GPZ1100 '82 HELP WANTED.

This summer I bought a “Project” racing bike based on a GPZ 1100.I already own one painted in ELR colors so I basically acquired a nice aftermarket set for my bike. 



The story is as follows, a guy bought a lot of 8 Kawas in Holland, there were several models, including one of the Police.
I had this ad for months until I was able to buy the bike for 800 euros, it was just 100 km. from home and I did not let him escape.
The chassis has Dutch title so here in Spain is almost impossible to legalize it, hence its price.

The chassis numbering corresponds to the model KZ1000 J. '82. 


Checked the numbering of the engine is identical to mine. 



When I got home I hurried to disassemble the bike and put it in boxes because my wife would not accept another bike in my garage, no matter how many technical explanations I could give her.

First surprise, the ENGINE HAS JUST BEEN REBUILT.

Pistons, valves, crankshaft, all brand new.



 



It had not yet been run in, the engine was ready to be oiled and started. 



I have all, fairing, tail, side covers, and more electric parts. 



 

Well, this weekend I had the bright idea to change the engine on my ELR, when the intention is good, what can go wrong?

So Saturday after lunch I took my wife's car out of the garage, my little workshop is occupied by partially disassembled Christine, and got down to work.

I was able to get the engine out by pulling the bike to the ground, I couldn't use my ternal of lifting loads as it is anchored right on top of Christine.

I convinced my two sons to come down just before dinner to give me a hand to put the new engine in place, we all directed the operation although I was the one who made the most effort holding the engine in the air.
Just before their mother called us to dinner we had it in place on the frame. 
 

After dinner I went downstairs to continue with my work, first I placed the injectors battery previously cleaned, the airbox and the wiring of the alternator and ignitor.
The three wires coming out of the alternator on both engines are the same color, they don't seem to have a specific order.

 
 

I changed the coil wires, it was two in the morning when I finished mounting the exhaust, took a shower and went to sleep.


This morning after breakfast watching the Malaysian MotoGP race I went down to the garage to finalize the details of the bike to get it up and running.
Just as on the 1300 you have a point to adjust the electronic ignition on the GPZ I could not find it, it seems that the ignition pads have a fixed position, it does not allow adjustments in its advance.

 
There is good spark on all spark plugs anyway.
I put the fuel tank in place, connect the pressure inlet and outlet pipes.
I turn on the ignition, listen to the sound of the fuel pump priming the circuit while the bike does the check.
I press the starter button and only two cylinders work, one and two, three and four are dead.
It does not hold the idle, it stalls. I try again, still the same failure.
As a last option, I disassemble the injectors again and install the ELR injectors that do work.


 

The problem continues, it is not solved.
I go through all the steps I have followed and find no fault in my procedure.
I change the fuel filter for a new one, nothing.
I change the computer for the one of the other bike, nothing.
I change the relays of the fuel pump, nothing.
There is still spark in all the spark plugs.

In an attempt to drain the injection system to disassemble it again, I close the fuel inlet valve, just when the fuel in the circuit was running out THE ENGINE STARTS TO RUN WITH ITS FOUR CYLINDERS.
I open the valve again to let the engine turn at 2 or 3000 RPM and it dies again.
Another attempt, I close the fuel and the engine ends up starting, I open it again and the engine stops after losing cylinders 3 and 4.
The fuel enters through the red arrow tube, it seems that there is an excess of pressure that cancels out cylinders three and four, while cylinders one and two work.
THE PROBLEM CONTINUES WITH THE TWO BATTERIES OF INJECTORS.


 

The pressure relief valve (green arrow) appears to be working.
The DFI is also working.
 
This injection system is one of the simple ones, it only has a temperature sensor in the engine block, I have tried to heat the sensor to see if there was any change but it still does not respond.
There is no sensor in the Airbox, it was incorporated in the following models.
I don't know what to try anymore.

ANY SOLUTIONS OR IDEAS FROM THE FORUM?

My wife's car has sleeping in the street for two days.
 

