1860army

Hi,

82, with a crate 350 less than 6k miles, Holley street avenger, stock electric fuel pump with a regulator. Got the car a year ago and the oil was dirty and seemed thin to me, I figured the PO put the wrong kind in, he did not know cars at all. I changed it to 10-W40 and ran it, the oil pressure seemed high, cold fast idle 65-70.. After 1000miles I put 10-w30 VR-1 and the pressure was a tad lower at temp. Recently the car was backed in and out of a garage every day for a month, not by me, but I'm sure they just got in and pumped the peddle a few times and started it, which it does not need. I got in it last week, first time since early November, noticed the oil pressure was a little lower than normal, 5-10 lbs and in cold weather. The oil had the smell of fuel and was 2K miles old so I changed it and the pressure went back to about normal, close enough. I checked the fuel pressure and lowered it from 7-6 and I've also turned in the mixture screw half a turn and it runs fine. I'd like to think it was from the way it was started and run for only a few seconds the past month but I am not sure and should mention I have zero sense of smell, not even gas-or skunks..lol

What are the main causes of Fuel in the oil? What should my Fuel pressure be. Any suggestions or Ideas of what i should check/do.

Thanks,
D/S

kossuth

Well, growing up on the farm this happened alot to our gas tractors when you left the sediment bowl turned on and parked the tractor for an extended period. In that case the needle valve was sticking and not shutting the fuel off and gravity did the rest (no fuel pump on most of those old tractors, the fuel pump was having the tank mounted above the carb.)

That being said this is obviously not the case. When you say factory pump I'm assuming your referring to the electric pump. 6-7 lbs is where your fuel pressure should be. I'd be checking to see if it's running super rich. Have you checked your plugs to see if they are all sooted up? That would obviously wash things down a bit if it was running super rich.

CanadaGrant

I noticed you are running a Street Avenger. Is it possible that your fuel tank vent system/canister has been closed off while still using the stock non-vented fuel cap allowing pressure to build in the tank while sitting and slowly flood the intake manifold?

7T1vette

If you still have the mechanical fuel pump operational, the diaphragm in that pump just 'took a dump'. Don't drive it until you fix it.

4-vettes

ahhhh, 82's don't have a mechanical pump.

MattoonVette

Correct 82's don't have a mechanical pump but the OP stated he has a Holley Avenger on a crate motor. I had the situation as 7T1vette stated above, I had a Mechanical fuel pump diaphragm go bad and pump gas straight into the oil. There was no signs of it leaking externally through the weep hole either. I just happened to notice my oil was thinned and smelled like gas.

1860army

Thanks guys

There is no mechanical pump so that's out. The gas cap is one of those old school locking ones from the gas crisis of the 80s, remember the lines..lol, don't know if it's vented but I don't recall hearing a whoosh when I stop for fuel and open it. Maybe get a vented replacement. Plugs are next, I ran out of time yesterday, I've had guys driving behind me and I asked about any smoke, none reported but it's been awhile.

I spent last night schooling myself on this carb and I need to check bowl levels and accelerator pump clearance as well as the plugs.. The engine runs really well, MPG is 12.5 -14.5 depending on the time of year & my foot, lower when cold.

Thanks Again
D/S

HeadsU.P.

What you really need to confirm is if the carb is at fault here. Is there raw fuel puddling in the Intake? Your first reaction would be to open the throttles wide open and have a look-see. That in itself will flood the plenum and give you a false illusion.

A better way is to not touch the throttle. Remove the four carb nuts or bolts and lift the carb enough to see inside the plenum. In some cases, you don't even have to disconnect the throttle cable, vacuum lines or the fuel line if rubber. If you can't see inside, place a mirror in there. You have to verify the carb is faulty or not.

7T1vette

Even if you had raw fuel get into the intake, it wouldn't make its way into the oil. The only way I can envision for such to occur is that raw fuel is somehow reaching the vapor recovery canister and then getting sucked into a valve cover via some faulty emissions control system / PCV valve. (And that is only an 'imagined' possibility.)

Torqued Off

I don't mean to question you, but just a comment...are you sure you are smelling gas in the oil? Oil has a smell as well, and both are petroleum products. And you stated you have zero sense of smell. I understand you changed oil and saw differences in pressure,.????, but could there be a different problem.

