Stihl TS 500i, no spark

[Poleman]

Ok guys.....I need some help....ya in more ways than one...I know.

Here's the situation: Playing with a 550 i that didn't have spark. Purchased a new module and a generator. I try ed the module first...nothing. next I put in the generator and it fired right up!!

Now the issue.....I thought (wrong thing to do) I'd put the old module back in and see if it was the generator....no start again. I then put the new module back in and have traced wires....wiggled this and cleaned that....nothing. I have pulled on this thing my right arm looks like Arnolds in his day.

Am I missing something on this? Being fuel injected I know I'm in way over my head here and any pointers and help would be much appreciated!!!

Thanks.......a LOT!!!

 

[o8f150]

fill it up with fuel

 

[Poleman]

Lol...I did, next...

 

[pioneerguy600]

Check for spark. No use pulling if it does not have spark. If it has spark then dribble a little fuel in the sparkplug hole and try starting it again, it should fire right up if its not already flooded.

 

[Poleman]

No...no spark...I did with new module and generator then I switched back to old to figure out what's was wrong and no spark again so I put the new module back on a like when it was running and no spark.....

 

[pioneerguy600]

If you have no spark now there is either a short to ground, disconnect the wires at the coil that go to the shut off switch to rule out they are not grounding out. If still no spark one of the new units has failed again. If the magnets in the flywheel have reversed polarity or even one reversed polarity it can take out a new module, seems to ruin the triggering switch in the module.

 

[Poleman]

There is I think 16 wires in 5 plugs going into the module/coil and a generator under the fly wheel which has a bunch of triggers on them like almost on a car.
Fuel injected....no carb..

 

[pioneerguy600]

That would make it very difficult to diagnose, hard to isolate one component at a time with that setup.

 

[Poleman]

Ya....really got me pulling my hair out.

 

[DND 9000]

Have it checked with the MDG 1 Engine Diagnostic Tool at the dealer.

 

[mjcarr90]

Ok guys.....I need some help....ya in more ways than one...I know.

Here's the situation: Playing with a 550 i that didn't have spark. Purchased a new module and a generator. I try ed the module first...nothing. next I put in the generator and it fired right up!!

Now the issue.....I thought (wrong thing to do) I'd put the old module back in and see if it was the generator....no start again. I then put the new module back in and have traced wires....wiggled this and cleaned that....nothing. I have pulled on this thing my right arm looks like Arnolds in his day.

Am I missing something on this? Being fuel injected I know I'm in way over my head here and any pointers and help would be much appreciated!!!

Thanks.......a LOT!!!

Ok, so this is a pretty old thread, but I'm in a similar situation, and wondering if you ever got to the bottom of this. Mine is a TS500i with no spark. Stihl dealer diagnosed it as a bad control unit. New control unit, still no spark. They say that the kill switch is bad, I tested it out, it isn't. They say Stihl tech support says check for a vacuum leak, or a compression leak/do a leak down test. If I wanted to fire the parts cannon at it, that would be one thing, but I don't. Before I order a new generator-as that's what I think is wrong, I figured I would see if you ever got yours fixed. Thanks!

 

[ZeroJunk]

We had one of those a few months ago and it was a hardly visible piece of insulation grounding the control cable to the magnesium. New wiring harness cured it.

Leak will have nothing to do with spark, unless there is some voodoo that I don't understand going on.

 

[mjcarr90]

We had one of those a few months ago and it was a hardly visible piece of insulation grounding the control cable to the magnesium. New wiring harness cured it.

Leak will have nothing to do with spark, unless there is some voodoo that I don't understand going on.

Thanks for the insight. Was it the section of harness running alongside the flywheel?

From what I understand, they have a sensor in the jug, and if they don't have compression, the fuel injection/spark is halted. I may be a little off base here, but I'll thumb through the service manual to double check that.

 

[ZeroJunk]

Thanks for the insight. Was it the section of harness running alongside the flywheel?

From what I understand, they have a sensor in the jug, and if they don't have compression, the fuel injection/spark is halted. I may be a little off base here, but I'll thumb through the service manual to double check that.

Yes, it was in that groove that routes it around the flywheel.

 

[mjcarr90]

Yes, it was in that groove that routes it around the flywheel.

Thanks, I'll double check there.

 

[sgriff144]

Just curious if you had an resolution with this?

I have no spark and compression is within spec. As mentioned above, not sure why compression would be part of the equation for spark, but I don’t understand efi algorithm.

I’ve used another saw for some diagnosis…the control module and kill switch on my saw will run the other saw. Wiring connections going into my module seem secure. I have not taken off the generator under the fly wheel to see if that functions on the other saw. Any thoughts? Thanks in advance.

 

[mjcarr90]

Just curious if you had an resolution with this?

I have no spark and compression is within spec. As mentioned above, not sure why compression would be part of the equation for spark, but I don’t understand efi algorithm.

I’ve used another saw for some diagnosis…the control module and kill switch on my saw will run the other saw. Wiring connections going into my module seem secure. I have not taken off the generator under the fly wheel to see if that functions on the other saw. Any thoughts? Thanks in advance.

From what I understand, if it senses no compression, it disables the fuel injection, and spark.

From the testing you’ve done, I would go ahead and swap the generator, to confirm if yours is good or bad.

I’m still dead in the water, and actually just spoke to the Stihl dealer yesterday. The control module they sent me wasn’t shipped directly from Stihl, but from another store. The tape had already been cut, and the box had been opened, so it’s possible I received a bad unit that somebody had boxed back up and returned. I’m brining it back Monday, and I’ll talk to them about the possibility of getting another actually new one, but without another saw to swap parts from, as you have, I’m limited in regards to how much I want to dump into this thing. Wish I could provide more helpful information. You don’t happen to be in central MA, do you? Maybe we can make 1 out of 2

 

[sgriff144]

I just recalled I sent a message to alexcagle on this subject about a year ago…yeah, that’s how long this thing has been in parts on my bench…

I’m guessing if the bearing/seal would have failed that I wouldn’t have compression…I might try to swap the generator this weekend

“Check, replace the fuel.
Even of it is canned premix. They get old too, eventually. Any water present will lay on the bottom of the fuel tank next to the fuel pickup.

Check your seal on the clutch side. If a bearing goes out, it will rip the seal. That would cause a no spark situation.

Pull the muffler and look inside for broken or scored piston.
Sometimes damage isn't visible, or is on the intake side. Look in the intake with the air filter off with the throttle open to see the intake skirt.
If a wrist pin clip comes out, you won't see the damage. Did you check compression with a guage. It should be above 120psi to run.”