Gas milage way too low


teakstone
10-15-2006, 11:41 PM
Hi everyone,

I have a '97 Sunfire 2.2L, 5 speed, with 185,000 kM on it. There are no codes to be read by my scan tool. The car gets lousy gas milage, about 200 miles to a tank full. It also has a bit of hesitation when the gas peddle is moderately stomped on (sort of feels like doing a lousy manual gear shift {the clutch is not slipping, it is an engine hesotation}).

I have replaced the fuel filter, IAC, and will replace the temperature sensor next.

Does anyone out there have any experience with this and what the cure is? Please help.

my99cavy
10-16-2006, 10:11 AM
Almost sounds like clooged fuel injectors.

muff34
10-16-2006, 10:32 AM
Maybe it cannot breathe ,give it a new air filter.how about some new plugs and wires if they have never been done. Maybe the catalytic converter is plugging up . Why are you changing Temp sesor? Get some good quailty injector cleaner and run it thru

my99cavy
10-16-2006, 10:46 AM
Injector cleaner really works too!! I used it on my car when it was bogging really bad and that shit cleared it up right away. (well the after a day of running it through the engine it cleared up)

Also not too sure to why you are going to replace the temp sensor :dunno: that wont effect how your car accelerates.

teakstone
10-23-2006, 08:48 PM
I have not changed the coolant temp sensor yet. The engine is not sluggish, the prob is poor milage. A coolant temp sensor that is out of calibration will cause the fuel injection system to run rich (sort of like a carburated engine with the choke on). That is the reason for changing that sensor

OverAllComa
10-24-2006, 12:42 AM
Sounds like the cat is getting clogged up. If it feels like you just kinda hit a wall when your RPM's get to a certain point, consider looking at replacing the cat.

I wouldn't reccomend injector cleaner, just premium fuel. But other people swear by the cleaners, so do what you want.

muff34
10-24-2006, 03:22 AM
I have not changed the coolant temp sensor yet. The engine is not sluggish, the prob is poor milage. A coolant temp sensor that is out of calibration will cause the fuel injection system to run rich (sort of like a carburated engine with the choke on). That is the reason for changing that sensorhmmm interesting. plugs must be crapped right up then

teakstone
10-24-2006, 03:53 PM
I guess I need to calrify how the car performs. It has great performance. Just bad gas mileage and when the gas pedal is satomped on it hessitates a bit and then picks up and goes.

jakegday
10-24-2006, 05:11 PM
so have you tried a bottle of fuel system cleaner? there is a major difference between fuel injector cleaner and fuel system cleaner, the fuel system cleaner costs about 3 times as much but its worth every penny, i was having the IDENTICAL problem you are right now, and i got a bottle of that and HOLY SHIT it made all the difference in the world, which is why i "swear by it" i KNOW it works

muff34
10-25-2006, 02:01 AM
so have you tried a bottle of fuel system cleaner???? there is a major difference between fuel injector cleaner and fuel system cleaner, the fuel system cleaner costs about 3 times as much but its worth every penny, i was having the IDENTICAL problem you are right now, and i got a bottle of that and HOLY SHIT it made all the difference in the world, which is why i "swear by it" i KNOW it workswhat brand,what brand.....LOL

chrisgore
11-06-2006, 08:35 PM
what brand,what brand.....LOL

yes...please do tell, i get fairly poor mileage myself....we'll see, i have a new airintake system and chip coming to me, but any bit helps

jakegday
11-07-2006, 08:52 AM
good luck with that chip

what kind is it anyways?

teakstone
11-07-2006, 02:05 PM
I replaced a few components and used tyhrottle body cleaner.

The air filter was slightly dirty, I replaced it. I replaced the fuel filter and the Coolant Temperature Sensor. I bleieve replacing the CTS made a huge difference.

TEXAS-HOTROD
11-11-2006, 06:43 PM
I had a car in the shop a while back, the guy complained about bad mileage and wanted a tune-up. It had over 100K miles and everything was original.
I did the usual pugs, wires, filters, etc...

A while later he came back, said it was better (I forget the actual mileage) but not like when it was new.
He booked another appointment and left the car. I scanned the electronics and everything checked out. I removed the t.p.s. and used a die grinder to elongate the mounting holes and adjusted the voltage to the bare minimum requirement. I told the customer everything I did and he agreed to another mileage test.

A few weeks later he called and stated that it exceeded original mpg. He couldn't believe the results.

Sometimes the computer has to be tricked for better-than-average results.
For better performance the tps can be set to maximum allowable voltage specs.
On several occasions, carefully denting in the top of a fuel pressure regulator (with a socket and a hammer) to raise fuel pressure has helped cure acceleration stumbles. Experience and an accurate fuel pressure gauge is needed.

BG makes the best fuel injection system cleaner.

Add your comment to this topic!