Ignition Woes: The Saga Continues

[Angry Joe]

At least one person on the board was interested in how our ignition problems are panning out, so here goes...

Background: We're running a Yamaha R6 Engine, Haltech E6S ECU and Bosch igniters (included with ECU)

We had problems with poor spark. Plugs fouled easily and the engine only ran on 2-3 cylinders until it warmed up.

I talked to Brian Lewis of Performance Electronics who suggested that the Yamaha coils were intended to work with CDI ignitors, which put out 40 volts instead of 12. Since we are using standard 12v igniters, this would expain our spark problems with the Yamaha coils. He mentioned that coils off any bike with inductive (12v) ignitors would work fine. Honda is supposed to use these ignitors so I got a set of CBR F4 coils which, it turns out, look similar to the Yamaha units. Even the connectors are the same.

When we tried the Honda coils, we had to retard the timing by 30 degrees just to get the engine to fire. When we got it running it was just as crappy as with the Yamaha coils. I think we got it up to three cylinders firing.

That's where we stand now, comments are welcome...

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Angry Joe]

At least one person on the board was interested in how our ignition problems are panning out, so here goes...

Background: We're running a Yamaha R6 Engine, Haltech E6S ECU and Bosch igniters (included with ECU)

We had problems with poor spark. Plugs fouled easily and the engine only ran on 2-3 cylinders until it warmed up.

I talked to Brian Lewis of Performance Electronics who suggested that the Yamaha coils were intended to work with CDI ignitors, which put out 40 volts instead of 12. Since we are using standard 12v igniters, this would expain our spark problems with the Yamaha coils. He mentioned that coils off any bike with inductive (12v) ignitors would work fine. Honda is supposed to use these ignitors so I got a set of CBR F4 coils which, it turns out, look similar to the Yamaha units. Even the connectors are the same.

When we tried the Honda coils, we had to retard the timing by 30 degrees just to get the engine to fire. When we got it running it was just as crappy as with the Yamaha coils. I think we got it up to three cylinders firing.

That's where we stand now, comments are welcome...

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[B Lewis @ PE Engine Management]

Just a stab in the dark here. I'm sure that you checked this but do you have the coils wired corectly? Having to retard the timing that much to get it running points to a serious timing problem.

Also what kind of open times are you running at idle with what size injectors?

Give me a call if you would like a "loaner box" to try (513) 777-5233.

Brian Lewis
Performance Electronics, Ltd.
www.pe-ltd.com (http://www.pe-ltd.com)
"$760 Engine Management Systems"

[Angry Joe]

We tried wiring them both ways. Same problem. We did absolutely nothing that could alter the timing, and the day before the engine was running great on the Cavelier coils (up to 9000 rpm anyway)

I forget what pulse time we're running now but I'll check that today. Injectors are from a Kawasaki 750cc bike. Don't know the flow rate off the top of my head.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Bam Bam]

I'm not sure what you're using for a trigger wheel
but if it's a magnetic type you'll need a very tight gap tolerance meaning all teeth should lie around exactly the same diameter. In addition to this, the tooth edges should be very square and free of any burrs.

A angry trigger wheel has a way of making your engine retarded at high rpm's.

I'd suggest backprobing the trigger signal with an ocilloscope as you approach your limit to see if it suddenly does something unexpected. If not you know at least your getting the right signal and can slowly work your way upstream from there.

Also vaccuum leaks (among a million other things) can take out a couple cylinders pretty easy and given the intakes we have to run, they have a tendency to show up on FSAE cars.

I did a million electronics tests to figure out why my cyl 1 and 4 were out and then realized an unused map hose had been knocked off.

Good luck and keep us posted.

[Angry Joe]

Not sure what you mean by trigger wheel 'teeth.' Our sensor is just two magnets in a plate and a sensor to pick them up. The way to avoid a bad signal at high rpm is to back the sensor as far away from the wheel as possible while still getting a good signal, which we have done.

As far as cylinders not firing, it was not a consistent refusal of certain cylinders to fire. It was a case of one or two cylinders (or even three) not firing until the engine warmed up. Eventually all would start firing.

Given that, with the cavalier coils, the engine fired right up on all four cylinders and our plug fouling problem dissapeared leads me to believe it was a spark problem.

