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onebadass87burb 12-20-2011 11:28 PM

code 45
 
good evening i'm new to the site and was looking for a little help with my 87 burb it started about a month ago with a bad map sensor which i replaced along with a new o2 sensor and rebuilt the trottle body but now it stll doesn't idle and i'm getting the code 45 now any help would be greatly appreciated thanks

ChevyTech 12-21-2011 04:29 PM

Re: code 45
 
Code 45 = Rich Exhaust

If it seems to be running rich, check the coolant sensor that the ECM monitors.

The computer uses the coolant temp to determine how much fuel to inject and how fast the idle speed should be.

It is common for these sensors to fail.

To test the coolant sensor, unplug the wire connector and test the resistance across the two terminals of the SENSOR with an ohm meter.

If you see any coolant leaking out the terminals replace it.

If the terminals in the connector are corroded replace the “pigtail”.

On the TBI trucks the sensor screws into the intake manifold, on the front passenger side, by the thermostat housing.

Coolant sensor approximate resistance specifications:
177 ohms @ 212 deg. F. or 100 deg. C.
241 ohms @ 194 deg. F. or 90 deg. C.
332 ohms @ 176 deg. F. or 80 deg. C.
467 ohms @ 158 deg. F. or 70 deg. C.
667 ohms @ 140 deg. F. or 60 deg. C.
973 ohms @ 122 deg. F. or 50 deg. C.
1188 ohms @ 113 deg. F. or 45 deg. C.
1459 ohms @ 104 deg. F. or 40 deg. C.
1802 ohms @ 95 deg. F. or 35 deg. C.
2238 ohms @ 86 deg. F. or 30 deg. C.
2796 ohms @ 77 deg. F. or 25 deg. C.
3520 ohms @ 68 deg. F. or 20 deg. C.
4450 ohms @ 59 deg. F. or 15 deg. C.
5670 ohms @ 50 deg. F. or 10 deg. C.
7280 ohms @ 41 deg. F. or 5 deg. C.
9420 ohms @ 32 deg. F. or 0 deg. C.
12300 ohms @ 23 deg. F. or -5 deg. C.
16180 ohms @ 14 deg. F. or -10 deg. C.
21450 ohms @ 5 deg. F. or -15 deg. C.
28680 ohms @ -4 deg. F. or -20 deg. C.
52700 ohms @ -22 deg. F. or -30 deg. C.
100700 ohms @ -40 deg. F. or - 40 deg. C.

Also check to see if the injectors are dripping fuel. The o-rings on the injectors can get damaged if the not lubed well when installing injectors. Try to look at the injectors as the engine is shut off too.

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