Help! Car won't start

ABZ-Elise · Post by **ABZ-Elise** » Fri Feb 01, 2008 6:39 pm

Got a spark?

My fuel pump was knackered a while ago. It was priming but when I tried to start it it wasn't giving enough fuel. Changed it out for a second hand one I got off Tut, runs spot on now.

Andy · Post by **Andy** » Sat Feb 02, 2008 3:37 am

tut wrote:Andy

Have you phoned Ali yet?

tut

Not yet mate, will persevere for a while yet then phone him

Andy · Post by **Andy** » Sat Feb 02, 2008 2:19 pm

Update...

Tried to jump start the car this morning, it eventually did but cut out when we were disconnecting the leads. Not hugely surprised as it is a bit of a pig when its cold.

Voltage on the battery was 11v when switched off, swapped the battery over for a good one and the car turns over much better. The fuel pump is now not kicking in, although it was earlier. The ECU is also not powering up.

Checked all fuses, all seem fine and properly seated. Spoke to Ali and checked the multifunction relay and it doesn't seem to have water ingress.

So I now need to get the bottom of why the ECU won't switch on. I've tried the plugs and they all seem properly seated as something could have been disturbed taking the plastic cover on and off.

Any ideas anyone? Not wanting to pester Ali again just yet.

meatball · Post by **meatball** » Sat Feb 02, 2008 2:26 pm

1. get a branch off a tree....
2. right thats it.......you're getting a damn good thrashing!

....or just get Ali to fix it?

I admit defeat too easily!

BiggestNizzy · Post by **BiggestNizzy** » Sat Feb 02, 2008 2:30 pm

anyone nearby you can swop the multifunction relay with ? that will at least rule it out.
or
bad earth ?

Andy · Post by **Andy** » Sat Feb 02, 2008 2:32 pm

Would that be enough to stop the ECU powering up though?

Andy · Post by **Andy** » Sat Feb 02, 2008 2:34 pm

Just found this on Elise parts

This unit operates the Fuel Pump, the Starter Motor Solenoid, the ECU power and the Oxygen Sensor.

So that'll be a yes, going to get it out now and try again.

Rich H · Post by **Rich H** » Sat Feb 02, 2008 3:18 pm

Where's robin when you need him! ECU with no power = no fuel and no spark. Dunno why it would run then stop though....

The_Rossatron · Post by **The_Rossatron** » Sat Feb 02, 2008 3:39 pm

Turn it off and then on again!

Perhaps try disconnected the battery for a while then reconnect, if something has tripped this may reset it?

Andy · Post by **Andy** » Sat Feb 02, 2008 3:55 pm

I've got the multifunction relay out and warming on the radiator. Not sure it'll do any good but its worth a try

Tried to open it but it won't budge and I can't press all the tabs down at the same time.

Has anyone got a spare one?

robin · Post by **robin** » Sat Feb 02, 2008 4:03 pm

I'm here.

How do you know the ECU isn't powering up?

One thing you should realise is that the ECU doesn't power down when you switch off the ignition - rather it does so about 30s later. If you immediately switch ignition back on again, ECU is still powered and does not re-prime the fuel pump.

There are some fuses on the ECU panel - you should check both of those.

Sooo ...

You turn the ignition off, go get a cup of tea.

Then come back out, observe that the immob light is flashing.

Press the button on the key fob that you normally press. The light should clear.

Put the key in the ignition and turn to the run position (that's not the crank position - it's the one the key jumps back to when you release it on cranking).

You should hear the fuel pump prime.

Turn the key to crank position. You should obviously hear the engine crank.

Release the key so it returns to the run position.

Open the boot and identify the IACV (that's the black thing bolted to the side of the alloy intake plenum on the engine side, just downstream from the throttle itself). Now get someone to turn off the ignition and wait quietly for about 30 seconds. You should hear a distinct clunk from the MFRU and also a whirring from the IACV as the ECU resets it before powering down.

Now have the volunteer turn the key back to the run position - you should hear a clunk as the master relay engages, the fuel pump should prime (almost immediately after the clunk), the IACV will whirr again as the ECU puts it to the correct position.

If all this works and yet the engine won't start I suspect you have a failed cam or crank position sensor (or no fuel).

I note you have the PTP kit - there's a bunch of piggy back cabling going on there - might be worth splitting and checking all the loom connectors. They all come apart without violence - if you cannot work out how to split them, don't pull harder than you would on a xmas cracker 'cos you'll break something.

Let us know what you find.

Cheers,
Robin

robin · Post by **robin** » Sat Feb 02, 2008 4:05 pm

While the MFRU does fail sometimes, I would be surprised if yours had - it's easy to test if you have a multimeter and the patience to prod the terminals with some wires connected to the battery ... I'll write something up if you're willing to attempt it.

Cheers,
Robin

mac · Post by **mac** » Sat Feb 02, 2008 4:07 pm

Robin,

I think the newer PTP kits come with emeralds rather than the piggy back system that I have - don't know how they deal with the wiring situation though.

Mac

robin · Post by **robin** » Sat Feb 02, 2008 6:35 pm

Badly would be my guess - there is no good solution. The original S2 kit was good because it came with all the plugs to make everything work properly with the standard loom; the emerald solution is to hack off the standard loom plug and recrimp everything into the new MEMS-type plug - this is not impossible, but for a DIY install without a good crimping tool, you can make a total mess of it quite quickly.

Cheers,
Robin

mattg · Post by **mattg** » Sat Feb 02, 2008 7:03 pm

andy, is the engine getting compression ok when you try to start it?
if not, it could be a snapped cambelt.