car falls on its face after shifting into next gear

[sevrus]

ok heres the deal just got my car back together and took it out. seems to run fine im running 16 pounds of boost my egts hang around 1450 to 1550 and im running the stock fuel pump injectors and regulator. when im driving and i floor it it runs ok a little weak in the higher r's but still pulls pretty good. then when i shift out of what ever gear i am in and go to the next gear and start to hit the gas it just falls directly on its face. ill have to let up on the gas and shift into the next gear let it idle for a few seconds and then its fine again.....wth could this be???? anyone have any clues of why i am having this problem???

 

[Woodsy0]

What kind of boost control are you running? If you don't have a bypass valve/blow-off valve that recirculates air back into the intake but rather vents to the atmosphere, you can have air metering problems during hard shifts that could cause the car to stumble or cut out completely. At the point of shift with a blow-off valve, the ECU thinks more air is in the cylinders than in actuality (the air, in fact, was pssst'd out, for lack of a better description) and will run rich.

If that's not the case, do a boost-leak test and look for any leaks.

 

[andymoraitis]

1. Boost leak test
2. Change plugs wires
3. Verify correct plug gap .028-.030
4. Change fuel filter

Most "falling on it's face" issues are fuel or spark related. Does the car spool late or stumble at part throttle? Are your vacuum readings normal at idle on an aftermarket gauge?

Some more info would help,

Andy

 

[sevrus]

I am running a Greddy type S and a safc. and the bov is vented back into the air intake.
I just put in new plugs and wires on it too. I am running ngk bpr7es' gapped at .030... the fuel filter is new too.
not sure about vaccum id have to check. I am running an evo16g and its spooling right around 3200 rpm. I checked it against my friends gsx who has the same turbo, and its spooling about the same time.
Here is something else too I can monitor my a/f ratio on my turbo timer. I know that its not really that great since it is narrowband, but its way off from what it used to read. Now its reading 10.5 at cruise and before it was more like 13 something. its odd too when I shift into the next gear, and hold the pedal to the floor It hangs right around 3k and wont go any higher untill I let off the gas. then it has time to re-adjus and its fine. Really the only things that are different on the car now than when it was stock are balanced lower end with no balance shafts, 1g cams, 16g, k&n, greddy type s, and exhaust. I left all the other stuff off so I can get the thing running right first. any clues or ideas??