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1Back to top Go down   Fuel injection module gone bad - update Empty Fuel injection module gone bad - update on Tue Nov 10, 2015 2:13 am

tonybob

tonybob
active member
active member
Hi all -
 
A follow-up on my 85 K100RS posting on Oct 9th.  I finally got some time to start troubleshooting using the EFI guide from the portal.  Here’s what I’ve found so far.
 
Fuel injector resistance is close to 16 ohms per injector.  I’m getting 19.4, 19.8, 16.8 and 17.1 for injectors 1-4 resp.
 
Checks of the injection module resistance and voltage values are for the most part good, for what I was able to measure.  However, I’m seeing these potential issues (or maybe I’m not measuring something correctly?):
1) power to hall sensors measured at the hall plug after the ignition module measures 10.60V, not 12V
2) pin 7 reads 11.58V with the starter running, not 0-1V – it does read 12.15V with just the ignition switch on, per the guide
3) pin 8 reads 2.5mV with starter running, not 10-20mV
4) pin 11 reads 11.60V with ignition on, drops to around 10V with starter running – not 0-1V per the guide.
5) I also checked the voltage at the coil end of wiring to see what pins 9/10/14 should be pushing to the coils (1.5-4V per the guide).  I’m seeing 0.08V for pin 9, 11.62V for pin 10 and 0.15V for pin 14 all with starter running. 
 
Resistance at coil primaries checks good.  However, high tension leads DO NOT measure any resistance (as if there’s an open circuit).  I suspect the coils have gone bad, but I’m curious if other owners have had this experience.  Both go faulty at the same time due to age?
 
Hall sensors check good.  I used a 12V LED and found that a feeler gauge of 0.012” or greater would break the signal.  Anything thinner (or Al foil) would not break the signal.
 
If I were to replace anything at this time I’d swap out the coils, although with the different readings I’m seeing with the ignition module I’m not so sure.
 
I’m going to continue troubleshooting, next up is the Fuel Injection module check.
 
 
Thanks,
Tony Marts

    

Holister

Holister
Life time member
Life time member
There are 2 control units on the K. The Ignition Control Unit (ICU) under the tank and the Fuel Injection Control Unit (FICU) under the seat. It seems you've been refering to readings for the ICU but you've measured the FICU. That would explain the vast differences. 
Unlikely too be the FICU or ICU as they're pretty reliable. 

HT leads should measure around 5 kilohm. Make sure you are on the correct range. Open circuit would be infinitely high resistance. 

Would be a good idea to post in your original thread so you keep your posts for this issue together. 
Cheers.


__________________________________________________

1989 K100RT     VIN  0097367 (naked)  
1996 K1100RS   VIN  0451808
  Fuel injection module gone bad - update Austra12    Fuel:  95 Octane
Engine Oil: Nulon Full Synthetic 15W50
Gear Box Oil:  Nulon Synthetic 75W90
    

tonybob

tonybob
active member
active member
Thanks Kaptain.  Yes, I was taking measurements at the female connector for the ignition control unit - ICU - located under the tank.  When I first started the checks, using the guide, I was reading the pin numbering incorrectly on the female plug.  So, the first check I made, pin 1 to ground, didn't read at all.  Then I realized that the numbering was mirror-image (looking at the description in the troubleshooting guide). Once I had that settled, all the other checks proceeded, although the values are off compared to the guide for some of the checks.

I've just started checks tonight at the Fuel Injection Control Unit female plug (the one under the seat).  I'll update once I've run thru those. For now ground checks good and the temp sensor resistance (pin 10) is 3.38k ohm at 14.4 deg celsius.

    

tonybob

tonybob
active member
active member
Well, after working through the EFI troubleshooting guide, I've found that my TPS is faulty.  Unplugged it yesterday and she started first try (although rough running initially due to all the accumulated fuel in the cylinders).  Also re-started a couple of times after sitting, so I'm thinking this was the problem all along.

I'm going to leave it un-plugged after reading many posts here on the forum and see how she runs.  Many thanks to everyone who provided suggestions!


Tony Marts

    

charlie99

charlie99
VIP
VIP
good to hear tony

pretty weird those tps switches ...I think we have seen one or two with those issues ...but not many


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%OFuel injection module gone bad - update Au-log10

'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
    

rawdonball

rawdonball
Platinum member
Platinum member
+1 for perseverance!


__________________________________________________
'88 K100RT, '86 K75C, '05 Yamaha TTR250
    

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