94 5.0 vs 93 5.0 Eng. Front End
07-08-2017, 10:17 PM
#11
3rd Gear Member
Thread Starter
Join Date: Jul 2017
Location: AZ
Posts: 849
160 degree thermostat may not allow the car to come up to the 180 degrees it takes to go into closed loop. Burning more fuel, and not running as it should.
A cooler thermostat will open sooner and the water never has a chance to get up to temperature, or at least not for a very long time since it is constantly circulating. Factory thermostats are 195. The computer starts cold in open loop, adjusts timing and adds fuel for a cold engine. As the engine gets up to temperature 180f the computer can add timing and cut back on the amount of fuel so it goes into a closed loop program.
Run a KOER check and I bet it comes back with a code 338 - ECT lower than expected. This could very well cause high fuel consumption.
A cooler thermostat will open sooner and the water never has a chance to get up to temperature, or at least not for a very long time since it is constantly circulating. Factory thermostats are 195. The computer starts cold in open loop, adjusts timing and adds fuel for a cold engine. As the engine gets up to temperature 180f the computer can add timing and cut back on the amount of fuel so it goes into a closed loop program.
Run a KOER check and I bet it comes back with a code 338 - ECT lower than expected. This could very well cause high fuel consumption.
Agreed and understood! I like that! And, given that my last Mustang was a '93 Cobra, running also 160 stat, emissions tested 0.0 CO and very low HC, easily gave 25 mpg consistently at road speeds, I can't help but think there is more here.....please keep in mind that with our Desert Southwest temperatures, I can't help but think 180 is always reached real easily and quickly, even with NO thermostat. Not trying to ridicule or be argumentative with someone obviously very knowledgeable. Trying to explore every possibility. Believe it or not, when I first left Illinois over 40 years ago, winding up an ARCO gas station dealer, I had customers who insisted that with no thermostat, an engine will run hotter! Argument was that "the coolant wasn't ion the radiator long enough"! Can you believe that?
Another question, if you don't mind? Are fuel injectors actually "coded" as to size by body color?? Some claim so; hard to believe. Thanks for hanging with me! imp
07-09-2017, 09:46 AM
#13
5th Gear Member
Join Date: Jul 2012
Location: ohio
Posts: 3,628
The 94-95 computers are alot more touchy than the older fox body computers. They are not near as adaptive.
And for the record,,
If you run your car without a thermostat it will run hotter ,,, eventually. It just takes a very long time to come up to temp,, the coolant needs to be regulated somehow ,, with no thermostat the coolant does not have enough time in the radiator. Also doesnt have enough time in the engine to properly pull the heat out. Dont think of coolant as a cooling agent, think of it as a way to transfer heat. Engineers design the cooling system to operate a certain way. They use a 195f thermostat because it allows maximum heat absorption of the coolant. While the coolant in the engine absorbs the heat from the engine, the coolant in the radiator transfers it to the air. Free flowing coolant does not have time to properly absorb or displace the heat it is carrying .
And for the record,,
If you run your car without a thermostat it will run hotter ,,, eventually. It just takes a very long time to come up to temp,, the coolant needs to be regulated somehow ,, with no thermostat the coolant does not have enough time in the radiator. Also doesnt have enough time in the engine to properly pull the heat out. Dont think of coolant as a cooling agent, think of it as a way to transfer heat. Engineers design the cooling system to operate a certain way. They use a 195f thermostat because it allows maximum heat absorption of the coolant. While the coolant in the engine absorbs the heat from the engine, the coolant in the radiator transfers it to the air. Free flowing coolant does not have time to properly absorb or displace the heat it is carrying .
07-09-2017, 04:16 PM
#14
3rd Gear Member
Thread Starter
Join Date: Jul 2017
Location: AZ
Posts: 849
They seem to look orange all right, top half only. I was hoping the hop-up artist hadn't installed bigger ones without MAF update.
Now, I'm thinking O2 sensors, far as poor fuel economy, but no CEL. Dunno if EEC-IV ala '94 had ability to diagnose bum O2s and throw a code. Dead, maybe, but still no knowledge of effectiveness level of cats.
