HELP
Here is the log from tonight. I had trouble getting it to idle right off, I had to adjust the throttle stop on the throttlebody. It will not idle under 900 rmp. After it was running for a while, I turned on the cooling fans which dropped the rpm I adjusted the throttle stop again, then turned on the head lights, it did not like that at all, almost died again, adjusted the trottle and let it run a little bit longer. I adjusted the idle down a little, turned the head lamps off, turned the fans off and the idle went up a little and improved in quality. Then I turned the fans back on and then the headlamps, the car soon died. end of log. Let me know what you think. Thank you for taking the time to help look this over.
Chevy 383 IAC TPI Idle problem ?????
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
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Re: Chevy 383 IAC TPI Idle problem ?????
If you are using the relay board, I would check the voltage at the relay board when you turn on these electrical items. You may be having a big voltage drop. Check to see that you are getting good connections and your alternator is putting out proper voltage. Billk
MSII V3 board, 2.891 revision, 330 inch '56 Desoto Hemi in a '50 Mercury. 350 Chevy throttle body. Stepper IAC. Innovate wide band O2.
Re: Chevy 383 IAC TPI Idle problem ?????
we're t-shooting he car electrical sys. i am going to totally separate the EFI sys from the rest of the car and see if the voltage drops are in the EFI or car sys.
Re: Chevy 383 IAC TPI Idle problem ?????
You may also want to recalibrate the open/closed values for the TPS after the physical adjustments to the idle screw. Also, check for a vacuum leak in the intake system anywhere down stream of the throttle body. TPI's have more 'opportunities' for leaks then other types of intakes. With the engine idling you can connect a vacuum gauge to a port behind the throttle blades and observe how steady the needle is; if it's bouncing around like some disco booty, you've got a leak. You can also try the flammable approach and spray some carb cleaner around the intake (behind the throttle body) and see of the idle surges. As always, keep a fire existinguisher at hand. A backfire with a can of carb cleaner in your hand is not a good situation. 
Cheers
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