Brian, I think we are going to try those Accel coils you reccomended (#140403 I believe). They should be good to 15k rpm. If those don't work, I'm going to pull one of the spark plug wires and use it to strangle the first electrical engineer I see. No particular reason.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Bam Bam]

Maybe your coils are firing or trying to fire too much and robbing you of spark energy when you need it.

"Hypothetical" situation here......

Let's say some calibration in your ECU was wrong, and each coil was trying to fire every time it saw a pulse from your trigger sensors instead of every second time or every 4th time as the desired situation may be. The result would be a stone wall in rpm at about 8500 rpm cause your coils couldn't charge in time and a pretty sick ass motor at low rpm's as your coils fired intermittently.

But not too sick. Just sick enough for it to run fairly smoothly but still cause you to wonder what the F was going on.....


Just a thought cause your symptoms sounded a little too familiar.....

Hope it helps.

[Angry Joe]

With the Cavelier coils the engine sounded good at low rpm, it didn't start sounding 'sick' until it was north of 9000. We hit the wall at 11k. That really doesn't surprise me considering the motors they are intended for don't rev past 7000rpm.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Dan Deussen @ Weber Motor]

My first suggestion would be to use a digital mulitchannel Oscilloscope and look at the flywheel trigger wheel and ignition output on top of each other.

First look how many times the coil fires per engine revolution. It should not be more than once per revolution.

Then I would measure the coil's dwell time (charge time). If for some reason the dwell time shrinks at higher rpm, the coil will not have enough power to produce a good spark.

Hope this helps.

[B Lewis @ PE Engine Management]

Angry Joe,

What's the status?

Brian Lewis
Performance Electronics, Ltd.
"Engine Management Systems"
www.pe-ltd.com (http://www.pe-ltd.com)

[Angry Joe]

Sorry for the lack of updates, it seems we've developed a whole new set of problems.

The first problem was when we hooked up the Accel coils, and the engine ran like crap. We swapped injector connections, spark plugs, spark plug wires etc. and every time Cylinder 1 would fire up good, 2 and 3 would 'sorta' fire and 4 did nothing. Good spark (visually) and compression on all four. For a sanity check we swapped back to the Cavelier coils, which at least had the engine running good at low rpm. Same problem.

The next day on a whim we pulled the injector assembly and turned the engine over. They did not fire. I put a charger on the battery. All four started firing! Unfortunately we never got to see if this solved the problem because this is when the REALLY baffling part happened.

We went to start the engine, and got nothing but backfires. It was like the timing got knocked horribly off. There were backfires out the intake and exhaust. The day before the engine had been running! It wasn't running great, but the timing was obviously in the ballpark. To confirm it we sprayed carb cleaner in the intake. The resulting backfire set the throttle position sensor on fire briefly (don't worry, it still works) so we are definitely not having spark or fuel problems.

I'm honestly out of ideas at this point. We did NOTHING between the previous day and that day to change the timing. The timing chain is properly tensioned. The timing sensor is still properly in place. The ECU is getting an accurate rpm signal. The gears are not obviously off. We are getting good compression on all four cylinders. There are no gummy bears stuck in the valvetrain.

In any event, I think I'm calling a Priest in on monday to exercise the engine and pour holy water in the cooling system. If anyone knows anybody that practices witchcraft, please let me know.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Frank]

ok now i have very little idea about the system you're running BUT.. a few golden rules i've learnt the hard way

have you messed with the cams?
i installed an engine years ago and got the cam timing wrong -doh!! you get really wierd stuff going on

are the coils (or coil drivers) wired back to front? the result is the timing "advance" often becomes "retard"

"popping from inlet"
usually only happens if the timing is too advanced
or.... 360 deg out of whack (in the latter case the thing dosn't start at all) \
OR worst case the inlet valve is not closing fully

"relative position of cam sensor and crank sensor"
i use modes 11 to 14 on motec M4 pro (sequential)
BUT.. basically if you're running a sequential system with one tooth on the cam and some teeth on the crank.. the signal from the cam tooth, comes in between TWO crank teeth signals...
cams flutter about a bit so if the signal is not in the middle it might trip out now and then.. it pays to put the cam sensor on the "driving cam" as opposed to the "driven cam".

have you put a scope on this thing yet?
check the signals from timing sensors and coil drivers.

dumb questions.. have you got the ECU set on the right configuration mode?

have you got the (please excuse motec term) "crip" angle correct... the angle from the signal from the crank sensor (the tooth signal that occurs after the cam sensor signal) to the actual position of TDC

Frank

"These cars feel great...SIDEWAYS"

[This message was edited by Frank on March 09, 2003 at 06:12 PM.]

