TOPIC:

Hi:

I recently purchased a 1981 GPZ 1100 that is pretty much bone stock and in great condition for its age. However, it does not run right, stumbling a lot before it hits around 4K RPM then is all right for the most part.

I would like to keep this bike stock, so I'm looking to hold onto the fuel injection. I figure that with bike being owned (till I bought it last week) by its original owner, its low mileage, and good care that it saw over the years, I should be able to get it up and running with all of its stock components.

I've begun to go through it, and it looks to be a winter-time project. With the factory service manual, I've started to do static electical checks of various componenets. I ohmed out the Mass Air Flow Meter and it checks out fine. I will be going through other components too.

When I was reviewing the owner's manual for these checks, I didn't see anything about checking out the ECU. Has anyone ever done any electrical diagnostics on this component? If so, can you steer me towards how it's done?

I saw one posting on one of the sites about some guy talking about the soldered connections cracking (or a potential point for cracking), and re-soldering them. From what I can see, the ECU is a sealed unit, but maybe it can be opened, for testing/inspection then closed back up with an appropriate sealant. I've been around enough sensitive electrical components to know about electrostatic discharge and what it can do to these components.

If anyone can offer feedback about checking out the ECU somehow, please pass along the information. I appreciate it.

Thanks in advance.
Marty

I got this from the www.kawasakimotorcycle.org website from a forum member "Kopcicle"


1981 Gpz 1100 B1 model questions

Looks like a real good example . Cost is irrelevant . If you can stand looking at it that's good enough .
Experience ? Sorry to laugh but with just 5 members here I could easily document 200 years total experience . I probably won't have to introduce you the post and the pic will draw them in .
From the looks of it the stock coils may have been replaced . At least the wires have been . The stock coils come in two flavors , crap and soon to be crap .
Now on to the real info :

1) adjust the valves unless you are confident that the PO has recently adjusted the valves . then do it anyway

2) never run or ride on anything but a fully charged healthy battery . the stator on these bikes has always been a wee bit suspect but the rest of the charging system is more or less bullet proof . Custom Rewind -- High Quality Remanufactured Motorsports Electronics, Rotors, Stators, Ignition Systems just in case . Gary just gets it right .

3) the front forks are ok for the era but marginal if they go without service for a long period of time . they respond very well to just a complete disassembly and reload of oil . if you're going to ride it consider progressive springs . this is one front end where I don't like the cartridge emulators . a good word for the emulators I tried would be spooky and disconnected from the road . up to you ...

4) if in need of a chain and sprockets you may want to consider a 530 conversion . the stock 630 chain is incredibly heavy and has a habit of transmitting it's inertia to the rear suspension . although the sprocket sets can be had cheaply on e-bay pass on the included chain . modern 530 O ring chains are every bit as tough as the original 630 and will with care last every bit as long .

5) The front brakes need constant attention . mainly just disassembly and cleaning . in the odd case a tiny bit of grease on the back side of the pad and scuffing the pad and rotor with some 80 grit will cure most ills . if the pads are still metallic (bronze sintered) get rid of them and use a quality semi metallic . full metallic will just trash your rotors in short order and unless you are racing the slight decrease in braking performance won't be missed or even noticed . replace the the brake lines w/ braided steel covered tfe . replace the the brake lines w/ braided steel covered tfe . did I repeat myself ? must have been a reason
optional :
these bikes are torque pits . near bottomless bucket full of low end torque. with a little bit of minor engineering an extra friction plate can be fitted . this is a better option than aftermarket clutch material in the long run . you need to acquire the kz400/440 clutch steel plates they are just enough thinner that an extra friction plate can be fitted with just a little modification to the release mechanism.

you should take a look at the swing arm pivot as most I've seen are corroded and just plain shot . a disassembly , cleaning and re-lube may be all it takes .

tapered needle bearings in the steering head . if it doesn't have them already it's just the thing to do .

that should be enough to wrap your mind around for now

~kop


1982 Kawasaki GPZ1100 B2 ECU Pin out


I have a 82 GPZ1100 B2, the wiring may be the same. I got out my well used service manual and copied the wire pin-out if you are going to use the EFI system.


The connector is numbered left to right with pin #1 on the lower row of pins
with #12 above #1 .

I'll give you the pin-out and wire colors that are viewed from the wire side.

