Siphoning gas

[NSXAndy]

Hi everyone:

I’m new to the forum. I haven’t driven my NSX since COVID and I think the gas is bad (engine won’t turn over). I tried to siphon the gas out but the tube doesn’t even get wet. There is a very old post that says the 14 mm plug on the tank has to be removed. I would prefer not to do this if possible. Do any of you have any tricks to siphoning gas out ??? Battery is new and charged.

Thanks in advance

 

[Old Guy]

If fuel can get into the tank from the filler cap, it can get out. The problem is that there is about a 45 deg bend followed by about a 90 deg bend and then another approximate 90 deg drop into the tank. Getting your siphon hose past those bends is the problem. It needs to be flexible enough to do the bends yet stiff enough not to bunch up in the bends. You can confirm that the siphon hose is all the way in by blowing on the hose and listening for bubbling. Your chance of doing this successfully is low.

If you don't want to access the drain plug, you could disconnect the inlet to the fuel pressure regulator and attach an extension hose to the hose that attached to the regulator and run this to a catch tank. Then make arrangements to power up the fuel pump and drain the tank that way. The pump's flow rate is about 2 l per minute so this will take about 1/2 hour to empty the tank so using the battery to do this may not be a very good idea.

Personally, I would use the tank drain plug rather than mess around with fuel line connections or trying to siphon the gas if you want the tank empty. The drain plug has the advantage that if there is solid crud in the tank the drain plug method will remove some / perhaps all of that solid crud.

and I think the gas is bad (engine won’t turn over).

'Engine won't turn over' is rather imprecise English. If you mean that the starter motor does not turn the engine over then your problem is something else that is totally unrelated to fuel. If you mean that the engine will crank (turn over); but, not fire and then continue running that might be a fuel system problem; but, probably not a fuel quality problem. The COV 19 pandemic was declared around March 2020. If that is when you stopped driving, the gas in the tank is about 3.5 years old. Gasoline definitely deteriorates with age and the engine will probably have poor operation on that gas; but, it should still be able to start and then perhaps run like crap.

Have you confirmed that fuel pump starts up and goes through the prime cycle to pressurize the fuel system? That would be a good place to start. I can't see a fuel pump failing after sitting unused stored in old gas for >3 1/2 years. If the fuel pump does not run and it is not the main EFI relay or the ECU that has failed then you are going to have to drain the tank anyway to access the pump. There are so many other things you should check first to evaluate a non start before jumping to the conclusion that it is the fuel.

Draining the tank and using the 3 1/2 year old fuel in your lawn mower or your neighbour's lawnmower would never be a bad idea. However, eliminate other possibilities before filling the tank up because if it is a dead fuel pump you are going to have to drain the new fuel out to access the pump.

 

[NSXAndy]

If fuel can get into the tank from the filler cap, it can get out. The problem is that there is about a 45 deg bend followed by about a 90 deg bend and then another approximate 90 deg drop into the tank. Getting your siphon hose past those bends is the problem. It needs to be flexible enough to do the bends yet stiff enough not to bunch up in the bends. You can confirm that the siphon hose is all the way in by blowing on the hose and listening for bubbling. Your chance of doing this successfully is low.

If you don't want to access the drain plug, you could disconnect the inlet to the fuel pressure regulator and attach an extension hose to the hose that attached to the regulator and run this to a catch tank. Then make arrangements to power up the fuel pump and drain the tank that way. The pump's flow rate is about 2 l per minute so this will take about 1/2 hour to empty the tank so using the battery to do this may not be a very good idea.

Personally, I would use the tank drain plug rather than mess around with fuel line connections or trying to siphon the gas if you want the tank empty. The drain plug has the advantage that if there is solid crud in the tank the drain plug method will remove some / perhaps all of that solid crud.



'Engine won't turn over' is rather imprecise English. If you mean that the starter motor does not turn the engine over then your problem is something else that is totally unrelated to fuel. If you mean that the engine will crank (turn over); but, not fire and then continue running that might be a fuel system problem; but, probably not a fuel quality problem. The COV 19 pandemic was declared around March 2020. If that is when you stopped driving, the gas in the tank is about 3.5 years old. Gasoline definitely deteriorates with age and the engine will probably have poor operation on that gas; but, it should still be able to start and then perhaps run like crap.

Have you confirmed that fuel pump starts up and goes through the prime cycle to pressurize the fuel system? That would be a good place to start. I can't see a fuel pump failing after sitting unused stored in old gas for >3 1/2 years. If the fuel pump does not run and it is not the main EFI relay or the ECU that has failed then you are going to have to drain the tank anyway to access the pump. There are so many other things you should check first to evaluate a non start before jumping to the conclusion that it is the fuel.

Draining the tank and using the 3 1/2 year old fuel in your lawn mower or your neighbour's lawnmower would never be a bad idea. However, eliminate other possibilities before filling the tank up because if it is a dead fuel pump you are going to have to drain the new fuel out to access the pump.

Thanks for the detailed information and clarification of terminology. The vehicle was only driven on very rare occasions so at the start of COVID the gas could have been 2 years old making it 5 1/2 years old now. Not sure that makes a difference.

Old Guy, I just took a quick glance under the car and didn't see a plug. It's a 1999. Is the plug on the passenger side or drivers side?

 

[Honcho]

Thanks for the detailed information and clarification of terminology. The vehicle was only driven on very rare occasions so at the start of COVID the gas could have been 2 years old making it 5 1/2 years old now. Not sure that makes a difference.

