ZX12R - goes onto 'get home' mode

[Skunk]

This request is from a friend of mine. The engine is fitted to an off-roader but he's a biker too and I'm hoping someone can help...

Quote: Is there is anything other than the temp sensor that when it gets hot makes it go in to go home mode (note temp gauge reads norm) and is re-set by turning computer off then back on to get full power.
The go home mode comes on gradually restricting first to about 8000 then 6000... till idle only (in any gear, temp reads still norm) seems to be an air flow problem over motor. Only seems to happen at very low speeds where the temp has time to build up around motor. Any ideas.

[CookMySock]

Sorry I don't know, but its quite simple to replace the ECU with a megasquirt or similar.

DB

[nodrog:Me]

it doesnt have an oil pressure sensor does it?

[RantyDave]

its quite simple to replace the ECU with a megasquirt or similar.

Eh? (tap tap tap) whoa!

"MegaSquirt® EFI Controllers are intended as an educational project for those who want to learn about electronic fuel injection"

Now, I write software for a living. And every now and then (more often than it should) it crashes. When it goes, my body suffers the following ill effects: Nothing. Pissing about with an EFI - now that's software engineering for men!

Dave

[Wheeliemonsta]

This request is from a friend of mine. The engine is fitted to an off-roader but he's a biker too and I'm hoping someone can help...

Quote: Is there is anything other than the temp sensor that when it gets hot makes it go in to go home mode (note temp gauge reads norm) and is re-set by turning computer off then back on to get full power.
The go home mode comes on gradually restricting first to about 8000 then 6000... till idle only (in any gear, temp reads still norm) seems to be an air flow problem over motor. Only seems to happen at very low speeds where the temp has time to build up around motor. Any ideas.

Gidday Skunk,
I think your problem may lie with the "Vehicle Down Sensor" I've had a similar experience with a ZX 12 motor that was used in a one off "Wings & Slicks" Race Car

The fact that the motor runs at all is testament to your mates knowledge on things electrical...

What happens is that when the motor comes out of the frame & goe's into a "car" style chassis its exposed to a lot more "lateral" loading than it ever was in the bike (think about it...) The vehicle down sensor can't compensate for the "new" set of load parameters & eventually starts shutting things down because it cant feed the E.C.U the right information...

Check this first - its an indicator flasher sized relay located in with all the gubbins on the battery tray... You can pull the lid off it & the damage will be fairly obvious !!!

We got round it by sourcing another sensor & very carefully glueing the guts of the sensor in a "Central" position...

Best way round the overheating is to use a "B" model radiator - it has two fans as opposed to the "A" models one

Alternatively Muzzy do a re-pitched fan blade for the "A" model which draws alot more air (& is consequently quite a bit nosier !!!)

Let me know how you go

Cheers

[Skunk]

Just had a chat to him. He's going to check out the 'tilt' sensor as that is still fitted. He doesn't think that's it as all he has to do to get full power again is shut the computer off and turn it on again.

it doesnt have an oil pressure sensor does it?

He said it has an oil light so he guesses so. He'll check it out. Are you suggesting the oil pressure is dropping to low?

[sAsLEX]

Eh? (tap tap tap) whoa!

"MegaSquirt® EFI Controllers are intended as an educational project for those who want to learn about electronic fuel injection"

Now, I write software for a living. And every now and then (more often than it should) it crashes. When it goes, my body suffers the following ill effects: Nothing. Pissing about with an EFI - now that's software engineering for men!

Dave

Guys at Uni made their own fully customizable EFI, not just the software but the hardware as well.

Everything was changeable and it would outperform a MOTEC at half the cost

[Chrislost]

Eh? (tap tap tap) whoa!

"MegaSquirt® EFI Controllers are intended as an educational project for those who want to learn about electronic fuel injection"

Now, I write software for a living. And every now and then (more often than it should) it crashes. When it goes, my body suffers the following ill effects: Nothing. Pissing about with an EFI - now that's software engineering for men!

Dave

Me and a few friends used these to power injection and ignition for Quad throttle bodies on old toyota engines.
their pretty easy to build and luckily there was a local guy who could tune them dam well.

[Skunk]

Can we stay on topic please. Megasquirt is not going to be fitted as to much else is linked into the existing ECU. He just wants a fix for the thing going into 'get home' mode every so often.

[nodrog:Me]

He said it has an oil light so he guesses so. He'll check it out. Are you suggesting the oil pressure is dropping to low?

on my RSVR the oil pressure sensor shit itself causing it to go into limp home mode. but in saying that the oil light would probably come on if that was the case.

[Wheeliemonsta]

Can we stay on topic please. Megasquirt is not going to be fitted as to much else is linked into the existing ECU. He just wants a fix for the thing going into 'get home' mode every so often.

Gidday Skunk,
If (?) the V.D.S proves to be in working order all well & good...

The other critical areas on ZX 12's are the condition of the battery & the earthing of the ECU itself - a problem in these areas can manifest itself as any one of a number of things...

Make sure both of these are absolutely 100% before going any further... If the battery is even the least bit suspect - replace it; in 99% of all prob's on E.F.I bikes it's the root cause of all evil

Attached is the diagnostic procedures for the Fuel Injection system, this is for the A1 & 2 models - the B models are markedly different, the main difference being that they run a two T.P.S system on the throttle bodies

Does your mate know what model engine he's got ?

I can get hold of the B model diagnosis info if need be

Cheers

[Skunk]

Awesome info mate. Cheers. I'm sure it's the A model.

[Skunk]

Just got this back:

Vehicle down sensor is OK, when activated kills motor.
All earthing checked and OK.
New large marine battery.
Have two large cross flow radiators both with two 12" fans each. Two of these on after market thermo switch coming in at about 92 deg which keep the motor at half way on temp gauge, the other two on factory thermo switch but rarely does the motor get hot enough to activate them.

[Wheeliemonsta]

Just got this back:

Vehicle down sensor is OK, when activated kills motor.
All earthing checked and OK.
New large marine battery.
Have two large cross flow radiators both with two 12" fans each. Two of these on after market thermo switch coming in at about 92 deg which keep the motor at half way on temp gauge, the other two on factory thermo switch but rarely does the motor get hot enough to activate them.

Gidday Skunk,
If your mate has been through all the basics I think all he can do now is take it out for a run; wait for it to start playing up & stick it into "Diagnostic" mode & see what fault code is coming up...

This is, of course, assuming he is using the standard instument set up & can observe the fault codes on the "FI" light in the instruments...

Cheers

[Skunk]

He is using the standard instruments. I was about to add to the post above that he's gonna give it a test and see what happens. This is a new fault too. I've been in the vehicle during a wet race. DNF'd because of a broken chain. Must find a pic of it.

The only pic I can find is in the early days of construction...