That aside from the too cold thermostat issue..........(160`). imp
07-09-2017, 05:00 PM
#15
02 sensors job is to help target lambda @ a 14.64 air fuel ratio. An 02 sensor will tell the computer if it is over 1.0 lambda or under 1.0 lambda. As 02 sensors age, they become slower in the rate at which they switch to help the ecu target lambda. This can affect mileage.
The heaters for 02 sensors go out as well without throwing a code. They 02s may finally get up to temp but, take minutes before they do so. This will cause the car to stumble when cold after it switches to closed loop.
A lot of times when you do get a lean code pointing at the 02 sensors with these cars, a vacuum leak is the cause.
Also, exhaust leaks before the 02 sensors will cause their readings to be off.
The heaters for 02 sensors go out as well without throwing a code. They 02s may finally get up to temp but, take minutes before they do so. This will cause the car to stumble when cold after it switches to closed loop.
A lot of times when you do get a lean code pointing at the 02 sensors with these cars, a vacuum leak is the cause.
Also, exhaust leaks before the 02 sensors will cause their readings to be off.
07-11-2017, 02:24 PM
#16
2nd Gear Member
Join Date: Feb 2007
Location: IA
Posts: 258
Also a thermostat doesn't snap open immediately and fully at its set point. It gradually opens as temperature rises and will close down some as temps fall to try to keep the engine at a steady temp. And yes the biggest reason for having higher engine temps on later model vehicles is for emissions.
A lot goes into a cooling system. It needs to be under the proper pressure, have sufficient air flow across the radiator, have the proper coolant, clear passageways and so on. If your coolant is more than a 5 years old you should change it. In your climate I would fill it with 65-70 distilled water and 30-35% antifreeze. That mixture typically gives the best heat transfer, at least in hot water boiler systems, and will give you plenty of protection for your "winter."
A lot goes into a cooling system. It needs to be under the proper pressure, have sufficient air flow across the radiator, have the proper coolant, clear passageways and so on. If your coolant is more than a 5 years old you should change it. In your climate I would fill it with 65-70 distilled water and 30-35% antifreeze. That mixture typically gives the best heat transfer, at least in hot water boiler systems, and will give you plenty of protection for your "winter."
Last edited by mongolchuck; 07-11-2017 at 02:33 PM.
07-11-2017, 10:50 PM
#17
3rd Gear Member
Thread Starter
Join Date: Jul 2017
Location: AZ
Posts: 849
Also a thermostat doesn't snap open immediately and fully at its set point. It gradually opens as temperature rises and will close down some as temps fall to try to keep the engine at a steady temp. And yes the biggest reason for having higher engine temps on later model vehicles is for emissions.
A lot goes into a cooling system. It needs to be under the proper pressure, have sufficient air flow across the radiator, have the proper coolant, clear passageways and so on. If your coolant is more than a 5 years old you should change it. In your climate I would fill it with 65-70 distilled water and 30-35% antifreeze. That mixture typically gives the best heat transfer, at least in hot water boiler systems, and will give you plenty of protection for your "winter."
A lot goes into a cooling system. It needs to be under the proper pressure, have sufficient air flow across the radiator, have the proper coolant, clear passageways and so on. If your coolant is more than a 5 years old you should change it. In your climate I would fill it with 65-70 distilled water and 30-35% antifreeze. That mixture typically gives the best heat transfer, at least in hot water boiler systems, and will give you plenty of protection for your "winter."
Distilled water is indeed good. As with any water, it "collects" CO2 readily out of the air when exposed, as in bottling and pouring. This drops the Ph of pure distilled water from 7.0 to as low as 5.2, definitely in the acid range. Acid = NO GOOD in engine. Most good permanent antifreezes have provision to cover that by containing a basic chemical like Sodium Carbonate.
The "chemistry" of it is CO2 in water forms HCO3, the H being the "Hydrion" or acid ion. Lots of H's = NO GOOD FOR ENGINE. imp