Checking for spark

[Klayfish]

Before removing my timing belt and diving into replacing the front seals, I wanted to see if I could get my Spider to start with a bit of fuel in the carb. The engine cranked over nicely, but never fired. I did find out by surprise that the windshield wipers work... The horn, lights, turn signals also work, which is cool. Anyhow, no luck with getting it started. Obviously, it's either not getting air, fuel or spark. Given that there is no air cleaner on the car, and I poured a bit of fuel in the carb, I'm guessing it's spark.

Simple question for most folks here. How do I check to see if there is spark getting to the plugs?

[maytag]

well there are probably a lot smarter folks than me who will tell you how to do this differently, but if you pull one of the plugwires from a plug, insert a screwdriver and then lay it on the block where the metal part of the screwdriver is not touchng ground, but close to it. have someone crank the motor, look for spark between the screwdriver and ground.

Alternatively, there are tools one can purchase that have a plug-shaped end and will insert into the wire. You ground it, and then you can adjust the gap on the tool to watch it. I bought mine from Motion-Pro, back in my motorcycling days. I don't see it on their site anylonger, but it is functionally just like this one:
http://www.amazon.com/Thexton-404-Adjus ... B0002STSBM

I don't know if these are available at local supply / tool stores or not?

[TronDD]

I think they sell a light you put inline between the spark plug and the wire.

I just put a rubber band or tie wrap on the trigger of my timing light, clip it over a plug wire, point it at the windshield, get in and turn the key.

Tim.

[fiat218]

touch it while your buddies crank it over

[Klayfish]

I actually wound up pulling a plug, inserting it into the plug wire and laying it on top of the block. This was suggested to me by several people. No spark... Now I have to figure out why.

Engine was converted from the original dual point to an electronic ignition. Never done any electrical work or testing in my life. This should be an adventure.

[azruss]

first check the basics. 12v to the + on the coil. all motor grounds in place (on an FI i think there are 3 that ground to the top of the motor). pull the cap and look at the condition of the wires that go to the mag pick-up (this is the #1 culprit). finally you may have a faulty ignition module. dont know how to test that other than replacing it.

[TronDD]

Are you sure the plug was properly grounded while sitting on the block?

Tim.

[Klayfish]

Tim,
I wish I could say for sure that it was, but being a novice mechanic, I can't be totally positive. I had it laying on the top of the engine with the threads in contact with the block. I tried moving it around a few times, and always the same result. No spark.

azruss,
The most electrical work I've done in my life is hanging and wiring a ceiling fan. Well...that and stringing Christmas lights... I don't have any tools. Guess I need to head to Autozone. The car is carb'd. The wiring has definitely been altered, as it has electronic ignition. The PO told me he removed all the relays in it and hard wired everything.

[azruss]

automotive electrical will be something you will get very familiar with working on a Fiat. go to Radio Shack and ask for a digital multi-meter. I think they are in the $10-20 range. you dont need anything fancy. these meters read volt (both AC and DC...your car is DC) and resistance (ohms). the ohms part allows you to test for bad connections, bad lightbulbs, broken wires, bad grounds.
example: to test the 12v to the coil, you plug the red and black probe wires into the meter. turn the meter to DCV (volt DC). sometimes with the new meters, the scale is self adjusting, you just need to make sure it is on DC and not AC (AC will be designated by a squiggly line, DC is a straight line. turn on the key. put the red probe on the + terminal of the coil and the black probe on any ground on the chassis. give it a couple a seconds and it should read 12v or something close.
Just that simple, my friend

[Klayfish]

Just wanted to bring this back up for an update. azruss was dead on. Digital multimeter was $14 at Autozone. Followed his instructions (and the ones on the meter), thanks azruss!

My father in law was over for the holiday and with his help, we checked out the electricals to find out why there's no spark. We found that power was getting to the coil OK. The coil was sending it to the distributor OK (I was inside the car turning on the key, but he was using a screwdriver and getting an arc inside the distributor). But the spark isn't leaving the distributor to go to the plugs. So that's where I stand now. Going to try the simple and cheap thing first, change the rotor.

[maytag]

sorry, is your car points? or electronic? the rotor could be suspect, and you're right, cheap-n-easy. But they rarely fail completely like that. Usually more of a gradual "crap-out".

I'm suspecting points. ???

[Klayfish]

The car uses points. Found out from the Mira group that it's a factory dual points distributor with one set of points removed.

The car hasn't run in many yeas (probably 8 or so), so I'm trying to bring it back to life. I don't know what was and wasn't working when it was "parked". Guess figuring that stuff out is half the fun.

Here are pics of the distributor and rotor.

http://s1197.photobucket.com/albums/aa4 ... 020383.jpg

http://s1197.photobucket.com/albums/aa4 ... 020285.jpg

[maytag]

I'm not completely following the part about your father in law getting an arc in the distributor. What was he pulling from? Arcing to what?

So, you'll note that at the base of your distributor, under the rotor, there is a cam with 4 lobes on it (its a collar encircling the shaft). you'll also see that your points have a "follower" that glides along this cam, and this is what opens the points, and allows them to close.

if you have 12v to the coil, and it's going to the distributor as well, then I'd check to see if your points are closing / opening correctly. The amount of time that the points are closed (and the timing of each break) is your dwell. There are ways to set this without a dwell meter, but your multi-function auto voltmeter may have a dwell meter on it. (mine does, but I paid more than $14 )
Either way: ceck to see that your points are closing completely between lobes, and that they open completely at each lobe. if they are not closing at all, or not opening at all, then you won't get spark discharge.

[Klayfish]

Thanks. I know this sounds dumb, but I'm not sure of the answer....do I turn the engine by hand when checking with the dwell meter? We didn't have a dwell meter (and had put my multimeter away, so I'm not sure if it has a dwell meter or not), but we turned the engine by hand and watched the points open and close. I checked the manual I have and if I remember right, it said the point should open .016". Need to get a feeler to see how far it opened, but it did open for sure, and then closed.

[bobplyler]

I used my little brother once to check for spark. "Here... hold this spark plug wire..."

I could only do it once.