Fuel Ain't Pumpin'

[Matt7c]

I have now renewed the entire fuel line from tank to fuel pump. I was pleasantly surprised by how easy it was to thread through the new pipe with body on, including the exhaust, because a forum thread I read a few weeks ago suggested that was difficult. I have a Spyder space frame chassis, so perhaps that makes a difference. The whole job took a while, including getting the car up onto axle stands and taking the carbs off, but getting the pipe threaded through was less than 5 minutes.

There is no air in the fuel now, but I'm not yet convinved I'm in the clear as the level in the glass dome still seems low. I'll take her for a spin tomorrow and see how far I get!

Thanks again for the help,

Matt

[Matt7c]

Well, as suspected, I still have a problem with the fuel system. The symptoms are that I start out with full carbs and a full bowl on the fuel pump, but that after less than 5 minutes of driving the carbs run dry (lots of fuel in the tank). I have overhauled the pump, renewed the fuel lines from tank to carbs, and blown compressed air into the tank through the fuel line to attempt to clear any blockage. The previous problem with air getting into the fuel system appears to have been eliminated as there are no bubbles any more. It just seems that the fuel pump is under-performing and not delivering the quantity of fuel it should deliver.

Any more suggestions on what to try before I give in and buy an electric fuel pump? If not, any suggestions on which fuel pump to buy and where to mount it?

Matt

PS: is there anything that could be amiss inside the fuel tank itself? I have successfully blown air back through into the tank.

[type26owner]

Yup, rusted hole in the steel pickup tube near the top inside the tank. Debris which will gets sucked against the pickup tube end blocking off the flow from time to time. Usually a large flat hunk of rust. There are cleaner/sealers to restore older rusted fuel tanks which are not rusted completely through yet. Good luck! Common problems with the Elan.

[Matt7c]

In which case, an electric fuel pump will solve nothing, I guess. The fuel tank is a Spyder replacement, which looks in very good nick - on the outside! I'll contact them to see what gotchas they are aware of. Looks like I'll have to have a look at the tank before spending any more cash. While I'm there, maybe its time to renew that sender which doesn't work as well...

This must must be a familiar challenge with any restoration - finding out which will be completed first: the car or the cash. <_<

[type26owner]

Bingo! You'll need to remove the fuel level sender to have a peek at the pickup tube. This can be done with a mirror on a telescoping handle.

Money and car problems aren't the most important issues to worry about. It's whether or not the wife is going to tolerate you WASTING all the money and your time. They have a nack at making one miserable if they wish too. I'm asking for forgiveness all the time.

[types26/36]

If you suspect there is a problem in the tank why not connect the pickup pipe to a fuel container in the boot, go for a test drive and see if you still get the same symptons, it would elimimate or confirm if the problem is the tank.
Brian

[gjz30075]

<!--QuoteBegin-Matt7c+Apr 24 2005, 05:05 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Matt7c @ Apr 24 2005, 05:05 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin-->
This must must be a familiar challenge with any restoration - finding out which will be completed first: the car or the cash. <_< [/quote]
It's always the cash.

Greg Z

[Matt7c]

Thanks Brian, that occured to me, too. In fact, that's just what I did tonight. I took a jerry can 3/4 full of 4-star and extended the fuel line into it, bypassing the fuel tank. Exactly the same problem ocurred! Fuel was definitely flowing from the jerry can, but it wasn't wasn't enough to keep the fuel pump bowl topped up above the level of the gauze filter. So the tank might be innocent!

By a process of elimination and deduction, having checked everything at the system level and then verified or renewed the components, I'm now convinced that its the pump. And I've spent far too much of my life on that thing already! :angry:

The next step: I'm going to get an electric pump and a length of fuel line and connect them up to the jerry can without installing them onto the car. The other end of the fuel line goes direct to the carbs. If it all works well, I'll connect the fuel line to the tank. If that works I'll go for the full installation and junk the mech fuel pump. Actually, I'll probably keep it but ... after all this trouble I might get some pleasure from squashing it with my lump hammer

[Matt7c]

<!--QuoteBegin-type26owner+Apr 24 2005, 09:22 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (type26owner @ Apr 24 2005, 09:22 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> Money and car problems aren't the most important issues to worry about. It's whether or not the wife is going to tolerate you WASTING all the money and your time. They have a nack at making one miserable if they wish too. I'm asking for forgiveness all the time. [/quote]
After 10 years of marriage, I think my wife is glad to see less of me! Although I know she would rather it cost less to do so <_<

[Matt7c]

Well, I finally got around to installing an electric pump. Its in the boot with the spare tyre and the old mechanical pump is back on the engine where it continues to look original, despite the removal of the driving arm! Well, I didn't have anything to make a blanking plate with...

At first, all was well and the car was running notably smoother with the carbs always topped up to the correct level. I even drove it about a mile to my car club which has a ramp so I could re-fit the exhaust. However, on the drive back, the carbs ran dry again and I finished the day with the (now almost routine ) exercise of pushing the car home

Now its got to be the tank - there is nothing else left. Just filled it yesterday. :blink:

[Matt7c]

Have just drained, removed and inspected the fuel tank. The fuel pick up pipe inside the tank appears to be in direct contact with the bottom of the tank. I can run a pipe cleaner and a metal wire through the pipe, but I can't see either emerge from the pipe inside the tank. Does anybody know whether the pipe is supposed to be in contact with the bottom of the tank, or whether it should be slightly above (as I would have thought)? Perhaps the pipe touches the bottom, but there is a hole further up that I can't see? Its a Spyder tank if that makes any difference.

On a similar subject, does anyone know whether the tank sender unit is the same in the Spyder as in the original? I need a new one, but don't want to order a pricey Lotus one on an assumption.

Ta,

Matt

[types26/36]

Mark,
Oviously the pipe should be as low as possible but you dont want to be blocking it off or sucking up dirt, when I had a tank made the original pipe was cut at an angle so even if it touched the bottom it would not block. If you think it is touching you could hook something round it and bend it slightly so it is not touching.
As a matter of interest did you make sure the tank was vented and not causing a vacuum inside the tank?
Brian.

[Matt7c]

Hopefully, the end of the thread and the end of my fuel flowing woes...

Spyder confirm that the pick up pipe should be raised off the base of the tank by several mm. Clearly, my pipe being in contact with the bottom is causing a restriction. So, I'll try to bend it back a bit. I've also ordered a new sender unit from Paul Matty - the old one was siezed.

Thanks for all your assistance.

[type26owner]

Hey Matt,
It's very likely you've now cured the fault that took that car off the road all those years ago. Way to go!

[Matt7c]

Thanks Keith,

Its such a relief now that this if fixed. Ever since I put the car back down on its wheels from the tressle, almost 2 months ago, I been dogged with the same problem of fuel starvation. No such problems tonight when I took her out for a spin. All the hesitation on acceleration is gone, the engine is delightfully smooth, the throaty roar through the carbs is thoroughly enjoyable and the road holding is incredible. Haven't yet topped 40mph (the private roads I drove on have a speed limit of 20mph!) but did manage to get into top gear for the 1st time and the transmission seems very smooth.

The carbs now need tuning, which seems quite complicated, so I'll need to read it through a few times before attempting it. I get quite a spit back through the carbs on cylinder 2 on idle and in the overrun, but all the plugs are a lovely golden brown, so it doesn't seem all that far out.

Keith, the fan was on almost all the time. Its currently set to 78 as per the manual, but I note a few times you have said 90 is a better running temp. Did you mean that you would set the fan to come on that temp rather than 78?

Matt :rolleyes: