Another TBI running rich
- Thread starter opus
- Start date
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evilunclegrimace
Does not always play well with others
That is not correct, 0.235 does not mean that the throttle plates are very far closed.If you do not adjust the throttle plates you can still change the TPS voltage.
arrg
I'm Awesome
Thanks for confirming that. You said you've done the IAC min air adjustment several times, but have you tried just adjusting the throttle plates so that you get around 15 steps on the IAC at idle? It's something easy to try, and it's free.
Steve A
I'm Awesome
Have you checked the stock pressure regulator for leaking raw fuel into the throttle bore(s)? I ran into that once upon a time, Standard Motor Products used to market a reseal kit for the regulator which caused me to think that it wasn't an isolated case.
That would be with the IAC fully extended and unplugged?
TBI has been rebuilt, including regulator. Again, its only for 45 seconds so I feel that would be a constant issue.
arrg
I'm Awesome
No, ignore the IAC min air adjustment for now. Start your truck, let it warm up until it has a stable idle. Use whatever tool you've been using to datalog to monitor the IAC Steps. With the engine running, slowly adjust the the throttle plate until the IAC steps come down. You're at 2500' so you may need more than 15 to get a stable idle, but your latest log shows you at 93 when the idle finally settles down. It doesn't need to be that high. If it doesn't change anything, put it back where it was, and you're only out a few minutes of your time.
She took the truck from me for a couple days. I did however sneak a quick, cold start log. Still pretty much the same. I did not touch the throttle at all. I went inside while it was logging but it ended up timing out after a bit.
https://docs.google.com/spreadsheets/d/1-ZuNLTi5wAIa6wHoWYgAKCl0L-tR7CCnhOxiydSjjJw/edit?usp=sharing
https://docs.google.com/spreadsheets/d/1-ZuNLTi5wAIa6wHoWYgAKCl0L-tR7CCnhOxiydSjjJw/edit?usp=sharing
.030 over increases displacement by 5 cubic inches. Totally inconsequential.
evilunclegrimace
Does not always play well with others
And, all things being equal you get a slight bump in compression ratio when you increase the bore size
