2006 Suzuki M109R fuel pump problem

[otto_kretschmer]

Hi Folks,

A friend of mine has a 2006 Suzuki Boulevard M109R that won't start.

The motor turns over but won't fire. A significant amount of fuel (a small puddle) will eventually spill out of both exhaust pipes. I pulled the dip stick for a sniff and it smells like gasoline too.

This morning I thought the fuel pressure regulator was bad. It was stuck closed and wasn't flowing the excess fuel back to the tank. So a higher fuel pressure was causing the gas puddles. This morning I went over to his house and we took the pump assembly out of the tank and took it apart for an inspection and blew compressed air thru all the lines hoping to dislodge any crud. Nothing came out and we put the bike back together with no change. The engine wouldn't start and fuel puddled out of each pipe.

So..my questions for my peeps here is does anyone know a way to test a fuel pressure regulator in a modern motorcycle or car that has the pump and regulator in the tank? I would expect they're all about the same today.

If we take the tank off, with the fuel pump in the tank, the engine will start and run for a few seconds on the residual gas in the intake manifold.

I got an idea of splicing a T in the fuel line that goes to the engine and attaching a pressure gauge and see what pressure the system has when the key is on. This may be what we do tomorrow.

I had a Porsche 914 with the 1.7 liter type 4 engine and that engine had a port on the driver side fuel rail that I was able to attach a pressure gauge but I didn't find anything like that on my friends bike.

My friend had this exact same problem about 3 years ago. He took it to the local dealer and they replaced the entire fuel pump assembly and charged him $950. A new regulator runs $115.

If he takes it back to the dealer he's going to get dinged for a grand again.

any ideas or suggestions?

thanks

[LakeCleElum]

Seems best to pay a dealer to plug into computer to diagnose and you take back to repair yourself.

Fuel pump bad on my ST 1300 at 148,000 miles.........Honda part was $440........Did it myself with the very same part for $58...........Online shopping is your friend.

[javadog]

I'm having a hard time understanding how an engine that is getting fuel to the cylinders isn't at least trying to fire. You sure the ignition isn't at fault?

If you want to test the fuel pressure, test it between the pump and the injector rail.

[otto_kretschmer]

Originally Posted by javadog

I'm having a hard time understanding how an engine that is getting fuel to the cylinders isn't at least trying to fire. You sure the ignition isn't at fault?

If you want to test the fuel pressure, test it between the pump and the injector rail.

the engine is flooded with fuel and when we take the tank off and hit the starter the engine will start and run for a few seconds off the fuel that's still in the intake

there is a reason I still ride my 1970 BMW R50/5

[unclebilly]

Do you have spark? If it is flooding, it has gas. Next step is to pull a plug and check for spark.

[DanielDudley]

Sounds like a regulator problem for sure, if it has too much fuel and fires off without the pump.

Live dangerously and take a chance on this. Or you could just drop in a new assembly Some people I know will reverse the leads to a fuel pump to try to free things up, I'm just not sure that this would help you with a regulator. 10 PSI of air backwards through the regulator???

https://www.bikebandit.com/oem-parts/2006-suzuki-boulevard-m109r-vzr1800-fuel-pump/o/m147607sch520453

[otto_kretschmer]

Originally Posted by DanielDudley

Sounds like a regulator problem for sure, if it has too much fuel and fires off without the pump.

Live dangerously and take a chance on this. Or you could just drop in a new assembly Some people I know will reverse the leads to a fuel pump to try to free things up, I'm just not sure that this would help you with a regulator. 10 PSI of air backwards through the regulator???

https://www.bikebandit.com/oem-parts/2006-suzuki-boulevard-m109r-vzr1800-fuel-pump/o/m147607sch520453

We took the pump apart and put an air nozzle to all the ports but it didn't do anything. My friend ordered a new regulator so hopefully that will fix it.

[rusnak]

You need to check for spark. I would pull the easiest to reach spark plug cable and plug it into an old spark plug. Crank engine over with spark plug grounded on the intake manifold.

The way to check fuel pump is the way the manuals say: with a pressure gauge. Check delivery rate with extra hose, bucket, and timer.

[otto_kretschmer]

the ignition system is ok, lots of spark

the engine runs for a few seconds with the tank removed

raw gas is running out of both pipes after a few seconds of running the starter

a fuel pressure test would be the next step but my pressure gauge is buried somewhere and my friend already ordered a new regulator so I'll wait and let you guys know when he puts it in

I think it will do the trick but I hate buying parts with not really knowing the original part is bad

[javadog]

He should make sure that the cylinders are clear of fuel and he should change the oil before he runs the engine again.

[john70t]

+1 to jd. Hydrolock will solve any engine problems permanently. New engine.

Could an injector or two be stuck full open?
On some vehicles you can pull them out, put in glass jars, and look at the spray pattern while cranking.

[otto_kretschmer]

raw gas puddles out of both pipes so if the injectors were a problem it would have to be both and I don't think that's likely the problem

[javadog]

Originally Posted by otto_kretschmer

raw gas puddles out of both pipes so if the injectors were a problem it would have to be both and I don't think that's likely the problem

The point is, if you’re getting raw gas all the way out the end of the exhaust, that’s a lot of gas and hydrolocking is a concern. I’m sure you have oil dilution too, so be safe, not sorry.