1980 Z-1 Fuel Injections problems

The "DFI" was a Kawasaki marketing term, they were both digital fuel injection, AKA Electronic Fuel Injection (EFI).

AFAIK, there have only been two types of fuel injection used, EFI and mechanical, and anything that uses a computer to control the injectors is EFI, any other name is just a marketing term.

The 80 system is weird, it doesn't really use a TPS, it is based on airflow info provided by a flapper door, I believe that the 81 models improved the system by using a TPS in addition to the MAF (flapper door), then the 83 model went to a MAP system, It seems like the best system so far is a hybrid MAP/AlphaN system, but I'm not sure when it became common.

Post edited by: steell, at: 2007/06/06 08:31

steell wrote:
[quote
The 80 system is weird, it doesn't really use a TPS, it is based on airflow info provided by a flapper door, steell, at: 2007/06/06 08:31[/quote]

I know the difference between digital and electronic. Like I have said before the 80' used a Bosch system from a car.

If Baja454 wants to try to diagnose this, I recomend to start by pulling off the tank.

(1) Buy a 3" 50 to 60 psi pressure guage about $12 - $15. Also buy a "T" and whatever brass or plastic fittings, Braided fuel hose and hose clamps, that will enable you to set the pressure guage perpindiqular to the pressure relief valve.

(1b)add the T where the pressure relief connected to the return line. Add a few inches of hose to the end of the T. Add 12 t0 24" of good quality braided fuel line to the T and fasten the pressure guage.

(1c) Reconnect the fuel tank to all lines. After your sure all your your fittings and clamps are secure You can turn on the key and check the pressure (40 psi is normal, greater than that fails)

If the pressure regulator is good:

(2)Remove the fuel tank, remove the coils and get all the gasoline out of your cylinders. (you are going to need to replace your oil when you are done diagnosing the system)

(2b)Buy 4 12volt LED's (not flashing type and not the type that uses a LED connected to braided wire)

I prefer red or green. The long side of it's two solid wires is the positive, the short side is the negative.

By installing the LED's into the injector's wire connectors, you can tell if the injectors are recieving a signal from control module whenthe LED lights up. Polarity of the LED's must be correct, if you don't know which color is the ground wire, resort to your manual.

(2c) Turn on the key and crank over the engine. The LED's should blink. If they are staying on, there can be a few answers.

(3) I would recomend to see if the MAF sensor (under the seat, connected to the air box, with the flapper valve inside)

Check to see if it's not closing all the way.

Bill

I know the difference between digital and electronic. Like I have said before the 80' used a Bosch system from a car.

What's the difference between digital and electronic?

In & Out > McDonalds

Digital makes better burgers

Also, in California, I am fairly certain we got the DFI in 81'? In reading these threads, I have started to see 49 state models.

Post edited by: Capt. Quirk, at: 2007/06/06 22:25

Ahh, I miss those In&Out burgers, and the PupNtaco's, and the weather, and lot's of other stuff (but not my ex-wife that still lives there, last I heard).

If it's Bosche fuel injection, and it don't have fuel lines going to a distribution block attached to a flapper door, then it's got a computer and is digital. DFI was a Kawasaki Trademark, just like TPI/TBI/CFI/etc were Trademarks of the appropriate automotive companies.

It sure confuses a lot of people, when I ask "what type of fuel injection are you running" I mean "Is it MAP, MAF, AlphaN, or a hybrid" and get answers like above :laugh:

baja454 wrote:

Could it be a faulty check valve in the tank... it does connect to the regulator.

Yes they do stick, especially when left standing with gas in the tank. This sends the fuel pressure through the roof, resulting in overfuelling.

A few other suggestions:

Get the injectors cleaned, your local "ASNU" place can do it or send them to Kinsler. They might be functioning but it's a fair bet that the spray pattern isn't that great. There is a small filter inside the injectors that can get blocked, you can blow this back out with an air line connected to the injector nozzle and a 3v battery to trigger the injector.

Check the ECU for fault codes. On the turbo there is an LED that flashes, maybe your G model has something similar?

Clean and check the engine temperature sensor connection, these are often corroded leading the ECU to thinking the engine is colder than it really is, again leading to overfuelling.

Make sure the fuel filter is the right way up. It's a common mistake to install them upside down which results in an engine which starts but then dies due to fuel starvation.

My work in progress is now complete. I'm in the fine tuning stages of the bike. It runs good. The problem I have now, I have tracked to a problem to the floats. It won't be long now

After all of the work I have done, I do have some advise for you. Listen to yourself. People mean well, but I spent a lot of time trying to track down what they thought was the answer to problem.

Just thought you might like some other things:
Kawasaki made 3201 1980 KZ1000G's

The frame numbers ran from 500004 - 503205.

Engine numbers were 000001 - 003357. So there must be some spare motors out there.

Paul Sr.
kz1000g
Old School Motorcycle Repair
Amsterdam,NY