reading plugs is a great tuning method also....dont depend solely on a wideband

Do you have a hood mounted gauge to where you can watch the FP. I prefer this so you can see what the pressure is doing under boost. You can have a weak pump that may supply good idle pressure, but not be keeping up with the demands under throttle. Another reason why I asked about the filter...will act the same way, both you will see on a gauge.
With a boost ref FP regulator you should see 1:1 rise on fuel prssure / pound of boost. If you dont have gauges, invest in some before you invest in a wideband IMO

 

well the plugs read rich today when i pulled the old ones. i know reading plugs is a good way to do it, but on an efi motor its not as exact as a carbd motor. the pump is a walboro 255 so i dont think its the source. i dont have a hood mounted gauge, but i did check it with a gauge when i set the pressure. im still chasing the problem, and its getting better for sure. thanks.

 

Plugs read accurately NO matter how its inducted. Dont count out the pump I put 3 Walbro 255's in my GN over 6 yrs. You have to double check that you have a good 12v to the pump...low voltage kills them

Put a piece of steel braided line from your rail gauge to the windshield just to check pressure under driving conditions

 

if i get the chance this weekend i will do that.

 

Should keep you busy for a little bit

 

couldn't you just pinch the fuel return line to see what kind of pressure the pump is capable of? That's how I've always done it, except on alot of the newer cars with the f-in nylon lines =/

 

That is shadetree there!

 

nothin wrong with shadetree wrenchin

the miss as of now is ever so slight. the plugs went a long way to clearing it up. i have another vam to test this evening (i dont think its the problem bu its a quick way of eliminating that option). if that tests fine im going to try and advance the timing. after talking with stinger (from stinger-performance) about this on his forum im convinced its just a rich mixture problem. all of the airflow mods and cooling mods ive done will make boost come on harder and faster, causing it to hit pig rich when that vam door slams open. so with this, i think im on the right track. we will see. one thing at a time for now.

 

I'm shadetree myself Yeah it will tell yeah the pump will push some more pressure but thats it. wont tell ya what its doing when you need it the most...under power

 

problem fixed! i swapped VAMSs last night and as it would turn out, my bypass valve was in backwards so it was leaking in stead of relieving pressure . not sure which one did it, but im certain the other vam was good since it ran on 2 other cars before this one thanks for the help everyone!