Interesting problem. I don't think it's a fuel pressure problem since #1 and #2 are working and yet when the fuel pressure drops, #3 and #4 come to life. Sounds like you have a weak signal going to the injectors on #3 and #4 and not enough power to open the injectors. Either the voltage to #3 and #4 is weak or the ground signal to #3 and #4 is not fully grounding. If possible, could you flip the wiring so that the injector wiring for #3 and #4 can fire #1 and #2 injectors and #1 and #2 wiring flipped to fire #3 and #4 ? If the problem moves to #1 and #2 not firing then you have your problem narrowed down to the signal.
Are you using the DFI box that came with the newly purchased bike? Could you use the DFI computer from your other ELR replica?

Thanks for the response Kawboy.
I had planned to change the position of the cables but I was late and I didn't have time to carry out the test, although with the tester I read the same number of ohms in all the injectors.

In case they fail I will change the wiring, I have a replacement but first I have to condition it, basically hairdressing and beautician since it hurts my eyes when I look at it.

Each DFI is attached to its injector body, I have not touched it for fear of worsening the situation.
The failure symptoms are the same in each set.

Mention that I also do not have ANY ERROR CODE on the dashboard.

It's a milliamp signal and a very small resistance in the circuit could be your problem. Let's not forget that the system is 40 years old. A lot of the wiring corrosion happens between the copper wires and the crimped on connections and not necessarily the connections between the crimped connections to each other.
Looking forward to hearing how you make out.

 Well, I will summarize the work done in the last two weeks.
Tired of being reminded day in and day out by my wife for having a garage full of shit and bike parts, I tried to hurry up and try to get the ELR up and running.
I changed all the electrical installation, but to no avail, it still failed on cylinders three and four.
I changed the injector battery again, the failure still did not go away.
I changed the fuel pump, nothing at all.
I was at a point of desperation thinking of reassembling the old engine.
Every time I try to start the engine, only cylinders one and two work, besides gasoline falls down the airbox drain, the gasoline not burned by cylinders three and four goes back to the airbox.
What the hell is going on?
I take out the spark plugs again and measure the compression of the cylinders, cylinders one and two give a reading of more than 100kg/cm2.
Cylinders three and four ZERO, the fucking needle on the gauge won't move.

I FIGURED OUT WHERE TO START¡¡¡¡

I disassemble the valve cover and check the valve adjustment.
Cylinder one and two are almost perfect, I have to change a shim of a lower numbering to give a little more tolerance.
In cylinders three and four the intake valves are stuck, they do not close and the compression escapes.
Using the shims I had saved from when I adjusted the Z13 I can finish the adjustment.
I check the compression again and cylinder three gives me a reading like one and two, cylinder four is still dead.
I pour some SAE 90 oil into the cylinder to check the compression again, it was not the case that the piston rings were broken, it still gives ZERO compression. With the intake valve closed I spray some VD40 through the intake duct and I see how the cylinder fills, the valve does not close although the adjustment is ok.

I have disassembled the cylinder head.

   

Valves on cylinders one, two and three are watertight, retaining WD40.

   

 

The intake valve of cylinder four does not close completely, after pouring VD40 it is drier than a one-eyed man's eye.

 

I don't know if the person who mounted this engine at the time checked the valve settings, in fact the engine was mounted on the bike but far from being ready to run.
Next week I will be taking the cylinder head of the engine in for repair, it will simply be a rework of the valve housings, I am looking forward to getting back to riding the bike and stop listening to my wife on this subject.
 

Compression testing will tell you if you have a problem. Leak down testing will tell you where the problem is and how bad it is. Leak down testing will also tell you how the engine is wearing down. A well sealed engine will read around 95% and an engine needing rebuild will read between 85-90%. One could argue that you should be able to tell this from a compression test but then you have to account for carbon build up in the head and on the piston crown, where the leak down test doesn't care about any of that. A reasonable leak down tester can be bought fora very reasonable price only a few dollars more than a compression tester. It's an invaluable tool and I won't be without one.

At least you're on the right track. It would be nice to get Eddie back up and running to give Christine something to look forward to.