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5/26/2026 10:35 AM  #1


Tune-up ?? still bad fuel smell !!

Just rewired the car thanks for the help from Boyd.!!.. 

While I had it all opened up  I decided to adjust my holley 650 dual pump mechanical carburetor with smaller jetting, 66 primaries  and 71 secondaries...

 Reason,  the car has always smelled like fuel, very rich is what I thought ?? But when I pulled the spark plug to check " doesn't look very rich to me " 




. .. So what I'm asking the brain trust here is give me your thoughts on my process to go through the entire tune up again, maybe I'm missing something !! I've adjusted timing, adjusted the curve in the distributor,  carburetor idle screws, throttle plates, fuel pump ...

 It'll Run great Just can't get rid of the fuel smell.. 


my 66 - 289 v-8 / gt-40 heads / .533 lift - .224 duration / all roller assembly / Intake edelbrock performer rpm / Hooker long tube Headers / Holley 4150 - 650cfm mechanical secondaries & choke / MSD 6A box - pertronix igniton - factory distributor..

timing at 850rpm 12dg.  at 2500rpm 38dg. / spark gap .50 

THANKS for the help !!
 


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
 

5/26/2026 12:59 PM  #2


Re: Tune-up ?? still bad fuel smell !!

How bout NEVER !
What you have is a mild race engine used as a street rod engine....(I'm proud of you BTW!!)
224 duration in a 289 is considered pretty 'rad' !  (see my above comment!)
A carb is just a controlled 'gas-leak' (BB referred to them as a 'dripping pot'!)
Your fuel system prolly is a typical 1966 style 'open system' meaning the fuel 'vapors' are NOT routed back to the tank
                                                                                                                                   (like a modern fuel injected system)
To get the carb adjusted as near perfect as possible you could weld in TWO bungs in those GREAT long tubes and buy an air flow meter (not the real name) and get the mixture near perfect. (still gonna smell the stinky modern gasoline)
They make a 'perfume' you can mix into the fuel (no kidd'in) cherry is my favorite...grape is cool too..(nitro smell is available!)
You got 'yo-self' a skreet-rod pardner!...
You DO have the exhaust exiting the REAR valance don't you?! (very important)
Insure ALL little holes and cracks are sealed up to keep smell OUT of the cabin. (in 1966 there were PLENTY!)
AC would prolly help too. (you're from TEXAS so that's a given...)
I would LOVEto take-a-ride in that 'pony BTW
Other-than switching to FI and a bunch of other mods (listed above) I suggest you 'enjoy-the-machine' ! 
I believe BITD (when all the mods you have listed) you woulda-had a "killer" street/strip rod. The only difference was..back then the gasoline was 100 octane pure gas and smelled REALLY GOOD ...so we didn't complain about the stink.
You could carry a 'clean shirt' wrapped in a plastic bag...and change when you get outta the ride !!
6sally6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

5/26/2026 4:56 PM  #3


Re: Tune-up ?? still bad fuel smell !!

I had a smell I couldn't find. It's worth checking.
https://fyi.boardhost.com/viewtopic.php?id=11193


"Those telephone poles were like a picket fence"
 

5/26/2026 5:11 PM  #4


Re: Tune-up ?? still bad fuel smell !!

6sally6 
Thanks for your reply ,,!!  
                         I needed a  good  laugh !!
                                                     I will consider you thoughtful suggestions..

PS.. your right back in 1974"  my "65"  289 mustang build had a 305 / 460 lift cam ..it didn't smell like gas , I loved the way it loped at idle,. and run 13tens in quarter with a c4 auto 2.80gears ...

maybe the way to go would be to change the cam ??
 


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
     Thread Starter
 

5/26/2026 5:23 PM  #5


Re: Tune-up ?? still bad fuel smell !!

50vert,.  
               Thanks !! 
                           been down that rabbit hole already ..
                                      It's diffidently in the carb !!


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
     Thread Starter
 

5/26/2026 6:55 PM  #6


Re: Tune-up ?? still bad fuel smell !!

Do you have a vacuum advance distributor?  It would likely idle better and a little cleaner with 20 to 22 degrees at idle.  You may need to recurve the distributor and/or change the stops to give you more initial timing or if you have vacuum advance, connect it to full manifold vacuum.  You may be able to lean out the idle once it has more timing.

 

5/27/2026 10:04 AM  #7


Re: Tune-up ?? still bad fuel smell !!

GPatrick wrote:

Do you have a vacuum advance distributor?  It would likely idle better and a little cleaner with 20 to 22 degrees at idle.  You may need to recurve the distributor and/or change the stops to give you more initial timing or if you have vacuum advance, connect it to full manifold vacuum.  You may be able to lean out the idle once it has more timing.

X-2
I have mine set up where the total advance is 36*@ just off idle !!
It's 'retarded' just enough to make cranking easier....I have no idea what the initial advance is...because it's sorta irrelevant.
Sharpens up the snotty idle when adjusting the carb.
6s6

 


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

5/28/2026 6:04 AM  #8


Re: Tune-up ?? still bad fuel smell !!

How does the oil on your dipstick smell?  If it smells like fuel, the diaphragm in your fuel pump may be leaking fuel into the crankcase.  In my experience that will definitely cause a gasoline odor to be present.


Founding Member of the Perpetually Bewildered Society
 

5/28/2026 8:33 AM  #9


Re: Tune-up ?? still bad fuel smell !!

GPatrick 
   Thanks' 
       Yes about vacuum advance ,, part of what I was thinking....

Jonh Ha 
     Thanks' 
           No smell in oil ,. fuel pump is elect  set to only 3.5lb at carb.....


 


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
     Thread Starter
 

5/28/2026 10:08 AM  #10


Re: Tune-up ?? still bad fuel smell !!

If my car ran great, the plugs looked good, I could find no fuel leaks, but it smelled like gasoline, I would count my blessings, have a cigar and enjoy the day.


Bob. 21.5 freeway MPG 69 Mach 1, 5.0 GT40P heads, SMOD Toploader, Armstrong  steering, factory AC
 

5/28/2026 12:07 PM  #11


Re: Tune-up ?? still bad fuel smell !!

rpm 
         Thanks' ..   
                  Your comments is what makes this group  FUN !!    to inter act with ..


66 PonySilverBlue-289/gt40/roller/650cfm/ram air-T-5-cable-w4way.disc/4-245x50x16"
     Thread Starter
 

5/29/2026 5:46 AM  #12


Re: Tune-up ?? still bad fuel smell !!

Carb bowls have vents, and there's always some fuel in the crab/manifold even when its not running.  I think we've just become hyper sensitive to the smell because EFI cars don't.  

 

5/29/2026 9:12 AM  #13


Re: Tune-up ?? still bad fuel smell !!

I can remember when I was about 7or 8 riding in my dad’s Model “A” swiping my finger over the weepy gas gauge in the instrument cluster and sniffing it. I used to love that aroma, gasoline back then smelled a lot better than today’s  chemical concoction.


Good work ain't cheap, Cheap work ain't good!
 

5/31/2026 11:33 AM  #14


Re: Tune-up ?? still bad fuel smell !!

TKOPerformance wrote:

I think we've just become hyper sensitive to the smell because EFI cars don't.  

X-2
6s6
(Although....gas DOESN'T smell as good as it once did...)
 


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

Board footera


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