twittyaustin

So the truck starts up no problem. but then at idle in park just sounds like i have a huge cam. then i put it in dive it almost dies untill i give it gas then it runs fine, untill i go to a stop then bam, idles bad and almosts dies.


iv cleaned the iac and the tb. but some say cleaning it isnt good enough, should i get a new iac? help please.

rrc86

Sounds like you have a vacuum leak

twittyaustin

that is what im thinking i have to overlook it tomrrow and see

rrc86

the best way is to unplug major vacuum ports on the engine and cover them with something sturdy (that wont get sucked in) and see if the idle evens out. then follow the individual lines for the leak. the idle will become normal almost immediately when you find the leaking port.

kebF150

Check your PVC hose. Mine was doing the same thing. Our trucks PVC hose have been known to go bad.

Dholla

Get a new iac. If you got a napa in the area they have a good warranty on it. My truck did the same thing till I replaced the iac. Its a 10 min job to fix and the part should only cost around $110

twittyaustin

its not a vaccum leak so it might be the iac, but i cleaned it and everything shouldnt it get better?

TRD-Toy

Could be an EGR valve sticking open. Would act like a vacuum leak. Give you a loping idle, low idle or stalling concern. You can use a vacuum pump at the egr and open and close the valve. Should pop closed. You could visually inspect the valve. Remove it and try blowing through it from the ex. manifold side. If you can its open.