Weak Spark

madebyme

Registered User
When running a wire from the coil pack to a spark plug and grounding it, I get a spark but it seems weak. When I use an inductive timing light it doesn't flash (also indicating to me that I have a weak spark). The previous owner told me he had already replaced the coil pack when he was trying to get it running. The battery is good but I am going to test with another one tonight. So rather then running out and blowing $50 on a new coil pack, anything else that would cause this or a test I could do?
 
make sure all your powers and grounds are good...how is the spark at the coil to the plug wire?

now how is the spark at the end of the wire to the spark plug? could be wires or coil pack.
 
BTW, it's a 95... Spark is present at the coil pack on all 6 (short lead wire), but yellowish. On longer lead wires (like the ones going to the sparkplug) there is no spark. So I suspect either the lead wires are bad (but they look new) or the coil pack is not throwing enough heat. As I mentioned, I believe that the privious owner had changed the coilpack but the capacitor looks original. Could it be that the cap is bad? I when I disconnect it the quality of the spark does not change. That should be a cheap part and one that probably needs to be replaced anyway. What do you think?
 
well, without seeing what the spark looks like at the coil, ibut if its not making it to the end of the wire you've got a problem. So you need to start there and throw a new set of wires in.

I'd recommend Ford ones. Thats up to you though. There are some aftermarket ones out there too that do work well. I've had good luck with taylors and OE ones. But it will usually take a few days to get the aftermarket ones from summitt or supercoupeperformance
 
Good way to test...what color was the spark?

Blue?

White?

Yellow?


However, the better way if you haven't already is to run the codes.
 
I would consider removing the EDIS Module and cleaning the connectors (Male and Female sides) and reinstalling it with dielectric grease in the connector. Make sure the bracket connections to ground are clean. If that doesn't do it...replace the EDIS Module with a known good unit and see what you get.
 
Also consider ringing out the wires leading to the coil from the EDIS Module. You should only have a few ohms resistance in any wire. Do you have an EVTM to identify the connecting wires?
 
Also consider ringing out the wires leading to the coil from the EDIS Module. You should only have a few ohms resistance in any wire. Do you have an EVTM to identify the connecting wires?

I don't have a EVTM but I've been collecting just about every bit of information I can find on this site and have a manual on the way... I'm going to ohm out the wires this weekend and get the EDIS tested. One question though, from what I have been reading, if the crank sensor was bad, I would get no spark, correct? I do get a spark but as I mentioned, it's yellowish... Thanks in advance for the reply
 
Good way to test...what color was the spark?

Blue?

White?

Yellow?


However, the better way if you haven't already is to run the codes.

Spark is present at the coil pack on all 6 (short lead wire), but yellowish.
 
I only have a 94 EVTM here but the wires should be the same. If things don't match up that I am giving you though (wire locations and colors) don't chase a wild goose.


The EDIS Module is also called the Ignition Control Module (ICM)

Pin 10 on ICM = Tan with white stripes goes to pin # 3 on the coil pack connector

Pin #12 on the ICM = Tan with Orange stripes goes to pin #1 on coil pack connector

Pin #11 on ICM = Tan with light green stripes goes to pin # 2 on coil pack connector.

Pin #9 on ICM = black wire is the ground

You might also want to pull the connector off the radio noise capacitor which has a red with light green striped wire connected to it as electrically it is connected to the primary side of the coil pack through pin #4. It should be near the coil pack itself....round small cylindrical device.

I am trying to establish that the proper signals are able to be passed to and from the coil pack without undue voltage drop (high resistance contacts) and want to make sure the capacitor is not shorting out or breaking down drawing down the primary side voltage to the coil.
 
these cars have very long plug wires so thats what im thinking , i also have had trouble with autolite platinums missing in my tbird and in a lincoln ls and in an escort gt , i either use autolite copper or motorcraft platinum mostly 1 range colder than stock
 
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