Welcome to the North American Subaru Impreza Owners Club Saturday September 20, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Factory 2.0L Turbo Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 09-04-2002, 09:36 AM   #1
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default PossumLink / Walbro GSS342 incompatibility thoughts

Folks,

This is an ongoing thread from www.clubwrx.net addressing the issues several of us are having with the Link PossumLink 44S plug and play ECU for the 01+ WRX.

Link to the ongoing Thread on ClubWRX

I am cross posting this information here because we are having serious incompatibility issues with the Link and I believe the i-club community has a right to know about it.

Anyone who wants to add/contribute/voice opinions please jump in here and do it.

Thanks

JaMa
* Registered users of the site do not see these ads.
JaMa is offline   Reply With Quote
Old 09-04-2002, 10:50 AM   #2
djerickd
Scooby Guru
 
Member#: 3782
Join Date: Jan 2001
Chapter/Region: South East
Location: Tampa B*tch!
Vehicle:
02 WRX WFC#040
Clean on 19's

Default

Good info!
djerickd is offline   Reply With Quote
Old 09-04-2002, 02:23 PM   #3
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

*bump*

So far, the list of people known to have this problem is:

Pace
JaMa
Phast
WRXThis
davidm_sh


Anyone else been experiencing random fuel cut/supply problems with the PossumLink?

-Pace
pace is offline   Reply With Quote
Old 09-04-2002, 03:00 PM   #4
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Thumbs down Bump for the Problem

Well, sure enough - the temperature topped 90 today out here and I parked the car at a Mickey D's in Aurora to have lunch, and about 20 minutes later the car turned itself off 3 times in a row in about a mile drive. I pulled out the laptop and watched what was going on, and sure enough there was 0% fuel flow right before it died.

Its almost like there is a thermostat set to 90 degrees which says "cut off the fuel pump above this temperature."

JaMa
JaMa is offline   Reply With Quote
Old 09-04-2002, 03:18 PM   #5
davidm_sh
Scooby Specialist
 
Member#: 5994
Join Date: Apr 2001
Location: Fort Collins, CO
Vehicle:
2004 Impreza WRX STi
Java Black

Default Re: Bump for the Problem

Quote:
Originally posted by JaMa
Well, sure enough - the temperature topped 90 today out here and I parked the car at a Mickey D's in Aurora to have lunch, and about 20 minutes later the car turned itself off 3 times in a row in about a mile drive. I pulled out the laptop and watched what was going on, and sure enough there was 0% fuel flow right before it died.

Its almost like there is a thermostat set to 90 degrees which says "cut off the fuel pump above this temperature."

JaMa
I am curious John-

You said you saw 0% FF before the car died. But I have to ask what kind of driving conditions you were under? If it was light cruise in traffic type stuff you really won't see anything over say 10-15% ... usually in the 0-3% range ESPECIALLY if your foot is off the gas and you are deceling.

I can't speak from experience since I have only had this problem happen to me once without my laptop BUT I would "assume" (there I go [heh]) that the %FF is showing what the ECU (Link) wants the injectors to be at for that particular place in the map. THe %FF is just the fuel injector duty cycle. It seems to me that it doesn't actually reflect fuel pressure so much. It's just the duty cycle the Link uses TOTTALLY assuming that the fuel pressure is there. But maybe I am way off too . I don't know.

However it IS nice to know that we are honing in on a set of parameters that is repeatable to bring this problem to the surface .
davidm_sh is offline   Reply With Quote
Old 09-04-2002, 04:21 PM   #6
JenisonWRX
Scooby Specialist
 
Member#: 6049
Join Date: Apr 2001
Chapter/Region: MWSOC
Location: Jenison.Doomhammer
Vehicle:
02 WRX & 99 RS
Black

Default

Quote:
It seems to me that it doesn't actually reflect fuel pressure so much. It's just the duty cycle the Link uses TOTTALLY assuming that the fuel pressure is there.
You are correct ... you need aftermarket fuel pressure gauge. I have one ... never had an issue. However, don't have a walbro...
JenisonWRX is offline   Reply With Quote
Old 09-04-2002, 04:34 PM   #7
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default WOT

I was at WOT in 2nd gear. I was purposely trying to make it fail and WOT in a low gear switching gears quickly is a good way to make it fail. Also, it seems always to do it when Im already moving and trying to give it some throttle from a cruise condition or right after I change gears.

