1981 GPZ 1100 fuel injected

[RickB]

I just picked this bike up fairly cheaply because I wanted to have something to wrench on again. Cant believe my wife said OK! Anyhow just thought I would say hello to the rest of the forum as I am new here and will most likely be stopping by to ask advice as I get into this thing and try to get it running which it is not right now. I wont ask any questions until I get a better idea of whats wrong other than it only starts if you hold the air flow valve open but stalls easily or if you try to feed throttle to it. Working my way thru the manual SLOWLY to try it on my own. So thanks in advance for any and all help everyone here may give me---

[StarGate]

Welcome to the nut house.

[gpzrider]

Welcome aboard. Post up some pics when you get the chance.

[RickB]

OK, I am ready to ask for some help getting this thing running. 1981 GPZ 1100 with fuel injection. I have tested every electronic part on it and they all check out, battery voltage is good, and good spark at the plug. Plugs keep fouling with carbon/soot I know that means to rich but that is probably from me trying to get it running by opening the air flow valve and feeding it a lot of throttle. It wont start easily at all and will not idle at all, can keep it running if I run the RPM up to about 4500 but it is stumbling and popping out the air flow valve a little. Anyone have any suggestions on what I should try next? It is getting frustrating as I havent really found anything I can put my finger on that is wrong yet!?!?!

[RickB]

Does anybody have any ideas? I really could use some help!

[MFolks]

Since on the fuel injected GPZ's richness is controlled by the Electronic Control Unit (ECU) or computer located back in the tail section under the seat. The first thing I would do (I own a 82 GPZ1100 B2) would be to check the intake and exhaust valve clearance for proper adjustment before you start trying to adjust the injectors. The valves are under the covers on top of the engine. The fuel tank has to be removed and associated lines and cables dis-connected to allow access to the valve cover bolts. The ignition coils will also need to be removed.


A new valve cover gasket will be needed as the old one will probably tear and leak. Just like my bike I think you have the shim over bucket set up which will make checking so much easier than the shim under bucket set up on the 83 model. If you go to the website KZrider.com - Home they have a good reson to check valve adjustment listed on thehome page.

Anyway you are going to need feeler gauges and an assortment of shims to properly adjust the valves along with possibly the special tools to remove and replace the shims.

I have some websites that may help:

1. OldKawMan's Vintage and Classic Kawasaki, Suzuki, and Yamaha USED Motorcycle Parts and High Performance
2. Motorycle Parts & Accessories - Find What You Need @ Old Bike Barn
3. SUDCO Motorcycle Parts Distributing
4. www.z-power.co.uk
5. Yamaha Vintage Motorcycle Parts, Vintage Kawasaki Motorcycle Parts, Vintage NOS Kawasaki Jet Ski Parts, Yamaha NOS, Honda NOS Parts, Suzuki Motorcycle Parts
6. Over Stock Parts
7. Redline Cycle Service, Inc. - Homepage
8. MRE - Murdoch Racing Enterprises - Main Page
9. DYNOMAN PERFORMANCE - motorcycle performance products

I have the motorcycle service manual for the 82 model and I think a lot of information will apply to your model.

[quader98]

another sight you might wanna check out is

KZrider.com - Home

[MFolks]

This is the pin out on the ECU (computer) connector on my 82 GPZ1100 B2 and what goes where. The connector is viewed from the wire side with #1 on the bottom with # 12 above it.

#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

Pm me if you have any questions.

[Zammy]

Could very well be dirty injectors . Kawasaki recomends after sitting all winter to use a full bottle of fuel injection cleaner in a tank of gas to clean them out . sometimes it takes a couple of times to get them clean. The richness is because the fuel is being spit in in droplets that won't ignite properly instead of a VERY fine mist.

[ratvespa]

cool! nice to see another early GPz owner. I got a 82 Im rebuilding now. Got it for free, although the engine was removed and top end was apart.





From what Ive been reading about these, the 81's DFI system is a bit more problematic than the 82.
here is a good wiki article about them
Kawasaki GPZ1100B1/B2 - Wikipedia, the free encyclopedia

I guess it's common for 81 owners to swap to carbs, if you are really adventurous you can go for megasquirt efi, I think thats the route Im going to go once I get the big bore cyl's on and the engine together.

good luck, I have the factory kawi manual for the KZ/GPZ with the B1 and B2 supplement pages, if you need anything scanned and posted let me know.

[Zammy]

The '81 had the injectors ported directly to the head and heat would cook them . The '82 had the injectors mounted in the rubber intake side boots insulating them from the heat .

