i have a early 99 7.3 and when im on the throttle and at about 1000 to 2000 rmp at a constant speed it surges it only does it when it is cold out. i am wondering if any one knows any cheap and easy way to fix this

Thanks Guys

 

Its not surging, its the EBPV (Exhaust Back Pressure Valve) closing due to the low oil temp and the air temp is low.

If you leave it running after about a minute it should idle up and then the EBPV will close, making a hissss sound. Same thing happens when your driving.

About the only way to stop it is to let the truck warm up fully. You can also unplug the EBPV under the turbo, but that is not the correct way to do it.

 

thanks it doesnt seem like my truck warms up enuf tho becaus eit normal wont go away at all what should i do about that

 

I also have any early 99 and I have never had or heard of an early 99 surging. I think that your problem is also ebpv related like joe said. I usually never drive mine when its cold I usually let it run but this is the first winter Ive had the truck. When mine high idles and I touch the brake it quits high idling. Not sure about that opening the ebpv back up though cause mine is on a switch anyway. I didnt think it closed the ebpv while driving cause I though I read something about it hurting the lifters not exactly sure.

 

if i unplug the EBPV will it hurt any thing or is it ok to do that cuz it never goes away

 

I think it will be fine mine is basically "unplugged" cause its on a switch so the pcm thinks its not there. If the noise persists after maybe its stuck?

 

ok thank guys

 

Where are you with that trailer ? Obviously not here

 

anyone have pictures or anything to tell me where to unplug that i have the same problem in the mornings

 

Underneath the turbo. It should be the only wire in the area.