[urq] hesitation at higher RPM & boost

Ben Swann benswann at comcast.net
Wed Jul 26 16:41:12 EDT 2006

Recommended plugs?

I have been using the Bosch triple prong WR7DTC I think - in most of my cars,
turbo and non, with exception of the later 20Vturbos.  Never had any problem
with these, except getting hard to find..

One of the big advantages I am sure I got from installing the Jacobs was that
I have a direct feed to Battery + and ground - no skinny wires.  I could just
as easily substitute for an MSD or other, but I believe the Jacobs is doing
the job regardless of if it is Multiple Spark or Capacitive discharge or
whatever - there is surely a big improvement in spark.  I will double check my
wires and plugs.  Cap and rotor are new and except for coil wire wires are new
too.  Coil is designed for use with the Jacobs.

I'd like to know how I can make it so the intake air temp sensor is less
picky.  I checked this out some time ago - wiring good and resoldered the
sensor after testing and cleaning.  Would substituting the one from an MC-1
work better - anyone know about the values on these.


-----Original Message-----
From: i.rautenberg at waratap.com [mailto:i.rautenberg at waratap.com] 
Sent: Wednesday, July 26, 2006 3:16 PM
To: Ben Swann
Cc: 'Pasqualoni, James E'; urq at audifans.com
Subject: Re: [urq] hesitation at higher RPM & boost

IME and based on what has been said, I also believe that spark is the  
issue.  Are you running the proper plugs?  Haven't used a Jacobs  
ignition in a VERY long time.  Currently running an MSD Blaster.  You  
may want to check voltage to see if you're not only supplying enough  
to the plugs, but also to the coil itself.  Pressurized engines are  
much more finicky to inadequate spark voltage IME.

Also, I'd do another test:  have the boost dialed back to 12 psi and  
remove the fuel pump jumper.  That way if you get the 4k cutout  
(depending on what the TAP computer mod is), then you'll have a better  
idea that something else is out of whack (like air intake temp sensor  
readings, etc.)

Good Luck.


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