Indeed...second time in a week the 86.5 has been road-sided. First time after cooling off, (it seemed) replacing the LH relay got it going. Odd...It really seemed that replacing that relay was the catalyst to getting spark.

But spark failed again today and I was roadsided again. Tried replacing the EZF relay, this time, to no avail. Same thing, the engine simply lost spark (based on testing with a known good timing light).

I know I have to do more homework with the FWSM....here are a few basic questions: 1) (For future reference) At the front of the engine, there is a screw-on cap on the fuel rail. Is this a pressure test point? I held back fully unscrewing it on the roadside...does it require a special fitting between it and a fuel pressure guage?
2) Mounted just in front of the radiator is a flat mounted plastic covered module(s) with two cables attached to it. I've seen this referenced as "Ignition Control Unit", but I've also seen the ignition ECU referenced this way. Is this module a spark amplifier?

Thanks

Mike

 

1 = yes, yes
2 = yes (amplifier)

 

That fuel rail cap seats against a ball bearing (inside the cap) which I guess is the actual seal to the opening. Be careful when removing the cap, if you drop the ball, you are out of the game.

 

Is your car auto or manual ? Does it only loose spark when hot ?

 

Right...discretion being the better part of valour, I decided to enquire before opening it up. Thanks for the heads up.

This 86.5 is an auto. For two occurrences, yes it failed when hot. It "healed" itself after the first incident when I replaced the LH relay. Odd.. I later discovered the problem was no spark, when It stalled days later. Not aware if there is any fuel delivery problem. It is still dead, so I should have some troubleshooting time tonight. I assume if there is no spark from either distributor that the problem is not likely to be one of the spark amplifiers (located behind the radiator). But need to verify this...

 

Check the condition/connections of the crank position sensor at the top rear of the block.
Glenn

 

x2.

You have already changed the EZF relay, and EZF ECUs are very reliable and do not fail intermittant.

Most unlikely that both output stages would fail at the same time.

I expect if you just waited at the side of thr road for it to cool down, it would have started again.

You have released the flex plate tension and checked crank end float recently, haven't you ?

 

Yes, but the roadside effort was less than satisfying. Not having a relay puller; I managed to butcher serveral relays while using pliers. Not sure the replacement relay wasn't affected. Yes....I am expecting a relay puller in shipment after failing to locate one anywhere at a storefront. I have received all new critical relays yesterday, but I won't touch them until the relay puller arrives. The car is still not seeing spark, and this gives hope that a methodical investigation will bear fruit.

Will verify this tonight....

You are correct, John in that this is how it behaved the first time, but it wouldn't start until after hours.

This was done as part of the PPI (May this year).

 

Understood....
newbie questions here: The 86.5 employs multiple distributors and rotors. Does it also employ a crank position sensor? I wonder why it would need one, with certain camshaft knowledge from distributors....
Have yet to get time to crack open the FWSM (this explains a lot)....should be able to get started tonight.

 

the crank sensor is on the back of the engine block under the airbox.

you will likely have to drill the bolt and use an extractor to get it off. Then good luck getting it out in one piece.

although replacing that is a good idea.

Although before you do you can test the RPM sensor in the car at the EZF connector by mearusing resistances.

 

Sensor should measure approx 1000 ohms...

 

according to an old post I found when reviving an S4 that hadnt ran in 1.5 years it was between 600-1600 ohms,
both the ones I checked measured at 1100-1200

 

Thanks....
Measured with the unit removed or across ICU cable contacts?

 

either or

 

OK....finally was able to get back into investigating this. I discovered the EZF relay spot was empty. Not having posession of a relay puller on the roadside (the other day), I was able to pull out the EZF, but lacking a puller, managed to mangle several less critical potential substitute relays, during extraction. I thought I had pressed one of the survivers in the EZF slot and obviously didn't, amidst the aggravation. I pressed in a new EZF relay today, and it fired up. There is spark from both final stages. Of course, it fired right up cold after the first time it stalled last week, as well. I will be replacing all critical ign and FI relays when the relay puller shows up. I will also replace the crank position sensor (having been through intermittent hell with an aging unit in the past). I will check ohmage on the old and new units and compare. I will do spring cleaning under the air cleaner, ridding old fuel hoses, augmenting aging insulation, so forth.
Are there other components besides the relays, and crank position sensor that commonly contribute to intermittent problems that I should be aware of? I understand that not every sensor ((including the MAF) will cause a black-out. I'm intending on focusing on those that can.

Thanks
Mike