HELP Horrible mpg horrible gas smell stumped.

fleming442

fleming442

Geezer
Dec 26, 2013
7,093
113
My 3.8 equipped Bonne had the feed on the passenger side and the vent and return on the driver's side...... I think. I do remember them split between the framerails, because I thought it was a dumb design. I ripped them all out to run -6 AN.
 
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Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
My 3.8 equipped Bonne had the feed on the passenger side and the vent and return on the driver's side...... I think. I do remember them split between the framerails, because I thought it was a dumb design. I ripped them all out to run -6 AN.
Yea mine has 2 hard lines on the passenger side never bothered to look on the drivers I’ll have to take a look.

So since I barely understand venting systems that second hard line could potentially be a vent? I couldn’t use it as a return and run a vent line straight from the fuel pump to the charcoal


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iains

iains

Not-quite-so-new-guy
Feb 25, 2019
23
3
Yea mine has 2 hard lines on the passenger side never bothered to look on the drivers I’ll have to take a look.

So since I barely understand venting systems that second hard line could potentially be a vent? I couldn’t use it as a return and run a vent line straight from the fuel pump to the charcoal


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Anybody catch an error please forgive me, but I thought that the charcoal canister is part of the evaporative emissions hardware. The vent lines from the fuel tank and carburetor send the fuel vapours/fumes to the charcoal can to be neutralized. I don’t think it would be wise to send fuel into the can.
Fuel, air, spark. Verify these are at specified settings
Is your air cleaner in good shape, and are the PCV valves functioning properly?
Can you do a compression test?
 
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Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
Anybody catch an error please forgive me, but I thought that the charcoal canister is part of the evaporative emissions hardware. The vent lines from the fuel tank and carburetor send the fuel vapours/fumes to the charcoal can to be neutralized. I don’t think it would be wise to send fuel into the can.
Fuel, air, spark. Verify these are at specified settings
Is your air cleaner in good shape, and are the PCV valves functioning properly?
Can you do a compression test?
Currently my vent line from the tank runs to the charcoal canister after research it seems it should run from the canister to the carb? Correct?

Also I do have the pcv valve in the passenger valve cover ran to the pcv port on the carb with the breather in the drivers valve cover.

Air cleaner is in awesome shape.

I have not done a compression test I’ll have to make time for that.


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Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
Fuel pressure testing on a carb isn’t my forte but I believe I may need a regulator though the way I had to set up the hosing likely contributed to at least somewhat increased pressure.

Within less than 10 sec cranking it pumped up to 7 psi and stayed there with continued cranking though of course it had to pump up to get there.

Then because there was still fuel in the bowls the engine started and I believe it was on a faster idle what I think is 11-1200 and the gauge was reading almost steady at 10 psi which I’m uncertain is correct or not for pressure while running


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Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
Got a mr gasket regulator for the time being I have it set to 4 for now because I read on line it usually allows higher psi than set for.

Tried to put the floats back at half and the temp was causing fuel drips etc so I put it back to a quarter. In the process of regapping the plugs down to . 45 the first plug pulled seemed to show white ash and from what I’ve read that means I’m too lean. So I’ll see what the rest read. Fighting some heat issues as well as detailed in my build thread essentially operating tempature for me is 220 not sure why honestly. I’m tempted to space the rear of the hood up to allow more heat to flow out for the time being until I get it figured out


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iains

iains

Not-quite-so-new-guy
Feb 25, 2019
23
3
The ash white plug porcelain and the high operating temperatures suggest that the timing is off by a fair bit. When you change several things at once, you cannot now which change was the god one. So slowly, one thing at stone
 
Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
The timing being off does it suggest too far advanced or too far retarded?

Also cylinder 8 seems to seriously have some problems it’s way worse off then the rest my dad said one of the valve seats I believe it was had to be welded and my bet is definitely that one the plugs always look terrible this is the plug just since I tapped it to .5 when I took it out today





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olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
4,937
113
Melville,Saskatchewan
That is a sign of oil consumption. Your timing should be close to bang on.
 
Stupidquestionspro

Stupidquestionspro

Master Mechanic
May 23, 2019
362
43
Tampa Bay Area
Yea the previous poster said my issues sound like timing off but I’m running 35-36 total with I believe 18 initial.

Yea I figured it was oil consumption though it seems like that specific cylinder is worlds worse than the rest so I’m assuming that was the repaired one the repair isn’t doing too great


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