car was running fine with 0.5 kpa running with stock fuel pump, after few days installed Boost controller and boost up 0.75 kpa now car has idle problem sometimes even dies up and it stumble when it rev.. do you guys think my stock fuel pump is bad? or there is something else? thanks!

What is "stock?"Id say its a really, really good idea to get a pump that can handle more fuel.

Sounds like the problem we had with my buddies SR. He is using the KA fuel pump, and after 6 months of running stock boost, and occasionally as much as 12PSI, he started having problems with his fuel system. As soon as he went above 9PSI, his car would sputter, like there was a fuel cutoff.

Anyway, we checked the MAFS, which was fine, the ECU was giving code 55, so we changed his fuel filter and all this black **** came out. Problem solved. We are going to change his fuel pump in the coming weeks pretty soon. Still don't think the engine is getting the amount of fuel it needs.

My advice. Check the filter first, that is a big restraint on your delivery system if it is clogged, but if it's good to go, then your fuel pump would be my next bet. I think my buddies car had a really lucky fuel pump on it. I can't imagine any fuel pump lasting as long as it has.

Also, check your injector pulses with a flathead screwdriver, just for arguments sake. We did that on my friends SR, and they came out fine. Another stop on the troubleshooting road.

Good luck.

BuudWeizErr wrote:Sounds like the problem we had with my buddies SR. He is using the KA fuel pump, and after 6 months of running stock boost, and occasionally as much as 12PSI, he started having problems with his fuel system. As soon as he went above 9PSI, his car would sputter, like there was a fuel cutoff.

That's what I though, too.. I have an Walbro fuel pump will put it on and see! thanks!

SR180SX wrote:That's what I though, too.. I have an Walbro fuel pump will put it on and see! thanks!

Let us know, or me at least, if that fixes it. I'm seeing first-hand that improper fuel setup on these engines is a real power degrader, and I would like to see what kind of gains you'll see when going from a KA FP to a Walbro.

BuudWeizErr wrote:Sounds like the problem we had with my buddies SR. He is using the KA fuel pump, and after 6 months of running stock boost, and occasionally as much as 12PSI, he started having problems with his fuel system. As soon as he went above 9PSI, his car would sputter, like there was a fuel cutoff.

:rolleyes