[MFolks]

Consider in 82 the going price (at least for mine was $4399.00)

[sidy]

G'Day,

I also own GPz1100's, both a B1 and B2 model. My B1 is injected and works great, the B2 was converted to carbs by the previous owner and is my regular touring bike when I am not riding my GPz900R rocket.

A few pointers on the GPz1100 EFI/DFI systems......

First of all the B1 and B2 have different injection systems. The B1 does not have a TPS like modern EFI system (the B1 TPS is essential an on or off switch at idle), the B2 does have a TPS that reflects the actual throttle position.

The B1 uses the air flap to determine engine load (as well as RPM) and hence calculate fuel requirements from these inputs. The air temp and engine temp determine enrichment.

The B2 has a TPS which shows the position of the throttle and so uses an algorithm called alpha-n the B1 uses a system similar to Speed Density control. The B2 is the basis of all modern EFI systems. The B1 is a hybrid car design that should have been better thought out.

In short the B1 needs to know how much air and the engine temp to work out the required fuel at a given RPM. If the fuel is wrong the temp sensors may be out or the flap may be giving a wrong reading. If it does not idle it could be the idle switch on the TPS.

On the B2 the position of the TPS is mapped to a table to give the required fuel and then the RPM range is used to narrow down the table, the air flap then indicates the load and hence the calculation is derived for the fuel. The temp determines the enrichment of the fuel for cold starts.

Check the idle sw, then the temp sensors. then the air flap.

Air flap is 350-400 ohm (pins 6 & 9)
Temp sensors are 2.1 to 2.9Kohm at 20C (72F)
idle switch - closed at idle, open switch when throttle opened.


Check fuel flow and mechanic injector operation (use screwdriver to listen for tap-tap-tap noise from each injector). From the sound of it the injectors and fuel delivery is fine, just one of the sensors or connectors are RS.


Good luck.
Email me if you get stuck (sid DOT young AT gmail DOT com)


Sid
Gpz1100B1/B2 GPz900R-84/85
z1a,z900-A4,z1000A2, z1000G, CB750K2/K4

My Restoration web site:
z900

[Zammy]

Sid , That's a cool site you have there. someone sent me the link as soon as I got my Ninja.

[horwood.james1@]

if u lose patience with efi the carbs and carb rubbers off z1000j fit right on.throttle cable also.standard j jetting runs good on my bike.will need carb brace to stop em dropping if using KnN's.

[jellymcg]

Hi I am also having similar problems with my the FI on my 81 GPZ1100, I put Techron in the tank & things started to get better. Still the bike won't rev above 5000 rpms & the plugs are carbon fouled. It even lost combustion on one cylinder with spark present & injector clicking. I took off the injectors/ t-bodies & sprayed them out , cleaned the plugs. I have a set of BS34 to put on but don't know what to plug the injector ports with. Does anyone sell plugs or does everyone fabricate their own.

[MFolks]

Have you checked the fuel filter? sounds like the flow is restricted or the pump is not putting out he pressure it should. Another possibility is the fuel pressure regulator, Check the vacuum line for cracks and I'd replace they all.

[jellymcg]

I haven't put the injectors back in yet, but I'm going to try one more time to mess with FI before switching to carbs. I talked to a speed shop that has done the conversion before. One thing that caught me by susprise was that he said it would need new ignition (Dyna) or it won't run right, said stock system linked to FI TP sensor. I thought the FI was stand alone from igntion, never see anyone mention the need to do this. THanks for the advice, lots of helpful info here, much appreciated.

[sidy]

Originally Posted by jellymcg

I haven't put the injectors back in yet, but I'm going to try one more time to mess with FI before switching to carbs. I talked to a speed shop that has done the conversion before. One thing that caught me by susprise was that he said it would need new ignition (Dyna) or it won't run right, said stock system linked to FI TP sensor. I thought the FI was stand alone from igntion, never see anyone mention the need to do this. THanks for the advice, lots of helpful info here, much appreciated.

The ignition circuit is separate to the EFI. The IC Igniter box for the ignition is behind the LH side cover, the ignition does connect to the EFI, only to tell it what RPM the system is doing, if you pull the EFI out the ignition works fine... they are bull****ting you.

[jellymcg]

Thanks for the info i will let you know how I make out. I was wondering how your GPZ1100 w/FI performs compared to the one w/carbs. Just seems that the whole airflap door, airbox setup is more restrictive compared with well jetted carbs w/individual air filters.