I do give it a little throttle after start up usually up to 1200 rpms then down but it sounds no different like a high idle activated. I will try the adjustments tomorrow though to see if they change anything. Thanks!
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