'09 GS won't start -- double checking fuel pump failed diagnosis

[Vec]

After a long winter rest (just moved, still getting used to life in Seattle) I needed to move my 2009 1200GS and it almost sputtered to life and then nothing. It had been sitting on a battery tender so cranking wasn't a problem.

At first I thought I flooded the engine with all the cranking so I replaced the spark plugs with a spare set I had. (The bottom plugs were looking a bit grungy, but that's expected from what I understand) I checked for spark and I had it. I checked the air filter to make sure nothing built a nest and that was OK as well. I pulled the fuel injectors and I had nothing spraying. I pulled the fuel hose from the injector and had nothing when I was cranking.

At this point it was obvious that it was the fuel system.

I hard-wired the fuel pump to the aux power port bypassing the fuel pump controller and I still didn't get any fire. As a last test (stupid, admittedly) I pulled the fuel line from the fuel pump assembly and didn't get the fountain of gas that I was expecting if the pump were working.

I'm just about ready to buy a new pump and the special tool to open up pump housing but just wanted to double check if I'm missing anything. I don't think I am... but I don't want to drop ~$500 on all of it and it be a waste of time and money.

The last question -- if I go down this path, do I need the special crimper tool for the fuel hose connecting the pump the the rest of the assembly or is that just some BMW upcharge for a standard tool?

Thanks!

[JimVonBaden]

It is highly unlikely that your pump has failed. Your pump controller might have though.

First, try starting it with the throttle open a bit, no more than 1/4 turn. If that works you are golden. If not, I would suspect the pump controller is bad, easy fix.

Jim

[lhendrik]

When you bypassed the fuel pump controller, did the pump pressurize? You can hear it spin up. Did it?

[Vec]

I used one of the pre-fab cables from BurnsMoto to bypass it. I figured the $35 cable would either be a diagnostic tool or at least something to bail me out in the future.

But I didn't get anything when I bypassed the controller. No spin-up or anything. I would expect that w/o the fuel hose connected that if I energized the pump I should've gotten a fountain of fuel, or at least a horrible, flammable mess. I didn't get either. I was hoping to rule out the fuel distribution system downstream from the pump and upstream from the injectors.

Honestly, I was hoping it was the controller since that's cheaper and easier to replace! Unfortunately, when I pulled it it was one of the new fully potted varieties.

[JStancampiano]

Originally Posted by Vec

I used one of the pre-fab cables from BurnsMoto to bypass it. I figured the $35 cable would either be a diagnostic tool or at least something to bail me out in the future.

But I didn't get anything when I bypassed the controller. No spin-up or anything. I would expect that w/o the fuel hose connected that if I energized the pump I should've gotten a fountain of fuel, or at least a horrible, flammable mess. I didn't get either. I was hoping to rule out the fuel distribution system downstream from the pump and upstream from the injectors.

Honestly, I was hoping it was the controller since that's cheaper and easier to replace! Unfortunately, when I pulled it it was one of the new fully potted varieties.

When you unplug the quick connects both ends will close so that fuel won't leak out. ( there is a spring loaded valve in each end)

Joe

[Vec]

Well, I guess that's a good thing to prevent a giant fireball...

But it still begs the question of what's wrong. Is there a conclusive way of testing the pump?

Here's the rundown of the facts I know:

• I bypassed the fuel pump controller so I think I can rule that out.
• I verified that I had power at the pump-end of the bypass cable.
• I pulled both injectors and nothing came out from either one while cranking the bike.
  • What's the chance that both injectors are clogged?
• I pulled the hose of the left-side injector and no fuel at all came out when I was cranking the bike. (A teaspoon or so of gas came out when I pulled the hose) I assumed this wasn't a self-closing quick-release... if I'm wrong that changes things
• I have spark -- visual verification + new plugs anyway
• Air cleaner is clean (removed a dead wasp while I was at it) and nothing but air in the air box.
• Disconnecting the quick-release didn't have a fountain of fuel -- but that just confirmed the proper working of the QR. I did get a small dribble of fuel when I disconnected it, but I'm assuming that's normal in any case.
• I'm not hearing a whine from the pump or feeling any vibration... but there's enough clicking and clattering going on that there's a small chance I'm missing something. I can try replicate tonight with nothing powered except the pump. I'm pretty sure I felt a small click, but that's it.
• I forgot to check the resistance across the pump. I'm assuming open or a dead short would be bad, but what is normal?

From looking at the parts fiche between the pump and the injectors is nothing but the fuel distribution system and that seems unlikely to be faulty... I think.

I'm still leaning towards the pump, but it would be nice to have more than a hunch before spending the big bucks.

[RomaDakota]

My friend's 09 GS acted similar. Will it start or fire a bit if the throttle is opened quite a bit (half-ish or more)?
We plugged plugs, tested spark, fuel lines, injectors... It was the TPS.
Do you have a way to check for codes?
Do you have a friend that will let you borrow a TPS?

[Vec]

I don't have a way to check for codes, but I'll likely pick up a GS-911. That doesn't help at the moment.

It's a bit rainy out and I don't have a garage here so I don't want to tear into the bike too much, but checking the TPS is easy enough even with a bit of a drizzle.

I pulled the connector and worked the throttle while looking at a multimeter. The two end pins have around 4.3k ohms between them and the middle has continuity to both smoothly varying between around 1.3k and 4.1k. It's hard to read, work the throttle and hold the probes blindly at the same time so the numbers might be a tad off. Putting things together (i.e. having the contacts wipe off any latent corrosion) didn't do anything either.

Any other ideas for things to check before diving into the expensive job?

[Vec]

Ok, the rain stopped enough for me to pull things apart again. I think I'm looking at the culprit now.

I measured the resistance across the fuel pump terminals and it was pretty close to a dead short: 1.1 ohms.

Next, I rigged up a really janky setup so I could put my multimeter in the loop to measure the current draw. For few moments I read 15A DC draw before the 7.5A fuse I had feeding that circuit blew -- it looks pretty much like a dead short. I'm happy the meter I'm using is rated to 20A for 10s!! The Fluke 87 took the hit like a champ!

I'm assuming that the normal draw for this pump is on the order of 3-4A... Does anyone know the actual draw?

[RomaDakota]

Can't say about the pump.
Numbers seem ok for the TPS; two outer pins should be about 4k constantly with no variation with throttle position. Inner to any outer vary with position 0-4k.
Here is the detailed link if interested.
http://advrider.com/forums/showpost....9&postcount=16
Best of luck.

[Vec]

Update time.

Last week I ordered up a GS-911 both for this and to reset the pesky service indicator which was just about to light up.

Here's the relevant stats:





It even detected the short that happened when ran the pump off the accessory socket. That's a fun little toy I have to say!

I'm happy I'm right because I already orded a new pump assembly and the damn wrench to R&R it. Too bad the wrench is a special-order part and is delaying the shipment.

Almost there!