DT/tclh 140 won't Idle

[bartow buddy]

Took your advice Solarman and tried the coil, the coil is bad put new plugs in and still can't get fire through that coil. you can pull the wire off plug and it won't change the running at all. can the emergency kill switch cause one coil to not fire or just every now and then? Thanks

[Solarman]

dt140EFI, running issues

Ellis, you might swap one of your other working coils, with that "bad" coil, and see if your problem followed the change.

[bartow buddy]

I changed it today but didn't have time to run it will try and do it tomorrow. Well got out there early and ran it for a few minuets and now I am really confused. put the third coil down from the top up where I thought the bad one was #2 and when i pulled the wire off didn't notice a change put it back down to #3 and pulled it off and it skipped untill I put it back on. When it is running at 1000 rpm it doesn't sound like it is skipping with all the coils hooked up but after it runs 5 min. or so the tach. hand will jump from zero to 1000 up and down and die. I unplugged the throttle valve sensor and it jumped from about 700 rpm. to 1200 rpm and ran good, but even now when you pull the top or second plug wire it doesn't change or seem to skip, that is pulling them off 1 at a time. don't have a clue what to do next. Thank you

[BillCon]

I, have been reading this post, and I'm wondering if this could be all the way back to the gear counting coil, it may not be sending the correct signal to the ICU when to tell the coil to fire. I've not seen one only be on a single cyclinder but it could be possible.

[bartow buddy]

I, have been reading this post, and I'm wondering if this could be all the way back to the gear counting coil, it may not be sending the correct signal to the ICU when to tell the coil to fire. I've not seen one only be on a single cyclinder but it could be possible.

Thanks BillCon I have taken the gear counting coil off and cleaned it and set it by the suzuki manual as per the clearance but didn't check the ohms on it as I don't have a meter, guess I will have to have that done. I took it to the lake today but didn't take it off the trailer just cranked it and tried to adjust everything it would run good for a few min. and then the tach. needle would start jumping from zero to about 1200 rpm. and sometimes it would just drop to zero for a min. and then start jumping again. I have noticed that there are numbers 1 2 3 4 on the back of the coils will they work on any cyl. and is the # there just because of the wire colors? And what do they mean in the manual by the secondary coil ? Thank you for your help Ellis

[Solarman]

dt140, running issues

Sorry Ellis, and bill, the gear counting coil would affect all cylinders. It affects all by telling the ECU the speed of the crankshaft. It has to count each tooth of the flywheel, why it needs to be proper distance. If it misses teeth ecu thinks crank is in different speed/ & position.

Yes Ellis, the 4 coils will work in other places, the numbers do relate to the wire color. That's the only difference I've found. yes, there are 2 coils on each unit, a primary coil and a secondary coil. The manual has an ohm test for each side of the coils. But if you swap places with another coil and problem is still in the same cylinder then the coil is probably fine. If the problem follows the coil you moved, the coil is likely bad.

if your coil wiring is repaired, and still having problems with same cylinder, let us know.
If you unplugged the tps, and motor stopped running badly, smoothed out, need to know.
Let us know what you find.

[bartow buddy]

Sorry Ellis, and bill, the gear counting coil would affect all cylinders. It affects all by telling the ECU the speed of the crankshaft. It has to count each tooth of the flywheel, why it needs to be proper distance. If it misses teeth ecu thinks crank is in different speed/ & position.

Yes Ellis, the 4 coils will work in other places, the numbers do relate to the wire color. That's the only difference I've found. yes, there are 2 coils on each unit, a primary coil and a secondary coil. The manual has an ohm test for each side of the coils. But if you swap places with another coil and problem is still in the same cylinder then the coil is probably fine. If the problem follows the coil you moved, the coil is likely bad.

if your coil wiring is repaired, and still having problems with same cylinder, let us know.
If you unplugged the tps, and motor stopped running badly, smoothed out, need to know.
Let us know what you find.

When I unplug the Tps. it usually smooths out and the rpm increases 200 or more rpm and it will run a few min and then the tach needle will start jumping and the motor starts missing then the needle will stop jumping and it will smooth out.

[Solarman]

dt140, carbs, running issues

Ok Ellis, do you have to run to the ramp to fire up your motor each time? Don't you have any muffs to run the motor on at home?

When you run with tps connected, does the motor run a few mins before it starts skipping, when the tach starts jumping? When tps is disconnected and it smooths out, then what happens?
Can you throttle up a little (200 to 300 RPMs) then idle back again, does it repeat again? Are all 4 carb air mixture screws set the same? What are they set at now? What does the manual say to set them at?
Are you sure that all the plug wires are good now? When it skips have you looked to see if any Sparks are jumping? It might be easier to look for Sparks if is dark when motor starts skipping. If you see something in dark, check it in daylight to see the problem.

Ellis, you have to be my eyes, ears, and hands. Anything you notice might help me understand a little more.
Let us know how it's going.

