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Fun game right? My backup lights aren’t working so I was tracing the nss wires back up through the engine compartment and noticed these blue connecters were not hooked up. They were kinda hiding down where I couldn’t see them. The silver cylinder is mounted to the driver side of the carb. Has a black rubber cap on it that I can pull back see the wire connecting. 78 f150 400ci. Something I have noticed is when I start the truck cold it idles really high for what seems like too long to me. Finally I tap the gas pedal and the rpm’s drop down to normal idle but it seems to take 2-3 minutes or more
. Not sure if that’s normal or not.
Thanks for the info. After knowing what it was I was able to find some old posts with pertinent info. I’d assume since it’s there I should connect it back up right? I can only assume in the 4 months ived owned the truck it’s always been unplugged.
Yes it's normal for the RPMs to raise above normal idle when started from cold. Fast-idle is triggered by the choke, which is triggered by cold temperatures, and helps the engine stay running and warm up a little quicker. Blipping the throttle is exactly how you open the choke and bring the idle back down.
Sorry to bring this one back but…I connected the wire for the throttle solenoid. Truck starts great. In the past it seemed to hard start when it was warm. I was wondering if the tsp being disconnected was causing it. It almost felt flooded at times when it was warm. Maybe not connected but in my mind it made sense. Anyway now that I connected the solenoid I have a really high idle. Just want to confirm that I should use this adjustment screw to set the idle. This is from the shop manual. I’m not sure what the “off” part means in the caption.
