I don't get it...

[chriswells78]

Don't know unless you read the voltage it's returning. Do you have the capability to read the voltage?

 

[Provokr]

Don't know unless you read the voltage it's returning. Do you have the capability to read the voltage?

are you saying low voltage=bad ignition? and less fuel gets burned???

 

[chriswells78]

no from your MAF to the PCM, the voltage returned from the MAF is what the PCM uses to tell the fuel injectors how long to stay open/how much fuel to use.

 

[Provokr]

no from your MAF to the PCM, the voltage returned from the MAF is what the PCM uses to tell the fuel injectors how long to stay open/how much fuel to use.

Where should I measure the voltage?
I have not noticed the gauge as being low... but I know how inacurate gauges can be sometimes

 

[X6StringerX]

I'm not sure what the problem could be here, Jed. When I owned the X, it consistantly got 16.5mpg. I hit 21mpg with it once and about every 5th time I would check, I'd average 18mpg.

Here's a thought. Are you doing a ton of city driving? 80% of my driving was highway.

 

[chriswells78]

Where should I measure the voltage?
I have not noticed the gauge as being low... but I know how inacurate gauges can be sometimes

It's easiest to do through a scanner if you have one.

You measure it at the voltage at the wires coming from the MAF itself otherwise, Red is hot, black is ground the other two go to the PCM

PS the gauge on your dash is voltage from the alternator output.

 

[Provokr]

I'm not sure what the problem could be here, Jed. When I owned the X, it consistantly got 16.5mpg. I hit 21mpg with it once and about every 5th time I would check, I'd average 18mpg.

Here's a thought. Are you doing a ton of city driving? 80% of my driving was highway.

It goes from 45 to 55 and I make like 5 stops. It's about 15 miles every morning. It is a combination of city and highway. I tried being REALLY easy on it (not going over 1.5k rpm) and it still did the same thing.

 

[Provokr]

Jordan... are you still driving the cavalier ??

 

[Rosscup]

SEAFOAM!!! i used it just the other day and it works! it added a couple MPG back and a lot more power back! try it. make sure to go through your break booster though.

 

[Provokr]

SEAFOAM!!! i used it just the other day and it works! it added a couple MPG back and a lot more power back! try it. make sure to go through your break booster though.

I used seafoam in my 4.0 because of studdering and it fixed it. But... now it has a harsh start up.

 

[X6StringerX]

I already Seafoamed the 5.0 you have, so I don't think its time for another treatment yet. I also cleaned the IAC. I didn't do anything to the MAF, but like I said, I was averaging much better gas mileage.

I'm still driving the Cavalier, but I have two people that are supposed to look at it. One on Friday and one on Saturday.

 

[Charlie]

Funny thing, there was a whole new row of gas siphons at a car parts place... wonder why? Good luck!

Haha, that's sure the truth. I'm surprised those companies haven't had lawsuits yet. Gotta love the pictures on some of them, too

 

[L4CX]

Could it be that it's Colder out side? I know my vehicles always get worst gas mileage in the winter. You're in NC though. I'm not sure what winter is like down there.

Try Cleaning the MAF like people have said. I did it and my truck ran fine before and even better after I did it. Just because it seems like it's running fine doesn't mean it always is. The Electrical Cleaner costs like 5 bucks a Bottle. It can't hurt. It took my RPM's at idle from about 1200 to 900. Helped alot.

If it was seafoamed check the Plugs. Sometimes it screws with them. That's what I've been told.

 

[X6StringerX]

I changed the plugs after the Seafoam treatment.

You actually get a little better gas mileage with cooler temps, BUT the "winter" gas formula usually yields worse gas mileage anyway.

Try cleaning the MAF. That's what everyone else says, lol. The only other reasons I can think of are obvious... driving style, % of highway/city, etc., but you've already modified your driving style. The truck is exactly as it was when I had, except for the M/Ts being replaced with A/Ts and I got a lot better mileage. The truck shouldn't be due for any major fluid changes. I replaced all of the fluids with Amsoil full-synthetic, with the exception of the tranny fluid, which was flushed at a VIOC center at 135k or so and of course, the motor oil. I used Mobil 1 5w-30 there. When is the last time you've changed the oil? How is the air filter? I used the K&N recharge kit on it right before we met, but if its dusty down there, you might want to clean it again. As a matter of fact, its possible that the oil from the recharge kit has accumulated on the MAF, so I would bump that up to numero uno. Clean it and check back in with a progress report.

 

[brianjwilson]

Your mileage doesn't sound that far off from what it should be, but I bet I know what a some part of it is. Your speedometer probably hasn't been recalibrated for the larger tires. Stock tires are around 29", you now have 31" tires. You are traveling a further distance for each revolution of the tire. A 13mpg reading calibrated for the new tires comes out to about 13.9mpg. Small part of it I suppose, but something to factor in. Driving habits make a huge difference. Winter blend gas often gives you worse mileage. Another small thing you can do is make sure you're a/c isn't running all the time. The compressor will engage in any position other than "off", "vent", or "feet", and will cause some additional drag on the motor.
Check your mechanical fan clutch. If the clutch is worn out (as it will with high mileage), it will often stay fully engaged all the time and the fan will cause extra drag on the motor also...