Old Guy, I just took a quick glance under the car and didn't see a plug. It's a 1999. Is the plug on the passenger side or drivers side?

The drain plug is on the passenger side (right side in a LHD car). The best way to do this is to drain the fuel into one of those clear plastic tubs (in a well-ventilated space!) and then transfer the gas to a proper fuel container.

 

[NSXAndy]

The drain plug is on the passenger side (right side in a LHD car). The best way to do this is to drain the fuel into one of those clear plastic tubs (in a well-ventilated space!) and then transfer the gas to a proper fuel container.View attachment 183932View attachment 183933

 

[NSXAndy]

Great pic! Thank you

 

[NSXAndy]

Update:

After learning about the number of angles/bends in getting to the gas tank I started twisting the siphon tube clockwise with no success. I then changed to counterclockwise and it effortlessly passed.

The gas is now out. A big thank you to everyone especially “Old Guy”

 

[Old Guy]

Thanks for the detailed information and clarification of terminology. The vehicle was only driven on very rare occasions so at the start of COVID the gas could have been 2 years old making it 5 1/2 years old now. Not sure that makes a difference.

5 1/2 years - that is going to qualify as skanky gas. If the tank was full to the brim when you stopped using the car the gas may be 'less skanky'. If the tank was partially full that means that there will have been space for air (actually O2 is the nasty one) to engage in oxidization reactions with the gasoline elevating the skank factor.

You might want to make sure your fuel pump is working before you drain and refill the tank. It would be wasted effort to drain the tank and refill it and then find out that you have a dead pump and have to repeat the process.

If the gasoline you were using was E10, I might seriously be thinking about sending those injectors out for cleaning. Ethanol blended gasolines are not so good for long term storage.

 

[NSXAndy]

Old Guy:

Thank you again for the expert advise. It is greatly appreciated

 

[docjohn]

3 skanks

yerrrr out...

 

[NSXAndy]

One final question before I add some new gas this weekend and try to start her up. Is any additive recommended for the injectors. Any reason to add or not to add STA-BIL?

Thanks in advance

 

[Honcho]

One final question before I add some new gas this weekend and try to start her up. Is any additive recommended for the injectors. Any reason to add or not to add STA-BIL?

Thanks in advance

Techron products do work in the NSX, but to be honest, you'll be better off sending your fuel injectors to RC Engineering to be cleaned and balanced. The fuel additives don't really do much in the way of cleaning compared to this service. I recommend it for most NSX owners, since the varnish/wax buildup in the injectors over 30+ years can be significant.

 

[NSXAndy]

Techron products do work in the NSX, but to be honest, you'll be better off sending your fuel injectors to RC Engineering to be cleaned and balanced. The fuel additives don't really do much in the way of cleaning compared to this service. I recommend it for most NSX owners, since the varnish/wax buildup in the injectors over 30+ years can be significant.

Honcho'

Thank you for the expert advise!

 

[fallen86]

So did your car start up with new gas? I’m having this issue now

 

[Old Guy]

Unless the gas is really really really old it is not likely the cause of a no-start problem. Run like crap and hard to start, yes. No-start, unlikely. The gas would have had to deteriorate so badly that the volatile components had pretty much disappeared and it was hard to ignite. However, if the aging gas resulted in fuel deposits and gummed up injectors and other fuel supply components, that can cause a no-start or incredibly hard to start condition. In that case, deterioration of the gas is the source of the problem; but, replacing the gas will not fix the problem. You need to clean the fuel system components.

 

[NSXAndy]

So did your car start up with new gas? I’m having this issue now

Unfortunately the car did not start after I replaced the old gas with new gas. I was waiting until the spring to take it in. Any guidance from the experts here would be greatly appreciated.

 

[Old Guy]

To riff off of Paul Simon, there are probably fifty ways to stop your NSX from starting. As such, we would need a few more details than just 'doesn't start' to provide useful guidance. Specific items to check could include

- in your very first post you said 'engine won't turn over. Does 'won't turn over' mean that the starter motor is not turning the engine over (cranking) or does it mean that the engine is cranking; but, will not run on its own? Perennial favourites for the starting motor not operating include a failed ignition switch and the infamous clutch interlock button
- did the no start condition occur all of a sudden or was it starting to become hard to start which gradually evolved to no start
- when you switch the ignition switch to the run position you hear the fuel pump prime (main EFI relay OK and ECU not completely dead)
- have you used the service check connector or an OBDII scanner to check for any stored error codes that might indicate what the problem is
- on an engine that cranks; but will not start the two primary things to check are ignition and fuel delivery. The ignition check is relatively easy

- pull an ignition coil and spark plug and do the spark test (ground electrode against the block) while cranking the engine to determine whether the ignition system is operating​

- beyond listening for the fuel pump and checking that fuel pressure is within spec, actual delivery of fuel from the injector tips is hard / impossible to do because of the fuel rail arrangement. The best you can do is use some 'noid lights and check to confirm that they flash while the engine is cranking. If the lights flash and you have fuel pressure then you would assume fuel delivery. In your case with 5 1/2 year old gas the next step would be to pull the injectors and have them cleaned out to confirm that gas is actually making its way into he intake manifold​

- if all of the above checks out (ignition works and fuel is being delivered) the nasty next step would be to check the valve timing