Chinese 110 atv cdi issue
#1
06-17-2012, 09:45 AM
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Chinese 110 atv cdi issue
Hello. i am new to these headaches but have done alot of research and testing to no avail. The issue is when i crank it over, I have weak or intermitent spark. coil is good, bypassed all saftey switches, all plug connections are good, and grounds are good. Changed cdi, bought 2 brand new cdi's from one company, and 1 cdi from another company. same result. I heat the original cdi up with a hair dryer and fires right up no issue. figgured problem was solved. both new cdi's have same result. heat them up and machine fires right off. thought maybe by an odd stroke of luck i got 2 bad cdi's. so i got another.... same issue. Im lost now. I have delt with plenty of cdi's quitting when warm, but not functioning only if warm. Tested input side from pickup and power feed and seem fine. The coil feed and ground are good also. I did notice backprobing ground on cdi to engine ground. .01 ohm with ignition off. With it on, resistance changes to 20 ohm's. ANY help would be awesome and greatly appreciated.
#2
06-17-2012, 10:16 PM
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This is a strange problem.
Some questions to get us started:
1) How many pins on your CDI? Four or Five?
2) Do all three CDIs produce "no spark" and produce "good spark" when heated with a hair dryer?
3) When do you see this "weak or intermittent" spark? Is that only when the CDI is cold, or do you occasionally see it when the CDI is warm?
On the ground resistance changing between ignition on and off: The resistance is not changing. Instead there is a voltage drop being produced across across the ground wire when you turn on the ignition, and that is fouling up the resistance measurement. So try this: Measure the DC voltage from the ground pin at the CDI to engine ground with the ignition off (should be 0.00 volts), and when the ignition is on. Let's see if this is something we need to worry about.
Some questions to get us started:
1) How many pins on your CDI? Four or Five?
2) Do all three CDIs produce "no spark" and produce "good spark" when heated with a hair dryer?
3) When do you see this "weak or intermittent" spark? Is that only when the CDI is cold, or do you occasionally see it when the CDI is warm?
On the ground resistance changing between ignition on and off: The resistance is not changing. Instead there is a voltage drop being produced across across the ground wire when you turn on the ignition, and that is fouling up the resistance measurement. So try this: Measure the DC voltage from the ground pin at the CDI to engine ground with the ignition off (should be 0.00 volts), and when the ignition is on. Let's see if this is something we need to worry about.
#3
06-18-2012, 08:35 AM
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Thanks for taking the time to try and help. It is a 5 pin cdi. All cdi"s do produce spark when cold, sometimes intermitentley. and as soon as they are heated enough, the machine will fire right up and run until you shut it off. Just wont fire back up after. The results are all the same with all 4 (including the original) cdi's. Temp is around 140 when heated. i use a hair dryer because im afraid the heat gun would destort them.
Now as far as the ground... it does read 0.00 when ignition switched off. It reads 0.86 mv(dc) when switched on, and surges to around 20.0 mv when cranking. And these results are the same with all of the cdi's. I assume it must be backfeeding or steeling ground somewhere. I always figgured heat created resistance, just not sure if that applies to this situation. also should mention that stator voltage ouput at cdi is 29v when cranking with cold cdi, 45 to 55v when warm and running. Obviousley a red flag. just not sure the cause.
Now as far as the ground... it does read 0.00 when ignition switched off. It reads 0.86 mv(dc) when switched on, and surges to around 20.0 mv when cranking. And these results are the same with all of the cdi's. I assume it must be backfeeding or steeling ground somewhere. I always figgured heat created resistance, just not sure if that applies to this situation. also should mention that stator voltage ouput at cdi is 29v when cranking with cold cdi, 45 to 55v when warm and running. Obviousley a red flag. just not sure the cause.
#4
06-19-2012, 12:45 AM
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This problem is so weird that I have to ask the following:
Is 100% consistent? The quad *never* starts up with the CDI(s) cold, and *always* starts up when you heat the CDI(s) up with a hair dryer? Or did this happen a few times, but maybe not every time? It is surprisingly easy to get locked into a train of thought that later turns out to be entirely circumstantial.
I also wondering about your 0.86 mV DC reading. What brand and model meter are you using? Meters with display resolutions down to 10 microvolts (0.01 millivolts) are not that common (and pricey too). Did you borrow this from work? Not that a few tens of microvolts (ten microvolts = 0.00001 volts) matter here or there, but I have to wonder if your actual value is actually orders of magnitude greater, and you have the scale wrong. It it was 0.86 volts (1000 times greater than 0.86 millivolts) than that would be very significant and something we need to look into.
