1995 Mustang GT 5.0 Coil Testing? - Ford Mustang Forums
 
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post #1 of 12 (permalink) Old 09-20-2010 Thread Starter
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1995 Mustang GT 5.0 Coil Testing?

Can anyone tell me or send a link that shows how to test the coil in a stock 95 GT 5.0.
We replaced the Ignition module trying to correct a no spark condition but still no spark. The next thing on the list to check is the coil. I want to test this part before replacing since it may not be the problem and I don't want to keep throwing parts at the problem..

Thanks for any help..

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #2 of 12 (permalink) Old 09-20-2010
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Pull the coil wire off of the distributor and hold it about 3/8" away from the block while cranking. You will get a nice fat blue spark if its working OK.

Matt

2006 GT - Vortech polished w/ intercooler, Eibach suspension, Hurst short-throw, some other goodies - tuned by Paul's High Performance. It moves...

and it collects dust admirably while parked for repairs in the garage...

SOLD - 1995 Black Mustang GT, AODE. Loved it, but I had to let it go...

mjmalegalsolutions.com
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post #3 of 12 (permalink) Old 09-20-2010 Thread Starter
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Quote:
Originally Posted by alleymad95GT View Post
You will get a nice fat blue spark if its working OK.

Still no spark after replacing tfi module, that's why i want to test the coil next.

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #4 of 12 (permalink) Old 09-20-2010
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Well if its not the coil then look at the inside of the ecm for corrosion.
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post #5 of 12 (permalink) Old 09-20-2010
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You should have posted this as a continuation of the other thread.

Quote:
Originally Posted by Blt2Lst View Post
No worries.

I did find it and got it replaced, it was held in with 7/32 hex head screws.
The problem is that it did not fix the problem, still no spark. Time to start another thread..

Thanks for the help..
Did you actually do the test that I wrote out for you? My guess is it would have saved you the cost of buying the new TFI...

Quote:
Originally Posted by alleymad95GT View Post
If you have a test light, you can check the TFI.

Find the wiring that hooks up to the coil. Put one lead of the light on the red/green wire on the ignition coil and the other on the dark green/yellow wire on the ignition coil. When you crank the engine, the light should flash. If it does, then the TFI is working OK.
Conversely, what if one of those two wires is broken? You could put 10,000 new TFIs on there and it wouldn't fix the problem. That is another reason that you need to check the wires from the TFI at the coil.

Now, if we assume that the signal from the TFI is reaching the coil, and the coil is not sparking, then the coil is bad. But, if, say, the red/green wire that runs between the TFI and the coil is broken or pulled out of a pin, then you are never going to get any spark.

It all turns on whether the signal from the TFI is reaching the coil or not.

Matt

2006 GT - Vortech polished w/ intercooler, Eibach suspension, Hurst short-throw, some other goodies - tuned by Paul's High Performance. It moves...

and it collects dust admirably while parked for repairs in the garage...

SOLD - 1995 Black Mustang GT, AODE. Loved it, but I had to let it go...

mjmalegalsolutions.com
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post #6 of 12 (permalink) Old 09-20-2010 Thread Starter
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Thanks for your reply.

I was going to test like you said but did not see a dark green/yellow wire. Looks like it had a red wire and a solid white wire at the coil connector so I did not do the test, just threw a part at the problem which proved to be the wrong thing to do. Since there were only 2 wires at the coil, I should have tested at those 2 wires.

Anyway, the new TFI did nothing for the no spark condition. I guess it still needs to be tested like you said to rule out a broken wire or no signal from the TFI.



Thanks again..

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #7 of 12 (permalink) Old 09-24-2010 Thread Starter
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Quote:
Originally Posted by alleymad95GT View Post
Now, if we assume that the signal from the TFI is reaching the coil, and the coil is not sparking, then the coil is bad.
It all turns on whether the signal from the TFI is reaching the coil or not.
Getting back to this problem.

I was finally able to look at the wiring at the coil and now see the two red wires are joined together at the coil and the other wire seems to be white or yellow, hard to tell, colors seem faded out. So according to your testing procedure, just pierce the two red wires at the coil connection and attach a test light between the two, crank and light should flash if TFI is good. Is that correct?

I keep meaning to buy some wire piercers just for this sort of thing but did not get around to it. I guess i will have to use some pins like i have done before.

I will test this weekend post back what happens and take it from there.

Thanks again

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #8 of 12 (permalink) Old 10-02-2010 Thread Starter
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Today I took the distributor apart and found a broken pick-up coil. Also noticed a fair amount of play in the dist shaft which probably caused the pick-up to break in the first place. Anyway, replaced the pick-up and reinstalled the dist, all of my reference marks lined up and the dist dropped in easily. Fired up the car and it finally ran but was running rough, we also changed the coil because I noticed some arcing at the coil tower also. Anyway, fired it up again to check the timing and could see no timing mark any where near the timing tab. also, spout connector was disconnected and at operating temp. I also checked the firing order and it was right on.

One thing we noticed is when the spout connector is disconnected, the car seem to run much better.

Anyway, I need to confirm TDC and the timing, I suspect the timing chain may have jumped and i need to verify since car has 240,000 miles.

Does anyone have a diagram of the timing tab for a 95 5.0?

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #9 of 12 (permalink) Old 10-03-2010 Thread Starter
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One more thing, I can only find a notch on the harmonic balancer and not the usual bunch of numbers stamped on. Are the balancers on the 95 5.0's stamped with these numbers and I am just missing it. I have read that the notch is for use with a pick-up type timing light.

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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The HB should have the timing marks stamped on it...

Matt

2006 GT - Vortech polished w/ intercooler, Eibach suspension, Hurst short-throw, some other goodies - tuned by Paul's High Performance. It moves...

and it collects dust admirably while parked for repairs in the garage...

SOLD - 1995 Black Mustang GT, AODE. Loved it, but I had to let it go...

mjmalegalsolutions.com
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post #11 of 12 (permalink) Old 10-03-2010 Thread Starter
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Quote:
Originally Posted by alleymad95GT View Post
The HB should have the timing marks stamped on it...
Thanks, I'll take another look..

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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post #12 of 12 (permalink) Old 10-05-2010 Thread Starter
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We swapped in a rebuilt distributor and the car fired up and ran great.
Also, finally did find the timing marks under the rust on the HB
.
While I had the old dist out, I was comparing it to the new one and noticed that when I installed the pick-up coil, I did not index it properly. That would account for why it ran better with the spout disconnected, it probably put the timing closer to where it needed to be.
Anyway, live and learn, I probably had my mind on the car babes or something..

Thanks for the help..

89 LX Vert 5.0 Mostly Stock
5 speed,
2.73, TracLok still blown, but, new Spec Stg 1 Clutch
Dynomax Super Turbo
s[I]

I'm a victim of circumstance..


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