[sec914]

first off atp kit 440 webber injectors t3/t4 50 trim garrett internal wastegate atp manifold/intercooler. fresh stock pump and filter. 18 vac at idle running 8-10psi.stock intake.
Alright now when im getting on it hard, it feels like it its shuddering up top. didnt before so i changed the fuel pump and filter. worked fine for like a day, then same problem. no vacum leaks when its cold then after a hot run the rpms jump like 200rpm. only code is a front o2 sensor. kinda broke at the moment could be anything else?

 

[BoostedDubVR6T420]

What kind of AFR's are you seeing it 10 psi and a stock pump? Should definitely be looking into an inline with any pressures over 9 psi.

 

[sec914]

i havent had a problem till recently. no afr gauge.... usually pulls like a train hence replaceing the pump and filter. had a walbro on for a week till it died but that was last year went from 15 down to 10 with no problems with the stock pump for 9 months now. new pump is a few weeks old (5psi same problem).


Modified by sec914 at 12:36 PM 4-26-2010

 

[BoostedDubVR6T420]

You really need to invest in an AFR gauge, and consider another walboro. What kind of fuel pressure are you seeing? Plug gap?

 

[sec914]

how do you check fuel pressure under a load. dont have a gauge on the car just the one u hook up in the rail line. shouldnt need a walbro on low 5-9 psi. my problem just started dont think its a fuel problem but will check... somehow goin to the shop tomorrow.

 

[sec914]

stock gap bkr7es?