Measuring AC ignition power voltage to the CDI when it is hooked up has a zillion caveats. The stator output is current limited, and the CDI yanks the stator voltage around in normal operation. So any voltage measured while the AC ignition power from the stator and CDI are hooked up doesn't give much info. For example, is low voltage the result of the CDI yanking the stator voltage too hard, or is the stator just not up to the task? There is no info in this measurent. The best way is to measure the stator ignition power voltage while disconnected from the CDI while cranking the starter motor. Thus it is measured completely independant from the CDI loading.
So for a five pin CDI here is a the troubleshooting procedure for "no spark". I would do the tests below while the CDIis cold and not starting. Report back values for all the tests with as much detail as possible. I'm fishing for clues.
Also, does this quad have a remote module? If so have you tried unplugging it?
Is 100% consistent? The quad *never* starts up with the CDI(s) cold, and *always* starts up when you heat the CDI(s) up with a hair dryer? Or did this happen a few times, but maybe not every time? It is surprisingly easy to get locked into a train of thought that later turns out to be entirely circumstantial.
I also wondering about your 0.86 mV DC reading. What brand and model meter are you using? Meters with display resolutions down to 10 microvolts (0.01 millivolts) are not that common (and pricey too). Did you borrow this from work? Not that a few tens of microvolts (ten microvolts = 0.00001 volts) matter here or there, but I have to wonder if your actual value is actually orders of magnitude greater, and you have the scale wrong. It it was 0.86 volts (1000 times greater than 0.86 millivolts) than that would be very significant and something we need to look into.
Measuring AC ignition power voltage to the CDI when it is hooked up has a zillion caveats. The stator output is current limited, and the CDI yanks the stator voltage around in normal operation. So any voltage measured while the AC ignition power from the stator and CDI are hooked up doesn't give much info. For example, is low voltage the result of the CDI yanking the stator voltage too hard, or is the stator just not up to the task? There is no info in this measurent. The best way is to measure the stator ignition power voltage while disconnected from the CDI while cranking the starter motor. Thus it is measured completely independant from the CDI loading.
So for a five pin CDI here is a the troubleshooting procedure for "no spark". I would do the tests below while the CDIis cold and not starting. Report back values for all the tests with as much detail as possible. I'm fishing for clues.
Also, does this quad have a remote module? If so have you tried unplugging it?
Is this a picture of your CDI?
Assuming the answer is yes, the first thing to do is eliminate all kill switches and kill switch wiring:
Method 1) Unplug the CDI and remove the kill switch pin in the CDI connector on the wiring harness. The pin is held in with a spring tab on the pin itself. You'll have to probe into the connector and push this tab in order to extract the pin. Plug the CDI back in (kill switch wire dangling) and see if you have spark.
Method 2) Unplug the CDI. Turn on the ignition switch and set all kill switches to the run position. Use a meter to measure resistance in of the kill switch pin in the wiring harness connector to engine/frame ground. If the resistance is infinite on the 200K ohm scale then your kill switches/kill switch wiring are OK. If you measure zero ohms then you have a kill switch/wiring issue.
The other inputs your CDI needs to make spark are AC Ignition Power, and the Trigger signal. Do the following:
1) Unplug the CDI. In the wiring connector measure the resistance of the AC Ignition Power pin to the Ground pin. You should see 400 ohms or so. What do you measure?
2) Measure the resistance of the Timing/trigger pin to the ground pin. You should measure 150 ohms or so. What do you measure?
3) Leave the CDI unplugged. Set your meter to measure AC volts on the 100 volt scale. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC while the engine is cranking. What do you measure?
4) Set your meter to measure AC volts on the lowest scale you have. Ideally this would be 2 volts but many meters don't go down this low. In that case use the lowest scale you have. Measure the voltage on the Timing Trigger pin to the Ground pin while cranking the engine. You should 0.2 t0 0.4 volts AC. What do you measure?
Now for measuring the output side of the CDI:
A) Leave the CDI unplugged. In the CDI wiring connector measure the resistance of the Ignition Coil pin to the ground pin. You should measure less than 1 ohm (but not zero ohms). What do you measure?
B) Plug the CDI back in. Set your meter to measure AC volts on the 20 volt scale. Set all kill switches to the run position. Crank the engine while measuring the voltage on the Igntition Coil pin to ground. Poke through the insulation of the wire if you can't probe the connector.
