• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

YIPS Took out 4&1/2 gal oil & gas from crank case

Share this page

Got_All_4

Got_All_4

Luke Skywalker
Country flag
Offline
Yes hard to believe. After not driving my TR250 for about a month I went to start it and to make a long story short it was hard to start. Once started I instantly noticed that there was only 5 lb of oil pressure. Immediately shutting it down and checking the oil, the mixture shot out of the dip stick hole. I more then filled a 6 gallon car 3/4 full. How can this happen? That's the question. I've heard of oil getting thinned out by a quart or two but this is the extreme. I had a sticking float problem off and on since August. Possibly the fuel pump diaphragm is cracked? Would that do it. However it was recently rebuilt.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

A friend had that happen recently. I believe it was the fuel pump. I will speak to him and let you know for sure.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

My brothers TR6 has done a similar thing. We've had to clamp off the fuel line to the carbs while it was parked, otherwise they would flood over and fill the crankcase. The car runs fine, so it's not a needle stuck permanantly open,or a ripped fuel pump diaphragm leaking into the crank. but every once in a while it does this while parked...
So, I'm curious as to what others have seen.
 
On a TR4/250/5/6 the fuel tank is higher than the fuel pump, so there is a positive pressure on the fuel pump. This is especially true if the tank is full or if the car is parked on an incline with the nose pointed downhill. Given this situation, a fuel pump with a ruptured diaphragm will empty the contents of the fuel tank into the engine crankcase. Also, if a needle valve is stuck open in one of the carbs, it will dump fuel into the intake manifold as the carb overfills.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

Another good reason for the TR3 fuel shut off valve or an electronic fuel pump.
I wonder if it has anything to do as to where the fule pump lever stops on the cam. If it does not close the pump and the carb floats don't deal the system you have an open circuit. Never would have figured that one.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

You guys are scaring me! I think I am going right out and change my fuel pump. Wait, I just did that.

A little tip. The replacement fuel pumps from TRF seem to be very nice. Look to have the same exact design at the original AC but made in Italy. So far, so good.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

That happened to my TR6.
So I installed a in line fuel shut off valve, before the fuel filter and pump. It also makes it easer to change the filter. I use the fuel shut off valve if I fill the fuel tank and park
the car for more than a few hours.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

[ QUOTE ]
That happened to my TR6.
So I installed a in line fuel shut off valve, before the fuel filter and pump. It also makes it easer to change the filter. I use the fuel shut off valve if I fill the fuel tank and park
the car for more than a few hours.

[/ QUOTE ]

Where exactly did you get that valve? I have looked high and low for such and have yet to find a satisfactory valve.
I pretty much have settled on a motorcycle shop where they install these things on bikes all the time. Just gotta go find one. Putting a pair of hemostats on the gas line before the fuel filter is a PIA. (Hemostats for when working on car, not to shut fuel off on regular basis. That would be OCD)
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

TR6BILL
I will look that up (where the valve was purchased, and get back to you. Give me till tommarow.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

Bill, I also got mine from TRF. Your right it looks like a quality part right down to the priming lever.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

[ QUOTE ]
Another good reason for the TR3 fuel shut off valve or an electronic fuel pump.

[/ QUOTE ]

I do run an electric fuel pump on my car (mounted in the boot where the factory PI pump would have been mounted). I assume the electric pump acts as a check valve, preventing any possible overflow. Anyone know of my assumption is correct?
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

TR6Bill, look at www.ham-let.com They have a stainless full port ball valve that has worked well for me so far. I changed my fuel lines to 3/8 and used a 3/8 valve. They have compression fittings that are reusable and work well. It wasn't cheap, but the quality is very good. David K.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

Regardless of who made the pump there would have to be a diaphram leak for this to happen. I've had this happen to other mech FP and it's normally found after an oil change when the oil gets contaminated quickly. The problem can go on for awhile as the pumps still perform correctly with a diaphram leak. I've never had this catastrophic issue but in our LBC's the gas tank sits higher than the pump/motor and gravity can take over. I would also guess that the leak could be assisted if the cam/lever was in mid stroke depressing the diaphram and opening the hole. Given enough time you could empty the tank. The seep hole in the pump only works to a point and the fuel would follow the pump lever into the block. Does this sound correct to you guys?
Mech FP should be on a sched for check/rebuild every few years.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

My fuel shut off valve came from a marine & boat supply store. Under $5.00
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

I have had exactly this problem on my Spitfire. Because the mechanical pump arm needs to ride on a cam inside the block, if the pump diaphragm get a hole in it, gas can go down inside the pump and run directly into the crankcase.

A hole in the diaphragm is typically small, and may not affect the pump's ability to deliver fuel all that much, so unless gas is leaking outside the pump, you may not notice it. This was the case for me. I finally noticed that the engine block below where the pump mounts was surprisingly clean....having been washed by an ongoing gas leak.

I haven't heard of that much gas being lost into the crankcase, but I suppose it can happen.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

How and where did you mount the cut-off switch? I want one that can be accessed easily, right before the fuel filter and pump.
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

RE: fuel shut of valve location.
I will try to take a picture and post it in the morning.
It is what I call "cheap and cheerful"
 
Re: YIPS Took out 4&1/2 gal oil & gas from crank

I had a '37 Ford flathead that had the exact same fuel pump as my '58 TR3. One day I also found the Ford's crankcase way overfull and smelling of gasoline. The diaphragm on the fuel pump had ruptured. I replaced the Ford's pump with the one from the TR3 and bought a Facet cube electric for the TR3. Problem solved.
 
Back
Top