Bad MPG

[keeler]

I did search but couldn't find any answers.

I'm getting between 10-15 mpg. I have replaced the plugs, wires, air and fuel filter, o2 sensors, boost leak test came back good, compression was good, new tps, new iac, seafoamed the car a couple times, cleaned butterfly valve, idles around 1300rpm which it always has. It just randomly started running rich. No particular reason why. I'm running stock fuel setup, stock boost, and a few minor mods. It's running pretty rich as I can smell it but I've found no leaks of anything. Anyone have any ideas? I'm at a lost and it's killing me driving 40 miles to work everyday. The car runs fine otherwise and has been doing it for about 3 weeks.

 

[sureshot971]

Most definetly could cause this problem.

 

[dsmdragon]

yea an injector could do this problem. but hard to try and find if it is the injector. only way is to buy one and keep swaping it until it solves the problem. or take it to the shop man.

 

[andymoraitis]

If you have a logger or a friend with one, try turning off the injectors one at a time and seeing if the idle changes. If it doesn't change when you turn one off it's stuck open and dumping fuel.

How do your plugs look? Are they solid black everywhere and is any one cylinder different from another? Have you tested the resistance on the coils and tried checking the PTU?

If none of those things work, I'd also look into replacing the fuel pressure regulator. These can go bad over time and cause similar symptoms (yes even the stock ones).

I should feel bad but I get about 12 mpg in the city but with my cam overlap I'd consider my mileage pretty normal.

Get back to us,

Andy