General Tech Question of the day?????

[gijohn40]

so I installed a cold air intake and E3 spark plugs about the same time as the cold weather hit... and my mileage went from an average of 15 mpg to about 11-12 mpg... I kinda a figured that it was the winter gas cause a few people have mentioned that they are getting less as well.

So I bought a bluetooth device that plugs into the data port and then downloaded TorquePro to my phone... it allows me to have gauges from my jeep (snapshot included)...

the one thing I was thinking about was the intake air temp that was showing between 19 and 54 degrees all night as I drove around.

So here is the question of the day?
Would this cause the jeep 4.0 ECU to think that the engine was still warming up thus run rich?

I guess I need to put the OEM air box back on and pull up the gauges for air fuel mixture ratio and see what it is both ways.....

OK what say you all?

 

[TRD270]

Not a tech guru so i can't answer that, but I will offer my mileage has tanked since the super cold weather has set in

 

[Tacoma]

also not a tech guru, but I can say that the cold weather and ethanol are likely the culprits. It has been cold enough that before I swapped it out, my stuck-open thermostat never let the engine get above 100*-- which definitely affected the mileage, via the ECM running in open-loop the entire way up to Vernal.

 

[rholbrook]

Normally, colder temperatures will make an engine run leaner thus making your computer try to richen the mixture up. Couple that with winter gas and I think you have your mpg issues

 

[TJDukit]

I had terrible luck with the E3's in my '03 4.0L, didn't gain any MPG likely lost some and number 2 plug fouled within 3 months. Went back to the cheap plugs and it ran better than ever with no issues with fouling again. The E3's worked great in my 5.3L with a very slight MPG increase. I had read that the 4.0L didn't like any plugs but the cheap OEM plugs and that's what seemed to work best for me.

 

[gijohn40]

I have to drive to st george saturday so I am going to be doing alot of testing this weekend... might buy me some good old autolite plugs and change them out on the way back just to see what gives...

 

[jevyguy]

In colder temps, the air going into your engine is more dense. Because the air is more dense the ecu has to throw more fuel into the engine to compensate.
Oh, and I ecco what the others say about spark plugs. Keep the cheap ones that are reccomended

 

[gijohn40]

ok so today I took the jeep and left it running for 5 mins to warm up the engine bay... then I took it and ran 40 mph down the frontage road in farmington (4 miles of level straight road) and here is what I found....

The IAT was 78 degrees and my mpg was 16.4 but as I was driving the IAT dropped to 40 degrees and the mileage dropped down to 13 mpg... it seems that as the temperature dropped in the engine bay my mileage dropped as well... so when it got down into the 30's the mileage was at 11mpg...

I think tomorrow I am going to figure out a way to get warm air to the air cleaner...

 

[TRD270]

Try and throw some cardboard in front of your radiator, and run the test again.

 

[UFAB]

Winter fuel blends work great, they don't freeze and my truck starts up.

The supercharger keeps my IAT around 125 in the cold.



Some OEM air boxes have therm switched heat ducts from the exhaust manifolds for cold starts..

 

[iamsparticus]

if you have the torque app you need to download the torque scan add on, then watch you long term fuel trims if they are +% or -%morethan say 10 or 15 percent youhave a sensor lieing to the computer like your IAT sensor jeeps operate off a air density system not a MAS system. So instead of a couple sensors controling the air mixture they have 4 sensors that dont change as well as a MAS and dont adapt to engine upgrades very well. It is not the winter blend gas with the strict restrictions on gas production today the gas is much better than it used to be 5or 6 years ago i would say yes but not today i have learned otherwise. Try throttling back you have denser air going in so you dont need as much throttle. Just my 2 cents

 

[STAG]

I ran the E3's in my jeep 4.0 and hated them, seemed to run boggy so I switched back and it ran better. That's about as much help as I am.

 

[TurboMinivan]

Now that Utah has essentially mandated* oxygenated fuel year-round, there is no such thing as "winter gas" any more. Something else is the culprit.

*: there are now only about a dozen stations throughout the state that offer pure gasoline. You can see them here.