I just swapped out my walbro for a new one. The one I took out was only a few months old.......I think I bought it in August or September.

Anyway, I was having a fuel pressure problem.......I was losing major fuel pressure under boost and getting alot of knock as a result. I tried all sorts of things before fianlyl deciding to try a new pump.

Swapped pumps and all is great.

So, today I was looking at the pump I removed and I noticed that there is a hole at the pump outlet end. Look at the pic:



Is this hole normal (the hole above of the gray vinyl cap?) If not, this must have been where all the flow had been going!!!!

If anyone has a pic of a walbro, can you post it up. I am not taking aprt my fuel assempbly again just to look at the new pump!

 

Not sure how much this helps but this is a shot of a Walbro 255 lph from another kit/car... can't really tell if the hole you are referencing is open or not.

 

Thanks for the reply, but you can't tell from that pic.

it is funny, the way that pump is modded is what I did to my 1st walbro (i'm on my 3rd now. ) By nipping off the plastic shown in that pic, it compromised whatever is under there because one of those silver caps popped out along with the spring behind it. I was out in the middle of nowhere when it happen (orange grove territory) and my car just quietly died as my fuel pressure hit Zero!!!!

so, on the second walbro, I decided to grind on the nissnapump housing so I wouldn't have to make any mods to the walbro......and then a few months later the walbro won't hold pressure and flow was way down!

I guess I have bad luck with walbros.

Maybe I should just change my fuel pump at every oil change interval....

back to the original question.........if anyone has a walbro sitting on a shelf, can you take a picture of the "business end" so that I can figure out if that hole is not supposed to be there.

 

Well the odd thing is that pic is of a Walbro pump for the Spec V. The 350Z and G35 Coupe pump is not like that. That grinding is not done on the Z pump. I'd attach every pic but it would take forever. Look at the guide here: http://turboneticsownersclub.com/tur...icsinstman.pdf The pump mods are nothing like the pic I originally posted. It looks like its a 100% different pump.

 

Request permission to thread-jack for 1 small tiny kind of related question.

Does the drilling of the fuel pump housing affect anything when you upgrade to a return system (IE. CJM) with new injectors (IE. 550cc)

 

It should not no. The FPR should keep fuel pressure stable even if there is a temporary reduction in fuel flow during very low fuel conditions.

 

robert,

The sedan pump housing is fairly different from the G Coupe / Z. At 1st glance, you might think they are the same, but they aren't.

 

Yeah I have heard that. I actually have never seen the sedan pump housing. However that should not affect which type of pump is used unless its DRASTICALLY different. I know at least one other person who made this kit work on their sedan and used the 350Z style pump in their car. Perhaps the issue lies with the type of pump used? I'm just trying to look at whats difference. I have 45k miles on my Walbro 255 LPH pump and never had anything like this happen. For you to have 3 go bad in this small period of time something has to be off and my first thing is to look at the delta (difference/change) between our cars.

 

I am having a similar problem, when I am hitting boost, the fuel seems to be cut. It just keeps hiccuping around 4-5k rpm. I have a 324 fuel pump.

 

Walbro has been having QC problems for the past couple years. I'm hearing failure rates of about 30% from shops around the country. I have gave up on using them a year ago. Unfortunatly they are cheap so people are continuing to use them. I know of @ least 3 failing in the last month @ one shop in the miami area.

 

Thats very interesting.. I'll admit Bosch pumps are my preference but it seems everyone uses Walbro these days so I didn't think there would be any QC issues. I haven't heard of much anyways at least personally. Does Bosch make drop in replacement high flow pumps similar to Walbro? I've never looked into it honestly. The last time I used a Bosch pump there was no "factory" pump assembly for it to drop into. It was on a 1970 Mustang.

 

I think you mean the GSS342.

That is the pump for all G/Zs including the sedan.

the sedan's housing differs in it's regualtor, siphon jet, lower unit, upper unit, most everything, but the same pump fits. on the sedan, the sock on the bottom of the pump is completely exposed to the tank so there is no restriction on the intake of the pump.


Rob, the first pump to go bad was my fault. I nipped off these 2 nubs that probably shouldn't have been nipped off. But, this second pump is just a bad pump in my opinion. I am on the 3rd pump now,.........keep your fingers crossed.

BTW, this is more of a reason to have a fuel pressure gauge in the car. I nver would have known wat was going on if i didn't have a fuel pressure gauge in the cabin!

 

i heard carter bought walbro about a year ago. i actually had a tough time locating a walbro locally a couple months back. i have been running my inline walbro for over 1.5 years now with no issues though, and even longer in my other cars.

 

Most people are making an 044 Bosch work in place of the Walbros. No one has put an 044 in a Z/G yet as far as I know.

The older Walbros seem to be holding together, it's only the ones made in the last year or two that seem to have this high failure rate.

 

Andrew I just so happen to have an extra Z pump here from something I was working on. It is in fact the GSS342. However as you said those two little things are not ground off on it and none of the Turbonetics Z/G instructions mention grinding them off so they clearly shouldn't be. Also that other hole you were asking about before is in fact open on the pump I have here. Sorry for the late answer I just remembered I had one in my garage.

 

Interesting, it would be interesting to see if it fits with little modification like the Walbro...

 

Has anyone tried the Kenne-Bell Boost-A-Pump. It is a voltage regulator for the fuel...rather interesting read:

http://www.kennebell.net/techinfo/ge...Focus_kens.pdf
http://www.kennebell.net/media/artic...WFORENSICS.pdf
http://www.kennebell.net/media/artic..._That_Pump.pdf


At 17 volts, they tested a walbro 255 to pump out 382lph!!!! @40psi

 

I would check it out myself but Greg @ IP has had my fuel assembly for about 16 months.
Might need to send him a request to return it and build a 044 friendly version. I've got alot of free time on my hands lately.

 

All of the really high HP VRT cars are using something like this. Could be the exact unit but knowing Jim Wolf its his own design. I like the idea AAM had on the surge tanks and Walbro drop in to feed it with a Bosch pump fed from the surge tank. I just don't like the position of their surge tank. I've been trying to think up a surge tank that mounts directly above the the stock pump assembly and replaces the factory glove box. I know space is already limited in the Z but I haven't opened my glove box in 7 months.

 

Look up the flowcharts for an 044 pump vs a walbro. Not even close. 044 ftw.