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Re: electrical caused ignition miss

To: "gregs672liter@netzero.net" <gregs672liter@netzero.net>
Subject: Re: electrical caused ignition miss
From: Pat Horne <pjhorne@mail.utexas.edu>
Date: Fri, 23 Jun 2006 06:43:52 -0500
Greg,

A number of things to try.

I'd start with the distributor cap and rotor and check your timing

Is it possible that you cam  timing is off?

Spray the intake manifold with some carb cleaner to see if there is an 
intake leak. (not all carb cleaner will make the engine speed up, so try 
spraying a bit into the carb to see if it makes a difference in engine 
speed).

Instead of turning off the key to stop the engine, try pulling the power 
lead into the ignition unit loose and see if the engine continues to run 
for a second or two. If the run on after key off is not the reserve 
power in the ignition module, I would check the connections on the 
ammeter. I can't figure out why these connections being loose causes 
this symptom, but it did on my car.

If all else fails, head for a shop with an engine analyzer and have them 
see if they can find the problem with their scope.

Good luck.

Peace,
Pat

gregs672liter@netzero.net wrote:

>Ok electrical gurus, I need some help.  I have an ignition miss that I cannot
>figure out.  I do believe it is being caused by an electrical gremlin.  Here
>is the set up:  Gary Boone EI, recently rebuilt; Jacobs Pro-Street ignition
>(multi-spark and captive discharge) with Jacobs coil and Jacobs wires;
>non-stock but new ignition switch; relocated batt in trunk; ground staps from
>starter to frame, from alt to frame, battery grounded in rear on body to frame
>mounting bolt.  I have rewired all wires to and from the ignition switch; to
>and from the alternator to the fuse box and amp guage; all wires leading to
>the EI; changed the EI box; changed spark plugs (can't remember if I changed
>plug wires yet but I think I did); GM one wire alt; newer starter; newer batt
>cables.
>Here is what happened:  Pulled the motor to fix a trans bearing last summer
>after Shasta.  Car had a slight miss then (always has) but ran very strong.
>When the trans and engine went back in after the repair something was
>different:  Car ran fantastic, like it should (very built motor), was smooth
>with no miss, clearly had more power, etc.  Then two days later it suddenly
>went back to it's old miss problems and has been getting progressively worse
>despite my best efforts.  Now it misses enough that I believe it is causing it
>to run hot (about 215 degrees even with a new 3 core rad, new and tested
>themo, electric fan, etc... ran cool at Shasta with same set up last summer.
>Head gasket is fairly new, head is studed, newer water pump... bad impeller?).
>I have bipassed the Jacobs; no difference.  Changed plugs, bought new carbs,
>jetted carbs with an analyzer (just today in fact), re-wired this, changed
>that... still no joy.  I am ready to tear the whole car apart and start over,
>but before I do that I thought I would ask and see if ANYONE has some ideas.
>The only thing I note is that the car will sometimes continue to run for 3-5
>seconds after I turn off the key... not run on, but run normally then shut
>off.  I figured this was from the CD of the Jacobs and happening now because I
>had removed my kill switch when I was re-doing the wiring, but could it be a
>short of some kind, and if so how can I find it?  Anyone suspect a grounding
>issue?  Ghosts?  I have had this car 20 years, built it from the ground up...
>I feel I know her well, but I am stumped.  I will be trying the obvious stuff
>once again (cap, rotor, plugs, wires, etc.) but electrical wiring is my weak
>point.  Any suggestions appreciated.  If no fixie, no Shasta for Greggie, and
>that means that Barbie will not be there!  Thanks.
>Greg Burrows
>67 2000 #588
>
>
>  
>

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