Perplexing no-start issue (Page 1/3)
Yorgle OCT 12, 10:35 AM
What in the name of every single blasted fruit bat is going on here?!: my daughter's 86 2M4 (everything stock) starts and runs great 99% of the time, but occasionally will simply not start-- just cranks but won't fire. Several months ago when this happened, I stuck a timing light on it to see if it had spark and it fired right up!. Next time it didn't start, just for the heck of it, I stuck the timing light on it again and IT FIRED RIGHT UP! Thinking two trees aren't yet a row, I left the timing light in the trunk and the next time it happened, I again connected the timing light and it immediately started. I've repeated this at least 5-6 times now and each time it's exactly the same situation- car cranks over but won't fire- put the timing light on and it instantly starts and runs fine.

For what it's worth, my timing light is a vintage series-type (non-induction) with the spring that clips in between the plug tip and the plug wire. The last time this happened, I connected the timing light's trigger wire to the plug without connecting the leads to the battery and it would not start. Connected the battery leads and it fired right up. I don't even have to press the trigger on the timing light for this trick to work- somehow, the car just knows the light is connected and starts.
Gall757 OCT 12, 02:27 PM
skywurz OCT 12, 03:56 PM
Im going to go with bad ground. And Somehow adding the timing light adds more grounding.

My first gut was that the fuel pump relay has failed and its kicking on due to oil pressure. You try to start build up a little oil pressure nothing then add the light try again and because things have pumped up it then starts. However it sounds like you are cranking more than a little.
Rexgirl OCT 12, 04:49 PM
If it hasn't been done for a while, a general ignition system service would be a good idea. Still, try removing and cleaning the bolts that hold the Ignition module to the distributor base first.
Yorgle OCT 18, 05:23 PM
I pulled the distributor apart yesterday and cleaned the ignition module bolts/mounting holes and baseplate, but first time I tried starting it, she just cranked with seemingly no spark. Stuck the timing light on, and just like before, fired right up. However, after I did that, the check engine light came on so I ran the ECU diagnostic and it spit out codes 21 and 33, which would seem unrelated to the ignition system.
buddycraigg OCT 18, 08:37 PM
The timing light is not doing anything.
Are you putting the spring connector on the plug or at the cap?
Yorgle OCT 19, 11:01 AM

quote
Originally posted by buddycraigg:

The timing light is not doing anything.
Are you putting the spring connector on the plug or at the cap?



In series between the tip of the plug and the wire.
Rexgirl OCT 19, 02:53 PM
My guess is that you have high resistance somewhere in your high voltage system. Have you looked at your plugs, cap/rotor, or sparkplug wires? You may have oil/fuel fouled plugs.
theogre OCT 19, 05:48 PM
Don't drive a car w/ problems like that.
May have some no-start problems now turning into a big problem latter or even have a car fire when some E-part finally dies.

Old T-lights put extra load on High side of ignition. That can do odd thinks even "solving" the above problem.

Does the tach moves when this happens?

Pull the Tach Filter any time you have problems w/ HEI system. That can cause weird problem too. But no filter = no tach for time being too.
See my Cave, HE Ignition


quote
Originally posted by Rexgirl:
My guess is that you have high resistance somewhere in your high voltage system. Have you looked at your plugs, cap/rotor, or sparkplug wires? You may have oil/fuel fouled plugs.

Could be... Even an Iffy coil.

------------------
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Yorgle OCT 20, 02:59 PM

quote
Originally posted by theogre:

Don't drive a car w/ problems like that.
May have some no-start problems now turning into a big problem latter or even have a car fire when some E-part finally dies.

Old T-lights put extra load on High side of ignition. That can do odd thinks even "solving" the above problem.

Does the tach moves when this happens?

Pull the Tach Filter any time you have problems w/ HEI system. That can cause weird problem too. But no filter = no tach for time being too.
See my Cave, HE Ignition

[QUOTE]Originally posted by Rexgirl:
My guess is that you have high resistance somewhere in your high voltage system. Have you looked at your plugs, cap/rotor, or sparkplug wires? You may have oil/fuel fouled plugs.

Could be... Even an Iffy coil.

[/QUOTE]

Thanks. Next time it happens, I'll be sure to watch the tach. The cap and rotor are new, and the plugs are clean- less than 1K miles on them. I'm going to pick up a set of wires and put them on and see if that helps.