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2001 Suzuki GSX-R 750
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Discussion Starter · #21 ·
No, the ECM controls the fuel pump relay and if it sees a problem with the relay it will throw a code. The ECM really doesn't know if the pump is running or not. These systems are really not that sophisticated.

Did the bike fire a bit when you squirted some starter fluid in the intakes?
Yea it sputtered a little bit when I did that, but the starter fluid I've got contains ether and I heard that's bad for the cylinders.. So I've refrained from using it and have just been pouring a little dash of gasoline in each cylinder.. It seems to gum up the plugs pretty quick doing that though.
 

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Discussion Starter · #22 ·
No, the ECM controls the fuel pump relay and if it sees a problem with the relay it will throw a code. The ECM really doesn't know if the pump is running or not. These systems are really not that sophisticated.

Did the bike fire a bit when you squirted some starter fluid in the intakes?
Yes the bike sputtered a little bit when I tried that. But my starter fluid contains ether and I've heard that's bad for the cylinders, so I've refrained from using it. Instead I poured a little dash of gasoline in each cylinder cause I was told that was healthier than ether and got the same result.. Although it did seem to gum up the spark plugs fairly quickly that way.
 

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SuperMod of the North
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Doing the fuel pressure and volume tests are a good idea. The secondary filter is inside the tube of the pump. Typically you would soak the pump with Gum Out for a couple days or so then back flush gently with seafoam.

The first thing you need to do is spray a little starter fluid down the bores to see if it fires like John said. Until we get the results of that test we really aren't narrowing down the issue.

If it fires then we continue to pursue a fuel issue. If it doesn't fire then you don't have a fuel issue at all and we move on to spark and air circuits, safety circuits, etc.
 

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SuperMod of the North
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OK, my bad...there was another page. In my experience ether won't damage your cylinders if you are just giving it little blasts to test fire. Using it as a power adder might be different but I have no experience there.
 

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Discussion Starter · #25 ·
Doing the fuel pressure and volume tests are a good idea. The secondary filter is inside the tube of the pump. Typically you would soak the pump with Gum Out for a couple days or so then back flush gently with seafoam.

The first thing you need to do is spray a little starter fluid down the bores to see if it fires like John said. Until we get the results of that test we really aren't narrowing down the issue.

If it fires then we continue to pursue a fuel issue. If it doesn't fire then you don't have a fuel issue at all and we move on to spark and air circuits, safety circuits, etc.
Do you really think that the issue could be that internal filter? I mean it's a brand new pump, I can't see why it would be gummed up and giving me any issues already.
 

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SuperMod of the North
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Damn, my bad. The "brand new pump" part went right by me...sorry Sir. No, it will be fine.
 

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Do you really think that the issue could be that internal filter? I mean it's a brand new pump, I can't see why it would be gummed up and giving me any issues already.
The fuel flow and pressure tests confirm that the whole assembly is performing well enough to support the bike.
Maybe its the filter, maybe the pump, maybe the fuel pressure regulator, maybe one of the o-rings between all the parts.
You can play "what if" forever or do the tests and know for sure.
 

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Discussion Starter · #29 ·
The fuel flow and pressure tests confirm that the whole assembly is performing well enough to support the bike.
Maybe its the filter, maybe the pump, maybe the fuel pressure regulator, maybe one of the o-rings between all the parts.
You can play "what if" forever or do the tests and know for sure.
I mean I replaced the pump, regulator, and filter just a few weeks ago.. And it was running just fine so I'm not sure why it quit on me.

I took it apart and did replace an o-ring, I'm hoping to do a pressure test soon.
 

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Discussion Starter · #30 ·
Is it possible that it jumped time a little bit?
Have you done a compression test?
I didn't know that could happen so easily, is there any way I could go about doing a pressure test at home? Or would I have to take it to a shop for that?

The shops are super busy at this time, I booked the bike in for the 29th of June just to get everything looked over.

My road test is the 28th so I'm really hoping I can figure this bike out before then
 

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I didn't know that could happen so easily, is there any way I could go about doing a pressure test at home? Or would I have to take it to a shop for that?

The shops are super busy at this time, I booked the bike in for the 29th of June just to get everything looked over.

My road test is the 28th so I'm really hoping I can figure this bike out before then
That's probably not the problem, it's just hard to understand why it won't run if it's got fuel spark and air.
 

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Discussion Starter · #32 ·
That's probably not the problem, it's just hard to understand why it won't run if it's got fuel spark and air.
It is very confusing for sure.. Especially considering it was running fine then just started sputtering and bogging, then died when I pulled the clutch in to slow down.

I've just sprayed some starter fluid in it, and it's making some more promising sounds. That would point to a fuel issue then right?
 

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Discussion Starter · #33 ·
Alright so I've done a pressure test and the pump is only putting out about 8psi..

Its a brand new pump, so I'm not sure why it would be putting out only 8.. It should be putting it closer to 43 or 49 if I remember correctly.

I'm wondering if the internals of the pump have sucked up some junk that may have broke loose on the tank, and if that's why it's only putting out 8psi..

What do you guys think? And how would I go about flushing out that pump?
 

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Alright so I've done a pressure test and the pump is only putting out about 8psi..

Its a brand new pump, so I'm not sure why it would be putting out only 8.. It should be putting it closer to 43 or 49 if I remember correctly.

I'm wondering if the internals of the pump have sucked up some junk that may have broke loose on the tank, and if that's why it's only putting out 8psi..

What do you guys think? And how would I go about flushing out that pump?
With that low a pressure, I would would check for a damaged/broken o-ring on the pump discharge side or a faulty/dirty fuel pressure regulator.

At least you know where to look now.
 

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Discussion Starter · #35 ·
With that low a pressure, I would would check for a damaged/broken o-ring on the pump discharge side or a faulty/dirty fuel pressure regulator.

At least you know where to look now.
Maybe I'll contact the company I got the pump from and see if they'll warranty the o rings, or I'll just go find some that will work.

How would I check that the regulator is fine? It's brand new as well.
 

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Did you install a whole new fuel pump assembly or just an aftermarket pump?
 

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Discussion Starter · #37 ·
Did you install a whole new fuel pump assembly or just an aftermarket pump?
The whole assembly was brand new, came from quantum fuel, I'm not sure if you've heard of them or not.

New pump, fuel filter, fuel regulator, o rings, and other hardware / wiring
 

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No I haven't heard of them but that doesn't mean much.

My point was that you did not get a whole assembly but parts that you assembled so likely it is an assembly error.

Since it ran fine for a while with a sudden failure, my guess is the regulator has popped out. There have been a couple of threads of this happening.
 
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