VACUUM LEAK??....1989 5.2L, 318c.i.

[hokietiger]

Hi gang,

I have a 1989 Power Ram W100 with a 5.2L / 318c.i. V8 and auto trans......I believe a vacuum leak is my culprit....at startup, It will idle normally and then almost die down (repeating the sequence over and over)..I've checked the idle air control valve and it's OK.

Any suggestions / opinions on a different diagnosis??
What vacuum hoses should I check and how many are involved??

Thanks so much for all help possible!!

Mike

[DodgeFreak]

spray them all down with brake clean\carb clean\ether\acetylene. Make sure you have a fire extinguisher handy if you use the brake clean\ ether methods. The truck is TBI right???

[DodgeFreak]

also I'd look at the O2 sensor if its tbi. I've seen them not throw a code but still need to be replaced.

[cougar]

Considering the ECM controls idle by bleed air through the IAC, a vacuum leak would cause a high idle instead of dieing down. Check for an exhaust restriction.