Engine cutting out

Message

anzacinexile · #1 Post by **anzacinexile** » Sun Jun 07, 2015 6:04 pm

Got a problem that I know others have suffered but I cant find the answer.

Symptoms are the engine dies but switching off and on again, she starts up like nothing has happened. Only happens occasionally but she did it once parked up on my drive and I could hear the fuel pump relay chattering like a jack hammer. Switching off, counting to ten and back on stopped the chattering and she fired right up. Having had this before (the chattering fuel pump relay) last time it was the fault of the ECU caused by a fried FP chip. Ha I thought so got meself another ECU and all was well for a while but she did it again today.

Anyone had this problem and more to the point, did you ever get to the root cause because it obviously isn't the ECU but somethings upsetting it.

Also, is Griff on this site because I cant find him in the members list and I want to pose the question to the Master of all thats Aprilia

Thanks

fatboy · #2 Post by **fatboy** » Sun Jun 07, 2015 6:47 pm

Had something similar happen when I fitted 4 led indicators, lost almost all dash display, would not turn over,mad relay clicking....
Seemed to be the 7 pin diode shaking the maraccas.
Sorry this just confirms another fickle wiring scenario, I cooked my ecu because of an almost severed earth on the voltage reg/rec.
Get some contact cleaner spray and look for shit connections,don't forget the dash, pump,diodes and relays all need to work in harmony.
Good luck mate

anzacinexile · #3 Post by **anzacinexile** » Sun Jun 07, 2015 7:44 pm

fatboy wrote:Had something similar happen when I fitted 4 led indicators, lost almost all dash display, would not turn over,mad relay clicking....
Seemed to be the 7 pin diode shaking the maraccas.
Sorry this just confirms another fickle wiring scenario, I cooked my ecu because of an almost severed earth on the voltage reg/rec.
Get some contact cleaner spray and look for shit connections,don't forget the dash, pump,diodes and relays all need to work in harmony.
Good luck mate

Thanks for your insight. I should have mentioned that I've bluddy examined every inch of loom for breaks/chaffs, replaced all the relays and emptied 2 cans of contact cleaner but the problem with intermittent faults is that all the time she's running OK, there is no fault to find.

Sometimes I wish she would break for good (like when my chip fried). At least you can track the gremlin down...........

DavShill · #4 Post by **DavShill** » Sun Jun 07, 2015 7:48 pm

here you go Anzac: I got your PM.

DRider - this is the post I mentioned in the "bar" thread. I put some small really tight cable ties around the wiring to restrict any movement and it's been ok for over a year (famous last words) but I will replace the fuel pump when I get around to it.

Unless of course DRider finds the real problem/solution.

http://www.apriliaforum.com/forums/show ... oday/page3

anzacinexile · #5 Post by **anzacinexile** » Sun Jun 07, 2015 8:09 pm

DavShill wrote:here you go Anzac: I got your PM.

DRider - this is the post I mentioned in the "bar" thread. I put some small really tight cable ties around the wiring to restrict any movement and it's been ok for over a year (famous last words) but I will replace the fuel pump when I get around to it.

Unless of course DRider finds the real problem/solution.

http://www.apriliaforum.com/forums/show ... oday/page3

Cheers buddy!!!

D-Rider · #6 Post by **D-Rider** » Sun Jun 07, 2015 10:28 pm

Thanks chaps - only just got back in from "Mum Duty" so only just seen the posts.
Thanks for the link Dave - I'll add that to my list of suspects.

Anzac - no, Griff isn't on Ridersite - easiest to get him on Aprilia Performance Facebook page - or give him a ring.

GregD-UK · #7 Post by **GregD-UK** » Mon Jun 08, 2015 5:05 pm

Hi all,

My intermittent cut-out was a bare wire on the back of a double black and black and white under the airbox. Happened when l was turning or leaned over abit! Searched all over and wiped away some oil and there was a shiney copper bit...

anzacinexile · #8 Post by **anzacinexile** » Fri Jun 12, 2015 6:56 am

Still down in the bowels of the bike checking stuff. Question for those rare boyo's that still have their sidestand switch working. When in gear with clutch out (running down the road as usual), if you drop the sidestand the engine will cut BUT, do you get EFI flashing on the dash? I bypassed my switch years ago and I cant remember that far back

fatboy · #9 Post by **fatboy** » Fri Jun 12, 2015 4:17 pm

The answer to that one is no, the stand cut out switch kills fuel supply and sparks so when it operates it is would not show a fault code like EFI but you would see the yellow icon idiot light above the main display

fatboy · #10 Post by **fatboy** » Fri Jun 12, 2015 4:25 pm

Tilt/tip switch?
Pump or injector relay?

anzacinexile · #11 Post by **anzacinexile** » Fri Jun 12, 2015 8:14 pm

fatboy wrote:Tilt/tip switch?
Pump or injector relay?

Tilt switch gone years ago, relays replaced (although the old ones checked out OK) last year. I asked because the fuel and sparks are interrupted by the fuel pump relay which is controlled by the ECU when it see's its input PG2 going low. Couldn't remember if it flashed EFI (even though not strictly a fault but more a fault condition)

anzacinexile · #12 Post by **anzacinexile** » Sun Jun 14, 2015 1:47 pm

Well that was fun – NOT

To recap, bike would run fine for a while then the engine cut only to restart if I switched off, counted to ten and restarted. Only clue was 3Hz click-click-click from the fuel relay. The fuel relay is controlled by the ECU so I got it into my head that the ECU for whatever reason was playing silly buggers particularly as I got the same symptoms when my FP chip fried itself.

Only solution was cowls off and try and get her to misbehave in the garage. It took over 45 minutes ticking over before BAM, she failed. Great I thought, diagnostic plug in without switching off – and – nothing, no fault code. OK, so the ECU wasn’t seeing a fault it could detect so it was cover off the ECU and armed with my trusty ‘scope, waiting another 30 minutes before she went pop again and discovering that the ECU wasn’t commanding a shutdown at all.

To cut a very long story short and after copious amounts of coffee and fags I’ve discovered the problem. The engine and fuel relay get their coil power from the same source, the only difference is the fuel relay feed goes through the kill switch which I bypassed years ago. Found out that when she dies, the engine relay was getting full volts but the fuel relay wasn’t. What was causing the 3Hz clicking was the feed volts were eventually marginal and the voltage pull from the pump was enough (eventually) to cause the relay to drop out whereupon the volts would rise slightly because the pump had stopped, the relay would kick back in, the pump would cause a volt drop again, the relay dropped again hence the 3Hz click-click-click. How switching off and counting to ten made any difference Gawd knows but it did.

Buzzed out the line and was getting a few ohms resistance from somewhere – where I couldn’t discover so I paralleled another feed and bingo – all is well with her world again.

fatboy · #13 Post by **fatboy** » Sun Jun 14, 2015 5:58 pm

Well done that man !
Frankly, I got lost just reading your report.

Viking · #14 Post by **Viking** » Sun Jun 14, 2015 11:19 pm

I think we should call you 'Sherlock' from now on. That was a very good piece of detective work.

#15 Post by **mangocrazy** » Mon Jun 15, 2015 8:15 am

Nice one Anzac, I wouldn't have had a clue in those circumstances. What exactly was 'the line' that you duplicated - i.e. between which two components?