Bad KLR , No Start Condition ??
07-01-2008, 09:59 PM
#1
Racer
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Bad KLR , No Start Condition ??
Other day I fired up the garage car and she ran for a few seconds and died ...
No spark condition, ended up being the KLR keeping it from running. I changed the chip with another , still no spark condition. I opened the KLR and resoldered joints, but did not notice any cold ones with naked eye. I did notice a capacitor that the bottom might of blew out, but I was not totally convinced.
Ok what keeps the ignition from firing when the KLR fails.
I think the capacitor is at location c303 , 10v 220uf ?? It is at the back right lower board of the KLR.. Thanks for any input ........... Dave
No spark condition, ended up being the KLR keeping it from running. I changed the chip with another , still no spark condition. I opened the KLR and resoldered joints, but did not notice any cold ones with naked eye. I did notice a capacitor that the bottom might of blew out, but I was not totally convinced.
Ok what keeps the ignition from firing when the KLR fails.
I think the capacitor is at location c303 , 10v 220uf ?? It is at the back right lower board of the KLR.. Thanks for any input ........... Dave
07-01-2008, 10:41 PM
#3
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You need to jumper pins 9 and 16 on th KLR plug for the car to start and run without the KLR. It's not recommended for driving just troubleshooting.
07-03-2008, 12:29 AM
#6
The jumper needs to be added to get the timing signal back to the DME which generated it in the first place. With the jumper added, the KLR isn't needed. As stated above, don't run it down the street this way.
07-03-2008, 12:07 PM
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This KLR produced no spark. I am thinking this capacitor blew out ? Battery was dead and I charged overnight , started for 5 seconds , killed and had a bad KLR ...... was hoping to find a fix to have an extra KLR Thanks
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07-03-2008, 10:41 PM
#8
The timing signal generates the injector and coil pulses that go out of the DME. So, the timing signal goes through the KLR to adjust for boost. No timing signal going through the KLR, no spark. The 944NA DME works without a KLR unit, the KLR was added for boost control.
Last edited by Bri Bro; 07-04-2008 at 01:06 PM.
07-04-2008, 07:47 AM
#9
The timing signal generates the injector and coil pulses that go out of the DME. So, the timing signal goes through the KLR to adjust for boost. No timing signal going through the KLR, no spark. The NA DME works without a KLR unit, the KLR has added for boost control.
07-06-2008, 11:04 AM
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Ok I understand how the KLR works, but are u saying theoretically that the KLR could not cause the car to run ? My KLR must have killed the timing signal coming from the DME. Should I try to replace this capacitor ? Thanks
07-06-2008, 12:36 PM
#11
No, the KLR passes ( or modifies) the timing signal to allow boost control. Try jumpering the timing signal at the KLR and see if that works. If it does, get the KLR fixed or replaced.
What capacitor are you talking about? The timing is controlled in the KLR by the uP, there is a driver and a input buffer. It isn't just one part that deals with the timing signal in the KLR.
What capacitor are you talking about? The timing is controlled in the KLR by the uP, there is a driver and a input buffer. It isn't just one part that deals with the timing signal in the KLR.
12-05-2020, 05:36 PM
#12
Three Wheelin'
I am reviving this thread to say thanks to those who have contributed---after years of working on customer 944 Turbos, I thought that I had encountered every manner of crank/no-start possible, but had never personally experienced a KLR-caused no-start until today.
I have a customer's '89 951 in the shop, had some crispy/broken engine speed and reference sensors and a suspected issue with an aftermarket alarm/immobilizer system that would intermittently squawk and chirp, so those items were suspicious. I got out the breaker box and oscilloscope and confirmed that all of the inputs and outputs to the DME were good, had injector pulse but no switching signal to terminal 1 of the ignition coil. I double-checked everything again and thought I was going crazy until I remembered about the KLR. The switching signal to the coil comes from the transistor in the DME, but is first fed via DME pin 31 to the KLR pin 9, and is then transmitted back to the DME from KLR pin 16 to DME pin 32 and then fed to the ignition coil via DME pin # 1.
Hopefully this helps someone even if they don't have a spare KLR to plug in. Even if you don't have an oscilloscope to check for the square-wave pattern of the ignition switching signal, you can use a test light to check for this at the coil terminal 1, then DME pins 31, 32, and 1, or jumper KLR pins 9 and 16 as noted above (though only for testing purposes, not for driving!).
