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2018 Ducati Monster 1200 - sometimes won’t start after a ride. Can’t hear the fuel pump run. If i wait for 20-30 minutes, it’ll start fine. Any similar issue/fix? TIA
The power supplied to the fuel pump is shared with ignition and I think the starter...if it cranks, and no fuel pump run...check the ground just under the tank...unplug the 4 wire clip and check to see the pins have enough tension to make contact....report back
 

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Discussion Starter · #3 ·
The power supplied to the fuel pump is shared with ignition and I think the starter...if it cranks, and no fuel pump run...check the ground just under the tank...unplug the 4 wire clip and check to see the pins have enough tension to make contact....report back
Thank you for your response. Should the bike. Ot start at all if there is an issue with the pins? I can reach the ground connection under the tank and tried to move it whilst/during the ignition and the fuel pump still not coming on. After waiting for 20 minutes, it’ll fire up with no issues.
 

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Is the 20 min wait in effect with a cold start or only once warmed up?.....cold has me leaning to a ground issue...warm has me leaning to a bad pin contact...expanding beyond contact pressure....I'm not thinking there's a faulty part but a bad connection...you could also swap around the relays...they're identical...see if the problem migrates to the ignition...won't fire....or starter...won't crank....mind you a bad connection can still "feel" good...you really need eyes on the terminals
 

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Discussion Starter · #5 ·
Is the 20 min wait in effect with a cold start or only once warmed up?.....cold has me leaning to a ground issue...warm has me leaning to a bad pin contact...expanding beyond contact pressure....I'm not thinking there's a faulty part but a bad connection...you could also swap around the relays...they're identical...see if the problem migrates to the ignition...won't fire....or starter...won't crank....mind you a bad connection can still "feel" good...you really need eyes on the terminals
I drove 45 minutes. Turned it off, after 2 minutes it won’t start, can’t hear the fuel pump run. I sat down for 20 minutes and tried again and it started. Which pins/terminals?
 

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I drove 45 minutes. Turned it off, after 2 minutes it won’t start, can’t hear the fuel pump run. I sat down for 20 minutes and tried again and it started. Which pins/terminals?
That is the million dollar question...if you have spark..and is cranking...the power to switch all the relays is good...it's the supply side that needs investigating...you could pull the clip under the tank and check for voltage...if you have 12v...you should... squeeze the little ground clip for a better contact...then remove the pins in the clip to the tank and give them each a better squeeze...if that doesn't change anything...go upstream from there doing the same thing

Before getting to involved...look at the fuse for the pump...same story...check for contact pressure
 

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Discussion Starter · #7 ·
That is the million dollar question...if you have spark..and is cranking...the power to switch all the relays is good...it's the supply side that needs investigating...you could pull the clip under the tank and check for voltage...if you have 12v...you should... squeeze the little ground clip for a better contact...then remove the pins in the clip to the tank and give them each a better squeeze...if that doesn't change anything...go upstream from there doing the same thing

Before getting to involved...look at the fuse for the pump...same story...check for contact pressure
Thanks again for you patience. I already squeezed the pin on the ground connection under the tank. The relay on the fuel pump is brand new replacement. I read some discussions about charcoal/canister filter for fuel overflow, any thought? I am tempted to take it to the dealer but trying to avoid hassle and paying too much for something could be simple. Thanks again.
 

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Thanks again for you patience. I already squeezed the pin on the ground connection under the tank. The relay on the fuel pump is brand new replacement. I read some discussions about charcoal/canister filter for fuel overflow, any thought? I am tempted to take it to the dealer but trying to avoid hassle and paying too much for something could be simple. Thanks again.
No worries...here to help... charcoal canister shouldn't have any effect on the problem at hand...and as to the dealer visit...these sort of gremlins pop up from time to time...anything dealt with personally is a good investment.
 

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Ok...try removing the pins to the fuel pump relay and cleaning them...do the same to the under tank connector....pins 1,2 are relating to the pump +,- respectively...image with probes shows the circuit continuity...the ground wire, is nested into multiple systems...so if the pump not priming is the only symptom... it's probably not the ground...not within the connectors anyway...but could be the ground pin at the ECU...this of course is backtracking from the pump...coming from the other direction....key, immobilizer, kickstand switch, clutch....all which checkout fine if it cranks...which brings us back to the ECU...if you were to run jumper wires from the fuel pump relay to it's corresponding clip....and then intercept the ground wire on the coil side of the relay....when it acts up....see if there's continuity to ground....then ground the wire and see if the pump then primes.... haven't found an ECU pin diag yet....but I'm thinking the issue is in there...not necessarily the ECU itself...but in the harness connecting it



 

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Discussion Starter · #13 ·
Thank you again. Sorry, i just saw your post. Will dirty pins explains why it starts normally but failed to prime the fuel pump every mow and then? When i replaced the fuel pump relay, i sprayed some contact cleaner in the pin connectors.
 
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