Checking for spark -- did I do this right?

1989 Caravan, 2.5L turbo 4 cyl.

Wouldn't start this morning, cranked but no start. Recently replaced the Hall Effect Switch which solved an intermittent dying problem.

This morning I pulled the coil wire out of the top of the cap, and held it next to the block while an assistant cranked the starter. I got no spark. Replaced the coil and repeated the above, still no spark.

But, did I do the spark test right? Does pulling the coil wire work for this, or do I need to pull a spark plug and try it?

Thanks in advance.

==>Tim

The coil wire feeds the cap which in turn feeds all the plugs. The cap rotor spins hitting the individual contacts one at a time. Each contact is attached to a different plug. If you don't have spark at the coil wire feeding the cap, chances are you have a bad coil.

The coil wire feeds the cap which in turn feeds all the plugs. The cap rotor spins hitting the individual contacts one at a time. Each contact is attached to a different plug. If you don't have spark at the coil wire feeding the cap, and you already replaced the coil with a good one, it's time to look into your ignition circuit. Blown fuse or link?

1989 Caravan, 2.5L turbo 4 cyl.

Wouldn't start this morning, cranked but no start. Recently replaced the Hall Effect Switch which solved an intermittent dying problem.

This morning I pulled the coil wire out of the top of the cap, and held it next to the block while an assistant cranked the starter. I got no spark. Replaced the coil and repeated the above, still no spark.

But, did I do the spark test right? Does pulling the coil wire work for this, or do I need to pull a spark plug and try it?

Thanks in advance.

==>Tim
Tim You did it correct. If you took the coil wire off of the distributor cap and held it close to ground. 1/4" max

However, you may also not have power to the coil in the first place. Place a volt meter on the positive coil terminal and crank. Should be 12v here. If there is not, then ASD(autoshutdown relay) may not be energizing the Z1 circuit.

pull a spark plug out and re-attach it to the plug wire, then put the spark plug against something steel, then get it to rest there with out touching it, making sure u can till look at it clearly, then get an assistant to crank enging while observing spark plug for spark. putting the spark plug tip to steel will make the plug ark to ground so u should see a spark

Thanks for the replies!

I'll put a voltmeter on the + terminal of the new coil and see if there's power there.

I recently replaced the Hall Effect Switch after the van was intermittently dying. I guess a brand-new Hall Effect could be bad? If so, could that cause this no-spark problem?

Thanks for the replies!

I'll put a voltmeter on the + terminal of the new coil and see if there's power there.

I recently replaced the Hall Effect Switch after the van was intermittently dying. I guess a brand-new Hall Effect could be bad? If so, could that cause this no-spark problem?


Remember to turn the key to "run" position when checking positive terminal.

Yes I believe a bad hall effect switch (under distributor cap) will leave no spark. But chances are low a new one is bad. Make sure it is installed corectly.

andy

I don't think the hall effect switch has anything to do with whether or not the coil wire is delivering spark? If you have 12 volts into the coil and no spark from the coil wire to the Cap, then your cap is probably bad or the coil wire itself is bad. (don't try to measure voltage on the coil wire to the cap,secondary, it's extrememly high voltage).
You can also check resistance through the coil itself. You should have continuity. I'm not sure what the resistance should be but I'm sure someone here can give you an idea.

I don't think the hall effect switch has anything to do with whether or not the coil wire is delivering spark? If you have 12 volts into the coil and no spark from the coil wire to the Cap, then your cap is probably bad or the coil wire itself is bad. (don't try to measure voltage on the coil wire to the cap,secondary, it's extrememly high voltage).
You can also check resistance through the coil itself. You should have continuity. I'm not sure what the resistance should be but I'm sure someone here can give you an idea.


If the computer gets no signal from the hall effect it cant ground the coil to make spark at the right time and wont work and you get no spark.

But after thinking about this a little more I remember that 85, 86 and 87 and later are different. i think the 86 wont run without it but the 85 87 will. My memory is failing. I give up

Hey, it's cool, Andy. I appreciate your replies.

I think from what I've read about Hall Effects that you're right about it not being able to spark without the signal. That's one of the things we're gonna have our local auto shop mechanic check. I've pretty much given up trying to diag this myself.

Thank you to everyone who replied. I'll post whatever we ultimately find as the solution so everyone can share in the knowledge.

The brand-new Hall Effect switch was bad.

>:-(

Just goes to show ya that ya can't always trust parts to work just because they're new. That's a lesson learned for me.