Been messing around trying to tune my new build.

Finally got it to idle at 15 afr. I can drive it around the block, datalog and change my values, but as soon as I come to a stop the afrs get very lean...my LC1 shows 18-21 afr. That is maxed out lean on the gauge. Sometimes if I shut the car off, I wouldn't be able to start it back up.

I'm getting spark when the car won't start.

What I'm not getting is injector pulse...or so I think I'm not. If I disconnect the injector, throw a injector clip on it and jump the injector to 12v it will open and I will lose fuel injector.
I am getting 12v at the harness if I disconnect the injector. During cranking I can see the voltage fluctuate.

The spark plugs are not wet when the car won't start.

I am getting 40-50psi on my fuel gauge which is on the fuel filter. I can hear fuel running through the return hose, but the injector pulse seems to get shorter and shorter the hotter the car gets.
If I let the car sit until it is cool again, it will start up and idle at 15 afr.

I am running crome, precision 1000cc injectors. I have specified my injectors and played with my offset until the car idles at 15afr.

I also pulled the main relay...solder joints look fine and dandy. No burns on the board.

I had it timed at 16 degrees idling, but my pulley moves a little because the tooth is kind of screwed up. Took my timing cover off, verified mechanical timing and made sure that the pulley did not move when I tightened it back down. I will time the car tomorrow with a timing light again when I get the time and go from there.

Any ideas would help...waiting on some 27sf512 chips to come so I can try a new chip as well.

 

You're describing fuel injector heat soak. The old EV1 injectors were terrible with heat soak. Conduct a cooling experiment to prove the heat soak theory. Drive around without a hood to see if conditions improve or when it wont hot start spray compressed CO2 onto the injectors to cool them.

Remediation steps
-You can use O2 closed loop feedback to add fuel.
-Or you can use the IAT fuel trim table as IAT usually correlates with heat soak.
-Or you can upgrade to a modern EV14 injector.

Here's a related Megasquirt article:
M54 Megasquirt 3: Fuel Injector Heat soak

 

****...ok. Well, going to measure resistance of the injectors when I get the no start condition and compare to the resistance of when they are cold.

Thanks for the idea.

 

I measured resistance when hot vs cold. 2.6ohms hot, 2.2ohms cold, not sure if that would make a difference, but I bumped up the latency timing or "offset" as crome calls it.

When the car is cold and initially started it up, it will idle high 11-12afr, but warm will give me 16-17afr.

For the hot start issue, you need to go into advanced tables and modify the ect cranking and ect post fuel setup and in the 170 and the 280 degree boxes, set the values to the 130 degree values. That seems to allow me to start when hot.

Other than that, my datalog fuel cells are looking awesome.