While the car is still running and still at high RPM, the datalog shows the %FF drop to 0 several lines before the car dies then the car shuts itself down from lack of fuel (assumption). You can put the throttle to the floor after it has died and it dosent matter what you do it, stops the motor.

JaMa
JaMa is offline   Reply With Quote
Old 09-04-2002, 10:56 PM   #8
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default Re: Bump for the Problem

Quote:
Originally posted by JaMa

..

Its almost like there is a thermostat set to 90 degrees which says "cut off the fuel pump above this temperature."

JaMa
I'm pretty sure it's unrelated, but you know there IS a temperature sensor in the pump assembly (according to the schematics in the shop manuals). Anybody know what the purpose of that sensor would be?

-Pace
pace is offline   Reply With Quote
Old 09-04-2002, 11:46 PM   #9
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default Another reply

Well, I got another reply from Neil at Link USA, which i hesitate to post since he gave me a hard time over posting the other one.

But, his general tone was "you guys should have voltage tested the fuel pump with the Link before you installed it" even though the pump works with every other ECU on the face of the planet. He said if we could fix it, go right ahead, but that Link wasnt going to do anything about it. I also repeated my request to him for an "approved" list of compatible products.

It was another very rude email and that alone makes me want to sell my Link. If he comes back with another reply like that one, Im posting the entire email chain, much of which is very rude on the part of Link.

JaMa
JaMa is offline   Reply With Quote
Old 09-04-2002, 11:49 PM   #10
teiva-boy
Scooby Guru
 
Member#: 22825
Join Date: Aug 2002
Chapter/Region: NWIC
Location: Seattle, WA
Default

DISCLAIMER: I have no f'ing clue if this applies to subies.


My friend had some fuel problems with his '97 supra. Apparently their fuel pump is controlled by the ECU(variable voltage or sumthin) He was telling me that the fuel pump doesn't get full voltage till about 4500 RPM. The Supra forums more or less told him to wire it to a switched 12V to bypass this fuel limitation. Sure the car will run rich, but he can compensate for that with his S-AFC.


So here are my questions...

1. Are the WRX fuel pumps also controlled in the same manner?

2. Could this same mod be done to our cars?

3. What would be the pro's/con's of doing something like the above?

4. Can your PossumLINK accomidate this?
teiva-boy is offline   Reply With Quote
Old 09-05-2002, 01:06 AM   #11
alfriedesq
Scooby Guru
 
Member#: 6788
Join Date: May 2001
Location: Stamford, CT 06902
Vehicle:
2005 STI
10.9 @ 130

Default

1- i think walboro pumps suck

2- I got a nice slightly used supra pump I'd let you have for 140.00 shipped that works fine with the link

3 - MSD has a fantastic new boost dependant fuel pump controller on the market - - - or try the boost a pump - either of which should fix the problem

4 - you didn;t say - or I did not notice - wether or not you had a fuel pressure gague when this was going on

*** - I say post the damm LINK emails - - dont punk out - inform us what they had to say - be a good member of the community
alfriedesq is offline   Reply With Quote
Old 09-05-2002, 01:20 AM   #12
WRX-ellent
Scooby Specialist
 
Member#: 9071
Join Date: Aug 2001
Location: SF Bay Area, CA
Vehicle:
2002 WRB Impreza WRX
FMIC/1820 inside & Link'd

Default

Hey Al,

Are you running the Link now? What FP are you using with it and are you having these issues?

I am currently running the Link with the stock FP but I am or was going to install the sti injectors along with a larger (Walbro) FP this weekend. But since this is happening, I don't know if I should install a larger FP...

~joe
WRX-ellent is offline   Reply With Quote
Old 09-05-2002, 01:52 AM   #13
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

Quote:
Originally posted by alfriedesq
1- i think walboro pumps suck

2- I got a nice slightly used supra pump I'd let you have for 140.00 shipped that works fine with the link

3 - MSD has a fantastic new boost dependant fuel pump controller on the market - - - or try the boost a pump - either of which should fix the problem

4 - you didn;t say - or I did not notice - wether or not you had a fuel pressure gague when this was going on

*** - I say post the damm LINK emails - - dont punk out - inform us what they had to say - be a good member of the community
Some of the Link emails are posted over on ClubWRX (follow the link). In fact; most of the valid points raised in yours and other posts in this thread have been addressed already. I think it's clear that this is a Link bug, not a Walbro bug per se.

