Author Topic: Fuel difference  (Read 1628 times)

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Offline QIK70

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Fuel difference
« on: December 24, 2017, 11:40:10 AM »

G'day all.

Has anyone experienced an issue when first putting Aust fuel into older mustangs??

Mine was running perfectly with the fuel that was in it during import, but after putting Aust fuel into it, it ran like a dog.

firstly it wouldn't start, but after changing plugs, leads and coil, it now starts but won't run smooth at all.

Offline GLENN 70

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Re: Fuel difference
« Reply #1 on: December 24, 2017, 11:47:31 AM »
Yes a few times ,but new spark plugs always fixed it . Put a new fuel filter on it and if it doesn't have one fit one . What carby is it ? .

Offline QIK70

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Re: Fuel difference
« Reply #2 on: December 24, 2017, 11:59:49 AM »

G'day Glen,

Carby is a Holly 650. The frustrating thing is, nothing else had been touched

Offline QIK70

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Re: Fuel difference
« Reply #3 on: December 24, 2017, 12:08:57 PM »


Is it a octane level thing? Or a timing thing? Or a combination of both?

I put 20ltrs of 91 octane

Online skinner36

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Re: Fuel difference
« Reply #4 on: December 24, 2017, 12:15:28 PM »
I always put 98 octane in mine or the equivalent from the brand I am putting in at the time

Offline evan

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Re: Fuel difference
« Reply #5 on: December 24, 2017, 12:31:02 PM »
Probably not fuel, most likely the crap from the fuel tank & lines clagging up the carb. Lower octane fuel will simply make it ping under load, not run rough.

Evan.

Offline Scott66

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Re: Fuel difference
« Reply #6 on: December 24, 2017, 01:33:27 PM »
I wouldn’t run 91 in my lawnmower let alone my Mustang.
I have found BP 98 the best followed by Caltex 98 and Shell 98 is crap makes it sound like it’s on 7 cylinders

Offline QIK70

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Re: Fuel difference
« Reply #7 on: December 24, 2017, 02:32:47 PM »

Inline fuel filter replaced.

Jets checked and all good there.

Timing checked and all seems good there.

It starts and runs very rough. There is zero response when the throttle is applied.

Again. Very frustrating as nothing else was touched

Online Husky65

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Re: Fuel difference
« Reply #8 on: December 24, 2017, 03:04:30 PM »
Definitely no ethanol in the fuel? Almost all 91 fuels around are a blend now.
I also only put BP 98 in mine and haven't had an issue. I have had an issue in a previous car with shell 98, so now I always use BP.

Offline QIK70

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Re: Fuel difference
« Reply #9 on: December 24, 2017, 03:49:37 PM »

Ive just thrown 20lts BP 98.

Hopefully there will be a improvement

Online skinner36

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Re: Fuel difference
« Reply #10 on: December 24, 2017, 05:34:38 PM »
Let us know

Offline GLENN 70

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Re: Fuel difference
« Reply #11 on: December 24, 2017, 05:36:13 PM »
Holley 650 you sure ? List number is on the front of the choke housing . Is it a points dizzy ? Mixture screws 1 1/2 turns out . No air leaks ? .carby not flooding and float levels correct . Are you sure the dizzy has not moved but closed points will change timing .

Offline QIK70

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Re: Fuel difference
« Reply #12 on: December 25, 2017, 10:23:33 PM »

Yep  Holley 650. checked the list number the day i picked her up.

tried the mixture screws. no change.

no air leaks, tried the old d40 around the base o the manifold, no change.

So get this............After putting in a container of octane booster and 20 ptrs of BP 98 Ultimate, there was a subtle change but it continue to be a dog, then after getting out of the car for 10 minutes, i get back in, try it again and it fires and runs better than it has! revs free, sounds bloody beautiful.
Then ti stops and goes back to what it was doing.
My only explanation is that it got a good gulp of 98 and loved it

Offline barnett468

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Re: Fuel difference
« Reply #13 on: December 26, 2017, 06:27:53 AM »
.
My only explanation is that it got a good gulp of 98 and loved it

That's ridiculous and as likely to happen as peeing in the toilet and not having it mix with the toilet water.


no air leaks, tried the old d40 around the base o the manifold, no change.

that was pretty much a waste of time cuz wd40 is nearly useless for finding leaks . use flammable brake cleaner with the long nozzle and spray it GENTLY so it doesn't waft into the carb throat giving you a false reading.


tried the mixture screws. no change.

