Need serious help, no spark please read

[rebel2k4]

A few months ago my car sputtered to its death. I started it up and it was misfiring, then sputtered and stalled. No spark.
My first guess is the disty. I checked for power on the 3 and 6 pin connector, both have +12V. Grounds are good. No other symptoms and no codes.

I have been trying to fix it for the past 3 months. I tried a 93 PGT disty (apparently was pinned different) and after searching through wiring diagrams, comparing readings on an ohm meter, and some soldering I had the 3 pin connector wired right, or so I though.

So I try to start the car and same deal. No spark. I ran codes and got like 5 or 6 different sensors (?). Knock sensor, VAF, etc. So I switched the wires back to how they were supposed to be and tried to start it, knowing that it wouldnt but I wanted to see those codes go away. The disty went up in smoke when i tried to start it after that. That NEVER happened before....

So I went and got a reman 94 MX3 disty (the RIGHT one) and also soldered the wires back to stock.I STILL have no spark! THe tach doesnt bounce when I crank the car either, but I checked the wire on the 3 pin connector for tach output and it has power when cranking. Fortunately the car isnt throwing any codes though.


I have no idea what to do now. SOMEONE PLEASE HELP!

<small>[ August 10, 2004, 12:50 PM: Message edited by: rebel2k4 ]</small>

[PATDIESEL]

You might have burned up something else when you blew the alt. I don't know aout the PGT ALts, but if you saw the magic smoke come out of the "Broken" MX-3 Alt, you might have blown somehting else as well. Also if you wired the alt correctly it should not have blown-up, so I'd first go back and check to make sure that you have all the wires correct and that you are using the right size wire if you had to extend them. I've seen plenty of your other posts and you seem pretty competant, but also make sure you use silver solder when soldering electronics or wires for them.

[rebel2k4]

Okay well when the PGT disty fried, it was wired in stock form (which I tried MANY times prior and never fried it then). When I had it re-pinned it did not fry either, only until I switched it back to stock.


Now I have everything wired stock, with a new 94 MX3 disty. Appropriate wires are getting power on 3 and 6 pin connectors, no codes, lots of fuel and fuel pump comes on, no spark.

[rebel2k4]

Wow. No ideas?

Does anyone have wiring diagrams for a 94 MX3?

[IanL]

Unfortunately, I don't have a diagram for a '94, only '93 and '95. Haynes says the changeover year was '95 for KL engines; the UK (not US) Parts Catalogue says November '93 for K8, May '94 for KL, so who knows?

I don't think wiring the 3 pin the wrong way will fry anything. The resistance of the coil primary is less than an ohm, so the igniter should be built to take a high current anyway. Guido in Italy connected his the wrong way (newer car, old style disty), and when he reconnected the right way it was ok.

The way you can tell whether you have the old or new style disty is this:

Measure resistance between A and B. Old style will be about 1 kohm (this is the series resistor in the line to the tacho), new style about 0.5 ohm (this is the coil primary).

Just to confirm the wiring:
Old style - RED (Diag Connector) to A, Yellow/Blue (Tacho) to B
Blue (Ignition) to C

New style - Blue (Ignition) to A
RED (Diag Connector) to B
Yellow/Blue (Tacho) to C

And to make sure no confusion about pin ID's, the A pin on the disty is the one closest to the 6 pin connector.

[rebel2k4]

My old disty is the new style. When I ordered a new one (remanufactured) for my MX3 I asked for a small rotor 94, and it was exactly like my old one so I know its right.

I checked resistance on the coil and its good. Same as my old disty.

I checked for power again, still getting good voltage. The car only has 101k and has lived in CO all its life, so the wiring harness looks great. NO corrosion or anything anywhere. Still looks new. I dont think its a wiring problem.

I checked for power at the VRIS solenoids and got 11.8V with the key "on" so thats good.

Still no codes. Tried different known good ECU, no change.

Do you have those diagrams scanned where I can see them? Preferably the 93, besides disty wiring I htink its very similar.

Although my disty is a reman I still suspect it may not be good. I spent $250 on it, but if anyone trustworthy with a 94 will test it out for me, I am willing to send it out their way.

Thanks for the help

[IanL]

Originally posted by rebel2k4:
My old disty is the new style. When I ordered a new one (remanufactured) for my MX3 I asked for a small rotor 94, and it was exactly like my old one so I know its right.

I checked resistance on the coil and its good. Same as my old disty.

