Turbo Pulsing

Hey I have just gotten a 2004 WRX from my uncle. It runs great except the turbo constantly pulses. It is most noticeable driving at a constant speed and then slowly accelerating over 3 thousand rpms. It sounds like maybe the waste gates are letting air our prematurely but I have had a few people look at it and they can't seem to find anything wrong. My uncle had some after market modifications done to it including some exhaust work, and a new up-pipe and down-pipe along with a GReddy system installed. I have heard that the GReddy doesn't work well on that year of WRX and have recently uninstalled it and put in a stage 2 engine management system in it. I think the problem has to be mechanical because the turbo still pulses with the management on or off. If you have any ideas or further questions please let me know. I would really appreciate it. Thanks a lot.

Reply to
jwbailey05
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snipped-for-privacy@hotmail.com scribbled:

What exactly do you mean by 'pulsing'? You hear it? Feel it?

Reply to
Mk IV

On Oct 13, 11:17 am, Mk IV

Reply to
Joe

Do you have a boost gauge on it (if not put one on its a easy job) - does the pressure stay constant or does the pressure surge during the symptoms. What pressure is the turbo producing? Does it have an aftermarket blow of valve?, some require adjustment that could result in the symptoms you describe. If you do, disconnect the small vacuum hose to it does the problem persist? Cheers Mike

Reply to
Mike

I don't have a boost gauge but I do have an access port that lets me read how much psi is being given from the boost. I ran it on the interstate at the boost is surging and dropping by about 4psi every time it pulses. It does have an after market blow off valve. Its a GReedy. I think I am going to get rid of that and go back to a stock

04 valve because I have been told by a few people the GReedy boost control isn't good on the 04 model. Have you heard anything about that? Thanks Joe
Reply to
Joe

much psi is being given from the boost. I ran it on the interstate at the boost is surging and dropping by about 4psi every time it pulses. It does have an after market blow off valve. Its a GReedy. I think I am going to get rid of that and go back to a stock 04 valve because I have been told by a few people the GReedy boost control isn't good on the 04 model. Have you heard anything about that?

Thanks Joe

Reply to
Joe

What is the maximum boost pressure you are getting? Mike

Reply to
Mike

I can get up to 17psi maximum but once the pulsing starts is will drop down to 13 or so and then back up.

Reply to
Joe

Hi If you want to know if the electronics are the culprate then there is one test you can do the will eliminate them. disconnect the vacuum hose conected to the wastegate. BE AWEAR ONCE YOU DO THIS THE COMPUTER CAN NO LONGER CONTROL BOOST PRESSURE! and this is also the reason to do this. It also requires the driver to control bosst pressure with the throttle. Try to fight the temptation to see how high the boost presure will go, it'll probably exceed 20PSI The computer does have one last resort to prevent overboosting & that is to cut the fuel but its best to avoid this. If the surging stops then the problem was most likly electrical, maybe a faulty air temperture sensor or boost pressure sensor or solinoide valve controlling the waste gate. There is one other possibility that I just thought of & that is the ECU is detecting detonation, what otane fuel are you using? If the problem continues then its most like something on the inlet side leaking air like the blow-off valve or impingin airflow like a clogged filter or obstruction.

"Joe" wrote in message news: snipped-for-privacy@i13g2000prf.googlegroups.com...

Reply to
Mike

Thanks a lot, ill try that and then let you know how it goes.

Thanks Joe

Reply to
Joe

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