Real strange non starting '98'

[astroshepawd]

Day 1, Start cold van to set off for work, get 10 feet, engines dies.........no spark!
Day 2, No codes found at all. A kind of elimination process after testing the coil in situ and all okay was to replace the crankshaft sensor and the distributor!
Reason behind replacing the distributor was that the cap was shall we say not in the best condition and also it covered the cam sensor as well so fitted complete.
Day 3, Parts fitted and first turn of the key van fires right up and revved high for a period before settling down to normal idle (presume CKP learning?). Bought engine up to temp turned engine off and on a few times all was fine.
Day 4, Start from cold again (this is the next morning) and no start! No spark again! Any ideas gratefully recieved.
Thanks

[AndyH]

Sounds like it could be dropping an ignition feed somewhere ?
Ill take a look in the circuits book

[astroshepawd]

Thanks,
The latest is now have a spark at HT into dizzy cap but none out to plugs (this a new dizzy complete?) So replaced new with old dizzy, alas the battery is to low to test properly so battery on charge see what we get tomorrow with a full charge battery.

[blacknome]

I know you "tested" the coil but I would be willing to bet that's your problem.

Mine would die out of the blue. It left me stranded at work twice and once in the middle of the road driving home.
All 3 times when it died I would have no spark. I would test the coil it would be fine.
Cap, wires, rotor all GM all less than a year old.

3rd time it needed to be towed and the tech couldn't figure it out because it started off the flatbed, and he drove into the shop. He then used it on parts runs for 3 days with no issue.

I ended up changing the coil being it was the cheapest and easiest thing and its been fine for 3 months now.

[Astrophysics]

Yes, sounds like it coil is intermittent.

The coil has many windings since it is a transformer that uses magnetic field to induce the hi voltage out of secondary windings. The primary winding gets the 12 volts and the turns ratio of the secondary divide by the primary gives the multiplication .

The fine wire is wound on the magnetic core. When the distributor points aka electronic ignition module opens the circuit , the magnetic field collapses and induces the high voltage, 20 K volts or so to jump the gap on spark plug. One or more windings may be intermitant and cause open circuit and faulty coil.

AP

[astroshepawd]

Thanks for the replies, it may well be the coil!
The latest is - With a now fully charged battery I have the same scenario, real healthy spark into the dizzy cap and even to the center terminal but nothing at the leads out to the plugs.
So replaced the cap and rotor for a new set (have disregarded the new distributor complete now this is back to my original old distributor) and first turn of the key the engine fired into life! Just as it did when the new distributor and crankshaft sensor were fitted. Engine up to temp drove it around, turning engine off and restarting a few times, all was good. That was yesterday afternoon, go to start the van this morning and nothing!!!!!!!!!! Grrrrrrrrrr!!!!!!
Exactly the same as before, healthy spark into cap nothing out! What the hell is going on? Talk about frustration? Only good thing is that the van is at least at home and not in some car park miles away.
I will now order up a new coil but really want to know what might be happening. I took the old rotor arm apart thinking that the plastic piece on top of the electrode was something significant! No appears it just connects the copper electrode and the stainless spring together.
Could the coil be putting out to much power? But affecting what, to stop it from firing once left overnight.
I just cannot understand how the second a new part is fitted (now x2) it bursts into life, then when left nothing.
I will try a new lead and coil, but just hate all this stabbing in the dark!
So near yet so far!
Shep

[blacknome]

trust me I can sympathize. My van is ever so reliable and for it to cut out in traffic in the middle of the road with no warning whatsoever baffled me. Then to call a tow truck and have the driver tell me he started it and drove it on and off the flatbed, that was enough and I had him drop it to my tech. No codes were thrown either. Not even a mis-fire because it would not fire at all.
I too had spark at the lead from the coil to the cap but I noticed it was on the yellow side and not a healthy blue. But when I would remove it from the van to "bench" test it the coil would perform fine. Then put it back together and the van would start LOLOLOL

[astroshepawd]

Well thanks guys, safe to say now after running van for just over a week it was the coil! New one fitted and 'Way to Go'.
So what has been learned? Just because bench testing says a part is fine, it isn't necessarily!
Ha, what do I know? I was told that apparently on later OBD2 systems the coil can actually show up on the scan tool as being naff but not in 1998!
Thanks again
Shep