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Walbro 255 problems.

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Old Mar 11, 2010 | 06:41 PM
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Default Walbro 255 problems.

I am trying to figure out what is going on with my truck. I installed a walbro 255 in line pump. At first it ran just fine. After a short drive without issue, the next trip didn't go so well. After 10 miles or so it didn't want to accelerate. I pulled over checked everything out and nothing seemed out of place. Started it back up and drove away without issue. It started sputtering and spitting again a wile later down the road. It seems to be flooding the motor or something because if I turn it off and let it sit for 30 seconds or so it will start back up and rev to the moon without spitting and sputtering. Is there something I am missing when I installed my brand new pump?

Thanks for any info.
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Old Mar 11, 2010 | 08:29 PM
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put a fuel pressure gauge on it.
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Old Mar 12, 2010 | 05:44 AM
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If it turns out that pressure is too high and I need a regulator, should I bypass the factory one or just splice the aftermarket one in and leave the factory one intact?
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Old Mar 13, 2010 | 09:51 AM
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im not saying it would be the regulator, im saying it would be a problem with your recent fuel pump install and a leak internal to the tank.
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Old Mar 13, 2010 | 10:17 AM
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You aren't making sense. It is an inline pump. therfore there can't be a leak into the tank. Also it is phat not lean so there is too much fuel. Maybe I am missing what you are saying but I don't think so. I will put a gage on it monday because our mechanic didn't have his with him friday.

I am 99% sure there is too much pressure because it is smoking black and like I said when I turn the truck off for a few moment it will start right back up and not have any issues for a little wile.
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Old Mar 13, 2010 | 10:27 AM
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missed the inline part. i'm up to speed now.

funny that it ran normal for a while.

you may very well need an adustable higher capacity regulator. can find that out with a gauge.
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Old Mar 13, 2010 | 02:33 PM
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Yea I also have colder plugs for the nitrous so the plugs are fouling out I am sure. I am gong to install the factory plugs as soon as it stops raining. They are stock heat range and aren't half fouled from the little bit of driving I have done with this pump. I am going to get a gage on it and order a regulator this weekend if I enough money. Any one recommend a regulator?
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Old Mar 15, 2010 | 08:21 AM
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External pump, and no regulator??
A bit of info on the application might be helpful....
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Old Mar 15, 2010 | 06:21 PM
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01 gmc 2500, 6.0.

I installed a walbro 255 in line and have the stock regulator. I have found a few people on the forum that have had the same problem. Guess most people's regulator can keep up, mine can't. Our mechanic forgot his gage today so i wasn't able to confirm my pressure. I am short on cash and can't find a good deal on a used regulator, so I am stuck in a hard place. I will get the gage on it tomorrow and once I confirm I have the problem I know I have, I am going to make sure there aren't any restrictions in the return line. Doubt I will get that lucky but it is going to be a week and a half till I can order the regulator.

Might have to do the old, ask mom and dad once I confirm the issue.
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Old Mar 16, 2010 | 08:51 PM
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Well pressure is high 50s to low 60s. Factory spec is 55-62 so it is in spec. Seems to do much better if I get on it a bit as apposed to to driving very slow.

Same thing today started breaking up after a little bit of driving, shut it down, coasted a tiny bit, started it back up, and runs without any issue.
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Old Mar 17, 2010 | 06:59 PM
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Well after driving the truck with the gage it is drooping to almost 0 when it started breaking up. Mechanic thought the fuel regulator needs replaced. I am guessing, being older the new high pressure, high flow pump is giving it grief. My Delmar is do I spend $140 and get an aftermarket one that I know will work well but needs plumed in, of spend $50-$75 on a factory replacement hoping a new one can keep up with the pump. This saves me from having to mess with anything besides taking the old off and new on.
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Old Mar 17, 2010 | 10:29 PM
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My factory regulator has never given me any problems with my Walbro hi-flow pump so I don't see why not!
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Old Mar 18, 2010 | 07:17 AM
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Originally Posted by conde'strans
My factory regulator has never given me any problems with my Walbro hi-flow pump so I don't see why not!
This is what I am leaning on. So many people run these pumps with factory regulators mine must just be worn out. I have 239,000 mi. and who knows if or when it was ever changed. Worse case I can get most of my money back by selling it I hope. We will see.
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Old Mar 18, 2010 | 08:33 PM
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Installed a new replacement regulator and in the short drive home only had one time when it acted up for just a second. Going to have to drive a bit more to see if it is cured or just didn't act up on the way home.

I am amazed that I am one of the only people to ever have a problem. If you have any info on any problems with an aftermarket pump it may help if the problem persists after the new regulator.
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Old Mar 24, 2010 | 06:02 PM
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I am still having the same problems. I installed a fuel filter today and it made no differance. I am going to order an aftermaerket regulator tomorrow unless anyone has ideas! I was hoping to noy have to do that bu seems like my truck is a special case and won't work right without.
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Old Mar 24, 2010 | 06:17 PM
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electrical connections?
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Old Mar 24, 2010 | 06:31 PM
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The problem is too consistant for electrical problems.
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Old Apr 10, 2010 | 12:43 AM
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Default regulator

I am running a LS1 M6 with a lil over 430 rwh in my '72SS Camaro I use AC DELCO GF 845(15077584) filter/regulator with no issues other than I am on my 2nd walbro 255lph pump( in tank).My fuel prsr stays about 59 psi at the rails.
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Old Apr 10, 2010 | 09:02 AM
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So you are using an aftermarket regulator?
I am going to order one next time I get paid. I have done everything else possible and for some reason my brand new replacement regulator is just not cutting it.

Relocated the return to the top of the tank, replaced the filter, removed the foam just in case a small piece was blocking the the hole, and nothing has mad e a difference.
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Old Apr 14, 2010 | 10:34 PM
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Maybe your inline pump is cavitating your intank pump.
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