The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 89 S10 4.3 Need help troubleshooting TBI/IAC Idle issue

76C10Stepside · 08-11-2014, 03:13 PM

Thanks for the links! Current status:

Changed the oil/filter last night (5W-30 synthetic blend, Purolator PureOne filter). Pulled the coil wire. Went to crank the engine to circulate the new oil and nothing. Brand new made in USA Exide battery was DEAD. Put it on the charger overnight.
This morning, put the freshly charged battery in, cranked engine for 15-20 seconds, put coil wire back on and engine fired right it up, went straight to 1750 RPMs and stayed there for about 1 minute. The oil pressure went straight to 60 PSI and stayed there for the 2-3 minutes I ran it. RPMs dropped to 1500 for the next minute or more, oil pressure remained at 60. Checked oil and added half a quart.

Questions:

How long should the ECM take to "relearn" and adjust the idle speed down?

Any suggestions on what to do next? I will not be driving it anywhere until I know I can trust it to keep running and not burn up.

08-11-2014, 03:13 PM	#29
76C10Stepside Registered User Join Date: Feb 2012 Location: Olympia, WA Posts: 300	Re: 89 S10 4.3 Need help troubleshooting TBI/IAC Idle issue Thanks for the links! Current status: Changed the oil/filter last night (5W-30 synthetic blend, Purolator PureOne filter). Pulled the coil wire. Went to crank the engine to circulate the new oil and nothing. Brand new made in USA Exide battery was DEAD. Put it on the charger overnight. This morning, put the freshly charged battery in, cranked engine for 15-20 seconds, put coil wire back on and engine fired right it up, went straight to 1750 RPMs and stayed there for about 1 minute. The oil pressure went straight to 60 PSI and stayed there for the 2-3 minutes I ran it. RPMs dropped to 1500 for the next minute or more, oil pressure remained at 60. Checked oil and added half a quart. Questions: How long should the ECM take to "relearn" and adjust the idle speed down? Any suggestions on what to do next? I will not be driving it anywhere until I know I can trust it to keep running and not burn up.