I've got 2004 DF140 Twins with approx 350 hours. I've been troubleshooting this problem for a couple of weeks and am running out of things it could be.
I've got the Factory Service Manual, Twins Installation/Setup manual and also the Suzuki Diagnostic System along with it's manual.
The Problem:
The VST/HP Fuel pump on one of my engines runs constantly. When I say constantly - I mean anytime the key is on regardless of if the engine is started or not. Also this same pump is very loud compared to the other engines pump. That engine also falters under high load conditions as if the fuel pressure is low.
What is supposed to happen when the key is turned to ON(w/o starting the engine) is the VST/HP Pump is supposed to run for approx 3 seconds and stop. If the engine is started it's then cycled by the ECM on whatever duty-cycle the ECM decides based on it's other inputs.
I at first thought the pump ran constantly because it was unable to reach it's target pressure but from my reading fuel pressure is not sensed by anything on the engine. There is a mechanical regulator that keeps the fuel circulating at a constant pressure but it has no electrical connection.
So my working theory is that HP pump in the VST is loud and not coming up to full pressure because it's failing due to being run at 100%. I've got another VST in hand and I haven't installed it yet - but I have connected it to the electrical connection on the engine and confirmed that it also runs 100% of time time. I'd like to resolve that issue before I put this new one on
I checked the engine using the Suzuki Diagnostic kit and it shows 2-3 previous errors related to Crank and Cam shaft position sensors however it keeps track of how many times the error happened and the number hasn't increased since I've owned the boat - which is about 10 hours of running time.
Things I've already tried:
I swapped the ECM between engines - the problem didn't follow - the "good" engines VST also ran 3 seconds as it should with the bad engines ECM installed.
I checked the ignition switches wiring and even swapped the key switches between them.
Does anyone have a clue what might be causing this?
I've got the Factory Service Manual, Twins Installation/Setup manual and also the Suzuki Diagnostic System along with it's manual.
The Problem:
The VST/HP Fuel pump on one of my engines runs constantly. When I say constantly - I mean anytime the key is on regardless of if the engine is started or not. Also this same pump is very loud compared to the other engines pump. That engine also falters under high load conditions as if the fuel pressure is low.
What is supposed to happen when the key is turned to ON(w/o starting the engine) is the VST/HP Pump is supposed to run for approx 3 seconds and stop. If the engine is started it's then cycled by the ECM on whatever duty-cycle the ECM decides based on it's other inputs.
I at first thought the pump ran constantly because it was unable to reach it's target pressure but from my reading fuel pressure is not sensed by anything on the engine. There is a mechanical regulator that keeps the fuel circulating at a constant pressure but it has no electrical connection.
So my working theory is that HP pump in the VST is loud and not coming up to full pressure because it's failing due to being run at 100%. I've got another VST in hand and I haven't installed it yet - but I have connected it to the electrical connection on the engine and confirmed that it also runs 100% of time time. I'd like to resolve that issue before I put this new one on
I checked the engine using the Suzuki Diagnostic kit and it shows 2-3 previous errors related to Crank and Cam shaft position sensors however it keeps track of how many times the error happened and the number hasn't increased since I've owned the boat - which is about 10 hours of running time.
Things I've already tried:
I swapped the ECM between engines - the problem didn't follow - the "good" engines VST also ran 3 seconds as it should with the bad engines ECM installed.
I checked the ignition switches wiring and even swapped the key switches between them.
Does anyone have a clue what might be causing this?