ac belt vs. gas milage

Hi Mud,

So I'm heading south to Padre for the weekend when my gauges all go dead. I pull the truck over to investigate and water the wildflowers when I notice a burning smell coming from under the hood. I had fried my ac compressor and the belt was melting. I grab my knife and slice it off, replace the fuse for my gauges and I'm off. I figure this is the best I can do at the time and decide I'll just leave the ac and defrost off and continue on my way.

I'm heading down the road when I noticed how much better my truck was running; much better in fact.

The best range I have had in my truck has been 235 miles. I typically fill up the tank, reset my tripo, and use the gallon tally from the next fill up to calculate mileage: 235miles/~19gal=12.4MPG. This time I got 280miles/~19gal=14.7MPG.

That is a pretty significant increase, which got me thinking. Why isn’t there some kind of clutch mechanism that stops internal parts from spinning when they are not in use? Like a means to freewheel the ac compressor pulley or even the pulley on the crank itself? If that were a reliable after market piece I bet I would buy it.

So that’s my request. Pm for my address and I will test out any prototypes. We can work out any non-disclosure issues at a later time.

I run a 1997 FJZ80 [127,000 miles] with most of the fixins.

the AC does have a clutch, yours does not apear to have been working propperly.

when the clutch is disengaged only the outler portion of the pulley turns, none of theiunards turn.

high 14's to low 15's is failry typical for a stock 80. (YMMV due ot driving conditions and style)

nice. I was hoping the ac pump was the mileage issue. I have weighed my truck down with bumpers/lift/roof top tent, which has affected my mileage lately. I just didn't think an effed pump would make that big a difference. I'll be glad to be up around 15 again.

I'm expecting tp pay $300+ to replace this with Toyota pump.

I'll give cdan a call tomorrow.

RavenTai said:

high 14's to low 15's is failry typical for a stock 80.

Click to expand...

Not the case on this rig - fully built 80 including rooftop tent (fawker ). I can only dream of that kind of milage - mines pretty much on par with your normal man. Must have had a tail wind ...

Tucker

yes, milage given was for a STOCK FZJ80, it goes down hill from there

to clarify, my figures above are without rooftop tent.

Hi Tucker!

PhILIE said:

nice. I was hoping the ac pump was the mileage issue. I have weighed my truck down with bumpers/lift/roof top tent, which has affected my mileage lately. I just didn't think an effed pump would make that big a difference. I'll be glad to be up around 15 again.

I'm expecting tp pay $300+ to replace this with Toyota pump.

I'll give cdan a call tomorrow.

Click to expand...

Good luck. If you can find a new Toyota compressor for $300 you are a better man than I.

You can get a reman for $254 and a new aftermarket one for $394 here:

http://www.ackits.com/index.cfm?fuseaction=FindAKit

This is a good source, but beware! A non-Toyota pump will probably not be as good as OEM. I bought a new aftermarket pump for my Audi from this place, and saved $850, but it definitely runs louder.

Don't forget to replace the expansion valve and receiver dryer without fail, and flush the black crud out of the system - the warranty will be void if you don't. Read the fine print carefully.

John Davies
Spokane WA

I wasn't expecting the pump clutch to be a separate piece. I guess this is what I was asking for in the original post so I shouldn't be complaining.

These are friendly prices for toy parts, not list. I'd like to compare this to cdans prices but he's out till Thursday.

pump $385
clutch $185
e valve $ 63.61
evap/dryer $65.84

$760 + labor is a small price to pay for my sanity in the Texas heat. I drove a black on black 72 chevelle for 5 years without ac and I was just grumpy on the road. I wasn't too happy with anyone that impeded my forward motion [read: breeze].

PhILIE said:

I wasn't expecting the pump clutch to be a separate piece. I guess this is what I was asking for in the original post so I shouldn't be complaining.

These are friendly prices for toy parts, not list. I'd like to compare this to cdans prices but he's out till Thursday.

pump $385
clutch $185
e valve $ 63.61
evap/dryer $65.84

$760 + labor is a small price to pay for my sanity in the Texas heat. I drove a black on black 72 chevelle for 5 years without ac and I was just grumpy on the road. I wasn't too happy with anyone that impeded my forward motion [read: breeze].

Click to expand...

Ouch - I know expansion valve is $53.17 and dryer is $54.49 from Cdan ... so the other should be a little less as well. Good thing it's not hot yet

Tucker

Yes, the clutch is *usually* a separate piece that can be replaced. You may not be able to find anyone that will sell one separately so how about having your rebuilt by an A/C shop? Assuming of course your A/C compressor is alright internally.

Just a thought!

Check out the prices on expansion valve and R/D at ackits.com - you can safely install aftermarket for those bits and they are way less.

R/D $25
Expansion valve: $39

If you already have, or plan on buying, an offroad front bumper, consider installing a shorter R/D that won't stick down below the bumper.

John Davies
Spokane WA

that's an interesting idea. I do have an ARB bull bar and that thing is annoying. Any drawbacks to using a shorter R/D? I know very basic info on ac systems and would consider performance pretty high on my list. Maybe this is a good time to relocate the stock part? I know I saw a write up on that here a while ago. Does it make a difference?