81 GPz1100 DOA

I've got an 81 GPz1100 in my shop that I am taking a look at for an acquaintance. He had a mechanic who tried to jump start it with a car battery and I suspect it blew up the electronics package that manages the fuel injection at the very least. When you turn the key to the on position, the fuel pump doesn't spin up to pressurize the system,. All the fuses are still in it and good. (I've yet to put a meter on them but will) This all happened 13 years ago so there are going to be multiple issues for me to manage. I only started to dig in but thought I would see if there are knowledgeable members out there. It looks like there used to be DFI PDFs and notes out there in the articles section. (I searched and snooped through GPz1100 posts) I don't see them out there now.

The owner is open to going to carbs. "Whatever makes it run for the least amount of money, do that" is his position. Any early DFI experts here? It looks like the service manual for the 83/84 GPz1100 isn't the same system as this 81 GPz1100 unit.

I am by no means a GPz DFI expert, but I am quite familiar with electronics and engine control. If he hooked up the cables backwards, he more than likely smoked the voltage regulator, on top of the engine control module, OR, it might be ok and the fuel pump is seized (they go out all the time). At any rate, and no matter what direction you go, a good battery is a must.
Also, I think disabling the electronics also will disable some other things in the process. Don't these bikes have several functions that go through the engine control module? (ecm) Get a test light or meter and verify with a hot battery if there is any signs of life / indicator lights. Verify if the fuel pump is getting power and what is or is not working. There is a supplement in the back of my 81 Kz1000 / Kz1100 manual, but not sure how in depth it is into the electronics of the early fuel injection setup.

If the module IS fried, getting it repaired would probably be cheaper than a carb conversion, and all of the existing stuff would still function as designed. .

From wikepedia "Rather than featuring carburetors, the B1 was fitted with electronic fuel injection (EFI)[3] a Bosch-derived Nissan fuel injection[1] as used on the earlier 1980 Z1000G/H models."

en.wikipedia.org/wiki/Kawasaki_GPZ1100

Hope this helps.

If the electrical system has not been badly compromised, to get the fuel pump to run, move the flap in the air flow meter toward the open position, with the key in the on position.

More Kawasaki DFI info:

kzrider.com/forum/3-carburetor/403310-in...-my-gpz1100-dfi-long

www.kzrider.com/forum/3-carburetor/59868...l-injection-question

kzrider.com/forum/4-electrical/401631-ec...y-way-to-check-it-ou

I fully support all the effort to try and revive the original fuel injection system.......but shameless plug here, I have some fully restored Keihin cr33 specials that I really need to sell. They even have the correct spacing and spigots to bolt right up to a gpz1100. Just so you know that you have a potential plan B


End of shameless plug....I return you to the original matter at hand.

Check to see if the pumps getting power . They freeze up all the time . Sometimes you can get them going if you soak them in gas then bang on then a little then put some power to them forward then reverse it . If the pumps not getting power check the pump relay .

first get fuel pump out of bike see if pump works direct off known good battery if it works then you have issue with power to pump if pump does not work try reversing leads from pump form pos to neg battery post do this in short burst sometimes that will get pumps running if no luck try bumping pump with soft mallet careful not to damage pump this along with reversing connections will sometimes free pumps , i have also had luck filling pump with PB Blaster and let soak over night keep in mind if pump is gummed up so are injectors you can send them off to RC Engineering to have them cleaned and flow tested , also they can supply new if old units cannot be revived, if a all possible keep the DFI although the 83/84 is a more refined system hope this helps.

Thank you one and all. Great stuff to get me out of the blocks here. I do have the service manual and supplement for the 80 Z1 Classic in my garage. The part number is different as is the packaging for the electronic. Its is physically different on the 81, but hopefully some of the flow charts/maps will still be relevant. I don't currently have the correct manual for this bike.

I did spend some time searching GPz1100 posts on this site. True or not I read the 81 DFI is a completely separate from the rest of the electronics. I like stock, it's just who I am, so if I can get it running with the DFI, that will be my goal if it isn't cost prohibitive. I've also got a set of Mikuni BS34 carbs off an 82 GPz750 I planned to use if the DFI gets to be too big a cash sink hole.

Did the 81 GPz1100 heads have fuel injector ports at the top of the intake runners?

The injectors fire into the intake before what we think of as carb holders. The injectors do not bolt into the head casting like they do on the 1980 Z1C.

ajsfirehawk wrote: The injectors fire into the intake before what we think of as carb holders. The injectors do not bolt into the head casting like they do on the 1980 Z1C.

yes that style had issues with injectors in the head they would hot soak when shut off that is why kawasaki later moved them into rack to insulate from the heat.

Phase one of cleaning the tank today. I pulled it, drained it, flushed it with hot water, the soaked it with hot water and Dawn with a chain in it. Soaked it left t foot in, left foot out.... Then flushed it until it ran clear. Air drying tonight, Metal Rescue tomorrow.

I pulled the fuel pump. Blasted some PB Blaster into it and quickly connected it12v, then reversed the polarity and tried again. Nothing. I metered the leads, shows as an open circuit on the 1M ohm setting. Windings must be open so I think it is shot.