1860army

You can question me all you want, thats why I'm here... I am not sure this is the problem but I think it's a good first start based on what I've seen with the Oil Pressure picking up with new oil... I had my son in law and wife do the sniffing for me,,,

[QUOTE[color=#000000]Even if you had raw fuel get into the intake, it wouldn't make its way into the oil. The only way I can envision for such to occur is that raw fuel is somehow reaching the vapor recovery canister and then getting sucked into a valve cover via some faulty emissions control system / PCV valve. (And that is only an 'imagined' possibility.)][/QUOTE]
I see your point, but there is not much of the emissions left, basic PCV and that's it. I just want to eliminate the Carb and I think I'll just drive it and watch, (and have someone sniff the oil)

I think that is next and a good idea, I'm gonna stick and inspection camera down the secondaries and check it for awhile, I can see it on my phone.

The Float levels are good and don't change or overflow with the pump running. Accelerator pump is correct and the plugs look good so it is running good. The plug threads have some sort of black goo on them that I've never seen, maybe some old antisieze?? (I wiped the goo off before the poc)


Thanks again guys

HeadsU.P.

So you are saying that if the fuel bowl or both bowls (Holley / Quick Fuel) emptied into the Intake, that gas would sit there forever and never drain into the cylinder?

7T1vette

Ahh, you are indicating that the leaking fuel is getting to the cylinders in a non-running engine. Certainly a possibility. The simple test for that would be to remove the carb, dry off the bottom and place it in a metal pan, then check for fuel draining out.

If that is happening, there would need to be significant amount of leakage so that some could run into an 'open' intake valve or two. Not sure how much fuel some carbs can hold....not that much in a Q-jet's fuel well.

1860army

So, I think I got this resolved but won't really know until the summer and here is why...

The car originaly had FI and a return fuel line which is not used presently, the regulator is a dead head type and I reduced it to 5 lbs at idle. I then loosened the carb and slipped a thin piece of cardboard under it covering all 4 ports, I pressurized the system and let it sit until the pressure returned to zero-4-5hours. I then slipped the cardboard out and check for stains from fuel dripping on it, I did this a number of times and sometimes there would be spots that looked like a drop or two but that could have been from me lifting the carb up and down putting the card board in, maybe I sloshed a tad out of the bowl. I am reasonably sure that my issue is not fuel supply related but I'm going to flush out the return line and get a bypass regulator when it warms up some outside, this should let the system depressurize as soon as I turn it off...

I believe the issue was fuel perculation or heat soak, I called Holley for advice on a new regulator and the guy talked with me for 40 minutes, I got edumacated about these carbs.. He said I could be on the right track with the regulator because it would be better if the pressure dropped off quicker when the car was off. But he said 9 out or 10 times it was heat soak and he bet me I had trouble starting the motor 30 min to an hour after shut down... I've had that issue since I've had the car, you have to hold WOT to get it started after it sits for 30 min or more...I always thought it was the Crappy electric choke... I have very little hood clearence so I ordered 3-4 different heat shields and phenolic spacers from Amazon so I can easily send back what I don't use. I ended up using the Holley one, had to trim 1/2 inch off one end but everything lined up good. I had off yesterday and ran it through three heat cycles where I'd run it fairly hard until I was sure it was as hot as could be and then let it sit for 45 minutes.. It started good each time and the carb was much cooler, huge difference. Tech said I probably did not have an oil splash guard under the manifold and man does it get hot. I'm going to run it a few hundred miles, change the regulator and then change the oil again. Then check for fuel in the oil after the ambient temps rise.

Holley heat shield

I need suggestions for a real small, low profile air cleaner, the heat shield and spacer raised the carb enough that it hits... I can trim the hood but would rather not..

Thanks all
60

HeadsU.P.

Look on Summit for "Drop-Base" air cleaners.
Another option is a 2.750" high filter instead of 3" And I believe there is a 2.5" tall unit somewhere. Both are difficult to find in 14" diameter but do-able.
I have a drop-base, plus a 2 & 7/8 tall filter I found at AdvanceAuto.

How Are You

augiedoggy

I have heard of this very thing happening on sbc's with electric pumps especially if the pump is running while the engine isnt for some reason. If I remember right I bought a boat once that had this problem.