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WTF? lost some boost after hard run

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Old 11-07-04, 02:55 PM
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WTF? lost some boost after hard run

Today i decided to see if anything would happen flloring it throughout 2nd gear.

Some background info... My car misfires/backfires a lot at high rpm so it was doing it a lot at this point since i was taking it to redline (my 1st time also).

Anyway... after i let off i get on it again and see that my boost drops below 5 psi when the secondaries kick in and my car doesnt sound the same anymore. It sounded a little different. I got home and looked under the hood. Nothing looked out of the ordinary...and there was no smoke coming out of my exhaust.

I was looking at the troubleshooting page and decided maybe it could be the turbo control actuator. How do i check this? Also if its not that what else can cause something like this?

Any help is appreciated. Thanks

- Art


BTW i have disconnected my wastegate/pre-control connectors so that i run 7 psi... just a FYI
Old 11-07-04, 03:16 PM
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7 psi, wouldnt you be running 10 psi and
Old 11-07-04, 03:18 PM
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if your car is breaking up at high rpms, that means your a/f ratio is not right and your probably not getting enough fuel. Has your car exibited any problems since your noticed this drop in boost?
Old 11-07-04, 06:37 PM
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not at all.. thats the weird thing. I was thinking if i blew my engine... wouldnt i know it?
Old 11-07-04, 06:45 PM
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sorry what set up are you running ?
john (88GT-R) was getting a similar thing on his FC and found it to be a mix of A/FRs and timing, dont know if that helps
Old 11-07-04, 08:16 PM
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streetport, dp, and exhaust.. I'm starting to think that its just a boost leak somewhere or still that turbo control actuator.
Old 11-07-04, 09:02 PM
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Could be the y-pipe coupler gone bad. Happened to me and I got similar symptoms. You can't see if its bad from the outside but when I took mine apart it had a long rip across the middle of it.
Old 11-07-04, 09:49 PM
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Check all couplers and intercooler hoses, THOUROUGHLY!!!
Old 11-07-04, 11:30 PM
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all of the couplers are silicon i believe so i don't think its a bad coupler. How exactly should i check the hoses? Should i rev the car and put my hand near it to check for air coming out? When i'm driving ive noticed that my car isnt as loud ne more and I'm pretty sure I'm hearing some kind of new hissing sound. I'm guessing thats the leak lol.
Old 11-08-04, 10:37 PM
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Jack up the rear of your car and put it in first. Lightly start applying the e-brake to where the revs drop down, but the car still idles fair. Go to the front of the car and get it boosting and feel around (being careful of moving and hot parts) for the boost leak all the way to the T/B and even at the BOV hoses. Make sure the car is on jackstands and the front wheel is chalked.


Hope that helps.............. =)
Old 11-08-04, 11:10 PM
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Are you running a stock ECU?
Old 11-22-04, 01:43 AM
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yes stock ECU but disconnected wastegate and precontrol connectors so only 7 psi.

What happens is RPMS go up pretty slowly compared to a working rx7, and primary boost goes up to like 5-6 then secondaries hit like maybe 1-2 psi. But sometimes if I let go of the gas and boost again it either doesnt boost or very little boost.

UPDATE: I went to my mechanics shop and helped him take a look at it. We couldn't find any vacuum lines popped off or any of the IC pipes cracked or ripped. We also checked under my car and looked around. Didn't find anything wrong except for a slight turbo leak. I dont think its big enuff to cause any problems right now as it only smokes (white smoke) on startup.

I dont understand what can cause my car to be quieter just like that. I used to hear my exhaust on the freeway but now i really cant...Also I put in a greddy type S bov and it has the faintest sound ever. Like I can't hear it unless im on a quiet street or something. Any other opinions?

Last edited by trancemaster; 11-22-04 at 01:56 AM.
Old 11-23-04, 10:32 AM
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bump
Old 11-23-04, 10:42 AM
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You probably popped off a vacuum hose. Pull off the small black vacuum chamber that is on top of the engine, and look around for a hose that has become disconnected.
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