Caution: There should be moderately high voltage spikes on this wire. Make sure your fingers are not part of the circuitry. Don't touch the probe lead tips while doing this test.
What you should see is a lot of random numbers with lots of zero values as well. This is because the meter may catch all or part of the spark event voltage, with a lot of nothing in between. Describe what you see.
Note: Using a meter to measure this point produces highly variable results depending on the meter. What you really need is an oscilloscope, but most always a meter is all that is available. We have to do the best we can with what's available. Describe the meter results as accurately as you can - there is information there to chew on....
Assuming the answer is yes, the first thing to do is eliminate all kill switches and kill switch wiring:
Method 1) Unplug the CDI and remove the kill switch pin in the CDI connector on the wiring harness. The pin is held in with a spring tab on the pin itself. You'll have to probe into the connector and push this tab in order to extract the pin. Plug the CDI back in (kill switch wire dangling) and see if you have spark.
Method 2) Unplug the CDI. Turn on the ignition switch and set all kill switches to the run position. Use a meter to measure resistance in of the kill switch pin in the wiring harness connector to engine/frame ground. If the resistance is infinite on the 200K ohm scale then your kill switches/kill switch wiring are OK. If you measure zero ohms then you have a kill switch/wiring issue.
The other inputs your CDI needs to make spark are AC Ignition Power, and the Trigger signal. Do the following:
1) Unplug the CDI. In the wiring connector measure the resistance of the AC Ignition Power pin to the Ground pin. You should see 400 ohms or so. What do you measure?
2) Measure the resistance of the Timing/trigger pin to the ground pin. You should measure 150 ohms or so. What do you measure?
3) Leave the CDI unplugged. Set your meter to measure AC volts on the 100 volt scale. Measure the voltage on the AC Ignition Power pin to the ground pin while cranking the engine. You should see 40 to 80 volts AC while the engine is cranking. What do you measure?
4) Set your meter to measure AC volts on the lowest scale you have. Ideally this would be 2 volts but many meters don't go down this low. In that case use the lowest scale you have. Measure the voltage on the Timing Trigger pin to the Ground pin while cranking the engine. You should 0.2 t0 0.4 volts AC. What do you measure?
Now for measuring the output side of the CDI:
A) Leave the CDI unplugged. In the CDI wiring connector measure the resistance of the Ignition Coil pin to the ground pin. You should measure less than 1 ohm (but not zero ohms). What do you measure?
B) Plug the CDI back in. Set your meter to measure AC volts on the 20 volt scale. Set all kill switches to the run position. Crank the engine while measuring the voltage on the Igntition Coil pin to ground. Poke through the insulation of the wire if you can't probe the connector.
Caution: There should be moderately high voltage spikes on this wire. Make sure your fingers are not part of the circuitry. Don't touch the probe lead tips while doing this test.
What you should see is a lot of random numbers with lots of zero values as well. This is because the meter may catch all or part of the spark event voltage, with a lot of nothing in between. Describe what you see.
Note: Using a meter to measure this point produces highly variable results depending on the meter. What you really need is an oscilloscope, but most always a meter is all that is available. We have to do the best we can with what's available. Describe the meter results as accurately as you can - there is information there to chew on....
#5
06-20-2012, 08:38 AM
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Sorry i am going to try and re-do my messurements later today. As far as the consistancey, will not start cold ever...as soon as there heated, it starts. And the voltage reading are consistant with two meters. A mac auto ranging, And a greenlee auto range. That cdi in the picture, IS the cdi i have. I have been doing these test so far already having pulled the kill pin out of the cdi plug. All saftey switches and have been tested and eliminted. So i will test from step 2 on again and let you know the results. Thank you for helping.
#6
06-27-2012, 07:27 PM
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Sorry for the delay. I have been busy on other jobs. so test #1 results for AC power to ground pin, i messured 509k.
For test #2. Trigger pin to ground i messured 155 ohms.
For test #3. ignition power to ground while cranking, i messured 56 volts AC.
For test #4 Timing trigger to ground while cranking, i messured 142 mv AC.
Cdi unpluged to ground resistance i messured .06 ohms.
Cdi pluged in ignition coil to ground, i messured .012 volts AC.
I hope this is good info for you. also i have changed stator and pickup and these messurments were using that.
For test #2. Trigger pin to ground i messured 155 ohms.