[Angry Joe]

1) We have not messed with the cams, they are stock and have not been removed since we picked up the engine. Certainly something could be screwed up when we bought the engine, but the timing was fine only the day before

2) The accel coils are not dependent on polarity, according to the instructions they can be wired any way you please. The cavelier coils ARE supposed to be wired a certain way, but I tried wiring them both ways, and even opposite ways, without any positive effect. The ignition modules have not been touched.

3) I've heard that backfiring out intake is an indication of timing being way too advanced. I just can't figure out how it got that way. We had simultaneous backfiring out the exhaust, but this could be a result of unburned fuel being ignited by the heated o2 sensor.

4) We only have a crank sensor, no cam sensor

5) We finally got an Oscilliscope... and promptly blew a fuse that we didn't have a replacement for. I'm working on getting the O-scope back on Monday.

6) I've checked the ECU settings countless times. The only thing I haven't touched is an ignition 'quickmap' that crashes the program every time I try to touch it, but its always been that way.

Remember, the engine ran the day before and we did nothing to change the timing since then.

Oh, and the specifics on what we're running are in my first post.

I get the feeling we changed something really stupid, and I am going to kick myself when we find it, but I just can't figure it out right now. Maybe me and the engine just need to spend a few days apart...

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Frank]

are the "ignition modules" wired the wrong way

ok so its not sequential...
get a scope on the crank sensor

frank

[MoTeC]

It does vary but a quick check for coils is the resistance of the primary coil, if it is around 0.2-0.5ohms it is probably a CDI, if it is 0.8 to say 1.1 it is probably an inductive which should run from just about any automotive style igniter/module, if it is very high, 3.0ohms it is a special bike style CDI used for very low current systems (sometimes total loss systems) and I don't know too many aftermarket ECUs that will run them, save for specific bike stuff.

Donna

[Angry Joe]

Okay, progress has been made. We re-did the seals on our intake and the engine now runs. A friend of a friend threw this out there (and I know Bam-Bam said it as well), I don't know why it works but it does. It makes me wonder how long we spent chasing down an ignition problem when we had a Vacum problem...

Engine fires up pretty good on the accel coils but we had to seriously richen the mixture. In fact we are now hitting 100% duty cycle at 12,500 rpm and I know we are still running lean (although cylinder 1 still is only sorta-firing, and we swapped the plugs around)

Our injectors are from a Kawasaki 750cc engine but I don't know their actual cfm rating.

In any event, I think at least part of our problem was solved. If your engine runs like ass, check your intake seals! Thanks to everyone for their help, especially Frank and Brian Lewis.

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Angry Joe]

Update: We swapped injectors 1 and 4 and now cylinder 4 runs cold. Second problem diagnosed, it would seem...

Lehigh Formula SAE

www.lehigh.edu/~insae/formula (http://www.lehigh.edu/~insae/formula)

[Bam Bam]

He who knows not and knows not he knows not he is a fool.....shun him

He who knows not and knows he knows not he is simple.....teach him.

He who knows and knows not he knows, he is asleep......awaken him

He who knows and knows he knows, he is wise...follow him

He who knows yet pretends to know not....He is laughing at you....Laugh with him.
http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Dan Deussen @ Weber Motor]

If you are having problems hitting 100% duty cycle, you can increase the fuel pressure. It's not perfectly, but quite close to a linear relationship. If you double the fuel pressure, you can cut your injector opening times in half (just to start out). As a rule of thumb I would try to set up your system to run about 75-80% injector duty cycle at peak torque. You will want to save yourself some room for transient fuel enrichment conditions.

Good luck.

Daniel Deussen
Walbro Italy
http://www.walbro-tdd.com

[Frank]

same as above,

but more specificly

ask yourself...

what pressure do the stock injectors run at?
what pressure do we have?
have you done a fuel pressure test?

i know nothing about kwaka's
but we run the bosch inj. run at about 3 bar
i dont think 5 bar would be excessive either

[MoTeC]

Just be a bit careful about upping the fuel pressure you can actually get to a point where the injector will not open due to the force holding it shut being over the force you have to open it. It is not really a problem with small injectors but just so you are aware of it. Also just before you get to the pressure that holds them shut you get to a pressure that makes them a bit irratic and that is when you really start having problems.

Donna