91 302 High Idle, sometimes idles down
04-09-2019, 06:09 PM
#1
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91 302 High Idle, sometimes idles down
Just bought the truck as a weekend project😀 I have replaced the pvc (cheapest option first). Before replacing the pvc it idled high 2000-2500. The truck would not idle down. After replacing the pvc the truck idles high, tries to idle down (gets rough), when it does idles down it is rough, if I give it gas it will rev up and stay idling high 2000-3000.
Options?
1. IAC
2. TPS
3. Intake gasket
I have been reading a lot of forums, just wanted advice on the symptoms listed if there was one that sounded like the most likely one.
Thanks in in advance for the advice.
Options?
1. IAC
2. TPS
3. Intake gasket
I have been reading a lot of forums, just wanted advice on the symptoms listed if there was one that sounded like the most likely one.
Thanks in in advance for the advice.
04-10-2019, 12:43 AM
#2
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Location: Memphis, TN, Earth, Milky Way
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PVC is polyvinyl chloride - a common type of plastic. The positive crankcase ventilation (PCV) system is regulated by a replaceable valve.
(phone app link)
The #1 option is to diagnose YOUR truck's problems; reading about how other trucks were repaired (or NOT, as is often the case) is much slower & more-expensive.
The engine is essentially an air pump. It can only run at higher RPMs if it's getting more air. Find out how the air is leaking in, and you'll find the root of the symptom. It might not require ANY replacement parts - maybe the hose has come off the brake booster, and just needs to be put back on. This caption describes the easiest, cheapest, safest, & quickest way to find vacuum leaks:
(phone app link)
(phone app link)
The #1 option is to diagnose YOUR truck's problems; reading about how other trucks were repaired (or NOT, as is often the case) is much slower & more-expensive.
The engine is essentially an air pump. It can only run at higher RPMs if it's getting more air. Find out how the air is leaking in, and you'll find the root of the symptom. It might not require ANY replacement parts - maybe the hose has come off the brake booster, and just needs to be put back on. This caption describes the easiest, cheapest, safest, & quickest way to find vacuum leaks:
(phone app link)
06-01-2019, 11:49 PM
#3
This is a shot in the dark...but,I would probably scavenge a (motorcraft only) IAC from the local bone yard,clean it and with new $1.99 gasket see where youre at? Tps maybe? Does it "surge" or simply never idle down? Could be a vacuum leak? I would start with Motorcraft IAC from local boneyad and see where youre at.JMO