VN1500 ECU Reprogramming

[Cajun]

I have a mate who has a vn1500 drifter.

He has had an on going issue where bike pretty much can't do anything more than 110-115kms an hour, as soon as it gets to that speed in top or like a certain rpm in any gear.

We has replaced many many parts with the electrical system(fuel pump, coils, coil leads, gone thru and check pretty much every electrical connection on the bike) with out much luck.

He was talking to someone other day who had simlar issue, and was told it was the ecu which had had droped its revlimit and it was hitting that (which i unsure why/how it could do that), but saying we have put a ecu from a vn1500 nomad in the bike and it did not fix it.

This guy said the fix was getting the factory ecu reset (not to sure how this can be done, i though they were locked unit), or a power commander put in.

I would think the ecu reset would work if it was that, but we have tried an ecu from a perfectly working bike, and did not fix the issue with the bike. I don't see how a power commander would fix the bike if it was revlimiter.

[TripleZee Dyno]

I have a mate who has a vn1500 drifter.

He has had an on going issue where bike pretty much can't do anything more than 110-115kms an hour, as soon as it gets to that speed in top or like a certain rpm in any gear.

We has replaced many many parts with the electrical system(fuel pump, coils, coil leads, gone thru and check pretty much every electrical connection on the bike) with out much luck.

He was talking to someone other day who had simlar issue, and was told it was the ecu which had had droped its revlimit and it was hitting that (which i unsure why/how it could do that), but saying we have put a ecu from a vn1500 nomad in the bike and it did not fix it.

This guy said the fix was getting the factory ecu reset (not to sure how this can be done, i though they were locked unit), or a power commander put in.

I would think the ecu reset would work if it was that, but we have tried an ecu from a perfectly working bike, and did not fix the issue with the bike. I don't see how a power commander would fix the bike if it was revlimiter.

Very Interesting
what happens at 110k?
does it just stop there as if you have put the brakes on?
misses & farts?
Does it start easy and sound ok at low revs?
Does it accelerate well until it gets to 110? or is it pretty gutless?
110k is about 2500rpm, will it rev over that when in neutral?
Has it always been like this or has it snuck up on you, getting worse over time?
or did it suddenly happen?
Any work done on the bike prior to the problem?
Swapping ecu's would I imagine eliminate rev limit and ecu problems.
If it is a rev limit problem doubt a power commander would fix it
good luck!!

[Cajun]

Very Interesting
what happens at 110k?
does it just stop there as if you have put the brakes on?
misses & farts?
Does it start easy and sound ok at low revs?
Does it accelerate well until it gets to 110? or is it pretty gutless?
110k is about 2500rpm, will it rev over that when in neutral?
Has it always been like this or has it snuck up on you, getting worse over time?
or did it suddenly happen?
Any work done on the bike prior to the problem?
Swapping ecu's would I imagine eliminate rev limit and ecu problems.
If it is a rev limit problem doubt a power commander would fix it
good luck!!

start missing and farting around, it will do it in all gears, even in neutral
Goes find at lower revs, not gutless or nothing
Just started happening one day
No work done on bike, it had some very free flowing pipes, but had been on bike for 6 months before it happened.
We have gone back to a semi stock one with out much luck.

Yeah i know pc3 wouldn't fix it, and don't see how reflashing stock ecu be any different than putting an ecu from different bike in.

[TripleZee Dyno]

start missing and farting around, it will do it in all gears, even in neutral
Goes find at lower revs, not gutless or nothing
Just started happening one day
No work done on bike, it had some very free flowing pipes, but had been on bike for 6 months before it happened.
We have gone back to a semi stock one with out much luck.

Yeah i know pc3 wouldn't fix it, and don't see how reflashing stock ecu be any different than putting an ecu from different bike in.

Sounds like it could be a regulator problem.
I would check fuel pressures and make sure they are within spec.
cheers
John



cheers

[classic zed]

Do you have an inductive timing light? if so clamp it round one of the HT leads (you might have to try all of them in turn) and see if it continues to flash when the misfire occures, if it does the problem is most likely fuel, if it stops flashing or flashes erratically then its probably more ignition related.

Do you know anyone with a diagnostic scope? you can check the pulse coming from the ignition pickups, maybe one of them has failed or come loose.

[TripleZee Dyno]

Do you have an inductive timing light? if so clamp it round one of the HT leads (you might have to try all of them in turn) and see if it continues to flash when the misfire occures, if it does the problem is most likely fuel, if it stops flashing or flashes erratically then its probably more ignition related.

Good idea. One of the first things I normally do because my No1 troubleshooting rule is "check the easy things first"
Something I forgot to mention is check the TPS for correct operation.

[Wheeliemonsta]

I have a mate who has a vn1500 drifter.

He has had an on going issue where bike pretty much can't do anything more than 110-115kms an hour, as soon as it gets to that speed in top or like a certain rpm in any gear.

We has replaced many many parts with the electrical system(fuel pump, coils, coil leads, gone thru and check pretty much every electrical connection on the bike) with out much luck.

He was talking to someone other day who had simlar issue, and was told it was the ecu which had had droped its revlimit and it was hitting that (which i unsure why/how it could do that), but saying we have put a ecu from a vn1500 nomad in the bike and it did not fix it.

This guy said the fix was getting the factory ecu reset (not to sure how this can be done, i though they were locked unit), or a power commander put in.

I would think the ecu reset would work if it was that, but we have tried an ecu from a perfectly working bike, and did not fix the issue with the bike. I don't see how a power commander would fix the bike if it was revlimiter.

Gidday Cajun,
Has the bike got a L.T.S.A V.I.N plate on it anywhere, if so it's an Import...

Can you get the actual chassis number off the bike - might be a California market model - these quite often need a significant amount of re-tuning to run properly on our fuel & to the best of my knowledge you cannot "Flame" an O/E E.C.U...

Chassis number will tell me everything I need to know

Cheers

[Cajun]

its an NZ new model, none california. And i pretty sure you couldn't 'flame' a kawa ecu.

Thanks for info Zed and Triplezee i will pass the infon on to my friend and see how he gets on