Persistant problem when hot

[jtalton626]

Ok, here's the deal. My car runs like a bat out of hell when you first start it up. It seems like it wants to stutter a little bit at around 4 grand on the tach and around 5psi of boost, but works through it and will hit around 13psi when it's cold. Once you drive more than about 5 miles, the car warms up and then it's all over. After it's hot, as soon as the boost hits 5 psi the car falls all over itself. It's almost as if I am misfiring. I thought it was fuel cut, so I changed out the fuel filter, took out the factory fuel pump, and put in a brand spankin' new walbro 255. I have an A/F ratio gauge (not a wideband). When the car is hot and hits 5psi, the fuel goes from rich to lean. As soon as it goes lean, it falls on it's face. If I toy with the gas pedal (letting it out), I can keep it in the green and it will go up to 6 grand on the tach without boost without going lean. What the hell is this? This problem has been persistant throughout a whole different motor, head, exhuast manifold, ecu, fuel pump, everything. The only things left on the car that were there when the problem started is the following. Fuel pressure regulator, Cam angle Sensor, MAS (factory), all factory intercooler plumbing, and the shocks. Only four of those could potentially affect fuel delivery...so my options are getting limited. Any ideas? How do I go about running a boost leak test? I have never done one before...but I'm starting to get suspicious. Are there any locals around here that would be willing to assist? I also have a ghost oil leak somewhere that I can't locate. I keep finding oil on the top of my valve cover...but it does not appear to have a point of departure.

 

[NOSLoGSX]

I have the exact same prob and I've replaced everything I can think of : Plugs, Wires, Coils, Injectors, ECU, o2 Sensor...when it's cold it idle surges but will run like a beast but when it warms up it runs like crap, I cant afford too much more of this what the hell could it be... Someone PLEASE HELP

 

[And_44]

Any word on what's up with your beasts? Got a similar problem been leaning toward either a bad leak at the intake manifold or CAS.

 

[NOSLoGSX]

I recently made a IC Pipe Tester and found 2 boost leaks one at the J pipe and another nasty one by the Throttle body cant find it though

 

[90 Talon AWD]

have you inspected you injector seals?