V6 Vortec idles cold

I have a 94 GMC Safari with the W engine that never seems to warm up too operating temp during idle. My main concern is in the winter when prewarming it with my remote start. I have replaced the thermostat, O2
sensor, plugs ....the injector assembly that is on the inside of the intake (forget what its called) It starts and runs good gets the factory rated MPG actually 1 MPG better. My conclusion is that the idle mixture is set to too cold of a burn. The exhaust smells rich....not like raw gas more like an old 60's non computer car Can the eeprom be replaced to make a hotter idle burn. I have a eeprom burner and just need the file to copy it to a chip. Or is there program to read and edit the existing chip? If I turn on the front and rear heaters they remove enough heat that the t stat never opens during idle.
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Do you mean the engine temp doesn't come up? scan it to check the gage accuracy, has a 195 thermo correct. Also when scanning the rich mixture you suspect can be checked. Also check for a locked up fan clutch, this could pull too much air thru the rad. and prevent full warm up.

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Scan checks out ok. Lots of new sensors bla bla bla no change. New 195 stat no change. New clutch fan when the water pump went no change. It warms up to normal when driving but not idling as a matter of fact it will cool off after driving hard then idling if it is around freezing temp outside. Me thinks it should have a hotter (leaner) idle mixture.
Shep wrote:

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There is no way to lean the idle mixture without a reprogram, I don't think this the problem, what does the scan say for eng. temp under these conditions, I've used AM clutches that were to tight and pulled excess air into the rad when cold, don't assume they are working properly.

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I said no change when I replaced the clutch and I even tried card board. A little better with the rad blocked but still idles cold
Shep wrote:

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Sounds like an air pocket or some debris near the sensor giving you a false reading. Could also be a water jacket opening has become almost completely plugged, causing the sensor to not get hot coolant at idle but it'll force through when driving...
On Sat, 04 Jun 2005 22:25:52 GMT, none of your business

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If that is the case then the whole block is plugged??? because nothing goes through the rad (hoses feel cold at idel) Heater/s is not at par at idel. I dont have an exact reading but lets just say it is about half of normal at idel (0 celsius 32 farenhiet outside) and steady 195 while driving. I have concluded the heaters pull away more heat than the engine can produce at idel at near freezing temps.
Mike Levy wrote:

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none of your business wrote:

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On Sun, 05 Jun 2005 06:36:49 GMT, none of your business

Try checking your thermostat housing gasket. i pretty much had the same issue you are having with a Vin Z engine, and what i found out is my thermostat housing was cutting my gasket and allowing water through the sides. i replaced the gasket several times and even used silicone sealant. i ended up buying a new housing made of cast iron instead of aluminum. physically the cast iron and the aluminum are the same on the outside...but on the inside, the "bubble" that surrounds the thermostat pellet is smaller, meaning a thicker wall, thus holding the thermostat and gasket in place rather than floating around like it did in the thin wall aluminum housing.
it took me two years of off and on checking to chase this down. i changed thermostats, gaskets, pumps, hoses, caps...everything...finally on a whim, i change the housing.
since then all my under-cooling issues have disappeared. 195 all the time, no coolant loss and 300k on the truck.
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Thanks any how but I dont think the stat is by-passing because the hose to the rad feels cold....
nanook wrote:

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On Fri, 10 Jun 2005 00:39:41 GMT, none of your business

true, mine was the same way, there was also very little pressure, i guess due to overcooling. the truck was basically running like it had no thermostat. therefore, there was no flow restriction to slow the coolant through the block to pick up heat. the highest temp my truck would get in the Texas summer was just under 160 f. in the winter, i could ride through Houston and never get above 130.
you may want to backfush the engine and check the heater bypass valve also. i had a friend whose ranger's valve got stopped up when he used some powdered radiator cleaner.
good luck.
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nanook wrote:

I did not see a heater bypass valve? Do you mean for the interior heater? Or a by-pass valve to the rad? WE are off track here In have checked all of the above. It is not a problem with the cooling system. It just simply has a cold burn on idleing. It was driven for years with a plugged o2 sensor that may have plugged the cat converter. Going to try that next. My main question is/was can the chip in the computer be modified for a leaner idle?
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