Here's some facts to chew over (as observed on my car):

1. The problem is aggravated by hot weather.
2. The problem is aggravated by running a low tank of gas.
3. The problem is aggravated by cruising / light-load driving.
4. The Walbro pump can theoretically circulate close to one gallon of fuel per minute back into the tank. This of course assumes zero fuel consumption (cruising would not be a big departure from that theoretical maximum circulation).
5. The fuel returned to the tank is going to have a higher temperature than when it leaves the tank due to the temperature differential between the rails and the gasoline.
6. The fuel pump assembly has a fuel temperature sensor that connects to the ECU.

Food for thought.

-Pace
pace is offline   Reply With Quote
Old 09-05-2002, 03:59 AM   #14
davidm_sh
Scooby Specialist
 
Member#: 5994
Join Date: Apr 2001
Location: Fort Collins, CO
Vehicle:
2004 Impreza WRX STi
Java Black

Default

Quote:
Originally posted by pace

1. The problem is aggravated by hot weather.
2. The problem is aggravated by running a low tank of gas.
3. The problem is aggravated by cruising / light-load driving.
4. The Walbro pump can theoretically circulate close to one gallon of fuel per minute back into the tank. This of course assumes zero fuel consumption (cruising would not be a big departure from that theoretical maximum circulation).
5. The fuel returned to the tank is going to have a higher temperature than when it leaves the tank due to the temperature differential between the rails and the gasoline.
6. The fuel pump assembly has a fuel temperature sensor that connects to the ECU.
Pace
Just a couple more things to note

7. This problem has occured on 4 WRX's (phast, I, pace, Jama) and we all have Walbro Fuel pumps. Is it possible they ALL suck that badly? I doubt it.
8. WRXThis has a PE or a Supra fuel pump (Supra I think) and he has had this problem occur as well
9. Vividracing.com Mike's car that was dynoed (in Pruven bragging forum) has the walbro fuel pump. I talked with him briefly and he mentioned that he never had any of the problems that I suggested. He has also driven his Link'd car to Colorado, Phoenix and LA (to get it tuned)

I only mention these facts to point out that it doesn't seem to be as easy of a problem as just "the walbro fuel pump BLOWS". Oh and that reminds me.

10. Jama, WRXThis, I, and pace ALL ran unichips at one point or another ALL with the walbro and NEVER had this problem occur.

Just curious Al have you taken your WRX out of town on any "weekend road trips"? Just curious. Because this problem only arises after cruising for 60+ miles and/or over an hour of light throttle.
davidm_sh is offline   Reply With Quote
Old 09-05-2002, 11:05 AM   #15
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default Posting the Emails

Quote:
Originally posted by alfriedesq
1- i think walboro pumps suck

2- I got a nice slightly used supra pump I'd let you have for 140.00 shipped that works fine with the link

3 - MSD has a fantastic new boost dependant fuel pump controller on the market - - - or try the boost a pump - either of which should fix the problem

4 - you didn;t say - or I did not notice - wether or not you had a fuel pressure gague when this was going on

*** - I say post the damm LINK emails - - dont punk out - inform us what they had to say - be a good member of the community
Al, I might post the emails, but I want to see Link's reply first. They are acting all sanctimonious about the issue and I want to give them the chance to come clear before I start smearing crap all over the i-club.

I dont think I buy the "Walbro pumps suck" overstatement either - its just a fuel pump- you give it + and - and a filter bag and it moves liquid from one place to the other. Its not that complex of a mechanism an I cannot honestly swallow the idea that there is something "substandard" about it - If anything, its more proven and tested in this country than anything else since 8 zillion Mustangs run then aftermarket. The problem here is clearly the Link. They stated quite clearly in their emails that they test every pump they install because not all pumps work with the Link.

JaMa

PS - Thanks to Leo for making this thread a sticky as requested
JaMa is offline   Reply With Quote
Old 09-05-2002, 12:09 PM   #16
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

I'm going to disconnect the fuel temperature sensor today if possible, 'just to see what happens'. I want to try and determine whether or not it is playing any role in this problem. Will try to take some readings from it with my multimeter also.

