L-Jet: Over My Head, Bad ECU, car's back on the road. Options

[Mike Sanford]

I'm a little above my skill set playing with this stuff.

Took the wife out yardsale-ing Saturday morning. This is Tucson, maybe 85 degrees at 8am. Drove two blocks from home, stopped at one. Drove another 5 blocks, car acted as if it ran out of gas. Gas tank is full. Key on, pulled fuel line off of rail and opened air flow meter, squirts fuel. Pulled injector out of a cylinder, moved air flow meter, no fuel.

Shoved my analog voltmeter into injector plug, no sign of a signal at the injector.

Played on the internet looking up l-jet trouble shooting, decided to start with checking the relay because it seemed less intimidating. From what I'm seeing there should be voltage between 88a, 88b, 88c, and 88z and 85 (the ground). I have voltage everywhere except 88c. Come back inside, back on the internet, 88c looks like it powers the auxilary air valve. Would this cause the whole system to shut down? Is there something else I should be checking?

Thanks,
Mike

[timothy_nd28]

Glad to hear this, but we still have to address a few house keeping issues. The CHT sensor, did you ever recheck this? Either pin 13 to ground with your multimeter, or by disconnecting the CHT connector and checking the resistance there? I personally would like to know if a failed CHT sensor would keep a Ljet from firing up, just for my own knowledge.

Now going back to post #10. I had you check the voltage at the dual relay for pin 88y, and you reported back with 11volts (battery voltage). So far so good, but then I had you check pin 88d and you reported back with 8-9 volts. This part isn't so good, which shows a drop across the contact points inside the dual relay. See red circle in the attached picture



To put this to bed, lets do one more test. With the car off (ignition off) set your multimeter for DC and put the red meter lead on 88y and the black meter lead on pin 88d. You should see 12vdc or whatever the current battery voltage is. Now, go ahead and start the car. With the car running, you should see 0vdc on the meter. If your meter shows anything higher than 0.5vdc, it will be imperative that you replace the dual relay soon, as it could leave you stranded on some desert highway.

If you wouldn't mind, I would love to have your failed ECU. These things rarely fail, and I would like to take it apart to see what exactly went wrong. (IMG:style_emoticons/default/beerchug.gif)