'93 Geo Metro Problem - Intermitant and Enigmatic

[DOCTORBILL]

I own the "Phoenix" - a 1993 Metro which I have posted repairs on here in the past.
Rebuilt a '93 Manual Transmission, Rebuilt the Engine, Cleaned out the Throttle Body, Repaired a bad Fuel pump,
repaired a front Wheel Bearing, replaced the head 2x - last time with SS Valves......can't remember all of it right now.

It was running GREAT until this Winter when it started this random missing which is now getting worse.
Happening more often - yet it can go for an hour w/o missing ? DRIVES ME CRAZY !

NOW, my Metro is exhibiting intermittent engine "Missing" and I cannot figure out what is happening.

Usually happens while driving (not at idle) and happens irregularly.
The engine bucks and I lose power for perhaps a half second to a second.
Like the spark is gone for that long. Maybe the fuel ?
Pretty sure it is electrical. When it happens it turns my after market Cruise Control turns off - but the memory is kept....

I have replaced my Spark Plugs, the wires, the Distributor Rotor and the Cap.
Replaced the Fuel Filter, also. Still does it.

I have put TWO very solid Ground Wires from the Block to the Frame.
Seemed OK then, but now it has come back with a vengeance !

It can go 30 miles to work w/o any missing, then on the way home bucks like crazy.
Up hill, down hill, accelerating or decelerating - random !

The rpms on the Tachometer can be anything.
I thought bums (rough road) made it worse, but no - it does it any old time.

I have to Sherlock Holmes this out !

Maybe the Throttle Position sensor ? Have to look at the Computer readout with a fuse in the Diagnostic socket yet.

Could the Fuel Pump (New 4 years ago) have crud blocking that small screen.
But then it should kill the engine outright until I stop....????

It could be a loose or broken wire, but not ALL the wires would cause that missing.

If it were the Spark Coil, why would it be intermittent and not just fail ?!

Would a failing Alternator do that ?

If it is a short - it does not blow any fuses.

Does anyone have a clue about this or has had this Goofy Problem happen before ? !

DoctorBill

[Crvett69]

you can get a voltmeter that plugs into the lighter socket to check your alternator but don't think thats the issue. i would suspect your distributor or coil or the ignitor. could also be a loose/bad connection in one of the power boxes, if its not missing at idle try wiggling and moving all the wires you can reach under hood and dash and wiggle the fuses and see if you can get it to miss. intermitents can be a real pain

[DOCTORBILL]

Seems like every vehicle I have EVER had eventually starts the Intermittent rubbish.

Auto repair places love them ! Their solution is (obviously) to want to start replacing all the parts with new and make a killing on me.

Wouldn't only some PARTICULAR wires be the problem ?

Not every wire connection would cause this missing if disconnected.

My engine is all oil covered (leaking Rocker Arm Cover Gasket) and just touching
anything in there leaves me sporting BLACK GREASY hands.

Playing the guessing game, I wondered what symptoms a bad TPS would have.
That is a potentiometer and the Carbon Pad that the arm touches must get worn
where the throttle is at most often.
If I connect a VOM and measure Ohms, then turn the shaft, maybe I'd see the resistance drop off on a worn spot.

I have been wracking my brain trying to rationalize what the problem could be !

Probably some stupid loose connection deep in the wiring harness beneath layers of sheet metal.
This Metro is 22 years old now. Served me well. But getting long in the tooth !
Bad wiring is awful to deal with. My frame is corroded from the salt here in winter.
Could corroded frame welds make this happen ?
Is there any way to ground the engine block directly to the computer ground wire and bypass the frame ?

I WILL take your advice (on the chat room a while back) and see what the compuker says with a fuse in the diagnostic slot.



DoctorBill

[Crvett69]

tps might cause a issue if its bad but not cause cars to just shut off for a moment. you can try unhooking and see what it does, will still run and turn light on but not sure it will act like it doies now. its possible its the map sensor on the firewall but still suspect the other parts i listed earlier. i would also put the fuse in and see if it has any codes

[DOCTORBILL]

Today I noticed that the Tachometer was jumping when the Metro bucked !

It jumps UP 100 - 200 rpm and drops back down when the car misses.
Once it jumped way up - maybe 1,000 !

NOW I am wondering if the Distributor is going South.....
the bucking (missing) is getting worse - especially going up hill.
Spark advance ?

