Dies after Idling after a few seconds (Phazer)

[grippo]

You have to check the timing. You need to position 2 pointers, one pointing at 0 at TDC compression cyl 1 and one pointing at 0 when cyl 2 at TDCC. Then you just read the timing of each relative to this, but you need a timing wheel with degrees all around. But even if you don't you can still tell by eye if the timing is grossly off on one cylinder vs the other. In other words, if the 0 deg mark is a little before the pointer on cyl 1 and grossly off when looking at cyl 2 then it has to be a configuration problem. You need to compare everything in geoffct's msq to yours. But if the spark is good, then what about the injectors. Are they flowing the same, is their spray pattern the same. Its also possible the fuel timing is off - again check what is in geoffct's msq. That can happen if the timing is not configured right and you have an odd fire engine.

[slobra96]

Well I am back, and we have still not figured out whats wrong. We tried to test the timing on this engine, and it seems to be nearly impossible. We tried using a timing light with a peak hole on the timing wheel that shows when the engine is at tdc and it is pretty much impossible to tell due to the the small size of the peak hole.

We also tried messing the with offset angle. The angle should be at is 180 degree because the cylinder 2 tdc is 180 degrees after cylinder one (which we verified from removing the valve cover). So when the engine is running at 180 degree offset, we can unplug coil 2 and there is no change. So we know its only running on one cylinder. We also tried 0, 270, 359, -180 degrees with the same result. Now when we go up to 190,200, 210 degrees the engines idle races in a matter where its almost chasing itself. The engine is not sucking air from any where else other than the throttle body because when you put your hand over the throttle body it immediatly dies. When the offest angle is at 210 and we unplug coil 2, it dies.

Like I stated in earlier posts, the ignition coils do not get hot, we get spark from both coils when we pull them out, we swapped coils and fuel injectors with no change, tried wiring in a diode in the vr sensor (not that our rpm is acting up, but we figured why not try it since everyone else has one in) and it would not even start , and I am sure there are a few other things we tested that I cant think of right now.

Could we have wired something wrong such as the coils? Did our configurator get messed up some how? You mentioned that our fueling could be off, but we dont really know how that could be off. There does not seem to be many settings that set the fuel timing, and the ones that are seem to be correct. Are there other setting that we are missing? We are at a loss still and do not really know what to try next.

We did notice on the one datalog of another person that is using the same engine as us that their pulsewidths were the same. Now ours are not, so should they be the same? I attached a datalog of it idling when it was at 180 degree offset.

Thanks again

[grippo]

The PWs for both cylinders in the datalog are pretty much the same - 2 to 4 ms which tracks with the accel enrichment jumping form 100% to 200%. They should be the same in steady state. There should only be a significant difference if you start accelerating and one cylinder picks it up first

In order to isolate whether fuel or spark, try cranking but TEMPORARILY set cranking rpm to 50 or anything that will always be below the actual cranking rpm and check if you are getting fuel/ spark in cyl 2. When you are in cranking mode the ecu logic is totally different than after cranking and may not reveal the problem. It doesn't matter if it starts, we are just looking for whether there is spark and fuel in both cylinders. By doing this we are forcing the ecu to use the same logic as it uses after start. If we could we would crank it at 2000 rpm, but a few 100 rpm is about the best we can do.

If this doesn't show anything, post the msq you used for the datalog you just posted plus the msq that geoffct sent you.

[slobra96]

Thanks, I will try this today and post the results.

[slobra96]

Sorry for being late, but we set the cranking rpm to 50. We then saw if we got spark and fuel and we still did when it was cranking.

I attached the msq file that was used during that datalog and also geoffct's from an earlier thread.

Thanks again

[slobra96]

I was wondering how the second ignition input works. In our case we have it as a one tooth halls effect cam sensor. When the tooth is being read by the sensor, cylinder one is at the beginning of the intake cycle while cylinder two is at the beginning of the exhaust cycle. My question is, how is microsquirt knowing when to spark from this? If you could clarify if for us, that would be great.

Thanks

[grippo]

The trigger offset tells the ecu where it is when it senses the first tooth after the missing. In your case -351 deg tells it that at that instant that it senses tooth 1 it is 351 deg ATDC of cyl 1. If, sometime during the previous 360 deg it did or did not sense a cam sync, then it would know whether the TDC was compression or exhaust. As for cyl2 it just adds the Odd Angle of 180 deg of advance to the spark table advance and sparks at that point.

Your msq is close enough to geoffct that I don't see any problems. And you say you are getting spark and fuel, so what is the problem - is it that it just won't combust or it combusts but dies ?

[slobra96]

With it at 180 degree offset angle (which it should be), Cylinder two does not combust (the spark plug is clean and smells like unburnt fuel) while the cylinder one spark plug is black and smells like burnt fuel.

I will clean off some spark plugs today and put them in so we can see the result again and see if it is still happening. I will post these result hopefully by noon today.

At first I thought that maybe the cylinder two spark is not as strong, but when you look at them out of the head, they look the exact same and cylinder two is sparking right after cylinder one. Is there some other setting that could cause it to miss so bad like dwell or something else?

We also checked the compression in both cylinders a few weeks ago, and they both are good and the same.

[slobra96]

Well today we could not really get it idling because the battery is shot. So hopefully tomorrow we will get a battery and have an update.

Thanks