sounds like your carburetor is dirty or the power valve might be leaking a little or the throttle is open too far at idle.

set the gas level so it is around 4 mm below the inspection screw hole at idle . if it has a clear window, set it so the level is 1/4 up the window.

remove the idle mix screws and spray flammable brake cleaner in the holes with the long nozzle for 3 seconds.

reinstall the screws set 3/4 turn out from full in.

place the long nozzle directly against the holes in the top of the carb and spray each one. watch your eyes and paint.

remove one of the bottom float bowl screws and drain the gas into a paint can lid in case there is water in it. put a wad of paper towels below it first.

make sure fuel comes out of both squirters as soon as you barely open the throttle by hand.

make sure there is zero vacuum to your distributor at idle.

make sure the timing returns to the same place every time at idle.

Offline QIK70

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Re: Fuel difference
« Reply #14 on: December 26, 2017, 09:13:28 AM »
.
That's ridiculous and as likely to happen as peeing in the toilet and not having it mix with the toilet water.

Instead of quoting and being critical do you have a possible explanation as to how/why it would of happened?
No word of a lie, it fired and ran better than it has. I thought it was a Christmas miracle.

Offline QIK70

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Re: Fuel difference
« Reply #15 on: December 26, 2017, 09:15:33 AM »

Barnett468.

Cheers for the other tips.
I'll get onto it today.

Online mcarnage59

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Re: Fuel difference
« Reply #16 on: December 26, 2017, 09:22:36 AM »
.
That's ridiculous and as likely to happen as peeing in the toilet and not having it mix with the toilet water.

Instead of quoting and being critical do you have a possible explanation as to how/why it would of happened?
No word of a lie, it fired and ran better than it has. I thought it was a Christmas miracle.

“Barney critical” you must have had too much brandy with the pudding yesterday. His response was his standard MO, direct and concise. Buckle up and enjoy the ride. You might not like the tone but there is plenty to learn.
 :cheers:
Always dreamed I'd have one!

Offline QIK70

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Re: Fuel difference
« Reply #17 on: December 26, 2017, 09:27:55 AM »

I'm here to learn trust me on that one!

Hence all the stupid sounding questions.

This issue is doing my head in. Its not making any sense at all

Offline barnett468

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Re: Fuel difference
« Reply #18 on: December 26, 2017, 12:22:02 PM »
“Barney critical” you must have had too much brandy with the pudding yesterday. His response was his standard MO, direct and concise. Buckle up and enjoy the ride. You might not like the tone but there is plenty to learn.
 :cheers:

LOL, I'm trying to keep in top form.  :thumb:

Offline barnett468

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Re: Fuel difference
« Reply #19 on: December 26, 2017, 12:27:41 PM »
Hence all the stupid sounding questions.

Questions are never stupid (well almost never unless fitzy asks them).  :lmao:


This issue is doing my head in. Its not making any sense at all

Don't try to figure it out or you might end up being a lawn bowler like GLENN with his hat.  :bolt:


.





Offline barnett468

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Re: Fuel difference
« Reply #20 on: December 26, 2017, 12:31:50 PM »
No word of a lie, it fired and ran better than it has. I thought it was a Christmas miracle.

A real Christmas miracle is when the pregnancy test your girlfriend took turned out to be a false positive.  :lmao:

Offline unilec5544

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Re: Fuel difference
« Reply #21 on: December 26, 2017, 04:53:06 PM »
In the picture I'm still not sure which is Glenn, is it the one in the blue shirt? :bolt: When you have exhausted all the things to do list and you still have a problem it could be electrical, try another coil or points.

Offline barnett468

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Re: Fuel difference
« Reply #22 on: December 26, 2017, 05:31:48 PM »
In the picture I'm still not sure which is Glenn, is it the one in the blue shirt?

ouch...you are even more cruel than I am.  :lmao:

Online JET445

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Re: Fuel difference
« Reply #23 on: December 26, 2017, 07:32:04 PM »
The Late Show with Barnett- tonight featuring a bunch of dopey Aussie Mustang owners, sorry I know I should'nt encourage him... :lmao: :lmao: :lmao:

Offline minipete

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Re: Fuel difference
« Reply #24 on: December 26, 2017, 10:08:59 PM »
I was having trouble with black smoke out the exhaust on acceleration in my 65 Coupe.

My carbie guy told me that the older cars have trouble burning 98 as it is too dense and I should use 95.

Switched to 95 and no more black smoke.

 

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