PossumLink / Walbro GSS342 incompatibility thoughts.
I've been running a Walbro GSS342 without problems with my Unichip for many months. Immediately upon installing the PossumLink standalone ECU, I began experiencing fuel supply issues.
The problem is manifested as the vehicle stalling entirely while in operation, especially after a long (30-45 minute) period of cruising. It feels as though the fuel supply ceases, and examination of PossumLink logs shows this to be exactly the case. There are also audible cues as the pump can be heard to erratically switch between duty cycles and finally cut out.
A key-off, key-on cycle is needed to restore fuel pump operation.
On my way to the drag strip this evening; the fuel pump cut out no less than 10 times within a 5 minute period, stranding me in heavy traffic twice, and once in the middle of a busy intersection. Normally the vehicle will run uninterrupted for between 10 and 30 minutes before the problem happens again, but on this occasion I could only travel 100 yards before fuel flow would once again cease. I was running the tank near empty (light not on).
I pulled into a gas station and added two gallons of (nice cool) 91 octane. This allowed me to travel the remaining 10 minutes to the drag strip before experiencing another cut. At the strip I added 2 gallons of 104 octane, taking me to just over a quarter of a tank of gasoline. I managed to complete two quarter runs, but experienced another fuel cut half way down my third run, while spraying Nitrous.
This time, I was able to keep the car running and cruise the remaining distance.
I left the track immediately, and filled up with 91 octane outside the drag strip. The car then ran the remaining 30 minutes to my home with no problems.
Phast and davidm_sh are experiencing a similar issue. I'm not sure if it is exactly the same problem or not. I have a long commute to work, so I seem to be more susceptible to this problem.
My variation on their theory: The pump is getting hot, possibly causing increased current draw. The PossumLink has some kind of failsafe (or unintentional trip) that is triggered when current draw for the fuel pump relay reaches a certain level. The full tank of gas helps keep the temperature of the pump down, and prevents or lowers frequency of the problem.
Link-USA are not being much help right now. I'm hesitant to get a different pump (such as an expensive PE) as there is no guarantee it will fix the issue. i.e Is this the responsibility of the Link, or is the Walbro at fault?
If anyone is interested, I have attached a log showing the portion of my quarter run where the pump temporarily ceased operation. The fuel flow appears to have ceased between count 533 and 535. Ignore the O2 values; I still have the MIL eliminator in place and its clamping the voltage.
Thoughts? Comments? Similar experiences? I commute 100 miles per day, so either the Link or the Walbro has to go! The car is rapidly attaining the point of being unsafe to drive in traffic.
-Pace
I've been running a Walbro GSS342 without problems with my Unichip for many months. Immediately upon installing the PossumLink standalone ECU, I began experiencing fuel supply issues.
The problem is manifested as the vehicle stalling entirely while in operation, especially after a long (30-45 minute) period of cruising. It feels as though the fuel supply ceases, and examination of PossumLink logs shows this to be exactly the case. There are also audible cues as the pump can be heard to erratically switch between duty cycles and finally cut out.
A key-off, key-on cycle is needed to restore fuel pump operation.
On my way to the drag strip this evening; the fuel pump cut out no less than 10 times within a 5 minute period, stranding me in heavy traffic twice, and once in the middle of a busy intersection. Normally the vehicle will run uninterrupted for between 10 and 30 minutes before the problem happens again, but on this occasion I could only travel 100 yards before fuel flow would once again cease. I was running the tank near empty (light not on).
I pulled into a gas station and added two gallons of (nice cool) 91 octane. This allowed me to travel the remaining 10 minutes to the drag strip before experiencing another cut. At the strip I added 2 gallons of 104 octane, taking me to just over a quarter of a tank of gasoline. I managed to complete two quarter runs, but experienced another fuel cut half way down my third run, while spraying Nitrous.
This time, I was able to keep the car running and cruise the remaining distance.I left the track immediately, and filled up with 91 octane outside the drag strip. The car then ran the remaining 30 minutes to my home with no problems.
Phast and davidm_sh are experiencing a similar issue. I'm not sure if it is exactly the same problem or not. I have a long commute to work, so I seem to be more susceptible to this problem.
My variation on their theory: The pump is getting hot, possibly causing increased current draw. The PossumLink has some kind of failsafe (or unintentional trip) that is triggered when current draw for the fuel pump relay reaches a certain level. The full tank of gas helps keep the temperature of the pump down, and prevents or lowers frequency of the problem.
Link-USA are not being much help right now. I'm hesitant to get a different pump (such as an expensive PE) as there is no guarantee it will fix the issue. i.e Is this the responsibility of the Link, or is the Walbro at fault?
If anyone is interested, I have attached a log showing the portion of my quarter run where the pump temporarily ceased operation. The fuel flow appears to have ceased between count 533 and 535. Ignore the O2 values; I still have the MIL eliminator in place and its clamping the voltage.
Thoughts? Comments? Similar experiences? I commute 100 miles per day, so either the Link or the Walbro has to go! The car is rapidly attaining the point of being unsafe to drive in traffic.
-Pace
