Slant Six Forum
https://slantsix.org/forum/

Raw fuel smell after parking
https://slantsix.org/forum/viewtopic.php?t=58722
Page 2 of 2

Author:  rich006 [ Mon Apr 11, 2016 4:44 am ]
Post subject:  fixed it?

The other evening I found a spare flange gasket and decided to install it. Since then I've driven the car twice and noticed no smell in the garage. So that seems to have solved the problem for now. I'm still wondering why covering the air inlet blocked the smell before.

*Side note: after I bolted the carb back down I forgot to reconnect the fuel line before starting the motor, so fuel dumped all over the engine and the garage floor. Despite the fact that I applied copious amounts of absorbent powder and concentrated Simple Green, for about 5 days there was a new fuel smell in the garage that was independent of the car.

Author:  rich006 [ Sat Apr 15, 2017 7:01 am ]
Post subject:  Not fixed

A few times I've mistakenly thought I had fixed this problem, but it was never fixed. I got sidetracked by a blowby problem (see here and here), but lately I've been suspecting maybe the bowl is overfull due to the floats being too high. Today I finally checked that. I also rebuilt the rest of the carb while I had it apart. Here are the findings so far.

1. The float setting was too high. According to the rebuild instructions the "toe end" of the floats should be flush with the top of the bowl when hanging upside down. Here's what it looked like:
Image
I did not replace the float, but I did weigh it at 12 grams, which seems to be the weight of replacement floats you can buy for the 1945. After installing the new needle/seat, I set the float so that the far tips of the floats were flush with the edges of the bowl.

2. The needle/seat from the kit has a rubber piece on the end, whereas the original one was brass. Anybody know what that means?
Image

3. The intake manifold has the same kind of gritty black crud that I found in my valve cover. The crud is concentrated around and inside the hole in the bottom of the manifold directly below the carb. I first noticed it about a year ago and it hasn't changed noticeably since then. I guess this is from the oil blowing in from the crankcase and getting sucked down the carb?
Image

The carburetor was installed a couple of years ago just before I bought the car, but it is a 70's or 80's vintage NOS carb. When rebuilding it I replaced the rubber parts on the assumption that the parts in the rebuild kit will be designed for ethanol gas, while the parts originally installed would not have been.

I'm going to replace my fuel filter and rubber lines before I reinstall the carb, but I'm crossing my fingers that adjusting the float level will help. Any words of wisdom before I put everything back together?

Author:  bboogieart [ Sun Apr 16, 2017 6:32 pm ]
Post subject: 

I'm guessing that black crud is from the carb running way to rich.
Might be oil but it shouldn't be oil in there. If it is there is too much blow by past the rings causing oil to enter the system. The E.G.R. valve is supposed to be allowing only vapor into the intake.

Myself, I wouldn't be worried about the small percentage of ethanol in the gas.
I have several old vehicles that run just fine on today's fuels, and have been for years...

Your on the right track.

Author:  rich006 [ Mon Apr 17, 2017 8:39 am ]
Post subject:  not fixed yet

Even with the float set correctly, the fuel smell still permeates the garage if the car is parked with the engine warm. I think the next step will be the fuel line mod.

One thing I couldn't figure out: the fast idle should be 1700 rpm with the engine warm, air cleaner removed, fast idle screw on the first step-down of the cam, and the EGR and vacuum advance ports plugged. But I couldn't get it over about 1600 even with the screw all the way in. This makes me wonder what other setting(s) I botched. When warm, the engine runs as well as ever. When cold it starts well and idles high, but as soon as I touch the accelerator the idle drops too low.
Quote:
I'm guessing that black crud is from the carb running way to rich.
Might be oil but it shouldn't be oil in there. If it is there is too much blow by past the rings causing oil to enter the system.
There is blowby. If I decide not to rebuild, I'll put a catch-can between the crankcase breather and the air cleaner.

Page 2 of 2 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/