No Spark

hdcrazyhombre · Nov 29, 2011

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oNotPromoteQF/> <w:LidThemeOther>EN-US</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w

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ontVertAlignInTxbx/> <w:Word11KerningPairs/> <w:CachedColBalance/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="--"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument> </xml><![endif]--> New member and new to Cougars. I just purchased a 1970 Cougar with a 351C motor. I drove it around a few days and when I went to drive it this weekend, no spark. The 12V lead going to the D.U.I distributor is zero. I check the fuse panel and all fuses have 12V on both sides.

What recommendations do you have to pinpoint the problem area? Does the ignition switch power run through the Cougar rev limiter before making its way to the coil/distributor?

As a sidebar, I was also looking at swapping out my D.U.I distributor for an MSD 8350. (DUI was clicking loud). Since the 8350 has a built in rev limiter, does the forum just run a new coil w/ the 8350?

Thanks. I figured I would get power back to my current setup before buying new parts.

Tim

1969XR7Vert · Nov 29, 2011

Do you have a factory tach? If so, it may have crapped out. Otherwise, the original wire which runs to the dist is a resistance wire, they sometimes go bad and additionally, the GM style HEI unit you are using would want direct (switched) 12V rather than dropped through a resistance wire. Trace the wire back and check for voltage at the firewall connector. If nothing there, you need to dig into the behind the dash to find where the voltage is being lost. As I mentioned a tach (XR7 models) would be highly suspect for this problem.

hdcrazyhombre · Nov 29, 2011

Good call. I traced the wire back and the previous owner did connect it to the resistor wire which had no power beyond the butt connector into the resistor. I spliced the wire prior to the butt connector which had full 12v and ran it to my DUI. Started right up and sounds a lot better without any hesistation. I'm sure the distributor was only getting 6-8V previously.

Thanks again.

TheRktmn · Nov 30, 2011

A bad tach will still allow the ignition to fire when the key is in the start position. A good clue to a tach being faulty is that the engine fires while cranking but will not continue to run when the key is released to the RUN position. This is because the "I" post on the starter solenoid delivers a hot 12V to the coil (bypasses the resistor wire & tach) during start.
If you have a non XR7 the symptoms of a bad tach can still show up when the run wire (which includes the resistor wire) or ignition switch is bad.

Pink wire explained: http://www.classiccougargarage.net/showthread.php?tid=87&pid=191#pid191

No Spark

hdcrazyhombre

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1969XR7Vert

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