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When will it end?

jcnoble

NAXJA Forum User
Location
Huntsville, AL
Trying to get my 88 to pass smog (which it still wont, running too rich the smog guy says, thats the next story), anyway i start having cooling problems. I replaced everything but the bottle (resevoir) and now the cap (new cap) lets go at 205 or so degrees . (Which is the hottest it gets idling in the sun with the hood down). WHATS UP??
 
Eagle has the cooling problems pretty well whipped, his advice has set me straight.
Only fill the surge tank about half full, with coolant (best with the motor hot). Most anytime you´ve done any coolant system work, you have to get the air out of the system. Filling the surge tank half full, gives the air someplace to go, that won´t blow much coolant out the cap.
Loosening the temp. sender at the back of the block works at initial fill, only to be attempted with the motor cool and not running.
Squeezing the top radiator hose, with the motor hot (be carefull of the fan), helps get some of the air moving. You can often see the bubbles moving into the surge tank.
Turning the heater on also seems to help, helps increase the flow to the surge tank area some, at least on mine.
Parking nose up and/or down and reving it also helps.
I´m sure someone else will chime in with some other techniques.
Temp. senders for the guage and maybe the guage itself are notoriously inacurate, at best an approximation. They measure the temp. at the top rear of the block, which isn´t necessarily what it is, at the thermostat or the front of the block.
Since installing the thermostat with the bleeder hole built in the stopper, I haven´t had much problem with air traps or blockages.
Smog test, first guess would be the 02 sensor. I had one that would lean out the motor at around 2000 RPM and the replacement would run real rich at idle, now I have one that seems to work well.
 
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Back before i did the convesrion i refred to bleeding the system as CPR.... I do not endorce this procedure but it did work for getting the bubbles out....

squeeze the radiator hose as stated... and blow into the pressure bottle... this would force the fluid thru the system and the bubbles back into the top of the bottle...

Glycol is tasty...

Removing the temp sensor really works alot
 
I second 8Mud's suggestion of a failed O2 sensor, as causing the rich condition. Here's the procedure for testing it:

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It's easy to test a Renix O2 sensor with a voltmeter. The O2 wiring routes right next to the fuel pressure regulator, at the front of the engine. Unwrap the small bundle of wires and locate the gray wire; that's the O2 signal wire. Press a straight pin into the wire, and touch the positive voltmeter probe to the pin, and the negative probe to engine ground. With the engine idleing, the voltage will switch from 0v to 5v once every second, if the O2 sensor is GOOD. A BAD sensor will show either 0v or a steady 5v on this wire.
 
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