Like what the title says. I have a gsr turbo with a walboro 255 lph fuel pump.
I checked through the forums and could not find anything about my concern. It seems that I have to prime the fuel pump 5 to 6 times before starting. If i start it on like the first or second try it starts to bog and idle fluctuates like crazy. I'm wondering I see of other heavy builds and it seems like they don't prime it like how I do. There car starts right up.


Turned on Hondata s300

Thanks for reading guys! Appreciate it.

 

Possibly a fuel pressure regulator not holding pressure.

 

yeah, sounds like the fpr is leaking.
is your fpr Oem or aftermarket?

 

Aftermarket on a aem fuel rail. I mean it's weird I've seen something like this before where they had to prime couple times because of the high flow fuel pump but others just start on the time with the high flow pump. If the fpr is leaking I don't see any traces of fuel and fpr gauge is holding pressure pretty good. I so didn't seem like I would have a leak in that area.


Thanks for the input! Really appreciate it

 

By "leak" we're talking internal. The diaphragm that moves to adjust fuel pressure is probably open too much and not holding pressure within the rail as it should. Also, the vacuum line that runs from the regulator to the intake- make sure that's sealed.

 

when you first prime the pump, what does the pressure sit at while the pump is priming, what pressure does it sit at the moment the pump stops priming, and how long does it take for the pressure to drop back down to 2psi or less?

 

How old is your Walbro? Mine failed after maybe 15k miles. Before I replaced it the idle was fluctuating, pump was humming very loud and you could hear the pump humming up and down even just sitting at idle. Replaced it and couldnt be happier with my quiet Grams 255.

 

Shouldn't have to prime anything. Do a fuel pressure test and see if it drops after key on. Pump won't have much to do with it if it drops. Look for fuel leak or FPR diaphragm problems if pressure drops. Sounds like u have an fpr problem with the way it "bogs down"

 

On the first prime it goes up to maybe 60, 62 psi then once I shut off it drops down to like 53 psi.

 

Funny you said this. I had this problem twice. I thought it was my iac. Cleaned it and never happened it again. Maybe a month or so also it happened again. I'm like what the heck?! I cleaned you up good. Shut the car off and started it back up. Car idled good.
Fuel pump is maybe like 3 maybe almost 4yrs old. Walboro.

 

Thanks for everyone's input! I really to appreciate the help!

Question if it happeneds to be my fpr would I have to go and get the car retuned again! Thanks guys

 

Pressure dropped from 62 psi from starting car to once I shut the key off it dropped to 53 psi.

 

sounds like pressures are ok, and fpr is ok. thats crazy high fuel pressure though. are yo running some special injectors that require that much pressure?

if you change the fuel pressure, yes you would need a re-tune.

where did you buy the fuel pump? there were a lot of knockoffs being sold on ebay described as "genuine walbro" a few years back that had a high failure rate.

 

In for this!!

Mine, needs 2 primes before start only at cold start, then start right away.

If I try just start it cold with the first prime it start and dies.

Someone told me about Walbro not having check valve and the system loose pressure after a few hours. (Not sure if this Info. is right.)

 

Running id1000cc injectors.

As for the pressure that was all done by the tuner.

Maybe it's time for a new fuel pump maybe?!

Motoxxxman appreciate it!

 

yeah, maybe a new pump would be a good idea. if you go walbro again, get it from a trusted source to ensure it's genuine and not a knockoff like I mentioned. also, get the 255HP, not the standard 255lph. the HP version is designed specifically for higher fuel pressures and boost. below 40psi they both perform the same, but above 50psi the HP maintains a much more consistent volumetric flow whereas the standard 255lph starts falling off.

and those injectors do well with higher pressure, I approve of your tuner's decision to up the pressure
if they were almost any other brand though, I'd say it was a stupid decision lol, as most other brand injectors are designed specifically for 40-50psi base pressure, and the spray pattern gets awkward above 50psi, not atomizing correctly anymore.