Whats wrong with my 1g GSX?

[GSXevolution]

I am having a serious ongoing problem wiht my 90 GSX 5 Speed.
I am having the problem that it wont boost all the way, it feels like the turbo pulls until it hits 7psi then its like not working. I have done everything i can think of:

New ECU
New plugs and wires
New BCS
Had my Turbo system and Wastegate checked proffesionaly and was told it was fine.

Still i cant get this car to act like it did 5 months ago.
I have no mods exept for a K&N and the removed silencer from the MAFS. I NEED HELP BAD, I cant throw anymore money into this abyss.
PLEASE HELP!!!!!!!!!

 

[Forced4]

What are the odds you hae a boost leak? Do you hear a "whistle" sound under boost? You can first try tightening ALL the hose clamps on the intake hoses. then check for a vac line that may be cracked. You may have a bad intake gasket or something too. A cracked exhaust manifold will have some affect too. That alone I don't believe would be your problem because it would be way loud. I had a crack and both outer studs were broken. I am making more boost now just by that corrction(well I also put new valve seals in) Just some ideas you can do to attempt to remedy this without spending $$$.

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[GSXevolution]

I had my head redone about 20K miles ago which means i had all new valve seals and valves put in too. The mechanic i took it to for the Turbo and Wastegate check also checked for boost leaks and came up with nothing. Everything pretty much checks out, thats why this hurts my brain so much. I havent checked the exaust manifold though but i agree i would ave heard it, actually when i rev i get a faint exaust leak sound but i never thought anything of it, thought it was just the engine, like it was always there but i cant remember for sure. I'll try checking that out though. Im not closing my wallet im just sick of spending money on parts that i dont absolutly need.

 

[Forced4]

I have a friend at Mitsu. He's a tech here in Tempe AZ. I will see if he has dealt with anything like that. He has also had a couple of these cars himself. I will let you know if he comes up with anything that could help.

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[ltvarney]

If the wastegate isn't weak, the BOV could be. For the exhaust, if you're only getting a small exhaust squeak at certain RPMs that's probably not the problem.

Also, have you considered the ECU seeing (phantom)knock? If you borrow a boost controller, the ECU would not be able to retard boost, only timing. That would eliminate that possibility if the problem persisted.

 

[mazdamx6pwr.com]

Hey I'm in NH. I'll take a look at your car if you want. I'm also interested in you spair ECU if you still have it.

Adam

 

[azkikr10]

u try coil pack?

 

[Forced4]

Originally posted by azkikr10
u try coil pack?

or the igniter for the coil pack?

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[GSXevolution]

Yeah ive checked the coils, they apear to be fine.
The other thing, the mechanic told me the wastegate was moving, not sticking or anything, but i looked at the thing and its rusted to shit, and when my father had the thing out tinkering with it, he said it was stiff and didnt move much at all. Maybe thats a start.

As for Adam, thats a great idea. Ill get back to you when i can set something up, i just work a hell of alot. I'll get back to you through email.

 

[Enigma_Man]

Where in MA are ya? If you're close enough, or feel like making a trip to where I live, I have a few tools, and a pocketlogger, and I can diagnose fairly easy problems well enough.

Send me a PM.

-Jesse