[Vouthanack]

Hey all,
My car is in the tune shop and I have a 255lph walbro intank pump w/ 675cc injectors. They're trying to push the power to 350+whp but it is running lean..... like 16:1 A/F Ratio at WOT. Could it be the stock fuel regulator causing the problem? The shop is claiming that the injectors and the fuel pump are not the problem. My goal is +400whp but the fuel system is somehow holding me back. If new fuel regulator is needed, I will get that upgraded.

 

[RSXING AZ]

re-install the stock pump for your goals.

 

[nine49kid]

strange, but nice set up though

 

[RsxrcR]

well the DP and exhaust could be choking you up a bit, but that wouldn't cause you to run lean. And the 675 injectors, are they high or low impedence? Make sure they are high impedence unless you are running a resistor box for low impedence. that is the only thing I can think of

 

[TRICKY912]

what's your injector duty cycle? Are you using the stock feed line? My suggestion would be to add a return line and adjustable FPR. But 1st check and see if the pump is installed correctly and make sure the system is fully presurized.

 

[nsted3]

the car shouldnt run lean with what they did. They prob. messed something up on the install would be my guess.

I used the walbro with a 220hp all-motor setup and it worked just fine. You can use it, a hose prob. wasnt clamped well in the tank and its causing your fuel pressure to tank.

 

[Vouthanack]

they said today they're reinstalling the stock pump and I automatically assume a power loss will occur. so... bigger injectors like 880cc and resistor box will do for 400whp or need more upgrades?

 

[RSXING AZ]

750cc's and the stock pump will push a little over 400whp, but the duty cycles are up there.

 

[nsted3]

I dont see the point of pulling the walbro, it will lower your duty cycle and its not the problem of you running lean, its a wrong install or something else that is causing the problem. Too many people on these boards had problems with the walbro to find out they secured hoses incorrectly.

 

[RSXING AZ]

^^Because if his pump is bad, that will eliminate playing the guessing game wondering if the pump is good or not. According to Evans and other tuners I've spoke with, they've seen multiple cases where the walbro had issues with low volume.

 

[Murlo26]

^^Because if his pump is bad, that will eliminate playing the guessing game wondering if the pump is good or not. According to Evans and other tuners I've spoke with, they've seen multiple cases where the walbro had issues with low volume.

I would say it is safe to blame the walboro. I had a similar problem with the walboro, except my car wouldnt even start. I then had to order a whole fuel pump assembly to get another cage for my stock pump so I could drive back to school, since i did the install on vacation at home. Then i paid another couple hundred bucks to have king motorsports put the walboro back in, but they tested it out of the tank and the walboro wasnt pushing any fuel, then the put the stock one on and it worked fine.

Anyway, a little off track, but yes, I would test the walboro out of tank, or simply pull the fuel line in the engine bay and compare the stock and walboro, I would not be surprised if it didnt work as well.

side note: this problem made me so frustrated i de'turboed my car and bought and evolution (bad idea now i am in a law suit for it because it was in a major accident, moral of the story dont get a walboro)

 

[chrisRSX]

well thats good incentive not to get one.

 

[Push]

I thought that most of the documented Walbro problems ended up being botched installs.

 

[hamburglar]

I would say it is safe to blame the walboro. I had a similar problem with the walboro, except my car wouldnt even start. I then had to order a whole fuel pump assembly to get another cage for my stock pump so I could drive back to school, since i did the install on vacation at home. Then i paid another couple hundred bucks to have king motorsports put the walboro back in, but they tested it out of the tank and the walboro wasnt pushing any fuel, then the put the stock one on and it worked fine.

Anyway, a little off track, but yes, I would test the walboro out of tank, or simply pull the fuel line in the engine bay and compare the stock and walboro, I would not be surprised if it didnt work as well.

side note: this problem made me so frustrated i de'turboed my car and bought and evolution (bad idea now i am in a law suit for it because it was in a major accident, moral of the story dont get a walboro)

Sorry to hear about your situation but I have a Walbro and have had no real problems. I make a mistake the first time and didn't do the install properly. Once I fixed the hose issue i've taken it to almost empty with no problems

 

[nsted3]

The reason why there are a lot of issues like that is because does anyone know how many fake walbro and bosch pumps are floating around here??!

Give stan @ fast-turbo a call to give you the rundown, or better yet hit up HT and find the thread with all the pictures and info.

A lot of people had probs with pumps making 0 pressure to find out it was because they were copies and didnt do anything functional.

 

[Laz's EP]

Keep the Walbro and upgrade to RC 750's and you'll be fine :thumbsup:

 

[Murlo26]

I wasnt saying that it was the pump for sure, i was merely pointing out the fact that there are many cases, and i am one of them, that show the walboro has some problems. And i am pretty sure King Motorsports knows what they are doing, they are honda guru's. And the pump was a legit walboro. I am not saying one way or the other, just consider that your pump may be deffective.

 

[RSXING AZ]

I thought that most of the documented Walbro problems ended up being botched installs.

This is usually the case when it comes to the walbro, but you never know for sure unless you pull the pump.

 

[NJslvrTypeS]

One thing to note here and some will agree and others will disagree. This is straight from the mouth of a very reputable tuner.

Walbros are not consistent in their output. You will see some get maxed out very quickly and others will hold pressure well over 400HP. Same goes in B series and other applications.