For test #3. ignition power to ground while cranking, i messured 56 volts AC.
For test #4 Timing trigger to ground while cranking, i messured 142 mv AC.
Cdi unpluged to ground resistance i messured .06 ohms.
Cdi pluged in ignition coil to ground, i messured .012 volts AC.
I hope this is good info for you. also i have changed stator and pickup and these messurments were using that.
#7
06-27-2012, 11:55 PM
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Test #1 cannot be 509K ohms. That would be 509,000 ohms. That would be a big problem except you also got 56 volts AC while cranking. Those two answers cannot coexist. One of them is wrong. Perhaps the resistance is 509 ohms?
So during the time you were doing these measurements were you getting spark? I realize of course that many of the tests are done while the CDI is unplugged so there won't be spark, but was there spark before the tests? Was there spark after the tests?
I don't see any red flags in your data other than the following:
1) The Ignition AC power resistance is way too high (already discussed above).
2) The trigger voltage is a little low. You are fortunate to have a meter with good low end resolution, so it should have a higher trigger voltage than this. If it were a harbor freight cheapo meter where the lowest digit possible is 0.1 volt I could see where meter limitations come into play. But your meter should not suffer this limitation. The lack of voltage at the ignition coil also suggest the trigger voltage is too low and not triggering the CDI. Or your CDI is bad, but you've put in multiple CDIs, as well as two stators.
That is why I'm asking the question about whether you had spark before and after these tests. If you did have spark then your trigger voltage is sufficient, and your ignition coil voltage should be higher so we have meter issues. If you didn't have spark then we are looking at trigger voltage and/or bad CDI issues...
And none of this makes sense where you have multiple CDIs that work only when heated with a hair dryer. Is this still the case with a new stator? Put on your skeptic hat and try to refute this hypothesis - because it seems so utterly unlikely. Is it still the case that you quad starts everytime when heating any of your many CDIs?
So during the time you were doing these measurements were you getting spark? I realize of course that many of the tests are done while the CDI is unplugged so there won't be spark, but was there spark before the tests? Was there spark after the tests?
I don't see any red flags in your data other than the following:
1) The Ignition AC power resistance is way too high (already discussed above).
2) The trigger voltage is a little low. You are fortunate to have a meter with good low end resolution, so it should have a higher trigger voltage than this. If it were a harbor freight cheapo meter where the lowest digit possible is 0.1 volt I could see where meter limitations come into play. But your meter should not suffer this limitation. The lack of voltage at the ignition coil also suggest the trigger voltage is too low and not triggering the CDI. Or your CDI is bad, but you've put in multiple CDIs, as well as two stators.
That is why I'm asking the question about whether you had spark before and after these tests. If you did have spark then your trigger voltage is sufficient, and your ignition coil voltage should be higher so we have meter issues. If you didn't have spark then we are looking at trigger voltage and/or bad CDI issues...
And none of this makes sense where you have multiple CDIs that work only when heated with a hair dryer. Is this still the case with a new stator? Put on your skeptic hat and try to refute this hypothesis - because it seems so utterly unlikely. Is it still the case that you quad starts everytime when heating any of your many CDIs?
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#8
06-28-2012, 09:34 AM
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Originaly i did have spark when doing this test. would not run unless heated. I just switched the staors back and forth with no difference. I will retest the ohms. and the redings where with two meteres. now out of no where last night i have no spark or voltage with either stator or different cdi. I know none of this makes scence. All the people i have talked to have had the same reaction. Also i am jumping this with another battery here and there to check for different results. maybe spinning faster? im pretty lost.
#9
06-28-2012, 11:10 PM
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Totally dead is *always* better than being intermittent. It's easier to troubleshoot since it's not any longer on the edge of working and not working...
While it is totally dead do all of the CDI tests and report those readings. Do the whole test routine with great care. This should help get to the bottom of your (now) no spark problem.
While it is totally dead do all of the CDI tests and report those readings. Do the whole test routine with great care. This should help get to the bottom of your (now) no spark problem.
#10
07-02-2012, 10:32 AM
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So here's an update. Test 1 was 510k. Test 2 was 156.7 ohms. Test 3 was 47.8v ac. when unplugged. With the cdi plugged in it was 28v ac. Test 4 was .054 v ac. Test A was .4ohms. Test B was 0.1v ac. I did notice when cdi plugged in i have 28v at the ignition power pin. if i unplugged the cdi it has 47.8v. these readings are with new and old stator and all cdi boxes.