Bad gas mileage only when engine is cold

[DiamondStarMotors]

I let the car warm up for a couple minutes before I drive to wherever. Usually it's short trips to school or work. When the engine stays warm, my gas mileage is fine. With driving short trips and then parking, I average about 50 miles for every quarter of the tank.

 

[dsm4lif3]

Do a tune up

 

[DiamondStarMotors]

should i also look at my fuel injectors and pump? I haven't done either yet.

the guy before me said he went turbo for some time using an old 12b, he gave the turbo to me. I'm not sure if he was lying or not, because I would have thought that he would have given me the downpipe too.

 

[rEclipserGST]

should i also look at my fuel injectors and pump? I haven't done either yet.

the guy before me said he went turbo for some time using an old 12b, he gave the turbo to me. I'm not sure if he was lying or not, because I would have thought that he would have given me the downpipe too.

What the hell is a 12b? Where's the manifold? All he gave you was a turbo? Post pics.

Your car runs more rich prior to warming up. The ecu adjust fuel trims based on coolant temps. You should read a lot more before posting. It'll save you & us time.

 

[My1GLaser]

Maybe a bad coolant temp sensor is keeping it in open loop too long.

 

[DSM1G90]

It's a DODGE motor and setup.

And the 2G chassis isn't the lightest thing to pack a base four cylinder motor in -thing weighs almost 2800 lbs. If you shaved off 700 lbs and still getting 50 miles on the quarter, then I would say you definitely got some economy issues.

Dodge are known for being fuel hogs when things aren't getting warmed up. 50 miles on the quarter..sounds about right for town driving for a 2.0L - even 4G motors get about the same when doing a lot of town driving since you're rowing through the gears causing increased demand of fuel when you romp on the gas pedal between shifts.

A no-brainer on this one.

 

[grothe3297venge]

the guy before me said he went turbo for some time using an old 12b, he gave the turbo to me. I'm not sure if he was lying or not, because I would have thought that he would have given me the downpipe too.

I don't get what this has to do with your question, when it's not even attatched to your car??

 

[DiamondStarMotors]

I don't get what this has to do with your question, when it's not even attatched to your car??

obviously when you add more air, you have to had fuel. I was thinking, maybe the last guy never put the original parts back on the car.

I know about the whole closed loop idea. I did do some ####ing research. I just thought 50 miles for a quarter of a tank was a bit low. These cars have a 16.9 gallon tank right? do the math and it works out to like 12 miles a gallon in the city. That's worse than my mom's Yukon XL.

But the one guy nicely pointed out that this is common with these cars being heavy and all.

What the hell is a 12b? Where's the manifold? All he gave you was a turbo? Post pics.

Your car runs more rich prior to warming up. The ecu adjust fuel trims based on coolant temps. You should read a lot more before posting. It'll save you & us time.

I posted a thread months ago with pictures of the turbo itself, and the alphanumerical code on the side and someone said it was a 12b off a late '80s lebaron. The said he cropped the manifold and it cracked and said I could get a new one off ebay, i'm pretty sure it has a T3/T4 flange, though I could be wrong.
Also, if you are so anxious about saving time, you didn't have to comment on this post.

 

[spyderdrifter]

Not trying to be an @ss or anything, but how can you tell you're having bad mileage when its cold, when it only takes a few minutes to warm up anyway? I don't see how your engine could be cold long enough to be able to tell its consuming more fuel, when as mentioned already, it'll consume more since its cold to begin with.

 

[DiamondStarMotors]

Not trying to be an @ss or anything, but how can you tell you're having bad mileage when its cold, when it only takes a few minutes to warm up anyway? I don't see how your engine could be cold long enough to be able to tell its consuming more fuel, when as mentioned already, it'll consume more since its cold to begin with.

I understand that what closed loop is. I just assumed that since i was getting 11.8 miles to the gallon, something was up. I delivery drive and when the engine stays warm and i drive often enough, I don't seem to get that bad of gas mileage, closer to 18 miles a gallon. That's why i'm assuming it's from being in closed loop. my coolant light comes on every few months, but i add some water/coolant mix and the light goes away.

 

[spyderdrifter]

If that's the case, just do what has already been mentioned. Since it's relatively cheap, do a tune-up. Check your coolant sensors and replace as needed, or replace them regardless. Do a coolant flush, clean out your radiator, hoses, maybe check your thermostat too. See how it runs after that. It'll help narrow down your problem if it persists after that work has been completed.