[urq] 28psi

[Mike Sylvester]

As many of you know, ever since I got my car together last fall, it has
been plagued with 2 running issues.

1. light throttle mis-fire
2. erratic full throttle acceleration and only 20psi of boost

I finally have it sorted out.

The light throttle mis-fire I solved a few weeks ago.
This problem is related to the proximity of the engine speed sensor and
timing reference sensor wires to the spark plug wires.  It is close
quarters in the urq engine bay with the 3b installed and apparently the
shielded cables aren't good enough when right next to the spark plug
wires.  After re-routing the sensor wires that problem has gone away.


The full throttle problem was about to have me committed.

It seemed like it wanted to get boost.  Sometimes it would spike to
20psi but immediately drop back to 18.
At full throttle in 4th gear on the highway I would occasionally see
24psi, but it took a few seconds to get there.

I tested every sensor per the Bentley.
I checked continuity from every sensor to the ECU.  
I checked and cleaned every ground.
I pressure tested the intake and checked the tightness of every clamp.
I verified the cam timing.
I checked everything.  

Along the way, I found numerous issues that I was convinced would solve
the problem and was disappointed every time.
bad rounds, loose hoses, etc.

My last resort was to try a stiffer wastegate spring.
I was hesitant with this because if the ECU didn't want the boost,
forcing the issue wasn't a good idea.
I nothing else to try, so I figured I would take it easy and see how it
drove.

When I took the wastegate cover off to change the spring, I found that
the installed spring was not correct.
I'm not real sure what it is.  The installed spring has been modified. 
It is longer than normal, but I can see that it has been cut.  It is not
a very still spring either.  I don't know what the previous owner of
engine was doing, but he wasn't increasing power, if that what he was
going for.

The sad part is that I had the wastegate apart when I powder coated the
cover.  I just put it back together without even looking at the spring.

After finding this, I didn't install the 2.2bar spring I had, I just
installed another stock spring from another wastegate.

With all disappointments in the past, I wasn't jumping for joy just yet.

Test drive...wow...28psi.  Finally. 
 
You may have to visit me in jail.
 

Mike

www.urq20v.com