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Hello everyone,

My stock 1989 3.0 Milano Verde died a while back and I have not been able to find the root cause. The fundamental problem is that it doesn’t produce any spark.
I searched the forum but really didn’t notice anything.

Checks with both timing light and simply grounding the spark plug shows no spark.
Put the timing light pickup on the coil wire and got no spark either.

Started something of a methodical search for the root cause and I’ve listed my checks as follows.

Checked fuses. All fine.

Checked spark plugs.
Plugs installed on Milano were measuring between 12 & 18Kohms. Seemed ok.
Replaced with a different set that measured between 4 & 5Kohms. No spark

Checked wires, all read approximately 2.5Kohms except #4 which measured 6.9Kohms.
Left them as is.
Replaced cap and rotor.
No spark yet.

Coolant temp sensor measures 3.6kohms at about 48 degrees F.
Could my problem be here ? This measurement is ok at this temperature but not sure what the hot running temperature reads.

Hall sensor output measures 3.5v square wave. Looks good I think from a multimeter measurement (i.e. not scope).

Coil voltage at (+) terminal = 12v, Coil voltage at (-) terminal = 11.9v.
Swapped out coil with my nice running GTV6. Milano coil runs great in GTV6, GTV6 coil still in Milano (same p/n).

Swapped out Electronic Module N1. Still no start. Darn ! I was hopeful on that one.

Swapped out the main ECU with another 3.0 unit it had. Still no spark.

Checked numerous wiring paths, although not all of them. They generally seem ok

I don’t have a spare Ignition Electronic Advance Control Unit (N20) but did disconnect and reconnect the connector. No spark.

I’m out of ideas. Really could use some suggestions.
Although I swapped the Electronic Module N1 and ECU, I don’t know 100% if those were good or not (worked before parting out from a Milano Verde).

Really could use some suggestions on this guys.

Thanks,
Merril

Wow ! No replys, and it's been a while.
I'd figure Mats, Greg, JJ, or some of those folks south of the equator would have something to suggest (thats car related).

I'm going to have a second look at the distributor even though I don't think it's the problem. See if the rotor is turning when the engine is spun.
I know the vacuum advance drives a signal to the solid state electronics and wonder if that signal could be playing into the equation.

Still grasping at straws,
Merril

While you have replaced the ecu does the ecu have power? does the spark box have power?

sounds like the problem is in spark control side as opposed to generating the spark itself (coil has power). Have you checked your grounds too?

hth,

Merril pay particular attention to the Hall sensor connection plug on the distributor.I assume you checked the Hall output signal by connecting your voltmeter directly to the pins on the distributor side (blue) of the plug ? The wiring on the connector (white) side of the plug is fragile and needs to be checked closely.
By the way I'm working from memory and could be wrong but I believe the Hall output on our distributor is closer to 12V not the 3.5 V you got ? Easiest way to check this signal is with a "noid" light which you can pick up at any autoparts store.

Is there fuel in the car..?

Immobiliser ?

John

Go through the non-start procedure using a manual from Craig's manual


http://www.users.on.net/~craigf/

replace the little igniter circuit under the coil?..there could be a bad ground here too

Does it have an inertia switch?

ECU has no power ? Good question, I’ll check.
Does the spark box have power ? Yes.
I agree with you MR2 Zig, I think the problem is on the spark control side but I’ve been wrong before. I’ll doublecheck the grounds but believe I’ve already went through them. Thanks for the suggestions.

Murry, I’ll confirm the documentation on the expected voltage produced out of the hall-effect sensor. I’ll also check the signal at the destination to make sure the wiring is ok.

Car fuel is good Mats and I have a pressure guage in the line which jumps right up to pressure when the key is turned to on. Problem is certainly related to spark.
Thanks for the suggestion regarding the inertia switch. I hadn’t thought of that one. I’m sure it has one so will check that. (Havent had any “sudden events” to trip it.)

I’m guessing the inertia switch is the “Immobilizer” that John suggests. Would be nice if that’s the problem. I’ll be looking at that one.

I swapped out the igniter circuit under the coil Xrad. A used one that worked in the last car but not 100% sure it’s still good. Hear they’re pretty reliable though. I forget the manuals name for it at the moment. But it’s the solid state type of device right below the coil. Ground was good there as well.

Bruce, I’ll have a look at Craig’s web site. Thanks.

Thanks everyone for your suggestions. Gives me something to work from.
Merril

Stock US Milanos do not intertia switch.

Your car has no immobilizer unless you or PO added it - I bet it hasn't.

Jes

Darn Jes,
You just eliminated a hopeful cause of my problem !
Thanks for the information though.
Merril

'imobilizer' is king's english for 'car alarm/ ignition cutout'

old ones have a habit of going bad and "immobilizing" your car

I'm sure you cleaned and check your fuses....

MR2 Zig wrote:'imobilizer' is king's english for 'car alarm/ ignition cutout'

Some refinement for the royals... In some places immobilizer was/is a term for a manufacturer option where the ignition key contains a micro chip that the car would ID at start (RF) and not start without - a bit more advanced than your general aftermarket alarm that typically can be disabled.

I guess current manufacturer's convenience systems that unlock doors based on sensing nearby key is an evolution of such systems.

Though, you could still have an old-fashioned alarm system acting up.

I have had two no-starts with my verde the last 6 months:
1. Connector on back of fuse panel had intermittent contact - basically fallen out, leaving ECU etc. without power...
2. The fuel pump was "stuck" - a tap with a stick and it was running again.

But, in both cases there was no fuel...

Jes