Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: jkirchman on October 31, 2005, 05:25:58 PM

Title: #7 Missing
Post by: jkirchman on October 31, 2005, 05:25:58 PM
The car I just got back from the shop with $1200 worth of AC work?  Yeah it's in the shop again.

Seems the #7 cylinder has a consistent miss.  They hooked it up to an o-scope and it's getting spark.  They think it's a fuel problem.  How plausible is injector failure?  Does anyone have any ideas about what else it could be?  Just looking for other possible causes and what the most common one would be.
Title: #7 Missing
Post by: SLEEPER T-BIRD 87 on October 31, 2005, 05:52:10 PM
id check the spark plug for carbon bridging or maybe they acidently unplugged the injector? .


at very least pull #7 and have a look
Title: #7 Missing
Post by: bondocougar on November 02, 2005, 07:55:30 PM
Geez, you have some bad carma going on, first this, then your wifes accident... 

Hope the insurance thing works out, and hopefully the number 7 problem is something simple. 

If it was missing from the onset of your AC work I'd guess a wire harness plug got a mangled or something.  The #7 injector is hard to get to with the intake manifold covering up that area, so its unlikely that wire got disturbed.

I wonder if those two salt and pepper connectors near the firewall may have gotten some contaminents on the pins, I think the fuel injector signals go through those.
Title: #7 Missing
Post by: bondocougar on November 29, 2005, 08:12:59 PM
Did they ever find what was going on with the miss?
Title: #7 Missing
Post by: jkirchman on November 30, 2005, 01:23:55 AM
Yeah it was just a dirty injector.  They took it out, cleaned it, and put it back in.  It's been running fine for a couple weeks now.

Now I just need about $3500 for paint, tires, a TC rear end, CHE Performance control arms, and an HO conversion.  :D
Title: #7 Missing
Post by: Sick88Tbird on November 30, 2005, 02:04:12 PM
I had a similar problem on the same cyl.  I kept fouling plugs in cyl #7 and is was driving me crazy...I had to crank it for a good 10-15 seconds before it would even fire up.  Just out of curiousity, I replaced that injector with an old injector from the SO motor and it started and idled smooth...just backfired and ran like hell under a load.  After I got new 19lbers it was a work of art in the way it ran...seems my cyl. 7 injector was hanging WIDE open.  Glad you got it worked out!
Title: #7 Missing
Post by: bondocougar on December 01, 2005, 08:07:20 PM
Wow, never knew the injectors could cause trouble.  I had 220k miles on my V6 injectors.  When I put the HO in, I bought my orange injectors off eBay.  The new ones are very pricey. :hick:

Now I know what to look at in case those used injectors act up. ;)

Thanks