C6 shifting problem, bad vacuum?? help haha

[Laine D]

Alright so here's the deal. I am 16 and i am learning all about my sweet little IDI. A couple months ago I acquired an 86' f250 xlt lariat with a 6.9 and a c6. I love my truck, i learned to drive on an 85 and I've been around them my entire life. Last month I went through my fuel system. From the lift pump to the injectors, everything new. Truck has never ran this good. When I put my new IP on I was aware that my VRV was gonna be all outta wack because I took it off to switch it to the new pump. I've been driving the truck for a couple weeks now and it wont shift out of 1st and 2nd unless I'm barely giving it the sauce and I gotta let off for it to shift. I tried to adjust the VRV and I have it racked all the way to point where it should be shifting super early. Still nothing different. BUT, when I am going through a parking lot or something just idling, the truck will shift into 2nd. If I touch the vacuum limes on the IP they make an air leaking noise too, not sure if that has anything to do with it.

So, because it is shifting when I am driving like 10 mph... could my vacuum pump be worn out? not enough vacuum at the proper shifting rpm?

Could there maybe be a vacuum leak or are these systems pressurized? I hate vacuum stuff and I dont know a ton about it

I am going to check the trans modulator to see if fluid comes out

What do you guys think it could be?

Please help, I hate having to let off when i want to shift and hear my U joints decide whether they are going to fly into my back seat or not.

 

[Thewespaul]

Welcome to the forum! Since you just changed the ip I’d focus on issues around there. Make sure the vacuum lines or the plastic body of the vrv isn’t cracked, it sounds like it is from the hissing noise

 

[Laine D]

Welcome to the forum! Since you just changed the ip I’d focus on issues around there. Make sure the vacuum lines or the plastic body of the vrv isn’t cracked, it sounds like it is from the hissing noise

Thanks man I will do that right away!

 

[Randy Bush]

You can also tell a lot with the use of a vacuum gage, Like if vacuum pump is ok or got leaks and not maintaining vacuum .

Welcome to the forum too.

 

[Laine D]

You can also tell a lot with the use of a vacuum gage, Like if vacuum pump is ok or got leaks and not maintaining vacuum .

Welcome to the forum too.

After school today I’m gonna ask around for a vacuum gauge to try to test the pump too. My brakes feel a little stiff so that might have something to do with it. Thank you