ZCar Forum banner
Status
Not open for further replies.
1 - 3 of 3 Posts

·
Registered
Joined
·
107,695 Posts
Discussion Starter · #1 ·
Carlos-

It's next to impossible to correctly diagnose a problem like this by e-mail.

However, I would guess that you have a problem with air flow. (you said the vacuum goes to zero... I'm assuming you mean the manifold pressure.)

Three things I would look for is obstructed air intake (i.e. AFM), bad turbo (i.e. not producing any boost), or obstructed exhaust (back pressure keeping turbo from producing boost).

Sorry I can't help beyond that.

Bob A.

P.S. Many years ago I had a problem with an industrial engine that kinda acted like what you describe. Turned out it was just worn out. Don't think that's your problem but might not hurt to check compression.
 

·
Registered
Joined
·
1,826 Posts
Re: Changed turbos yet?

I remember you were upgrading turbos. Did this occur after the swap or what? Maybe you don't have enough injectors to feed the turbo. You may have good pressure but not enough flow? I say that because it looks like your problem only occurs under a load. Can you check exhaust temps or air fuel ratio? Make sure you oxygen sensor is not reading under .750 milivolts at full throttle. If you did change turbo you may not have enough injector and you are leaning it out. Kind of hard to diagnose,
greg
71 240z
 

·
Registered
Joined
·
107,695 Posts
Discussion Starter · #3 ·
HAVE YOU CHCKED YOUR DUMP VALVE?
YOU KNOW YOUR WASTE GATE FOR TURBO IS IT CLOSING ALL THE WAY?
AT WHAT R.P.M. DOES IT OPEN?
AND HOW MUCH?
MIGHT CHECK INDUCTION TUGE FOR CRACKS? IF ENGINE TORQUES IT MAY
OPEN THE CRACK BY STRETCHING THE TUBE. TO MUCH AIR WILL BLOW OUT YOUR FLAME (AIR TO FUEL RATIO)
LET US KNOW
 
1 - 3 of 3 Posts
Status
Not open for further replies.
Top