The Metro has no mechanical points - as of old.
Does it have a Magnetic or Optical point type spark input ?
Is that fixable ?

I will call around to see if the Foreign Parts people have a Distributor.....

Maybe NAPA or O'Reilly's or Autozone have rebuilt ones.

DoctorBill

[Crvett69]

the inside stuff is spendy to replace, just go to your local picknpull and grab a used one. just get a 94 or older and with or without the vacuum advance to match yours. might also grab a ignition module by the coil while your there

[DOCTORBILL]

"Ignition Module" - please edicate me on THAT !

Never heard of it.....

EDITED IN _ Just now.....Distributor at WHITIES Wrecking - they have one for $65 ! Whoopie !
.......................................They don't know what an "Ignition Module" is either !

Found it from O'Reilly - "Ignition Control Module" Part # 2-7106 $134. OMG !
Amplifies Signal to Coil.

DoctorBill

[DOCTORBILL]

The Compuker says 12 - no errors - that is all !

I tried jiggling all the wires I could find with a wood stick (ever been zapped by the plug wires !?),
and not a single cough from the engine while idling. I guess no loose wires.......

Here are four photos of my coil and surroundings.









I don't see anything that looks like an Ignition Control Module anywhere near the Coil.

They evidently look like this.....



No Codes - so.....I will buy the used Distributor tomorrow morning and play
'change-out' until I figure this out.......

DoctorBill

[Crvett69]

it might be just a little square in the wire bundle towards the drivers side with only 2 wires. i looked at the one im stripping and pics didn't open

[DOCTORBILL]

If it is the red thing you are referring to, that is a splice into the coil for the Cruise Control. Otherwise, I do not see one.

What is the doodad with the metal fins to the right side of the coil ?

DoctorBill

[Crvett69]

its a resistor

[DOCTORBILL]

I'll be damned if I know where that ICM is !
From the photo of it on O'Reilly, it looks to be attached to the frame somewhere.
Don't know where, though.

No Diagnostic codes.....has to be the Dist'r - no ?

I'll try the Distributor...buying it tomorrow (unless someone beats me to it).

I'll be awfully pissed if it isn't ! Damn this intermittent stuff !

DoctorBill

[DOCTORBILL]

I bought a used '93 Metro Distributor at a local Wrecking yard this morning for $65 + tax.





I suppose the O-Ring should be replaced. I'll swap out the old one from mine.


Here you can see the vanes that sweep past the Magnetic Pickup Coil.


This is a close-up of the pickup coil's magnetic bar that the vanes sweep past.


I will remove the old one and insert this thing - warranted for 101 days by the wrecking yard.

I have to be careful and note the rotor position on mine in the vehicle and match this on to it.

I also suppose I will need to re-time the distributor with my timing light.
Means I'll have to clean off the timing mark and Indicator plate.
You can barely make it out covered with crap as it is !

I'll get at this when I can and report the results here...............

BTW - from the Chilton Manual (our Bible ?) it looks like from 92 - 00, the Ignition Control Module
(ICM) is an intergral part of the Ignition Coil. (page 2-6 upper right corner).
But then page 2-2 shows an ICM (fig-1) as part of the '89 - 98 Metros..... I am very cornfused as this even
says something about vacuum/centrifugal spark control.....(????)

My Metro was assembled in Canada if that helps any !

DoctorBill

[Crvett69]

only takes a few moments to change it. if you need a new o-ring bowens in chat room sells genuine suzuki ones. don't put cap on as it easier to line dist slot up when you put it in

[DOCTORBILL]

I'm back !

Had a BIG problem - my Computer was infected with the
"PUP.OPTIONAL.SEARCHPROTECT.A" bug....not a virus or a Trojan...???
Couldn't use my PhotoshopLE 5.0 for a couple of days.
Finally got it fixed - (I hope).

I changed the Distributor. It was simple to do.
Car starts etc, but I have not driven it a long way yet to see if the problem is solved.

Here is the "old" distributor - nothing seems wrong with it visually.
The vanes are all clean and bright. The coil looks OK.




Nothing obvious - maybe even fine ! Coil resistance is 220 Ohms. (?)
Some axle type grease at one side near the bottom vent hole.
Maybe came in or leaked from the input coil. ?????

I'll report back when I drive at 55 to work 30 miles away.....Holiday for me.

DoctorBill