1998 Ford Ranger truck idles rough only at start up

JOELH

MEMBER
1998 FORD RANGER
4 CYL
2WD
MANUAL
89,000 MILES

When I start the truck it sputters and idles rough. Once I drive it a couple blocks it runs fine. It no longer idles rough or has any problems, but if I stop turn the truck off and restart it the same problem occurs. I can tap the gas and it helps but after 30 seconds to a minute it is just fine again. I considered the iac vavle but if this was the case wouldnt it idle rough consistenly not only while first starting up. Any ideas on what I could try to trouble shoot this problem would be appreciated.

1 Reply

BLACKOP555

MECHANIC
10,371 POSTS

Has battery been recently disconnected? If so the KAM was wiped clear and the vehicle will have to be driven to clear things up. Also have you noticed extended cranking times before the vehicle will start. If you give gas after its started up will it run good unless gas is let off, or does giving it gas cause it to hesitate and run rough until vehicle has driven a bit.

After its running good do you notice any issues with drive ability at all.

The iac may be bad and just taking a bit longer to open up if its starting to plug up. Remove it and make sure the pintle on it moves freely in and out along with no carbon being built up inside of the throttle body ports for the IAC