sr problems please help !!

[flatblacksr]

Hey everybody im new to this forum but i have a 240sx with a blacktop sr inside. when i start the car it starts up and revs fine, but when im driving and i step on the gas the car kind of shrieks a little bit from the engine bay and i make no power, it sounds almost as if the turbo is working way harder than it should be and i look at my boost gauge and it says 7.5 psi all the way across. When i first installed the sr it ran perfect and it flew with wide open boost but as i drove it a little bit more without my new fuel pump when i ran into this problem. I checked the timing and reset it perfectly and the problems persist. My mafs is good and my cas is also good. If anyone has any ideas it would help a lot. Thanks

[9240sx]

boost leaks,or maybe a bad gasket on the turbo,Check all the intercooler pipes,and clamps.

[flatblacksr]

yeah i've checked all the intercooler piping meticulously but im still running with the stock exhaust and catalytic converter what would the catalytic look like if its bad because ive been goin kinda rich and i think that might be the problem.

[iliketocrash]

is the shrieking sound constant under WOT?

[nismostate]

you need to get an exhaust. that's a whole lot of back pressure on your turbo. if the cat is bad, it would be hollow all the way through.

[Luke]

you need to get an exhaust. that's a whole lot of back pressure on your turbo. if the cat is bad, it would be hollow all the way through.

At stock boost, an open exhaust isn't a necessity. I would recommend it though, as it's a good power improvement and is a must if you plan to upgrade.

If the cat was bad, it would be the opposite and is clogged completely. When the engine runs rich and there's excess fuel entering the exhaust, the fuel ignites and melts the material in the cat and causes it to clog up. This could be the cause of your problems and you may just have a blown exhaust gasket as a result. You could knock the insides out of the cat if you don't care about emissions or more noise.

[flatblacksr]

yea man i pulled off the cat the other day and it didnt look bad at all so i dont think thats my problem. Im having problems under wot the car doesn't really buck that much and now im thinkin that its a fuel issue. Does anyone know what kind of fuel issues would have these symptoms.(fuel filter, broken line, bad fuel pressure regulator). one thing that i have noticed is that when my car has been sitting still for a little while my car smells like gas. Also i checked my ecu codes for the third time and it looks like my knock sensor might be bad which wasnt showing up when my problems started.

[Luke]

Would that shrieking you describe be the engine pinging? From everything you tell me, i would guess it's ignition related. Meaning, if the engine was pinging or detecting knock, it would pull the timing way back to prevent detonation.

That would explain your power loss while still boosting. You've checked your base timing, so that's correct.

I would get a new knock sensor in there as I don't know how the engine behaves without the knock sensor working correctly. You don't want to risk detonation if it's unable to detect knock. If i had to guess, the engine runs rich because ECU sees no knock sensor. Or it's running with a retarded ignition timing as a safety precaution as a result of that sensor being bad. If the ignition timing is way retarded, it would cause high egts and excess fuel i think.

Hope all that points you in the right direction.