Bad Walbro pump. Look at this pic.
12-07-2006, 05:38 AM
#41
Sponsor
Injected Performance
Injected Performance
iTrader: (15)
Join Date: Jun 2004
Location: Houston
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
It has been sitting on the shelf along with the intake manifold for well over a year. Let me know where to send it and I will ship it out. Haven't touched it in forever.
Originally Posted by UnderPressure
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.
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.
12-07-2006, 05:42 AM
#42
Sponsor
Injected Performance
Injected Performance
iTrader: (15)
Join Date: Jun 2004
Location: Houston
Posts: 636
Likes: 0
Received 0 Likes
on
0 Posts
We have sold 1,251 Walbro Pumps to date. I guarantee the failure rate is not 30%. People are making 1400rwhp through Supras with 3 pumps, we made 900rwhp with two pumps with our Supra, and 780rwhp with two pumps with the z. I know one shop who has had 4 out of their 10 fail and another shop who has not had one fail yet and has ordered over 75. They might not be as good as the Bosch, but they have worked fine for me for years. Now that I say that...
Originally Posted by UnderPressure
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.
12-07-2006, 11:51 AM
#43
I still have my fuel pressure dropping off a little as boost rises with my vortech setup. I'm running 750c injectors, CJM stage 1 return system and a walbro pump along with a MSD booster pump. The booster pump helped it out a lot, but it does still try to drop in pressure.
My shop has changed out the pump and regulator and even some of the lines - and injectors. At this point the thinking is there's something wrong with how the walbro was installed or something about my fuel pump assembly itself is messed up. My fuel pressure I think is somewhere around 60-70 then slowly drops to 35-40 at redline last I saw, but I think that might have been improved on since I last saw it.
Before the booster pump, pressure would hit 30-32psi at redline
One thing that seemed to help was hooking the fuel pressure regulator directly to the boost pressure on the blower instead of the manifold. Less delay and more accurate
My shop has changed out the pump and regulator and even some of the lines - and injectors. At this point the thinking is there's something wrong with how the walbro was installed or something about my fuel pump assembly itself is messed up. My fuel pressure I think is somewhere around 60-70 then slowly drops to 35-40 at redline last I saw, but I think that might have been improved on since I last saw it.
Before the booster pump, pressure would hit 30-32psi at redline
One thing that seemed to help was hooking the fuel pressure regulator directly to the boost pressure on the blower instead of the manifold. Less delay and more accurate
Last edited by sentry65; 12-07-2006 at 11:55 AM.
12-07-2006, 12:00 PM
#44
I have had to replace 2 Walbro's recently in my workshop.
One was a GS342 that had siezed solid.
The 2nd was a GS317 that came with the Stillen Supercharger Kit that had started to loose pressure.
I now recommend & use the Denso 260 LPH pump Part # 195130-0771
It pops right in & is as quiet as the OE Nissan pump
This is the OE pump used in the Mazda Cosmo with 20B triple rotor motor
One was a GS342 that had siezed solid.
The 2nd was a GS317 that came with the Stillen Supercharger Kit that had started to loose pressure.
I now recommend & use the Denso 260 LPH pump Part # 195130-0771
It pops right in & is as quiet as the OE Nissan pump
This is the OE pump used in the Mazda Cosmo with 20B triple rotor motor
12-07-2006, 02:20 PM
#45
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by InjectedPerf
It has been sitting on the shelf along with the intake manifold for well over a year. Let me know where to send it and I will ship it out. Haven't touched it in forever.
It seems that there are good and bad batches from Walbro. Some shops just can't seem to buy a good Walbro while others haven't had problem one.
Last edited by UnderPressure; 12-07-2006 at 03:57 PM.
12-07-2006, 02:31 PM
#46
Registered User
iTrader: (3)
Join Date: Jul 2003
Location: Escondido
Posts: 11,373
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by phunk
The only way you could do this would be to put a balance tube under the driveshaft that keeps both sides of the tank level at both times. IF you did that, all problems would be solved and you could run a stock 350z assembly on both sides of the tank, as it will bolt right into both sides (as long as you swap the potentiometer chip in the level sensor for drivers side).
The only problem with this, is that I dont think most people would approve of driveshaft loop that is made out of out a hose or pipe connecting two sides of the gas tank!!!
The only problem with this, is that I dont think most people would approve of driveshaft loop that is made out of out a hose or pipe connecting two sides of the gas tank!!!
Fuel system guru I was referring too
What if you dropped the tank and repalced the current tube? Could it even be done?
03-09-2007, 07:51 AM
#50
Registered User
Join Date: Oct 2003
Location: Marietta, Georgia
Posts: 984
Likes: 0
Received 0 Likes
on
0 Posts
Not a voltage regulator but a voltage booster.
http://www.stealth316.com/2-fuelpumpguide.htm
Has anyone tried the oem Nissan 300zxtt/90-96 Q45 pump?
Some of these pumps draw 15 amperes at max load, system wiring may create too much voltage drop for wiring size used.
Before condeming a pump measure the voltage at the pump terminals!!!!!!!!!
All pumps are speced for 13.5 vdc at the pump terminals........impossible with small wiring. You need #10 all the way from battery don't rely on a chassis ground [unless you measure everything] even #10 will drop the voltage 3%!
http://www.stealth316.com/2-fuelpumpguide.htm
Has anyone tried the oem Nissan 300zxtt/90-96 Q45 pump?
Some of these pumps draw 15 amperes at max load, system wiring may create too much voltage drop for wiring size used.
Before condeming a pump measure the voltage at the pump terminals!!!!!!!!!
All pumps are speced for 13.5 vdc at the pump terminals........impossible with small wiring. You need #10 all the way from battery don't rely on a chassis ground [unless you measure everything] even #10 will drop the voltage 3%!
Thread
Thread Starter
Forum
Replies
Last Post
