Hello all,
A few months ago i became the proud owner of an F-150 and it seems to want to stutter going up hills at certain acceleration. I also noticed it has some rotten vacuum hose coming from the throttle body that goes to a y connector. It was completely rotted between the Y and the throttle body, and I want to replace it all. Im trying to trace where it should be going and I can't seem to find the diagram in my Haynes or Chilton books. I want to replace the hose. If anyone can help I'll attach photos and my truck info is in my signature. I thank anyone that can help. I also noticed where this line terminates at the moment, there is another one that was apparently hooked up to something right below other hose. Also, is it possible my EGR valve could be causing the stumbling? Just so you're aware, I bipassed the mid fuel tank because i was sold a huge 38 gallon rear tank for $25. Oh, how much vacuum hose would you buy in my situation? If you can point me in the right direction, I'd very much appreciate it. Glad to finally join yall today!

 

I used 25-ft of 5/32" vacuum hose plus two tees on a 1993 302. Following the vacuum line diagram on the underside of the hood and doing each line one at a time, the whole thing took maybe an hour.

Most lines broke during removal. There was a cluster or manifold right behind the intake at the firewall where several lines came together. I didn't bother trying to salvage it and just ran the lines individually.

 

You need to post some pictures, because I really don't know what specifically you're talking about. There are a lot of vacuum components in these trucks.

 

Here are the pictures. The first shows the one nipple at throttle body completely bare because the vacuum hose going to it was so rotten and there is another rotten one behind it attaching to a second throttle body nipple. Second picture just ahows it snaking its way fown the the passenger side of the block. Next up, the elbo at which it terminates with a more rigid rod right before the elbow - this is just to the right of the battery and hangs there. You may also notice another line, completely unattached below it. 4th picture is an alternate view of theae two unattached hoses. Top one coming from the y at the throttle body and bottom one leading to who knows where. Thanks for taking the time to point out the obvious to me. I appreciate all feedback. Also. My engine is stumbling mainly on upward or downward inclines. I tried closing the EGR valve last night with no success. I do have a fuel filter for it i was planning on putting on... Many thanks to any and all advice.

 

Here's the vacuum diagram for your truck:



The dashed line going to the throttle body on the right hand side is that nipple without a hose on your truck. That goes to the canister purge valve, which goes to the charcoal canister(s). Your charcoal canisters seem like they might be missing.

 

Ah, ok, I thought it was strange that i couldn't find a can or somethin. Many thanks. Also, in regards to my stuttering engine problem, it quit when I unplugged my throttle body conrol module wire harness. So I'm gonna start with the module. Thanks all!

 

Just a quick check back. It was my throttle body control module that was causing my sick truck and stumbling problems. Thanks all!