Hey, hows it going?
So first things first, I have a 93 fd with a bone stock motor. Now my problem is that when I gas the pedal and reach about 4500 rpm my gauge starts to fluctuate from around 11-8 psi constant and I start to hear hissing sounds inside he cockpit on the driver side and also start smelling fuel. Anybody have solid concrete clues to what exactly is going on. Help would be well appreciated... I've tried searching for the problem on the site as well but for some reason the search bar is down and it keeps giving me topics that's not even close to what the problem I'm having.

 

10 8 10 is normal boost pattern 4500ish is when your other turbo should be kicking boost will drop. If your car is running well its like a kick in the ***. If its not jumping back to 10 after have a look at your charge relief valve. pull the hoses off the air box one should be sucking very little the other blowing hit the gas and see what happens

 

double check all vacuum lines for leaks, you can use a can of break cleaner to help you find out if you have amy.

 

hissing sound might be a boost leak
check all vac hoses and clamps

 

Im having the same problem. Stock 95. not a boost leak, car is perfect till the change over and then loses most of its power and i hear the hissing sound. I read the archives and even though this is a common problem i cant find any solid list of causes and their solutions.