Troubleshooting Guide
THRASHER Turbo Regal Chips
Important! Please read the section titled
"Preparing your car" first!
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Problem: The SES (Service Engine Soon) light is
flashing rapidly a mile a minute.
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Problem: The SES (Service Engine Soon) light is
lit.
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Problem: My car idles poorly.
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Problem: My car continues to "stutter" after I
leave from a brake torque.
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Problem: My car stutters too slowly or tends to
bog during or leaving the brake torque.
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Problem: My car over/under boosts and/or
detonates.
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Problem: My car has the Anti-theft chip and
will not start.
1. Problem: The SES (Service Engine Soon) light
is flashing rapidly a mile a minute.
You are running in backup fuel mode due to a bad chip, or a chip thats
incorrectly seated. Try re-inserting your chip making sure good electrical
contact is made. Failing that, your chip may have been damaged.
2. Problem: The SES (Service Engine Soon) light
is lit.
Check malf codes. If code 51, your chip has been damaged.
3. Problem: My car idles poorly.
Check fuel pressure with an accurate gauge. Remember, the Thrasher is calibrated
for 45 psi. We stress the accuracy of the gauge as weve yet to see
a perfectly accurate small diameter (2" or less) gauge. Weve experience
with a rather pricey Autometer gauge that was over 10% off! Too lean or rich
and your idle quality will be poor. Unlike other chips, the Thrasher runs
in open loop in idle in order to achieve its signature smooth idle
quality. Unfortunately, this also means that it will not compensate and adjust
for varying fuel pressures. This is why sticking to the recommended 45 psi
is so critical.
The regulator must also operate properly by increasing pressure as boost
increases and decreasing pressure when manifold vacuum is high (i.e. at idle).
A regulator that does not lower pressure with vacuum (as some stock appearing
adjustable ones do) will cause the idle to be too rich. Misadjusted fuel
pressure or an inoperative regulator will cause erratic idle and poor
driveability. For those who own a scan tool, with the engine fully warm,
your O2 volts at idle should be in the 650-800 mV range.
Another important adjustment is the minimum air setting (i.e. the throttle
blade gap at idle). A detailed procedure for setting the throttle blade gap
is outline in the service manual or available on the Buick WWW site. Opening
the gap too wide will cause the Idle Air Control (IAC) to completely close
and no longer be in control of the idle speed. Too small a gap will cause
the IAC to open too wide and be unable to react quickly enough to control
idle well. For those with a scan tool, IAC counts in P/N should be around
10-20, in Drive 20-40 at idle.
With the engine fully warm, check (using a scan tool) to see if the system
is in open loop in idle. Idle speed should be 750 rpm in P/N (Park/Neutral)
and 675 rpm in Drive. If this is not the case, and IAC counts are reasonable,
check coolant temperature to see if that is reasonable. If not, suspect a
bad coolant temp sensor or wiring, maybe even a bad thermostat. An erroneously
low coolant temp reading will cause idle RPM to be incorrect and fueling
to be too rich.
Check that your P/N (Park/Neutral) switch is working properly. The P/N switch
is located on the steering column, regardless of whether the vehicle has
a column or floor shifter. Weve experienced some cars to have misadjusted
steering column collars which misalign the P/N switch in relation to the
gear selector.
If everything has checked out, and the scan tool still indicates the system
is in closed loop at idle and idle rpms are not correct, suspect a bad IAC
motor/valve. Remember, the chip is not a magic cure-all, and nothing we do
can compensate for existing mechanical/electrical problems!
4. Problem: My car continues to "stutter" after
I leave from a brake torque.
Note: the following only applies to chips with the "Launch Control
Stutter box" enabled.
Youre not flooring the throttle and going WOT. A fairly deep stomp
into the throttle is the signal to quit "stuttering". If you continue to
have problems check your TPS for misadjustment. With a properly adjusted
TPS (measures at least 4.0v at WOT assuming a 5v reference) there will be
absolutely no perceivable lag in releasing the stutter.
