Attached is a picture of the reason for the drive ability problem I have been having with my 4.9 installation for several years. It all started with a sudden change in the idle speed (it went up) followed by some unusual cruising issues. I searched and searched for a vacuum leak when the issue appeared but could not find it. Today I was looking over the installation comparing it to my other 4.9 and spotted this. The vacuum line controlling the carbon canister purge valve and the purge line are both melted where the hard plastic line passes the exhaust cross over. Now that I have found the issue, I will have to remove the plastic lines and replace them with metal ones.

Never an end to the fun of owning a hot rod car!!!

Rolland

The best part is you found the problem! Now to fix it and get it out a drive it again.

[This message has been edited by FIEROPHREK (edited 07-07-2017).]

What a difference!!!! I had forgotten how well this car could run and had just been accepting the bad issues as a sign of aging. I went to the local pick-n-pull today and got the metal charcoal canister vent and purge lines from a GT. Installed them, removed the melted plastic lines and voila. Drives like a whole new car.

Rolland