Fuel problem? Fitment of inline fuel filter?

[the rolfie]

Hi all, just had a four hour drive from my local lotus meet which normaly takes 30mins!!!! Car seems to be running out of fuel and then stops? However then if left off for a while will drive fine for half a mile and then die again! I managed to get home by pressing in the clutch in and out and drifting seemed a better option than the two hour RAC wait! I have changed the fuel pump after I had small air bubbles coming in the glass bowl from the tank side? A jammed valve and need a rebuild? I then fitted a metal type pump which you can't see what is going on in side! Any help you can give would be great. Also now thinking need to fit inline filters has anyone simple plan for this on the tank plastic pipe side?
Don't you just love these problems that you think have gone away! Or should I just fit an electric pump? Thanks

[Hamish Coutts]

Certainly sounds like fuel starvation. I take it there is no smell of petrol (or no more than usual ) That could indicate a leak upstream from the pump that is allowing air to be drawn into the fuel circuit.
There may also be something blocking the fuel line or outlet from the tank. It could be rust, bits of rubber filler elbow or other foreign bodies in the tank, or something as simple as a kink in the fuel line.
Depending on your carbs, it may also be worth checking the fuel filters at the banjo bolts (found on Dellortos).
Also you could try gently blowing some air back upstream from the pump to the tank to see if that cures the problem.

That aside, a fuel filter between the tank and the pump is a good idea. I have one fitted on my +2 and when I had the old rusty fuel tank in place, it was amazing how much crud it caught.

When the mechanical pump went, I fitted a facet red top pump and pressure regulator which worked OK for a while then started to jam. Cause? Rust particles.
Then fitted a filter upstream from pump. Things were OK but tank got worse and rust started clogging the filter. I too only got about 50 miles before the car stopped, in my case with a blocked filter. It was a bugger on a 200 mile run having to keep cleaning the filter. Sods law had it that it always seemed to stop the car at junctions.

I now have a new tank with the same pump/filter set up and all is fine although I did have a bit of trouble with the pressure regulator allowing the fuel pressure to go too high.

I didn't like the idea of when a mechanical pump diaphram failed, there was a good chance that fuel would leak directly into the engine diluting the oil! That, apart from the mechanical pump giving up the ghost anyway, was why I fitted an electric pump.
That was not the end of the problems though, as these pumps are susceptible to crud in the fuel. I also had problems with high fuel pressure causing flooding. (See above.)

These problems are all cured now (fingers crossed ) and I wouldn't like to go back to the old mechanical set up.

See my previous recent posts on these problems.

Regards,


Hamish.

[the rolfie]

Thanks for the reply I have now worked out the tank has got some rubish in it and will need to come out! Can this be done from the boot? or from the inside of the car? Any help and tips on removal and cleaning would be great. Thanks in advance.

[Hamish Coutts]

Roy at Paul Matty's always said that the tank could be taken out via the boot. Personally I have never managed this and have taken the tank out through the main part of the car.

It's a bit of a fiddly job I'm afraid.

Underneath:
1. you need to drain the tank (drain cock, nearside) then .....
2. undo the banjo connection in the middle. That's right above the diff and a pig to get at. (when was anything ever easy in a Lotus?). You'l probably find some crud in the banjo. Mine was full of flakes of rubber and rust particles. Made me wonder how fuel had got through. Then .....
Topside:
1. Remove rear shelf and back seat. Then ...
2. There are 2 tank straps that need to be undone. They are attached to the floor at the front of the tank and the adjustment nuts, which you fully undo, are in the boot at the bottom rear of the tank. Then ....
3. Disconnect the fuel guage terminals from the sender and the filler elbow. If the tank has not been out for a while (if ever) the elbow bill be rock solid and probably starting to break up (thus the stuff in the tank). If need be, put a saw through it as it won't be used again. ( new ones from Matty's, they are not expensive) Then ....
4. Lastly disconnect the breathers at the top of the tank and remove them. (te, he, it sounds easy but it can be a right pain in the ar$e).

