Belt size change

[Krazzee]

I have a 98, 3.8 Grand Prix GT and want to remove the air cond. from the loop. Can I do this and what size belt will i need. Also I have tryed everything to get gas mileage down and I am getting 130 miles to a tank of gas. Its not showing any codes.

[richtazz]

Due to the way your belt routes, you cannot simply remove the A/C compressor and put on a shorter belt. To eliminate the compressor, you would have to fabricate a bracket and idler pulley to take it's place.

On the mileage issue, how many gallons does it take to fill it when your guage hits empty? 130 miles on a tank (if it's truly empty when you're getting gas) is less than 10mpg!!!!

[Krazzee]

I was lookin at it and I could make a braket but then i would be no further ahead in freeing up some hp. I dont think, unless the pump for the A/C is seized or something. I use my odometer to watch how much gas I use and if I dont drive with a lead foot i get 130miles to one regular tank of gas over and over again. It is a regular sized tank prob around 40gal giver or take. I just orderd new plug wires and I think I will try new O2 sensors. Any other ideas. Would my cat be pluged or something mabe.

[BNaylor]

I agree with Rich. It doesn't sound like a feasible remedy. Contrary to belief modern AC compressors like the Harrison V5 really don't rob that much horsepower or mpg. Plus the PCM controls operation of the compressor depending on driving and engine conditions.

The are other solutions or causes to poor fuel economy.

[Krazzee]

I realy just wanted to get rid of the rest of the AC so I could sell the rest. And if its not effecting my fuel econ. then I have other things that need to be taken care of before I do this.

[richtazz]

Removing the A/C compressor will not free up any HP, except when the A/C is turned on. The HVAC system uses the A/C in defrost mode as well to help dehumidify the air and speed defogging, so it's not adviseable to remove the compressor on a daily driver. Does your car have the DIC, and if so, what does it show your mileage to be? Our cars fuel tanks are approx 16 gallons, not 40. If it were 40 gallons, you'd be getting 3.25 MPG. Try the tune up parts first, and I would change the o2's as well. My car is a 99 GT, and I get 20+ mpg overall (mix of city and highway driving), even driving leadfooted occasionally. I took it on a trip, and cruising at 75mph, I got over 32 MPG.

[BNaylor]

He may have been referring to liters. He's from Canada. The poster should clarify.

[richtazz]

good point Bob, but they did say 40gal and they said 130 miles (not kilometers). I think there is some serious confusion here.

[Krazzee]

sorry guys its a florida car so its in miles and I just made a quess at the tank size. But I am only getting 130miles to a tank and it sucks. The tank is about 40 LITERS though

[richtazz]

Next time you fill up, write down how many gallons (or liters) it takes to fill it up and post here. I can't believe you're getting less than 10mpg and you have no CEL on and the car deosn't drive like a pile of doo-doo.

[Krazzee]

The tank holds 40 Liters and I get 130miles from it. Highway is a little better but not much. The car runs fine with a small miss when idleing but that just started. It has lots of power but it does run a little rich. Everything I have done has shown zero results and I mean none. The tires I have on it are 225/60/R16 are these the right tires for my car or would they effect mileage. I just did some welding on the u bend right by the O2 sensor on the exaust about the middle of the car but it didnt change anything. What elts could I change or check.

[BNaylor]

Originally Posted by Krazzee

The tank holds 40 Liters and I get 130miles from it. Highway is a little better but not much. The car runs fine with a small miss when idleing but that just started. It has lots of power but it does run a little rich. Everything I have done has shown zero results and I mean none. The tires I have on it are 225/60/R16 are these the right tires for my car or would they effect mileage. I just did some welding on the u bend right by the O2 sensor on the exaust about the middle of the car but it didnt change anything. What elts could I change or check.

Are you sure about that? 40 liters is only 10.57 US gallons. The fuel tank is supposed to be around 18 gallons. (approx. 68 liters). Are you filling up to where the fuel nozzle clicks and then a little more or going by the fuel gauge? If you are putting in 40 liters and getting 130 miles then you are getting around 13 mpg which is very poor.

The tires are correct for stock. You can verify by looking at the data label located on the driver's side door.

[Krazzee]

I fill up at the empty line every time so there is still some gas in my tank and it has been constantly the same 130miles everytime. It is very poor and I realy cant figure out why. If i look at the tail pipes when the car is running it puts out a small amount of black smoke. The car is a rebuild, would there be any wrong parts that would make this happen.

[BNaylor]

Originally Posted by Krazzee

I fill up at the empty line every time so there is still some gas in my tank and it has been constantly the same 130miles everytime. It is very poor and I realy cant figure out why. If i look at the tail pipes when the car is running it puts out a small amount of black smoke. The car is a rebuild, would there be any wrong parts that would make this happen.

Are you getting the black smoke when the car is first started and in the process of warming up or after it has reached normal operating temperature? The black smoke definitely indicates its running rich. Bad part is you're not getting any indication other than the poor gas mileage.

Have you inspected the front and rear 02 sensors to see if they are OEM or aftermarket replacements. Have they ever been replaced? Make sure they are AC Delco. The front is AFS-109 and the rear is AFS123 for a '98 GT. Do not use Bosch 02 sensors.

Also, try cleaning the throttle body with throttle body spray cleaner. Remove the MAF sensor located on the top of the throttle body first. Clean MAF sensor with electrical contact or MAF sensor spray cleaner. Also, remove the idle air controller (IAC), clean the spring loaded pintle and the seat where it mounts on the throttle body. The MAF sensor if defective or improper can give poor gas mileage too and not trigger any codes or SES light.

[gprixgtp]

Don't feel to bad my 97 gtp gets worse fuel mileage that my 70 mustang with a 429. The gtp gets just over 8 mpg. I haven't done anything to it but exaust, cai. I changed plugs, fuel filter, o2 sensors, cleaned t.body, maf. There is no smoke and the car runs like a champ. I quit worrying about and just deal with it. I don't drive it to far so I don't yet know what it gets on the highway. All the driving I do ith it has been in the city. One of these days I will get a bug in my pants and really try to figure it out, but for now it doesn't bother me.