[bartow buddy]

Thank [QUOTE=Solarman;15545]Ok Ellis, do you have to run to the ramp to fire up your motor each time? Don't you have any muffs to run the motor on at home?

When you run with tps connected, does the motor run a few mins before it starts skipping, when the tach starts jumping? When tps is disconnected and it smooths out, then what happens?
Can you throttle up a little (200 to 300 RPMs) then idle back again, does it repeat again? Are all 4 carb air mixture screws set the same? What are they set at now? What does the manual say to set them at?
Are you sure that all the plug wires are good now? When it skips have you looked to see if any Sparks are jumping? It might be easier to look for Sparks if is dark when motor starts skipping. If you see something in dark, check it in daylight to see the problem.
Thanks Solar Man I had the thing running 20 to 30 min on the hose and thought i had it so i took it to the lake to see if the back pressure would change the rpm and cause the problem and it ran fine at idle and up to about 2/3 throttle and seemed to miss or bog down some and i tried to lower the idle just a little and the tach. started jumping and then just stopped untill i raised it back up but the tach. still moved 1/8 inch up and down. unplugged the tps. and tach. didn't work at all and engine revs. went way up up but tach. still was on bottom.
The last time i ran it on the muffs i found that after it was first started and dropped down to idle it would just jump and die so i set the idle screw up and as long as i have it running around 800 rpm it will run fine but if you back the idle screw up the tach. will start jumping and then sometimes it will stop jumping and level back out. and when it is running at that rpm on the muffs it doesn't appear to be skipping but has a distinct sort of popping sound out of the exhaust. and yes when i had it running at 800 i could raise it and lower it back down to 800. when it is running and you pull the cap off the plug it will shock you but i haven't looked at it in the dark again but will do it. the idle speed switch still doesn't have any effect on it at all. but what i can't figure is when you pull the top or 2nd. plug wires it doesn't change but you pull #3 or 4 and it will skip. I'm sorry to skip around so much but Thank you for your time.

[BillCon]

I, do remember on mine when the TPS was out of adjustment at Idle it was popping too, turned out it was slightly off and kicking the timing up at idle when it was supposed to come in at 3-5 degrees throttle advance, if that is happening your trolling speed switch will seem like its not working and reeks havoc trying to set the idle speed, and will sometimes die when you come off a run down to idle speed.

[bartow buddy]

I, do remember on mine when the TPS was out of adjustment at Idle it was popping too, turned out it was slightly off and kicking the timing up at idle when it was supposed to come in at 3-5 degrees throttle advance, if that is happening your trolling speed switch will seem like its not working and reeks havoc trying to set the idle speed, and will sometimes die when you come off a run down to idle speed.

Thanks Bill Con Will try that as well I am still looking for loose wires and cleaning and looking for all the grounds to make sure that everything is properly grounded.

[Solarman]

dt140, carbs, running issues

Ellis, the tps has to be set properly. It is possible that it was removed during carb cleaning, and never set back up when reinstalled. You should have the manual on your motor by now. As Billcon mentioned it does tell the computer to advance timing according to throttle position. Read the section carefully before adjusting.
The tach is part of the system and you might read up on that as well. I think between the two sections (unless wires are still faulty), you should be able to get your motor to smooth out, and run properly again.
Good luck, and keep us posted.

[bartow buddy]

Ellis, the tps has to be set properly. It is possible that it was removed during carb cleaning, and never set back up when reinstalled. You should have the manual on your motor by now. As Billcon mentioned it does tell the computer to advance timing according to throttle position. Read the section carefully before adjusting.
The tach is part of the system and you might read up on that as well. I think between the two sections (unless wires are still faulty), you should be able to get your motor to smooth out, and run properly again.
Good luck, and keep us posted.

Wires are good now and yes the tps. was removed during vatting of the carbs. I have had the suzuki manual for over a week now and have read the parts you mention and I am trying to get all the grounds and other wiring plugs checked and cleaned. haven't been able to work on the last 2 days but will tomorrow. Thank you for your help.

[Solarman]

dt140, carbs, running issues

Good to hear. The tps is not easy to get just right without some of the dealer tools, but you should be able to get it close enough for your motor to run good. Many dealers don't work on the older two stroke motors, they try to sell the 4 stroke. Not sure in your area.
Keep us posted on how it goes.

[bartow buddy]

Good to hear. The tps is not easy to get just right without some of the dealer tools, but you should be able to get it close enough for your motor to run good. Many dealers don't work on the older two stroke motors, they try to sell the 4 stroke. Not sure in your area.
Keep us posted on how it goes.

Well I put a new ignition coil the #2 cyl. today and it won't fire and the top one doesn't fire either, it cranks and runs and doesn't seem to be skipping but you can take the two top plug wires off and it runs the same. could this be because of the low oil sensor or because of the tps. or idle speed switch? Thanks