Retune after a bad TPS?
#1
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Retune after a bad TPS?
A little background: I had my car dynotuned in the fall after an HCI swap and we found that I had a pesky idle when warm. After drilling the IAC port, it was good, but occasionally it would idle high at ~1500RPM. We eventually found issues with the TB and I replaced it (Don't ask, hard to describe).
While tuning the new TB we experienced a really annoying high idle again. After drilling out the IAC a little larger than the old one (1/32 up to 3/16"), the IAC counts dropped from 85 to 83. I ended up looking on here and found the post about adjusting the TPS sensor voltage and after reviewing my data logs, saw my TPS voltage was .06 at idle. We tried adjusting my TPS sensor voltage and the highest it would get is around 1.88 volts and even then, it took about 1/4 turn before it started registering voltage. Put a new TPS in and adjusted to .67 and all is well.
My question (hence the title): Should I retune the car? Just asking because if the voltage at WOT is supposed to be at least 4.5 volts at WOT, is my PCM thinking it was only getting about 42% throttle?
Thanks, everyone!
While tuning the new TB we experienced a really annoying high idle again. After drilling out the IAC a little larger than the old one (1/32 up to 3/16"), the IAC counts dropped from 85 to 83. I ended up looking on here and found the post about adjusting the TPS sensor voltage and after reviewing my data logs, saw my TPS voltage was .06 at idle. We tried adjusting my TPS sensor voltage and the highest it would get is around 1.88 volts and even then, it took about 1/4 turn before it started registering voltage. Put a new TPS in and adjusted to .67 and all is well.
My question (hence the title): Should I retune the car? Just asking because if the voltage at WOT is supposed to be at least 4.5 volts at WOT, is my PCM thinking it was only getting about 42% throttle?
Thanks, everyone!
#2
TECH Veteran
The PCM resets what it sees as zero throttle every time you turn the key ON. You can easily watch TPS voltage or percentage with a scanner (engine does not have to be running, but the key must be ON). Nothing to do in the tune.