M8T fuel pump problems

[crew]

I have a ’07 M8T with an aftermarket fuel pump (Walbro F20000110) and regulator. The problem is that when the sled sits, I can’t get it to start without jumping the pump with a battery (then it will run fine on the electrical system). I did some checking and found that when the engine is running, the pump draws about 5 amps compared to my stock M8 that draws 2 amps. The max voltage that I can get when pulling on the rope is 2.5V (I get about 10-12V on my stock M8). Also, I checked both my M8 and M8T generators and they can BOTH source about 30 watts on the stock fuel pump wiring system when the engine is running so I don’t think the problem is my generator or AC/DC voltage converter. So basically this means that there is no way you can pull the rope hard enough to run the fuel pump and generate any fuel pressure; hence it will not start unless there is fuel right there at the injectors.

So, I see two possibilities: (1) I have the wrong fuel pump or (2) I have a leak in the injectors (or fuel line). Any opinions?

 

[product tester]

that pump works great but you do have to wire it diffrent to get to start and run right call me I can help shain 801 668 6344

 

[Jred]

I ride a 07 TM8. It has a Race boondocker kit put on in 07. I've just got through some electrical problems myself. I have a few questions.
What does your fuel pressure read?
When I hooked up the empty fuel lines I had to pull the rope about 7-10 times before fuel got to the injectors with around 20 psi allowing the motor to kick over. A few more pulls and the sled started and worked its way to 40 psi. The sled should start on the stock fuel pump only even if the walbro is unhooked. The walbro is only utilized when your hitting high boost 7lbs or more from my experiance.

So basically this means that there is no way you can pull the rope hard enough to run the fuel pump and generate any fuel pressure; hence it will not start unless there is fuel right there at the injectors.

So, I see two possibilities: (1) I have the wrong fuel pump or (2) I have a leak in the injectors (or fuel line). Any opinions?

My CCU (Chasis Control Unit) was weak on my sled. Voltage was very low and eratic. I would go down to 4 volts with everything running. The reverse servo motor didn't have enough juice either to function. The sled would still run good down the trail, although the injectors would run out of power to open on the top end. This is when I suspected problems. I replaced the $200 CCU and it ran a constant 14 volts. With everything on it never dropped below 12 volts. Its ran like a champ since.

Another problem area are the pins inside of the wire harness plugs. They sometimes get tweaked and don't contact. Good luck.

 

[glassman]

What kind of voltage upgrade do you have? I bought the $200 special and it solved all of my electrical problems.

 

[crew]

Thanks for the good ideas. I'll do some checking on it and let you know. However, I do believe the voltage regulator is stock. Who sells the upgraded system?

 

[Fuel96]

Same Issue

I had a very similar issue with my 2008 M8 With an OVS aero 53. Fuel reg had dropped of because the spring weakened, and even found amperage probs like yours. But in the end, my stock fuel reg in the tank had packed it in !!

The things we do for these turbos !!!


Good luck !

 

[sweperformance]

How did you solve this problem?

 

[Tonysnoo]

There are a couple of ways to wire that pump for start up. I just wanted to pass on another option.

I run an old school carb primer to my TB boots on my TM8. It's stupid simple and reliable. Three squirts and the motor starts second pull every time and occasionally first. Once it fires the voltage is right there. I run an external pump but the current draw is similar and you don't have to have the extra wiring and co-mingling of circuits. One other bonus is having a squirt of fuel if ya don't want to use a "hot start" switch.

Good luck!

 

[catmanm7]

tony is the one that helped me with my sled, and like he said, a couple pumps on the primer and the thing starts. Mine is on an M7.

 

[product tester]

Use booth power sources with a switch.

 

[sweperformance]

Use booth power sources with a switch.

I already use the secondary power source for my turbo oil pump.

 

[product tester]

I already use the secondary power source for my turbo oil pump.

Use the stock fuel pump power for oil pump and gauges and switch it with a relay from stock power to acc power after start up.
We have these plug n play in stock.
have been running in sleds sence 2007.