Gas milage

[FB71]

oh yeah, I forgot!!!!

[Click_It]

FestYboy:
I'm taking Winnie to a carb shop on Tuesday to have a quick look over. Had a good chat with the guy he said a common thing to go bad is the choke, something about a wax choke that can stick and run too rich. Any other relatively easy things I should have him look at whilst it's there?

Being carb I don't have an o2 sensor right? The EGR valve is an obvious one but I can do that on my own watch. Do I have a coolant temp sensor? He also mentioned something about coolant temps being responsible for poor mpg so I'm guessing I do. I'll write down a little list for him

BTW I just replaced my spark leads and discovered they've been there since new, 140k miles. The new ones didn't really make any difference either, slightly smoother low down that's about it. Amazing how long a set of leads can last sometimes...

I've been getting so many bits and pieces from my auto-parts wholesaler they now give me trade price discount (commercial account)

[FestYboy]

FestYboy:
I'm taking Winnie to a carb shop on Tuesday to have a quick look over. Had a good chat with the guy he said a common thing to go bad is the choke, something about a wax choke that can stick and run too rich. Any other relatively easy things I should have him look at whilst it's there?

Being carb I don't have an o2 sensor right? The EGR valve is an obvious one but I can do that on my own watch. Do I have a coolant temp sensor? He also mentioned something about coolant temps being responsible for poor mpg so I'm guessing I do. I'll write down a little list for him

BTW I just replaced my spark leads and discovered they've been there since new, 140k miles. The new ones didn't really make any difference either, slightly smoother low down that's about it. Amazing how long a set of leads can last sometimes...

I've been getting so many bits and pieces from my auto-parts wholesaler they now give me trade price discount (commercial account)

you should have an electric choke... not aware of a thermo cuppled choke in any festy/pride. in either case, it's operation should be verified.
you DO have an O2 sensor (computer controled carb), and if they go bad, they tell the ECM things are too lean so the ECM then adds more fuel making things too rich (a safer condition than too lean). the engine temp sensor (located on the underside of the intake) sends info to the ECM for fuel and timing control. if that sensor goes bad, it reads cold all the time telling the ECM to add fuel (go rich).

did you replace the plugs as well? if not please do so with a good set of NGK or Denso coper core units. also have them test the output of the coil, a weak one can cause poor MPG.

[Click_It]

you should have an electric choke... not aware of a thermo cuppled choke in any festy/pride. in either case, it's operation should be verified.
you DO have an O2 sensor (computer controled carb), and if they go bad, they tell the ECM things are too lean so the ECM then adds more fuel making things too rich (a safer condition than too lean). the engine temp sensor (located on the underside of the intake) sends info to the ECM for fuel and timing control. if that sensor goes bad, it reads cold all the time telling the ECM to add fuel (go rich).

did you replace the plugs as well? if not please do so with a good set of NGK or Denso coper core units. also have them test the output of the coil, a weak one can cause poor MPG.

Thanks FestYboy
Yeah I replaced the plugs 6 months back with some quality NGK's though I didn't notice any difference. Hmmm so I DO have an o2 sensor, I originally thought I did but 2 local places told me I don't. I might see if my auto-parts store is still open (Saturday here) and buy that DENSO unit. Might price the engine temp sensor too.

Many thanks, I'll jot these down. The coil is a good idea too, I've been thinking about changing that for awhile too but may as well have it checked first, I've changed enough things in this car that didn't need replacement already

Oh and I just switched from 20W-50 (the oil it's always ran from day-dot) to 10W-30 (API-SL), I'm hoping that'll make some difference too.

[Click_It]

Just got it back from the carb shop, it's running lean.
Carbon Monoxide on idle is 3.2%, 0.11% driving if that means anything to you, apparently the latter figure should be much higher. He determined that it's running lean, possibly from bad fuel but I always buy higher octane so I'm doubtful this is to blame however I'll try a different brand for a few fills just to see if anything improves. He said a carb overhaul may or may not fix anything, it's a different story if it's running rich which I thought it might have been.

He did say it's one of the best running festy's he's seen in a long time though so that was good to hear

[FestYboy]

are you running a cat?

[Click_It]

Yeah I am. Could it need replacing? I thought the cat was responsible for burning unburnt fuel (ie: rich) which is not the case here, the carb guy was certain there was no unburnt fuel going through.

From the little I understand, I'm thinking I should double check all the hoses for a vacuum leak. I found a crack and repaired one hose the other day though this was prior to the gas analysis so it obviously didn't fix much, maybe there is something else I've missed.

But I'm still learning as I go so the above might be completely wrong.

[TominMO]

How many miles on your cat? I find that over 125 - 150K they start getting clogged up. If the car is otherwise running fine but getting bad mileage, the cat may very well be the problem. Especially if you've replaced the O2 sensor already.

[navdoc101]

Hey, good tip, TominMO. I may get my friend to "repair" my cat, & see if that helps. Almost all the parts Iv'e replaced;CV Axle & muffler-exhaust; were original. cat problely is also.

[Click_It]

How many miles on your cat? I find that over 125 - 150K they start getting clogged up. If the car is otherwise running fine but getting bad mileage, the cat may very well be the problem. Especially if you've replaced the O2 sensor already.

You may very well be right there, my car has about 116k miles on it but for years was used only for short trips which may have accelerated clogging the cat? Either way it's worth a shot, something I'd never even thought of thanks. As you say, other than poor mileage the car is otherwise running great.