m2cupcar

iTrader: (5)

Can't get the new engine started. Spark is messed up. This is a totally stock setup.

Hooked up the timing light and I'm getting the exact same scenario as when I had trouble with the FE3. Light flashes immediately upon crank and right after shutting it off. This was indicative of the cam timing being way off- so I checked it and it was. I left it as I received the engine and never verified it. It's now set per the manual and the spark is doing the same thing.

Those two sparks are the "root" trigger from the CAS, unmodified by the ecu. ECU makes cranking ign adjustments after it sees the TDC slot on the CAS.

Help me!

dustinb

Maybe a screwed igniter? When mine went bad cylinder 1 and 3 shut off.

m2cupcar

iTrader: (5)

I hate when I forget important lessons I've already learned. It dawned on me that the car shuts off aux power during cranking. SO if I'm running the timing light off the car I'm cranking, it stands to reason I won't see any spark triggers during that time. Once I figured this out last time, I powered the light from another source and found my crank pulley timing mark about 30* away from the marked timing zone. So I need to follow the same trouble shooting path this time around.

tripp

I am having a similar problem with a megasquirt set up (might be a few problems actually). First issue I had was cut out at mid/high rpms and backfiring (unburned fuel). Next I tried adjusting my timing to correct this and I started to not get spark at hot start. I let the car sit for a while and now I am only getting a single spark when I crank the car.

I checked power at the cam angle sensor and the ignition, both are good. Does this sound like a timing issue? If so, how should I get it running to adjust the timing back? If not, what else could I try (I already tried ignition coils and a cam angle sensor).
Could I have shorted something in the MegaSquirt?

thanks

tripp

How did you check the timing without being able to get the car to run, just on crank?

I am getting the same single spark when cranking and no other spark.

I thought it was related to issues I was having with spark cutting out at mid/high rpm (no tach so not sure what rpm). After adjusting timing through MegaSquirt, I had a no spark when hot issue. I let the car sit a couple weeks and started having the single spark issue.

I tried a cam angle sensor and ignition coils: no improvement.

I am getting power to the cam angle sensor and the ignition, but the signal at the ignition seems constant, not pulsing for spark, and suggestions on where to start.

If this is just timing how should I start adjusting (my timing was off when I last tried to adjust it).

thanks
Tripp

tripp

sorry for the double post, my computer is acting up (also) I guess I am not doing well with electronics today

m2cupcar

iTrader: (5)

To check IGN timing while cranking with a timing light, you must provide a power source other than the car you are cranking for the timing light. The car cuts power to AUX during the cranking process mostly in the interest of providing sufficient power to the starter and for spark.

The easiest tool for simply verifying spark (vs. checking the cranking timing) is one of those inline spark checkers.

tripp

I tried pulling the plug and grounding it on the turbo and was not seeing spark, and checked with a test light at the source pin for the igition coils and was not seeing any pulsation, so I am fairly confident that I am not getting spark.

Thanks for the tip on the tool, I think I might pick one of the inline spark checkers up for good measure and to double check though.

What would you recomend as a next step assuming no spark (as I can best see currently is the case).

y8s

iTrader: (8)

ordered. checking spark/timing with a super tight COP harness is my nemesis.

tripp

I created a post: https://www.miataturbo.net/forum/t37409/#post434061 in the megasquirt section to get more ideas. I will double check the timing with another power source for the light but I am pretty confident that there is no spark after the first one.

tripp

I finally figured out my problem and it makes me feel like an idiot, my megasquirt was partially unplugged so it was not sending a signal. I plugged it back in and now it works!