[junq1968]

Hi All,

It seems like i'm seeing more and more problem with my '68. I changed the oil over the weekend and it smelled like gas. Any advice? Thanks.

 

[lunchmeat5000]

Mechanical fuel pump? If so, the diaphragm in it might have a leak. That would be my first guess. Fairly simple fix.

 

[ZFORCE]

I agree, the mechanical fuel pump will pour gas into your oil if the diaphragm rips. The fuel pump is on the driver's side and is held in with two bolts, a fairly easy job to replace. Here is a picture of what it looks like on my 289, it is the circular shaped unit, right in front (left) of the oil filter.

http://www.mustangphotos.com/photopost/data/505/medium/P7301505.JPG

Make sure you don't run the engine...the gas will thin out the oil and you could cause some severe damage. After you change the fuel pump, change the oil and filter before running the car.

 

[caveeagle]

I think this can also be caused by a problem with your PCV valve operation. If Piston blow-by does not get sucked back into the intake (through the PCV)the unburnt fuel can end up contaminating your oil.

 

[67mousetang]

Looking at your previous posts, hard starting, draining batteries trying to start it, sounds like you're flooding gas down the carb

 

[slim]

Most likely fuel pumpdiaphram. Most auto parts stores will have the pump
about $20.

 

[1968mustang6]

make sure to change your oil and fuel filter after replacing the pump. do it all at the same time.

 

[slim]

In many regeons it's required that 10% or more alcohol be mixed in with the
gasoline. The rubber compounds used in fuel systems of old cars were not
intended to be used with alcohol. Some alcohol is worse than others. Today's auto
fuel systems use rubber compounds that are alcohol resistant. My point is
many of us old car owners have a car with 30+ years old fuel pump and accelorator
pump and we put in modern high alcohol fuel and we have failures.

 

[junq1968]

Thank you all for the advice. I will check all the suggestions. I'm itching to drive this car. I have not had a chance to post pictures but will do as as as I can get it moving without worrying something wrong will happened. Thanks again and have a great weekend.

 

[junq1968]

Okay, the previous owner has a modification manual on the car and he installed a Holley Electrical fuel pump mounted near the gas tank, Powered through a Holley Fuel Pump cut off switch next to the oil filter. Does this change the diaphram leak solution?

 

[slim]

Just a little! Maybe 100%!

 

[67shelby]

Looking at your previous posts, hard starting, draining batteries trying to start it, sounds like you're flooding gas down the carb

I would agree. Bad power valve in the carb. If the bowl empty between starts, it is the power valve. What kind of carb?

 

[OldMil]

I had a problem with the float settings on my carb. When the car was wiggled, the fuel would flow down the carb. It was a bigger issue during transport, but worth checking into.

 

[junq1968]

HOLLEY 0-80670
670 CFM Four Barrel Carburetor
No Trouble Quick Change Adjustable Vacuum Secondary
4th Generation No Trouble Power Valve
Built-In No Trouble Secondary Fuel Filters
Adjustable Needle and Seat
No Trouble Electric Choke
Four Vacuum Ports
Street Avenger Fuel Metering System

 

[67shelby]

HOLLEY 0-80670
670 CFM Four Barrel Carburetor
No Trouble Quick Change Adjustable Vacuum Secondary
4th Generation No Trouble Power Valve
Built-In No Trouble Secondary Fuel Filters
Adjustable Needle and Seat
No Trouble Electric Choke
Four Vacuum Ports
Street Avenger Fuel Metering System

I'm not a carb expert by any means, but I didn't think the Holley carbs had the same type of power valve problems the Autolite carbs do.

That being said, a pretty easy test is to take a look at the bowls after you've run the car (take off the top of the carb) and see if they empty over time. You can also do it off the car.

From the sounds of it, if it is really hard to start after it has set for awhile, there may not be gas in the carb and it is leaking down into the oil.

My Autolite 4100 had that problem for awhile. You do NOT want to let this continue to be a problem becuase you'll thin the oil and if you thin it too much, obviously, the engine will not be properly lubricated. Change the oil often untile you can figure it out.

 

[VictorII]

Might be a good idea to pull the gas line at the carb. and check the pressure. If the pump overpowers the needle valve, you'll get too much gas to the carb and it'll run into the engine. How does the engine run? It is also possible that the intake gasket(s) could be letting fuel mixture into the lifter valley and therefore into the oil.

 

[junq1968]

Thanks for the advice, How often should I change the oil and do I have to change the filter as well. I'm hoping to get this thing fix asap but it'll all depends on funds. I just change the oil last weekend and I'm planning to change it every 3000 miles. Is this too long of an interval?

 

[junq1968]

The engine runs smooth on the freeway but idles hard.

 

[Tonys65Pony]

I have experienced this before! Get rid of the carb, it is dumping fuel.. It is actually a bad and serious thing because the fuel washes down the cylinders and removes the oils left for some start up lubrication!!!Plus it will eat up the gaskets etc! It's the carb.

 

[Wootdog]

As the others have stated. It appears to be a carb problem. Had the same problem with two different Edlebrock 600s in the last year. They took the first one back. Not the second though. I had to ship it to Edlebrock. They rebuilt it and told me the secondaries had a bent rod. These were brand new carbs I obtained from Advance Auto Parts.
Kerry