Our latest software release has relaxed this somewhat and allows half to
3/4 throttle launches for "fun" and "playing around". However, if the stutter
does not immediately release on launch, you didnt go deep enough into
the throttle.
5. Problem: My car stutters too slowly or tends
to bog during or leaving the brake torque.
You may be going too deep into the throttle and causing the engine to load
up. Try to hold the throttle open just enough to hit the stutter RPM. Too
light or too heavy on the throttle will result in a slow stutter. Youll
know you have it right when the stutter is most rapid. If bogging problems
persist we may have calibrated the brake torque fueling too lean for your
combination.
6. Problem: My car over/under boosts and/or
detonates.
You do have an ACCURATE boost gauge right? (No, not the stock one in your
dash.) As you well know, an accurate boost gauge is mandatory for any serious
turbo racer! How about an adjustable wastegate? Those are nice to have also.
In our experience, weve found some cars with wastegates or wastegate
solenoids that varied greatly from the norm. Some varied to the point that
no matter how the wastegate rod was adjusted, we could not control boost
to the desired level without modifying the wastegate control parameters in
the chip. Basically, the Thrasher chips have boost levels similar to other
manufacturers, dependent on the length of the wastegate rod. For example,
in one of our daily driver development vehicles running the Street Thrasher,
we run approximately 22 psi in 1st, 19 in 2nd, and 17 in 3rd on 93 octane
pump gas. Obviously, you may not be able to run these exact numbers, but
if youre not able to achieve anywhere close to these levels, you have
some other problems a mere chip cannot solve.
Another area to look would be the orifice in the plastic "Y" connector between
the wastegate solenoid and the wastegate actuator. It has been determined
that replacement Y connectors may have a different orifice size which will
affect wastegate control.
7. Problem: My car has the Anti-theft chip
and will not start.
First of all, make sure it's really the Anti-theft feature that's causing
you problems, and not something such as a dead battery or a bad neutral-safety
switch. An anti-theft induced no-start will allow the car to crank
and fire, but just not continue to run. If it is truly an anti-theft
chip induced no-start, replacing the chip with a conventional chip will allow
the car to run. Additionally, removing the chip totally will also allow
the car to run in back-up fuel mode. It is perfectly fine to drive
the car without a chip for short distances in an emergency. The
car will run a bit rich, but no damage will occur as long as you take it
easy and don't beat on it.
There are only 2 failure modes for the anti-theft chip. The anti-theft
software has been tested extensively and is well validated. The only
2 ways the anti-theft will cause a no-start (assuming the driver is performing
the "start sequence" correctly) are due to problems related to the car
itself!
The first failure mode is a marginal battery that is low on charge. With
a weak battery, the voltage will dip for an instant below 10v when the starter
initially hits, after which the starter will have enough voltage/current
to crank normally. Unfortunately, this quick drop below 10v is enough
to wipe out the ECM memory, thus wiping out the fact that you performed the
"start sequence". With loss of memory, the ECM then doesn't know you
successfully completed the "start sequence" and assumes you're a thief.
Unfortunately, there is nothing we can do about weak batteries, and no amount
of trick programming will get around the fact that memory is being erased.
Note that your battery may not necessarily seem weak, as the
starter will operate fairly normally, and conventional chips will not have
any problems starting and running the engine. However, the fact remains
that the battery has gotten weak enough to momentarily dip below 10v on starter
initialization, and is definitely on it's way out and will only last a few
more months at best. We like to think of it as an early warning sign
to change the battery before you're left stranded somewhere, even with a
conventional chip!
If you can jump or charge the battery, and your starting problems go away,
a marginal weak battery on it's way out is the cause of your no-start problems
with our anti-theft chip. However, if a strong battery does not
solve the problem, it's likely the second failure mode is to blame.
Unfortunately, for security reasons (your car's security, not ours!)
we cannot discuss this failure mode as it would reveal the actual secret
"start sequence" and we cannot discuss that on a public forum such as this!
As a hint, just think about the start sequence and what the ECM needs to
see from that. If you're not getting those inputs correctly into the
ECM, the ECM will never know you've successfully completed the "start sequence"
right?

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