What you'll find is that the tank drain cock will be rusted solid (like mine). Fuel, therefore, has to be drained via the fuel pipe at the pump end. Mmmm.
There will always be a little fuel left in the tank which will dribble out as you remove the tank from inside the car.
The breather pipes will also be solid. What I found is that they soften off with the application of a cloth soaked in very hot water. (remember this is pertol - no electrics )

If you decide to get work done on the tank - be very careful. I did this and the guy cocked it up. The flux used for mild steel is acidic and he didn't wash out the tank properly after he had finished silver soldering. Result? serious rust problems and eventual replacement of the tank with an alloy one at ?300+ squids and I'm still waiting, after a few months for Matty's to send me the right guage sender. Ok the guage works but the low fuel light doesn't (like they said it would).

After various trials and tribulations the whole fuel system is fine. I have now gone several hundred miles without any problems. That is good.

This is really a cautionery tale. Please try and solve your tank problems but be carefull and not create the problems I did. (see my previous posts on rusty tanks etc.) All I was trying to do was to solve a fuel leak problem in the tank by getting it souldered and also cleaning it out. In my view not worth the effort.

I now have a nice new shiny alloy tank, again from Matty's, (steel ones are like hobby horse shit to find) an in line fuel filter between the tank and the pump, a facet red top pump (mounted in the boot) and a fuel pressure regulator (now adjusted to 1.9 lbs/sq in - thanks guys for the advice on pressure). All is well and the sun shines from the exhaust - again.

Until the next problem!!

Regards,

Hamish.

[the rolfie]

Hi thanks for the reply, last night attached a bike pump to the fuel line and cleared the block in the tank! The car is now running fine and I have the pump in the boot just in case. Will be taking the tank out in the next couple of weeks and have a look inside. Thanks again for your help I am thinking of changing the breather system as suggested in the Club Lotus mag last year have tried this? Any good ideas of where to get new breather hose from? Thanks Paul

[Hamish Coutts]

Yes I have tried the tank mod. I did it as part of the repair job mentioned earlier. The mod worked fairly well apart from:
- the tank filled really slowly as it now has to breath through 1 smaller hole rather than 2 normal ones.
- I found it awkward to fit the breather into the filler kneck and then get that lot fitted to the car.

That is all history now as I have the afore-mentioned new alloy tank. Breather wise, what I have done there is connect one tank breather to one of the original cross roof plastic hoses and made sure it is properly sealed. The other tank breather I have attached to the filler kneck connection. Reslut? a fast filling tank and no petrol smells.

I recon a good part of the petrol smell from a garaged +2 comes from loose breather connections. The plastic goes as hard as rock over time which must make it susceptible to leaks.
Spyder do a breather mod which some of the guys on this forum have done. It seems fine - going by the feedback. Probably better (and cheaper ) going that way rather than getting the Club Lotus mod done locally and running into the same problems that I did with some twerp ruining my tank.

Hamish.

[Hamish Coutts]

Forgot to mention, I don't think Spyder show the tank mod on their web site. It would be better to give them a call.

Hamish.

[the rolfie]

Thanks again for the info, what do you think of:-
Remove and clean the tank, refit with one new full size pipe in the original place and the other pipe feeding to a breather in the filler neck. In theory should fill quick and get rid of the smell!!

[Hamish Coutts]

That sounds like a very reasonable proposition. Are you going to replace the original breather pipe? If so, That might be fun. Can you connect into the original. I did that and used a piece of 15mm copper pipe for the joint. You can push it in if you heat the old plastic say with a hot air gun. Remember to watch out for petrol fumes.

Hamish.

[chrishewett]

I strongly recommend the spyder breather system. I fitted it and it works perfectly. Search for my post on the subject. I read the article in the club lotus mag about that mod and felt it was not as good and too complicated.
Chris