Fuel Injection running rich.

I'm still on the steeper portion of the learning curve and I'm still struggling with a fuel injection system that runs too rich. I'm trying to grok my way to a solution rather than addressing every possibility even though they may already be in line.

My latest decision point is: Are my injectors in need of a cleaning? I've had two professional fuel injection mechanics tell me that clogged or varnished injectors will always run lean. I've had some advice to the contrary saying that poorly atomized fuel mist will result in a too rich condition.

How about it clogged injectors, rich or lean? It can't be both.

KZCSI

Not enough information. What system is this? Generally I would suspect...

1)electrical connection
2)sensor
3)sensor out of adjustment

before messing with the injectors.

-Duck

ostfuel injection systems are looking at a few things, engine temp, o2 sensor readings, and air flow, I know this basic, but you have to think like a computer to figure them out.

IIRC, it's a 83 KZ1300

Generally, one or maybe two cylinders running rich or lean would indicate problems with the injectors, running rich or lean on all cylinders generally (99% of the time) indicates a prolem with the system.

I just looked at the parts diagrams on buykawasaki.com, and it does not appear to have either a MAP or MAF sensor, so that means it's an Alpha-N system. And that means the computer uses three inputs to determine the amount of fuel to inject, RPM, Engine Temp, and Throttle Position. I remember you had a problem with your Temp Sensor in the past, and got it fixed? I suspect that either the Engine Temp Sensor has gone bad again, or the TPS is out of adjustment. Have you been to the KZ1300 site to see what EFI help is available there?

Did you do the GM coil pak conversion (just trying to eliminate an ignition problem)?

Just for grins I think you should verify that you are getting proper voltage to the coils.

And no, I don't think a partially clogged injector will make it run rich, especially if it's all six cylinders. If it's one or two, then OK, strange things do happen.

Hi Steve,

All my sensors check out fine. I have two igniters and two DFI computers. I have swapped them every which way to no avail. The TPS still had the factory tamper paint on the screws so I know that it hadn't been messed with before I got started. For a while I was getting a code for the TPS but I managed to clean it and that cleared the code.

I just got my fuel pressure regulator back from Pouge Engineering. They charged me $90 to modify it so that it's adjustable. If I can't find the cause I'm going to dial down the pressure as a work around solution.

Regarding the GM Coil pack conversion. Check out my article in the articles section. That particular modification ranks right up there with magnets on your fuel line for better mileage.

I did check the voltage to the coils and found 12 volts. I did just now replace the coil wires and plug caps as most of the springs in the caps were gone. All of the plug caps were just resting on the plugs instead of gripping the threaded end of the plugs. Before I go adjusting the fuel pressure I'll run it with a new set of plugs to see if the wires and caps were the problem.

The folks at KZ1300.com are telling me to have my injectors cleaned as partially plugged injectors, according to them, will result in a rich condition. Pogue Engineering tells me that whomever said plugged injectors run rich has got it backwards.

You and I exchanged about my problem some months back. If you recall I said that my system was running at 35PSI and still held 20 PSI 24 hours later. Which tells me that my injectors are not leaking when closed.

Actually it's an 85 ZN1300. Fortunately, this bike is a long term project so I'm not without wheels.

Thank You

Bill

Well, considering that's it's been awhile since the temp sensor discussion, missing by two years on the model ain't to bad
Pogue is right, the info on the 1300 board is wrong, think about it, what are the chances of six separate injectors being wrong in exactly the same way (Ok, maybe greater than the chance of me winning the Lottery)

Assuming you have a manual for it, I'd look and see what it says regarding testing and setting the TPS. If the TPS is outputting (is that really a word?) a higher voltage than it should, then the computer is going to think that the engine is under a greater load than it actually is, and is going to inject more fuel to compensate.

but you have to think like a computer to figure them out.

Heh, not like I have not been accused of thinking like a computer a hundred times :laugh:

Hey Steve,

Well I put it back together and it ran fine for ten minutes till it started to bog when I opened the throttle. I took the seat off and there was that damn code for a bad throttle position sensor again. I should have replaced it the first time I saw the code a year ago.


I can get a new one for $500.00. I also have a set of carbs but I'd prefer to keep it fuel injected.

I'm sure I'm not finished with my troubles with this project. So please hang in there with me. I really appreciate the feed back.

Thank You
Bill

Post edited by: KZCSI, at: 2006/02/18 16:52

$500 for a TPS! I have a hard time wringing that much $ out of my pocket for a WHOLE BIKE

Is this a concourse restoration or do you just want to ride it?
TPS is a potentiometer. With specs you can fabricate a suitable replacement. Without specs you can disassemble the bad one and measure the specs. If it is indeed bad, as per the FSM test procedire, I'd take it apart and see if it's not something mickeymouse like a bad solder joint.

If you just want to ride, I suggest putting the $500 toward a more modern comntroller.

I may well be facing the same shakedown and wallet squeeze on the 82GPz1100/KZ1100B2 (these model numbers are confusing). Finally fixed PO's damage to head and fished around in case for missing head parts. Will have her back together as soon as the gaskets get here and then attack the original problem that got PO messing with head in the first place. His description of symptoms suggest running lean....How that translated to "jumped timimg chain" is a mystery.

Where are you at?


-Duck

Hey Duck,
I'm in Central Oregon, Bend to be exact. At first the readings were off the scale resistance wise so I dunked the TPS in denatured alcohol and twirled it about a bit. After blowing it out with compressed air the readings returned to just where they should have been. I suppose that now that I've decided that it's toast, I could get a bit more agressive with my attempts to fix it. I'll take it off again and see what needs to be done to see it's innards.

Thanks
Bill
KZCSI

Bend. I used to sell a lot of used unix hardware to a guy up there.

If you get it apart, take some photos with a scale and let me know the specs. Don't forget taper (how the resistance changes with position, most likely linear or logrithmic, I doubt it's anything funky). I may be able to scare up a suitable mil spec potentiometer for replacement. You'd have to fab a mount and a housing but if you can do this in home workshop it's way cheaper than $500.

-Duck

81-84 (at least) GPz1100
84-85 GPz750 Turbo
Use the same TPS as yours, 21176-1004 is the part number.
$330.82 at www.ronayers.com/index.cfm although Z1 Enterprises may be able to get it cheaper.

And you can get a complete GPz750 Turbo or GPz1100 throttlebody on eBay for ~$100 and I need some other parts so I'd split the cost with you :laugh:

Test yours and if it actually bad PM me and we will work something out.

Hi Steve,

That's a great offer but I already made a deal for a complete set of throttle bodies with the TPS and the pressure regulator and the MAP sensor for $250.00.

How did you cross reference those part numbers?

Of course I do have a KZ1100 that needs to have the carbs reinstalled.

It really would be fun to have a generic fuel injection controler to use to replace carbs.

What do you know about Mega Squirt?

Thanks for the offer.

Bill