I got a 97 civic hx d16y7 with a t3/t4 turbonetics. walboro 255 fuel pump. when i reach about 4500 rpms (5psi boost) it starts breaking up. does not do it in neutal.

 

what do you mean by "breaking up"?

and is this tuned?

do you really have a D16Y7?? HX is suppose to have a D16Y5.

Manual transmission I assume?

 

No its not tuned yet. by breaking up i mean it seems like under full boost its not getting enough fuel or spark going out. and yea its a d16y7 i got rid of the y5 and yes manual.

 

Is this symptom more like power loss or misfire? Is the CEL ON?

 

I would say go get it tuned. Its not meant to need that kind of fuel naturally. You shouldnt really be driving it anyway without a tune.

 

Well if it's not tuned of course you're not getting enough fuel...

Seriously, why are you driving in boost without a tune?

Go get a tune.


Misfiring can also happen from not having a tune. Timing and fuel maps need to be adjusted and that's his definite problem.

 

Though you may be right, there remains a real possibility that the problem is more fundamental than needing a tune. We've both seen this previously on other occasions. That's the angle that I'm trying to pursue.

 

True, but you're not going to be able to diagnose his problem with such a big other problem fuzzying up what's going on.

The only way you can diagnose this is for him to go get a tune and then see if it still "break[s] up" at 5psi.

 

Trust, this is not necessarily true. We have very little information at this point. It's still quite possible that a fundamental issue might be revealed. Just as an example, what if we learn that the CEL is ON and a MAP sensor or TPS code is being thrown.

Be more open minded.

 

yes the cel is on but it ran fine previsoly without a tune for 6 months. then started to "misfire".