#1 Black/Yellow Ground
#2 Blank
#3 Blank
#4 White/Red Battery +
#5 Blue/Red Sensor Ground
#6 Blue Air Temperature Sensor +
#7 Blue/Yellow Control Unit +
#8 Green Engine Speed
#9 Blank
#10 Gray Engine Temperature +
#11 Blue/White Throttle Opening Angle
#12 Yellow Injector Drive Signal
#13 Blank
#14 Blank
#15 Blank
#16 Black/Green Control Unit Ground
#17 Blue/Orange Throttle Sensor +
#18 Black Engine Speed
#19 Red/Black Starter Signal
#20 Blank
#21 Green/White Fuel Pump Relay Drive Signal



1981 Kawasaki GPZ1100 B1 EFI To Carb Conversion

I purchased an 81 GPz1100 this winter, and knew it had EFI issues. AFTER I bought the bike, while scrolling thru old posts to this list, I saw several posts from the PO mentioning all of his problems and headaches getting the bike to run. He had done a pretty thorough job of t-shooting the electrical system, but from what I hear, even a well-sorted 81 GPz1100 EFI is an ugly prom date. New rule: Before buying a bike, search these lists looking for posts from the current owner, mentioning unsolvable tech problems!

So...a set of BS34 carbs from Ebay, new carb mounts, and a set of 7/16" allen bolts to plug the injector holes, and it runs! so far this has only been driveway time, running off of a 1qt squeeze bottle of gas that keeps vapor locking. The bike has only 7000 miles, so everything else seems pretty tight. right now it is running thru V&H open headers, which sound pretty nice!

Thanks for the tips from this site...it is super helpful!

Here's a PDF on the 1981-1982 Kz1000,Kz1100 bikes. Your 1981 GPz 1100 will be in there too.

www.kawiworld.com/index.php?option=com_c...icle&id=77&Itemid=99

The 80/81 fuel injection system was a pain. The 82 system was much better and pretty much trouble free. What you may want to do is keep your eye on eBay and update the bike to an 82 system.

One of the problems with early Electronic fuel injection systems was the lack of on board diagnostics. Systems these days make it pretty simple.
Don't know of any other way than to rule out everything else. If it was a No-Start then maybe a computer, but if it runs, rarely a computer. Those tests in the manual for resistance and voltage, looks like they have you testing each component. That's all good, but you may want to confirm those readings at the corresponding pins at the computer connector. This will show if there is a good connection along the current path. Look real close at both sides of all the EFI connectors for loose, damaged, pushed or pulled out pins, or corrosion. Good connections will be needed for accurate signals to the Computer. The temp sensors have to be checked under both a cold and hot test, many temp senors have 2 resistance ramps built into their construction, cold can be OK but fail hot, or vice versa.
Before trying to resolve a potential fuel problem, be sure of the engine basics, vacuum leaks, and definitely the Ignition.

Actually the biggest problem was that it did not use a throttle position sensor. The 82 did.

bama.ua.edu/~darren/bosch/Page00.html

I don't know if reading through some basics about the system design will help. There is not very much in the FSM for diagnostics on the 81 year. Like Otto said, no TPS in 81, just a throttle switch and a "Flapper Box" Air flow meter. These were used on many many vehicles in the 70-80's. Some have a mixture adjustment hole, with a plug to be removed first, for tuning the Air Fuel Ratio at Idle. Not sure about the Kawasaki system, but it is all under Bosch license.
Good Luck.

E-Bay will have the injector bodies and injectors for sale now and then.Hopefully the tps will be there too.

More than a few GPz 1100 owners have switched to BS34 carbs, so I'd imagine finding the FI systems will be relatively easy.

I'm not sure if the 81 and 82 computers are interchangeable.The newer 82 injectors are better isolated from the engine heat than the 81's were.

In 83, I think Kawasaki added a fault code flashing light for diagnosis.

The ECUs were interchangeable retro but not forward starting in 82 and on.

I seem to recall that there is an led or two on the side of the ecu that flashes an error code (like morse code) that let you know what has failed,
I think I might have something in an old manual in the shed. I will try and have a look on the weekend

Dave Sloan wrote:

I seem to recall that there is an led or two on the side of the ecu that flashes an error code (like morse code) that let you know what has failed,
I think I might have something in an old manual in the shed. I will try and have a look on the weekend

The error light was put on the 1983 and later ecu units.

I don't know on this application, but many of the 80's EFI computers had a way to retrieve codes, 1 pin was for ERR codes, and an analog meter was used between it and ground. Then you counted needle swings, some people used a test light, but there was actually 2 voltage levels for the pulses. This way you could tell the "Start" of the sequence.
Does anybody know about this model, would it have a similar type of code retrieval? Otto?