Scottish Elises

Reaching end of my teeny little tether with the Liz at the mo...

Have been trying (in spare time over the past 3 weeks) to trace why my fuel pump won't run....

Have ruled out almost everything leading to it (new fuse, tested inertia switch, replaced MFRU, temporarily bypassed immobiliser) So I guess it's looking like a new fuel pump

Does anybody know if Gaz is actaully selling the uprated ones he mentioned a while back and how much they cost?

You have tried applying power direct to the pump haven't you?

If it won't run, pull it out and have a look see why, it's only a motor and some mechanical gubbins. If it's fecked you can then show us all how it works...

RICHARDHUMBLE wrote:You have tried applying power direct to the pump haven't you?

If it won't run, pull it out and have a look see why, it's only a motor and some mechanical gubbins. If it's fecked you can then show us all how it works...

TBH, not yet. The access panel over the top has seized solid (mild steel cap head bolts in ally, with no duralac, turnip farming fcukwits) and I can't be arsed grinding the heads off the bolts today. Already been swearing deep inside the wheelarch for a couple of hours.

Pretty sure you have to drop the tank to actually get the pump out though - although you can get access through the hatch....

Shug

Was talking to Gaz yesterday, not about pumps, but he may well be doing them by now.

Just left a message with his wife, and he will call me back in the morning.

tut

Shug

Gaz just called me and he can send you an uprated pump directly from home, good for upto 260hp, at the special tut price of £169 inclusive, which is over £80 less than the standard Lotus one.

You can call him on 01423 815868.

tut

ps you do have to drop the tank to change the pump, but seems that it is not a big deal.

tut

tut wrote:ps you do have to drop the tank to change the pump, but seems that it is not a big deal.

tut

You wouldn't say that if you'd done one.

Shug, give me a call if you want any advice on getting it out.

Dan@JPS

Dan,

If you know Shug you would know that he would never admit to need advice on "how to get it out"



Mac

Tut,

Is Gaz VAT registered? I am looking for a supplier of uprated pumps.

Cheers

Dan@JPS

I would not think so Dan. He is a pilot with KLM, but has been off work for two years now with an injury.

He designs the various Elise uprated parts, then has them made by a tooling company. He sells both through suppliers, and also directly from home.

I have his first uprated front wheel hub fitted, far stronger and lighter than the standard item and not much more expesive.

tut

Tut,

He called me today. Thanks for the info. I think his driveshafts may be of interest too.

Cheers

Dan@JPS

Shug,

If you have the bridging link for the immob installed you should be able to test most of the motor functionality from that same point.

Remove the link so motor is isolated.

Ignition off.

Identify pin 1 of the immob connector. It's important you find the right one. If you are not sure you cannot complete these tests.

Measure resistance from pin 1 of the immob to ground. It should be no more than 2.0 ohms and no less that 0.2 ohms (6A to 60A static). If you get zero, the motor is fused. If you get more than 2.0 ohms you're looking for an earthing problem or corroded connector most likely.

Assuming that's OK ...

With the link still removed and ignition off, jumper a thick wire from battery +ve to pin 1 of the immob. It will probably spark a bit when you hook it up, and the pump should run. Listen carefully for clicks and whirrs which might imply the pump is stuck.

Assuming the pump doesn't run ... Fd's ninja move is called for. Get a spare car battery. Connect it's +ve to the chassis. Make sure you don't connect the -ve to anything except what I tell you to. If you touch it to the wrong pin, you might cause some damage (remove MFRU to be safer)! With the immob link still removed and the ignition off, briefly touch a jump wire from the second battery -ve to pin 1 of the immob connector. This will make the pump run backwards, which might release whatever is jammed in it.

Best of luck.

Thanks for all the advice - will get to it now. Been off in Edinburgh for the last couple of days...

Righty-ho.

Resistance at pin 1 was about 1.8 - so well within limits.

Jumped a positive from the battery to pin 1 - pump ran like a dream (proven by disconnecting fuel line and pumping into jam jar)

So, have now tried getting the pump to fire whilst simultaneously bypassing all that I can (immobiliser and inertia switch)

Tested the fuse, by the way, and it's fine.

That's 2 different MFRUs that it's doing it with, so I'd be surprised if it was that....

Any more ideas?

Shug wrote:Righty-ho.


Any more ideas?

Cool, so you didn't need the -12V trick - just as well as that's last resort

OK, so the next question is whether the ECU is actually trying to run the fuel pump. First you need to reinstall the immob bypass connector (or the immob itself if you prefer).

Assuming the ECU works the MEMS (and presumably M3DK) will run the fuel pump briefly at power up. It does this by pulling pin 20 on the MEMS connector to ground. This engages the fuel pump relay in the MFRU and runs the pump.

So you should be able to unplug the M3DK, turn on the ignition, use a jumper wire to jump pin 20 to earth and that should cause a click from the MFRU and the fuel pump should run.

If the relay doesn't click then you have a wiring fault between the MEMS plug and the MFRU or between the MFRU and unfused ignition. I'm sure you have the wiring diagram - it shows all the MFRU pins.

If the relay clicks but the pump doesn't run then you have a wiring fault between the MFRU and the inertia switch or the MFRU and the fuel pump.

If the relay clicks and the fuel pump runs, there is no problem in the fuel pump circuit but rather a problem in the MEMS side of things ... let's get into that only if we need to!

Cheers,
Robin