scatfox331

ok so here is my problem. i have a 91 gt. stock with headers and a throttle body. when its cold it will start right up and idle fine. then after afew miles of driving and it warms up the idle kicks up to 1200-1500. and while driving its like having cruise contol. then if i shut it off after it does this and restart it it acts like its flooded and you have to it the gas for it to start. when it starts it will jump to 3000 rpm and hang there for a few seconds then come down and stay at 1200-1500 rpm.scanned codes both koeo and koer tests came up with: 21, 31, 51, 67 and 94. anyone have any ideas? this is driving me crazy! any help would be appreciated. thanks in advance.

Bubba 95SN

Find out how to properly run tests.21&51= engine not up to operating temperature, did you get engine up to operating temperature before entering run test?67= did you keep clutch depressed during test?31=evp egr. 94=secondary air system inoperative.Smog pump diverter valve or tab tad

scatfox331

yes the motor was at operating temp. yes i had the clutch pushed in i think the 67 code was from another time that i did not have it pushed in. will any of these code cause my problems?

Bubba 95SN

Vacum leaks?

KNS1

Engine coolant temp sensor may be bad.

Force4

+1. Had same problem turned out to be a vacuum leak