I have a customer's '89 951 in the shop, had some crispy/broken engine speed and reference sensors and a suspected issue with an aftermarket alarm/immobilizer system that would intermittently squawk and chirp, so those items were suspicious. I got out the breaker box and oscilloscope and confirmed that all of the inputs and outputs to the DME were good, had injector pulse but no switching signal to terminal 1 of the ignition coil. I double-checked everything again and thought I was going crazy until I remembered about the KLR. The switching signal to the coil comes from the transistor in the DME, but is first fed via DME pin 31 to the KLR pin 9, and is then transmitted back to the DME from KLR pin 16 to DME pin 32 and then fed to the ignition coil via DME pin # 1.
Hopefully this helps someone even if they don't have a spare KLR to plug in. Even if you don't have an oscilloscope to check for the square-wave pattern of the ignition switching signal, you can use a test light to check for this at the coil terminal 1, then DME pins 31, 32, and 1, or jumper KLR pins 9 and 16 as noted above (though only for testing purposes, not for driving!).
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divil (12-05-2020)
12-05-2020, 06:45 PM
#13
Three Wheelin'
I am reviving this thread to say thanks to those who have contributed---after years of working on customer 944 Turbos, I thought that I had encountered every manner of crank/no-start possible, but had never personally experienced a KLR-caused no-start until today.
I have a customer's '89 951 in the shop, had some crispy/broken engine speed and reference sensors and a suspected issue with an aftermarket alarm/immobilizer system that would intermittently squawk and chirp, so those items were suspicious. I got out the breaker box and oscilloscope and confirmed that all of the inputs and outputs to the DME were good, had injector pulse but no switching signal to terminal 1 of the ignition coil. I double-checked everything again and thought I was going crazy until I remembered about the KLR. The switching signal to the coil comes from the transistor in the DME, but is first fed via DME pin 31 to the KLR pin 9, and is then transmitted back to the DME from KLR pin 16 to DME pin 32 and then fed to the ignition coil via DME pin # 1.
Hopefully this helps someone even if they don't have a spare KLR to plug in. Even if you don't have an oscilloscope to check for the square-wave pattern of the ignition switching signal, you can use a test light to check for this at the coil terminal 1, then DME pins 31, 32, and 1, or jumper KLR pins 9 and 16 as noted above (though only for testing purposes, not for driving!).
I have a customer's '89 951 in the shop, had some crispy/broken engine speed and reference sensors and a suspected issue with an aftermarket alarm/immobilizer system that would intermittently squawk and chirp, so those items were suspicious. I got out the breaker box and oscilloscope and confirmed that all of the inputs and outputs to the DME were good, had injector pulse but no switching signal to terminal 1 of the ignition coil. I double-checked everything again and thought I was going crazy until I remembered about the KLR. The switching signal to the coil comes from the transistor in the DME, but is first fed via DME pin 31 to the KLR pin 9, and is then transmitted back to the DME from KLR pin 16 to DME pin 32 and then fed to the ignition coil via DME pin # 1.
Hopefully this helps someone even if they don't have a spare KLR to plug in. Even if you don't have an oscilloscope to check for the square-wave pattern of the ignition switching signal, you can use a test light to check for this at the coil terminal 1, then DME pins 31, 32, and 1, or jumper KLR pins 9 and 16 as noted above (though only for testing purposes, not for driving!).
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Droops83 (12-07-2020)
12-06-2020, 03:14 PM
#14
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Good advice. It's also worth knowing that pin 31 from the DME drives both the KLR ignition input *and* the tachometer, in parallel. That's why it's so important to note if your tach needle bounces while cranking. If it does, then your DME is definitely outputting an ignition signal. At that point, if you still don't have a spark, it's down to the KLR or the coil. So you can eliminate a lot just by watching the tach.
12-07-2020, 01:56 AM
#15
Three Wheelin'
And...the factory boost gauge is driven by the KLR, and should read about 1 with the ignition on and the motor not running. That's a pretty good proxy for knowing if the KLR/DME is getting power. Between tach bounce and the boost gauge, you can tell quite a bit without leaving the car.
Last edited by Droops83; 12-07-2020 at 02:04 AM.
