Backfires and wont idle

GSROOSE11

MEMBER
1999 FORD F-150
4.2L
6 CYL
2WD
AUTOMATIC
247,000 MILES

I tried to start it and got a backfire from under the hood, but it did not start. I turned the key again and it started, but it revs to 3000 rpm's, and then tries to drop to stall unless I work the gas peddle. It gives of a thin white smoke from the rear of the engine when I force it to stay running for a minute, and whistles from what sounds like somewhere in the front or passenger side of the engine.

2 Replies

HMAC300

MECHANIC
48,601 POSTS

Try cleaning throttle plate on both sides and IAC hole with choke cleaner then check for a vacuum leak like hose off broken etc. Finally scan for codes.

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Sunday, October 30th, 2016 AT 3:37 PM

RENEE L

ADMIN
1,257 POSTS

Hi GSROOSE11,

If you decide you would like to conduct the scan yourself here is a link to an article that features written step by step instructions and pictures explaining how to do the scan yourself, also I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin