I was really hoping the 155 was a typo as i didn't know they really made them that small. DEFINITELY upgrade it. A 255 walbro is cheap insurance, and the install isn't that bad (drop in).
Meanwhile I'm changing to Autolite 24's and gapping at .032.
As the demand for volume rises the pump cannot keep up hence the flat spotMakes perfect sense. Exactly what happened to me. Stumble on high RPM, the motor was starving for fuel
Duty cycle on a forced induction engine brings down the horse power rating on pumps greatly coupled by pump being rated to run at x psi when raising pressure changes the rating as well.I'm gonna take a test drive before I change the pump to see if the plug gap adjustment changed the situation. The stumble feels more like an ignition flutter than a nose dive fuel starvation thing.
The 155 lph pump is 40% more volume capacity than a stock 110 lph. Hard to believe my moderate setup would need more than that. Maybe.... We shall see.
Here's the Walbro GSS340 255lph on amazon for $65. It's pump only.
I just installed the 155lph Walbro not long ago so can use the pick up sock and harness that's already on the car with this higher volume pump?
Amazon product ASIN B002ERGI7QView: http://www.amazon.com/Walbro-GSS340-Fuel-Pump/dp/B002ERGI7Q/ref=sr_1_1?ie=UTF8&qid=1445991021&sr=8-1&keywords=gss+340+walbro
Yes. The gss340 pump uses the stock sock, wiring, and metal housing. I have this pump in my hatch.Here's the Walbro GSS340 255lph on amazon for $65. It's pump only.
I just installed the 155lph Walbro not long ago so can use the pick up sock and harness that's already on the car with this higher volume pump?
Amazon product ASIN B002ERGI7QView: http://www.amazon.com/Walbro-GSS340-Fuel-Pump/dp/B002ERGI7Q/ref=sr_1_1?ie=UTF8&qid=1445991021&sr=8-1&keywords=gss+340+walbro
Error I meant I have in my notchYes. The gss340 pump uses the stock sock, wiring, and metal housing. I have this pump in my hatch.
I'm glad it's running great . One last thing on the pump and I'll stop breaking balls - I wouldn't want that pump maxed out all the time like that Even if it's working . Takes one lean pull to hurt it bad . If the pump gets to hot etc that's all it takes esp if it's at its peak . I'd consider the 255 or the 340 for piece of mindFirst test runs after reducing plug gap from .054 to .035 are in.
Still running 155 lph pump.
3rd gear pull WOT straight up to 6000 rpm before letting off the pedal. No stumble, no hesitations.
Boost exceeding 8 psi approaching 6k rpm but took eyes off boost gauge to monitor tach.
Looks like the pressure was blowing the spark out!!