I installed a walbro fuel pump on my '05 MR, and now the SOB won't start. Checked all the fuses, they're good. At the fuel pump, we get a small stream(not nearly enough to start the MR). Also, I re-installed the original fuel pump, and the same situation. Does anybody know where the fuel pump relay is located? At the fuel pump, no voltage with key on, has some voltage(8-9v) while cranking, but isn't enough to start. The only thing I can think of besides the fuel pump relay is the immobilizer. Any input is appreciated. A 20 minute fuel pump install has turned into a 2+ hours issue(and counting).

 

Thats odd.I had mine the car and all put back together in a hour with no issues.Did you connect everything?You didn't break or damage any of the connectors or possibly not reconnect all the plugs?

 

With the Key on you get no fuel pressure?
When Cranking, if the starter motor is turning not just in the crank position, the voltage should be 8V-9V. The reason is the starter pulls alot of current and the batery voltages drops due to that. I believe with the key on there should me a 1.5 second prime signal sent to the pump, you should get a breif reading of approximately 12 V. A economical multimeter may not be fast enough to catch this so I would suggest using a test light or 12v lamp across the connector to check the prime signal. Also if you supply the fuel pump battery voltage, with a 10amp fuse in -line, does the pump produce adequate fuel pressure? If not check the connections in the tank, fuel lines and electrical. If all that checks out the fuel pump must be defective.

 

Very interesting...................we have had our first ever Walbro pump failures in the last month or two. I don't know what is going on but one certain fuel pump number we use we went through 5 pumps last week in ONE EVO to get it to run. We ended up returning an entire box full of pumps.

My guess is you have a bad fuel pump.

 

My guess is you either poped a fuse or one of your lines or connectors is no reconnected. He mentioned that he returned the stock pump and still no start.

You didnt load a flash at the same time and forget the immobilizer did you

 

no flash yet. i've never had this problem replacing pump(s) on mercedes benz vehicles and they have computers and sensors out the a$$ just to control a fuel pump(s). I have yet to find a wiring diagram. And one more thing i had my roommate bring me my other key. Still nothing.

 

Sounds like a gasket issue if the stock pump still didn't work. There is a rubber gasket on the pump outlet that occasionally gets screwed up if you don't put it on the pump first and then push it into the housing. I'd pull the pump back out and check the rubber gasket on the pump outlet.

-Paul

 

bump

 

Get a hold of KevinD, I'm sure he can figure it out.

 

I'm Laramie's roommate. Everything was plugged back in(1 wiring connector), 3 hoses connected tightly. I hate to say it, but it's a simple *** mod, and we've managed to find a way to screw it up .

Not sure if you consider a Fluke 88 a economical multimeter, but we get no reading at all when we initially turn the key. Sorry, I wasn't trying to ignore you, it's just that we're gettin' a bit frustrated. We put 12 volts to the fuel pump(directly), and it flows *some*, but again, not nearly enough of fuel to start the car.

Laramie installed the stock fuel pump, and same situation(trickle for a flow, more or less). The only thing I am thinking of right now(not a Mitsu pro by any means) is that it may be an immobilizer issue.

Laramie just spoke to Kevin, and he said that the only time he's seen stuff like this happen is when he reflashed a car and the customer turned the key off. So right now we're .

 

If putting 12 volts directly to the pump does not show significant flow, then your problem is not electrical, it is mechanical. I still think it is a problem with the rubber gasket that goes between the pump and the pump housing. If that is not installed properly the fuel will spray directly back into the tank from the underside of the top of the housing. I would pull the housing back out, pull out the pump, and make sure all your gaskets are installed properly and not torn.

-Paul

 

It looks like the imm. has disabled the vehicle. We have put 12v to the pump and it still does not start. I do have spark. Oh and we put <12v earlier just to test the pump. It wasn't a full 12v, more or less 6-8 volts.

 

I hate my car right now.

 

It is incredibly unlikely that you did something during a fuel pump install to cause the immoblizer to disable the car. Also, if it were the immobilizer the immobilizer light on the dash would light up. It is very likely that you have a mechanical problem based on what you have said thus far (12 volts not helping, stock pump not working). As I've written twice already, it is probably a gasket/grommet issue. The one in step 12 here: http://evomoto.com/tech_info.php?tPa...d74fa6cfacb260 is probably not installed correctly. Without it properly in place you will not get proper fuel pressure in your fuel lines.

-Paul

 

The injectors are not firing. It however runs on carb cleaner.