Just installed Walbro 190, some issues.

[tatersail]

I just installed a Walbro 190lph fuel pump in my 97 GSX. Install was pretty simple besides breaking the fittings loose. The car before was hitting fuel cut above 4,000rpm in any gear above 1st (RC550's). Now the car wont pull in any gear and seems to idle and drive normal ok. But as soon as I get on the thottle it must be super lean or pig rich or another issue. Could be to rich take away all power. Before the 190lph the car pulled great in 1st. Now it wont do anything. Also it is quite tough to get the pump assembly to seat correctly on the tank. It took a bunch of tries but I believe it is seated. But now when I take the gas cap off I dont hear any pressure being relased. So I am going to check it again. But even if the pump assembly wasnt sealed correctly would that effect anything besides leaking vapors into the cabin. Finally when putting the Walbro into the pump assembly you put a white plactic cap, them 0-ring, then black plastic retainer, then pump. What is the second white plastic cap for. I will attach a picture. I couldnt find anywhere in instruction or vfaq for what the second one was for, so it wasnt used.

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You can see the white caps in the picture. They are the only things in the picture that there are two of.

 

[DSM90AWD]

Did you put a dab of oil on the new o-ring before instralling the pump into the hood?
If not, it will likely twist up preventign a good seal whcih would cause low fuel pressure and difficult startups

 

[tatersail]

I will check the seal when I take the assembly out again tomorrow. Thanks for the help. Does anyone have answers to these questions.

1. What is the second white plastic cap for?
2. Could the car just be way to rich now with the 190 and 550's with no correction.
3. If the tank isnt pessurizing because the pump assembly isnt seated. If the tank dosnt pressureize would that effect the pump?

 

[DSM90AWD]

1. What is the second white plastic cap for?

Are both white caps exactley the same? Either way you only need one for the pump install.

2. Could the car just be way to rich now with the 190 and 550's with no correction.

Yes adding 22% more fuel at all airflow/rpm points without correction is going to make you run like ass. An AFC, EPROM, DSMLink, MAFT is needed to get your tune back in line. Or you coudl do a MAS hack (e.g. remove screens) but that's not recommended.

3. If the tank isnt pessurizing because the pump assembly isnt seated. If the tank
dosnt pressureize would that effect the pump?

The fuel pump seating woudl have nothing to do with "presurizing" the fuel tank. more likely you disconnected the vapor line (that one-way valve that leads to the vapor canister / purge valve in the engine bay)

 

[steve]

Are both white caps exactley the same? Either way you only need one for the pump install.

It's difficult to tell from that picture but usually one of those is the longer spacer that goes under the o-ring and the other the cap that goes over the o-ring and keeps everything in place. I'd say you need both.

Steve

 

[DSM90AWD]

It's difficult to tell from that picture but usually one of those is the longer spacer that goes under the o-ring and the other the cap that goes over the o-ring and keeps everything in place. I'd say you need both

Per the VFAQ (and my own install on my 1G AWD) I reused the stock spacer to get the correct clearance to the pump hood

 

[tatersail]

First off how would the pump assembly not being seated correctly not affect the tank pessurizing. It goes directly into the tank and has a gasket for a reason, if that isnt sealed then the tank would never pressurize correct. Also I didnt touch anything under the hood so something during the pump install changed and made it so the tank dosnt pressurize. Secondly I do have a AFC-II and a wideband. But I have been waiting for my logger to come to tune. The car ran ok but rich with just he 550's could just adding the 190 pump make such a big difference. Some say use the second cap some dont I will have to take it out again and check it again.

 

[DSM90AWD]

First off how would the pump assembly not being seated correctly not affect the tank pessurizing. It goes directly into the tank and has a gasket for a reason, if that isnt sealed then the tank would never pressurize correct

The fuel pump is pressurizing the fuel line, which terminates back in the tank via the return line. Gas is a volitile liquid. The pressure you get in the tank is from the vapors produced from the fuel sloshing around, heating up front the pumping, compression and rail temps and the pressureized return line which unpressurizes releasing vapor in your tank.

The vapor line connects to your gas tank and to the charcoal canister via a purge valve. I remember on mine I had to remove the one line near the fuel filter access panel (had a blue check valve on it)

 

[tatersail]

I understand. But the tank would not be able to hold any pressure if the pump assemly isnt seated on the tank. It would just leak vapor into the cabin. With the pump assebly loose or not seated it would be the same as the gas cap loose. I think the problem must be the o-ring isnt sealing and the fuel pump is loosing fuel pressure. Cause that is the only thing that makes sense. Even if the pump assembly isnt sealed it should still run ok, just like if the gas cap was loose.

 

[DSM90AWD]

I understand. But the tank would not be able to hold any pressure if the pump assemly isnt seated on the tank. It would just leak vapor into the cabin.

Ahh, I was referring to the pump connection to the feed line itself. You are also concerned about the fuel bracket assembly's mounting gasket not sealing to the tank.

If you are worried about gas fumes in the cabin, then that is a realistic concern. However the gas tank itself needs not be "pressurized" for your car to operate well. I've even gone a step further and removed my charcoal canister / purge valve so my tank vents to ATM.

An emmissions yes, but my car being ODBI, the emissions police don't pressure check my gas cap. Yours being ODBII, I'd definitely make sure your tank holds pressure, at least come emission testing time

Another Tuners member had actually "capped" the vapor line thinking it the correct thing to do when removing the charcoal canister / purge valve. He experienced excessive pressure in his tank which restricted the flow of fuel on the return line to the tank causing excessive fuel pressures at idle/cruise

Hope this helps

 

[tatersail]

Ok it makes more sense now. I am going to take the pump assembly back out again right now. I am just assuming the o-ring sealing the pump isnt working and fuel is blowing back into the tank. It seems like the only thing that could be causing a problem. I will let you guys know how it works out.

 

[tatersail]

I just took the pump back out checked everything and put it back in. Now there is pressure in the tank when I remove the gas cap. Also I oiled the o-ring before installation again like I was told to do and I dont see how it isnt sealed. But the car still runs much worse than it did before the pump install. I tired leaning it out and the car runs better but still dosnt pull like it did before. Could this all just be tune related. One plus is that is isnt hitting fuel cut at 4krpm in 2nd gear and up. It was doing that with the old pump.

 

[tatersail]

The only part I was confused about was what way the L-bracket that bolts on with the phillips screw that holds the bottom fuel pump bracket in place. My firend took it off when I wasnt looking and I am not sure which way it goes. I could see where the washer was sitting on the bracket and I think I am have it the right way, but I am not 100% positive. Does anyone know what that bracket does. I guess I can take it out again and take a picture if someone wants.