I checked for power again, still getting good voltage. The car only has 101k and has lived in CO all its life, so the wiring harness looks great. NO corrosion or anything anywhere. Still looks new. I dont think its a wiring problem.

I checked for power at the VRIS solenoids and got 11.8V with the key "on" so thats good.

Still no codes. Tried different known good ECU, no change.

Do you have those diagrams scanned where I can see them? Preferably the 93, besides disty wiring I htink its very similar.

Although my disty is a reman I still suspect it may not be good. ...

If your disty is the new style, the appropriate diagram should be the '95, but I'll email both to you - the filenames will tell you which is which.

You won't get codes from a duff disty, it isn't in the diag scheme. It does sound like the igniter is defective; I wonder if we could work out an easy test?

[bmwm3guy]

as stupid as this sounds, check your timing belt to see if it hasn't snapped. That JUST happened to me a few days ago... That woul explain the car not starting at all.

[rebel2k4]

Thanks for the diagrams Ian.

I double checked the wiring and disty. Pin A on the ignitor has 11.8V, between pin A and B on the disty i have 1 ohm resistance on both my reman disty and my original. So this shows I have the correct disty for my car.

I put a fresh charged battery in the car and hooked jumper cables to it to ensure good voltage. Still no spark.....

Oh and BTW I did happen to check for a snapped t-belt when I first got this problem. I took off the disty cap and cranked the car over and the rotor turns so the belt is good.

<small>[ August 11, 2004, 02:20 PM: Message edited by: rebel2k4 ]</small>

[PATDIESEL]

you might want to double check that the timing is set properly, it may have jumped a notch or two. when was the last time you changed the belt and the tensioner?
When you say that you have no spark are you using an arc tester to see the spark, if not at least pull a plug wire but leave it in the hole it should arc to the block and you will be able to hear it from the engine bay when you turn the key.

[IanL]

Not sure about this, but I have some confidence that the igniter can be tested by putting a high impedance averaging meter on the IG- terminal in the Diag Connector. With ignition on, it should read battery volts, when cranking (or running) it should swing down to zero every spark signal from the ECU, as the igniter switches, so the average should drop to (say) 8 to 10 V. An oscilloscope, if you can get one, would be better, because you should see the pulses. If there is no effect, the igniter isn't working.

One would need to be sure the signal is getting from the ECU to the igniter. The place to monitor that is Pin F on the 6 pin connector on the disty (Orange wire). It should go from OV with the ignition on, to about 0.6V when idling, so a little less when cranking.

[rebel2k4]

Timing belt and tensioner were changed at the time I did the KL swap (550 miles on swap to boot)

Even if it was off, I would still be getting spark, just at the wrong time. My car does not make spark ever.

I tested for spark with a screwdriver in a plug wire and held it about 1/8-1/4" from a good ground.

Ian thanks for the advice, I will check that tonight.

[rebel2k4]

Wow. Get this....

I did a voltmeter test on my battery, showed 11.8V. I figured I'd swap it out with my MX6 battery because it read 13.02V.

After that, I swapped ECU's to a 93 K801 that is known to be good.

Then, I proceded to check voltage at pin F with the 6 pin disty connector disconnected from the disty. With key on, I got .04V then while cranking I got .3

So I reconnect the connector and put the voltmeter lead in the same wire (pin F)

Test it, and I get the same readings. I walk back up to it, and shove the lead in furthur. Go back, start cranking, the voltage jumps to around 2.5V while cranking and at the same time I hear "snap snap snap..."

I was like WTF! I put back on the spark plug wires, and guess what happens? Crank it over and it roars to life!!!
After 3 months it is running once again. I think it was a combination of a low battery, bad ecu, and bad disty. Whatever the case is thanks for your help guys, especially you Ian!!

[IanL]

That's good news

You learn something every day - I thought the voltage when cranking would be a bit lower than the idle value, with the starter taking a large current and dropping the battery terminal volts, and it turns out to be much higher!

Just wondering whether it was a poor connection in pin F, and jamming the probe in pushed it into good contact?

[hgallegos915]

HAHAH omg...when all ign components are fine..the one thing that needs to be swapped out is the ecu..the symptom of a bad ecu..its that itr trows out codes that make no sense..like the vaf...knock and al those giodies at the same time. Maybe this can be a learned lesson for some of us whenever we have this problem. I had this problem on a maxima...but since the ecu was trowing alot of codes..i just swapped it out and walla. When an ecu makes no sense...drop it..