Is it the TPS?

alancordeiro at alancordeiro at
Sun Aug 9 17:51:27 PDT 2009


The higher the throttle opening, and also the higher the boost, the harder 
it is for the spark to jump across the gap in the plug.
Therefore, if there is a small amount of moisture in the distributor cap, or 
you have marginal high voltage wires going from the cap to the plugs, the 
spark is more likely to arc across a path of lower breakdown voltage. So it 
may be fine at idle and lower manifold pressures, but not work at high 
manifold pressures.

Does the jerking start as soon as you mash the pedal, of does to come on 
after the boost builds up?


----- Original Message ----- 
From: <kneale at>
To: <pjrose at>; <kneale at>; 
<200q20v at>
Sent: Sunday, August 09, 2009 4:35 PM
Subject: Re: Is it the TPS?

MM is a Samco with the fancy clamps, but I'll check 'em out.  I'll also try
a pressure check to look for leakages.

Original Message:
From: Phil Rose pjrose at
Date: Sun, 9 Aug 2009 15:27:19 -0400
To: kneale at, 200q20v at
Subject: Re: Is it the TPS?

Possibly TPS, but also consider possibility of a torn hose or loose
clamp--suddenly "letting go" at some level of boost pressure. I
assume your car is chipped? Have you looked closely at the throttle
boot lately? A tear (near the edge of the clamp on the inner side you
can't see easily) caused a similar symptom in my car. I detected the
source of the leak with a pressure tester. Also, a split Michelin Man
hose can sometimes "burp" suddenly when near the max boost pressure.


At 12:05 PM -0400 8/9/09, kneale at wrote:
>I've been mashing the accelerator pedal of my 200q20v Avant and enjoying
>the results ever since getting it rolling again a couple years ago.
>Yesterday, after a night of very heavy rains, I experienced a really heavy,
>jerking, scary hesitation when I had the foot to the floor.
>I can run the engine up to near red line by slowly advancing the
>accelerator pedal as long as I don't go to WOT.  Sounds, runs normally.
>But hit the floorboard and I get this horrendously heavy jerking like the
>engine cuts out completely.  It's worse than the A/C clutch spike I got on
>my 200q20v sedan before the Audi mod was performed.
>Would this result from a bad throttle position switch?

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