-Pace
pace is offline   Reply With Quote
Old 09-05-2002, 12:15 PM   #17
alfriedesq
Scooby Guru
 
Member#: 6788
Join Date: May 2001
Location: Stamford, CT 06902
Vehicle:
2005 STI
10.9 @ 130

Default

No - I have never gone very far since I got the LINK in

on the 14th I am going 250 miles to PA for teh suby shootout - will test then

BUT - I rarely cruise - - Its always ALL the way down or all the way on the breaks so I may not get this problem

Just check out the new MSD unit - - that will take the fuel pump control out of the LINK's hands and give your car a perofmance upgrade at the same time
alfriedesq is offline   Reply With Quote
Old 09-05-2002, 12:26 PM   #18
Jaxx
NASIOC Supporter
 
Member#: 177
Join Date: Aug 1999
Chapter/Region: NWIC
Location: Boise,Idaho,USA
Vehicle:
The 93 Imp W/EJ20K
flat black

Default

have you talked to Walbro (not saying that it is their fault/proublem)
there was a guy that posted here from walbro he was very responsive if not here then at the vishnu forums
-j
Jaxx is offline   Reply With Quote
Old 09-05-2002, 12:48 PM   #19
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default Couple of units

Quote:
Originally posted by alfriedesq
Just check out the new MSD unit - - that will take the fuel pump control out of the LINK's hands and give your car a perofmance upgrade at the same time
Heres a couple of units I have found...

MSD Fuel Pump Booster

Is this the one you're talking about Al? If so thats the same one all my RX7 buddies use, and works very well from what I hear.

Theres also this one...

Aeromotive Fuel Pump Controller

This is the one that controls the pump based on RPM, which dosent seem as preferrable.

One last thing is that there seem to be two fuel pumps in that Walbro lineup - the GSS 340 and the GSS 342. Anyone know what the differences in these two pumps is?

Also Al, one of the guys locally has the Supra fuel pump and he only gets these issues with the air conditioning turned on. That could even be another issue and may explain why your Link dosent get these problems. Also, everyone I know of who is experiencing this problem is at 5000 feet plus out here in Colorado so Im wondering if the altitude is exaggerating the problem as well.

Cheers

JaMa
JaMa is offline   Reply With Quote
Old 09-05-2002, 03:38 PM   #20
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

JaMa,

I was actually thinking that the mapping of fuel pump duty to RPMs was a good thing. We could account for the variance in fuel pressure easily within the current Link mapping architecture. (Since RPMs is one of the dimensions of the fuel map).

Mapping fuel pump duty to TPS presents more challenging problems as David outlined in the other thread, although mapping from manifold pressure would also be acceptable.

Anyway, I got a response from Aeromotive today. They said that this controller is not as sophisticated as I had implied in my questioning.

Quote:
The p/n 16302 is far less sophisticated than you are postulating. It is a two step device with one voltage reduction level equal to 20% less than the input voltage. If input voltage is varying, so would output voltage.
I'm not sure I fully grasp the implications of this statement, so I will attempt to clarify with them.

-Pace

Last edited by pace; 09-05-2002 at 03:53 PM.
pace is offline   Reply With Quote
Old 09-05-2002, 04:27 PM   #21
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Default Almost like hardwiring

Quote:
Originally posted by pace

I was actually thinking that the mapping of fuel pump duty to RPMs was a good thing. We could account for the variance in fuel pressure easily within the current Link mapping architecture. (Since RPMs is one of the dimensions of the fuel map).

Anyway, I got a response from Aeromotive today. They said that this controller is not as sophisticated as I had implied in my questioning.
Wow, only 2 voltage levels? That does sound rather low tech. Thats almost the same as hardwiring the pump, then. So, basically it still needs a clean voltage signal from the Link, fuel pump controller or some other source to properly drive it and it varies that voltage in 2 steps. Kinda bogus if you ask me.

Im still willing to try it, but I am skeptical of the effectiveness of it as a fix for this problem.

JaMa
JaMa is offline   Reply With Quote
Old 09-05-2002, 05:47 PM   #22
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

I'm just looking for a low duty cycle for idle and cruising, and then the ability to go 100% at some RPM level that I specify. If the Aeromotive has that capability, then I'll get it.

