Mini Mad
Posted 25 May 2013 - 09:52 AM
What are the symptoms of a torn mechanical fuel pump diaphragm?
How can I diagnose a torn fuel pump diaphragm?
Let's say it's just a small leak with maybe 10hours driving:
Will it increase oil level by a lot? Double triple etc etc, or just by a little then it evaporates?
Not sure how to check by smell, because oil (in any car) always smelled like gasoline to me. Like almost all petrol products do.
Sparkie
Posted 25 May 2013 - 10:01 AM
Symptoms will be oil and petrol mix and depending on how severe the pumps leaking, if you have any thoughts your pump diaprham is leaking fuel into the crankcase change it immediately as it will be dialating the oil and thats not good for the lubrication system and you could end up with a expensive engine rebuild.
Change it now if I was you there not that expensive/
Camshaft & Stage Two Head
Posted 25 May 2013 - 11:19 AM
They also have a bleed hole (or they did), you'll be able to see a leak on the outside of the pump sometimes.
Easy way to check is to pressure the system up with the engine off by lifting the prime arm, and come back in 10 mins and see if you are pumping fuel or it has held pressure.
From memories 30 years back, they tend to fail quite dramatically rather than weeping.
Edited by Captain Mainwaring, 25 May 2013 - 11:20 AM.
On Sabbatical
Posted 25 May 2013 - 11:41 AM
The oil will feel thin and gritty, and you will not confuse the smell believe me.
If you suspect this is happening DO NOT DRIVE THE CAR. The gear case is essentially a live bomb when this happens and if it goes up it will not be pretty.
Mini Mad
Posted 25 May 2013 - 01:27 PM
Change it now if I was you there not that expensive/
The oil will feel thin and gritty, and you will not confuse the smell believe me.
If you suspect this is happening DO NOT DRIVE THE CAR. The gear case is essentially a live bomb when this happens and if it goes up it will not be pretty.
Violent reactions hehe. But yeah totally agree where this is coming from. Thin oil = no bearings.
They also have a bleed hole (or they did), you'll be able to see a leak on the outside of the pump sometimes.
Easy way to check is to pressure the system up with the engine off by lifting the prime arm, and come back in 10 mins and see if you are pumping fuel or it has held pressure.
From memories 30 years back, they tend to fail quite dramatically rather than weeping.
So does this mean when they fail little to no fuel pressure and the oil (with fuel) level rises dramatically?
Sparkie
Posted 25 May 2013 - 07:40 PM
The fuel pump will obviously not be working at peak efficiency so yes a reduction in volume/pressure. The oil level if it raises dramitically then if your using the car then its most likely to late to prevent damage.
Get a new pump on
Edited by KernowCooper, 25 May 2013 - 07:42 PM.
Mini Mad
Posted 26 May 2013 - 12:30 AM
Based on what you guys said, I don't think mine failed yet. But gona change out the fuel pump to electronic.
And oil pressures haven't dropped. Its around 50psi @ idle then drops to around 30 psi. I think that's a good sign
I actually already have the Facet (edit: SS501) just too lazy to fit it in.
Edited by classicoop, 26 May 2013 - 12:32 AM.
Mini Mad
Posted 26 May 2013 - 12:30 AM
Anyways thanks for the info guys =)
Camshaft & Stage Two Head
Posted 26 May 2013 - 12:33 AM
Change it now if I was you there not that expensive/
The oil will feel thin and gritty, and you will not confuse the smell believe me.
If you suspect this is happening DO NOT DRIVE THE CAR. The gear case is essentially a live bomb when this happens and if it goes up it will not be pretty.
Violent reactions hehe. But yeah totally agree where this is coming from. Thin oil = no bearings.
They also have a bleed hole (or they did), you'll be able to see a leak on the outside of the pump sometimes.
Easy way to check is to pressure the system up with the engine off by lifting the prime arm, and come back in 10 mins and see if you are pumping fuel or it has held pressure.
From memories 30 years back, they tend to fail quite dramatically rather than weeping.
So does this mean when they fail little to no fuel pressure and the oil (with fuel) level rises dramatically?
If they split, then there will be no fuel pressure - I'm not sure if the position on the block is low enough to drain the tank. The oil level will rise, but the petrol will flash off an ultimately get burnt through the breathers. It will of course dilute the oil which will wreck the bearings and other things.
Camshaft & Stage Two Head
Posted 26 May 2013 - 12:34 AM
Based on what you guys said, I don't think mine failed yet. But gona change out the fuel pump to electronic.
And oil pressures haven't dropped. Its around 50psi @ idle then drops to around 30 psi. I think that's a good sign
I actually already have the Facet (edit: SS501) just too lazy to fit it in.
Doesn't mean a thing. You could get pressure on the gauge with water in the sump.
Mini Mad
Posted 26 May 2013 - 12:46 AM
If they split, then there will be no fuel pressure
Ahh ok. So mines definitely not split.
Re oil pressure my thinking is if it gets diluted = oil gets thinner = lower oil pressure. The same way with temperature. Cold = high pressure Hot = low pressure.
Mini Mad
Posted 26 May 2013 - 07:20 AM
Just replaced the pump with a Facet. Stock mechanical is still there just not hooked up to fuel lines. Will remove after month maybe, just to make sure the electric one isn't a dud.
Weird thing though, without a pump hooked up, fuel would continue to flow to the carb (which I would think is higher than the tank). Car would actually run continuously with the pump turned off. Idle only, didn't try driving without the pump.
What exactly does solid state mean? I thought no moving parts, which intrigued me on how it would pump without a diaphragm or screw type pump. But the Facet ss501 has definitely some moving parts inside..
Does solid state mean a magnet that turns on/off to move a diaphragm?
Camshaft & Stage Two Head
Posted 26 May 2013 - 07:44 AM
Sounds like the tank isn't venting...and I wouldn't mind betting your carb float valve is letting by.
Mini Mad
Posted 26 May 2013 - 07:55 AM
The tank vent check valve on the top of tank was disconnected, to replace the hose. I also remember blowing air thru the vent when the tank was out of the car. And the tank cap was removed as well.
What does carb float letting by mean?
The fuel wasn't coming out of the overflow, it was from the hose when I pulled it to replace clamp, fuel just kept flowing. It didn't overflow either when I left the electric pump on (with engine off), to check for fuel leaks. I did hear the pump straining after a few minutes. Probably the hose getting pressurized because engine was off.
Edited by classicoop, 26 May 2013 - 07:57 AM.
Camshaft & Stage Two Head
Posted 26 May 2013 - 08:34 AM
I'm pretty sure carb is higher than the level of the fuel in the tank......you tell me, how is it flowing? pump not running, fuel isn't higher than the tank unless you really brim it - tank has to be pressurizing.
Those hose should be pressurized with a couple of seconds, not minutes. For what it's worth, the pump should be on an ignition dependent feed, not running all the time.
The carb has a float chamber to meter fuel into the carb as it is required.
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