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

76C10Stepside · 08-05-2014, 10:55 PM

I'd like to thank all who have offered me help so far!!!

Just confirmed that the oil is contaminated with gas. I could actually SEE gas on the dipstick, too! Dang, just changed the oil and filter a couple weeks ago. Since my problem is still not fixed, I don't want to change the oil/filter until I fix the cause (fingers crossed).

I installed a new FPR when I rebuilt the TBI. When I turn the key on, I hear the fuel pump cycle the normal amount, then total silence. When I replaced the fuel filter, there was still a TON of pressure in the lines. So the FPR is probably not leaking, right?

So, I guess testing the coolant temp sensor that feeds the computer is my next task.
Problem: Don't have a shop manual for this truck! So, here come the dumb questions...

Where is the sensor on this engine (4.3 Vortec with non-Vortec intake)?

Can I test it without removing it?

If I have to remove it, do I need to drain the system first?

How do I test it?

08-05-2014, 10:55 PM	#10
76C10Stepside Registered User Join Date: Feb 2012 Location: Olympia, WA Posts: 300	Re: 89 S10 4.3 Need help troubleshooting TBI/IAC Idle issue I'd like to thank all who have offered me help so far!!! Just confirmed that the oil is contaminated with gas. I could actually SEE gas on the dipstick, too! Dang, just changed the oil and filter a couple weeks ago. Since my problem is still not fixed, I don't want to change the oil/filter until I fix the cause (fingers crossed). I installed a new FPR when I rebuilt the TBI. When I turn the key on, I hear the fuel pump cycle the normal amount, then total silence. When I replaced the fuel filter, there was still a TON of pressure in the lines. So the FPR is probably not leaking, right? So, I guess testing the coolant temp sensor that feeds the computer is my next task. Problem: Don't have a shop manual for this truck! So, here come the dumb questions... Where is the sensor on this engine (4.3 Vortec with non-Vortec intake)? Can I test it without removing it? If I have to remove it, do I need to drain the system first? How do I test it?