Printable Version of Topic

Posted by: oakdalecurtis Mar 8 2017, 10:18 PM

'76 2.0 FI, stock motor except for a Crane ignition. All engine parts are functioning properly, no vacuum leaks, motor does not run hot, 600 to 700 rpm idle, just passed CA smog easily today. The car runs perfectly EXCEPT for 3 to 5 seconds or more of "run on" after the ignition key is turned off. Dave D suggested unplugging the four pin connector on the relay board in the engine bay at shutdown to see what happens (it powers the FI). I did that experiment and it stopped the engine "run on" instantly. That would suggest that the FI is getting power somehow after the ignition switch is off, right? What does anyone think I should try next to narrow down the source of the problem? (BTW, DaveD does not recommend a diode on the alternator light wire, could adversely effect charging, and I would prefer to find the actual problem too). Any ideas?

Posted by: Mike Bellis Mar 8 2017, 11:39 PM

Why do you keep starting thread after thread about the same topic?

Clearly you have a voltage feedback problem. If it started after you installed the Crane ignition, that's your problem. If you don't like the diode idea, install a relay to isolate the circuit.

Posted by: oakdalecurtis Mar 9 2017, 12:59 AM

QUOTE(Mike Bellis @ Mar 8 2017, 09:39 PM)

Why do you keep starting thread after thread about the same topic?

Clearly you have a voltage feedback problem. If it started after you installed the Crane ignition, that's your problem. If you don't like the diode idea, install a relay to isolate the circuit.

Posted by: Tom_T Mar 9 2017, 10:35 AM

Hey Curtis,

I don't know why you switched to the Crane, but IMHO you'd be better off with the OE ignition etc., since it won't conflict with the rest of the system.

That said, you could first check with known working new parts, the various realys & voltage regulator, just to make sure it's not a fault with one of those, but it won't rule out a short in the realy board itself.

Again, my preference on a nice original 76 2L would be to keep it completely stock, but it's your car & your tinker time!

Cheers!
Tom
///////

Posted by: oakdalecurtis Mar 9 2017, 10:39 AM

QUOTE(Tom_T @ Mar 9 2017, 08:35 AM)

Hey Curtis,

I don't know why you switched to the Crane, but IMHO you'd be better off with the OE ignition etc., since it won't conflict with the rest of the system.

That said, you could first check with known working new parts, the various realys & voltage regulator, just to make sure it's not a fault with one of those, but it won't rule out a short in the realy board itself.

Again, my preference on a nice original 76 2L would be to keep it completely stock, but it's your car & your tinker time!

Cheers!
Tom
///////