It would solve the problem in the same way that hardwiring the pump would. Tap the Link for the RPM signal, and then drive the power source from the OE relay or some other ignition souce. It removes the OE controller and Link from the equation, so I'm pretty confident it will fix the issue one way or another. However, I'm still waiting to hear back from Aeromotive to see if it even has that capability.

I want a solution that is a little more refined than hardwiring the pump and running constant 100% duty.

-Pace
pace is offline   Reply With Quote
Old 09-05-2002, 06:50 PM   #23
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

Ok; I just posted the latest Link email over in the ClubWRX thread. Tariq just confirmed that we are getting the shaft in regards to them having no intention of supplying us with a fix for this PossumLink bug.

I think I'll load up my Sig 9mm with some JHPs when I take the PossumLink 44S out back for target practice.

I strongly suggest that anyone considering this EMS 'solution' for a WRX that has an upgraded fuel system go look at the UTEC instead.

-Pace
pace is offline   Reply With Quote
Old 09-05-2002, 10:08 PM   #24
JaMa
Scooby Specialist
 
Member#: 5206
Join Date: Mar 2001
Location: Centennial, Colorado
Angry Damned Shame

Pace et al,

I must express my extreme disappointment to hear of Tariq and Neil's attitude. I received an email or much greater length and of much greater detail than the one you posted. I would be happy to post some of it, but the majority is the same kind of crap he said to you in your email. He also said that they do not produce a list of products that are compatible with the Link because the 44S is a "Race only" product and that they cannot be held responsible for incompatibilities. Translation: They are more interested in the profit margin than the engineering, so they let the folks in New Zealand do all the work and they are basically resellers.

I know for a fact that they watch all 3 of the forums all of us are on, and this subject has come up a few times before. Why did no one from Link jump in then?

Neil also stated that the only pump other than the stock WRX pump that they have "tried" is the "STi pump" which I am not aware of. I asked on the i-club early on and no one responded and I was not able to find a part from FHI or SOA so Im not sure where that part is or where we should search for it.

As for the Link, I guess I have a $1500 door stop as I cannot stomach having to worry about whether or not my car is going to run every time the temperature goes up outside.

UTEC here I come, I guess...

:monkey: Link USA

JaMa
JaMa is offline   Reply With Quote
Old 09-05-2002, 10:39 PM   #25
pace
Scooby Specialist
 
Member#: 11606
Join Date: Oct 2001
Location: On top of Gary's momma
Vehicle:
2004 Pilot
1995 Miata

Default

I was somewhat disappointed by their commentary that 'the Walbro cannot handle the continuous duty cycle'. The Walbro can't? Really? Well, it sure as $hit isn't shutting itself down, is it. They omitted to clarify exactly 'what' was telling the fuel pump to shut itself down. It's funny that a key-off, key-on ignition cycle instantly restores power to the fuel pump. Plus, in the previous breath he had admitted that the problem was 'caused' by the fact that the Link dictates a 20/100 duty map, not the 33/66/100 OE map. So basically, the Link is frying the OE controller by driving a high-draw fuel pump at 100% duty when it could be running at 33 or 66. Great!

The solution they offered me was to 'try another pump'. Really? Which one.? We know for a fact that the same problem exists with the Supra TT unit!! Maybe I'll try that high-flow OEM unit!! After all, why would anybody running a Link need to move away from the OEM fuel system.

The 44S is race only???! Heck, the car isn't even usable as a race car. It can't make it down a quarter-mile drag strip without suffering from fuel starvation and stalling in the middle of a run.


-Pace

Last edited by pace; 09-06-2002 at 07:20 PM.
pace is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
whos using a walbro gss342 with stock turbo? swol3 Factory 2.0L Turbo Powertrain 5 03-04-2004 01:51 AM
I just ordered a Walbro gss342 "high pressure" fuel pump?? Is this right?? eightballrj Factory 2.0L Turbo Powertrain 2 04-03-2003 08:46 AM
Walbro GSS342 or GSS341? ScrambleBoost Factory 2.0L Turbo Powertrain 2 01-04-2003 04:17 PM
cheapest place to find Walbro GSS342? Mr.Freeze Mid West Subaru Owners Club Forum -- MWSOC 9 06-25-2002 12:50 PM
Walbro GSS342 vs. GSS317 TurboRex Factory 2.0L Turbo Powertrain 3 02-20-2002 12:31 PM


All times are GMT -4. The time now is 02:04 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.