Startup issues - Dodgy Immobiliser?

[Ben Fung]

The first attempt to start the car has been a little disappointing.

 

I've cranked for oil pressure and it register barely 1 bar, checking the dry sump tank the oil has moved from the engine and into the tank ok, there were also leaks from the inbound and outbound hoses on the dry sump so I'm pretty sure there's oil flowing in the system. So tightened the hoses, reconnected and reset the inertia switch then tried to start it up. Everything seems ok so far, unless I should be registering more pressure than this?

 

In key position one all seems ok.

 

In key position two, the immobiliser (Sterling Excel) light flashes rapidly then goes out when the fob is brought close to the dongle by the key barrel although the instruction manual says it should turn a solid red. The fuel then pump primes and MFRU clicks despite the LED switching off.

 

Now here's where things get funky. The dongle seems to heat up quite rapidly (too hot to hold but no fuses are blowing) and while the engine cranks it's just not firing up. Removing a plug we checked for a spark - no love there and also not smelling petrol from the cylinder/exhaust. So it looks like I'm not getting fuel or a spark. The immobiliser reciever doesn't cool down until keys are removed, it actually could be getting hotter but I didn't want to leave it in and chance it.

 

To top this off, when trying to start it up the oil pressure gauge whips up past 8 bar for a second or two then drops back to zero for a few (maybe 5 sec) seconds before whipping off the scale again for a couple of seconds repeating this bouncing oil reading.

 

So looks like an immobiliser issue, any ideas on what might be causing it and a solution for the problem?

 

Also is the erratic oil pressure an issue or am I safe in assuming it's just happening while trying to fire up?

 

Edited to mention that the inertia switch is not being tripped when trying to start the engine up.

 

Edited by - Ben Fung on 24 Feb 2009 09:39:27

[shn7]

I have no knowledge of that type of immobiliser but the oil pressure swinging to full scale indicates it's getting a full 12v across it suggesting a sensor or wiring fault. This may/may not be associated with the dongle getting hot.

 

What car is this on? New Sigma Seven? That may help someone else offer more detailed advice.

 

Steve.

Sussex (West) AR

Not forgetting Percy the Polar Bear

[Ben Fung]

Cheers for the reply - we're looking at a Duratec R400.

 

The oil pressure sender arrived already plugged in, are the connectors for the sender specific on polarity?

 

I guess a manual pressure gauge might be handy to check whats really happening but that's not a toy tool I own. Anyone able to help out and lend me one?

[Mike Molloy]

Don't exactly know what you mean by an immobiliser "dongle" but no way should any low current electronic unit be getting too hot to touch!

Something is donald ducked with your wiring and the immob is probably toast by now as well.

 

Aah, OK. Quick google reveals it is a Toad Powerkey aftermarket immobiliser. Cuts two circuits apparently, and it won't be doing anything clever like the K-Series MEMS code.

Did you wire this in yourself? If so, which circuits have you broken? Fuel pump and crank enable?

 

Edited by - Mike Molloy on 24 Feb 2009 15:23:36

[Ben Fung]

When I typed dongle I meant the transponder reciever (it's like an RFID type setup) as you can tell I'm not too clued up on the terminology of it.

 

A mate suggested that the immobiliser may have been wired in incorrectly with the wire to the ignition circuit and the wire to the transponder being swapped around resulting in a few amps being pushed through the poor transponder reciever and a few mA through the ignition circuit.

 

Does this sound plausible?

 

I'm holding out (poss vain) hope because it still detects the key fob when it's brought near the transponder reciever with all the clicking of MFRU and change of LED status (albeit to off).

 

Called CC but haven't had much luck getting through today

[Mike Molloy]

Mmmm. Diagnosing aftermarket security systems is a nightmare. Given that they are designed to be secure they make it as difficult as possible! ECU is in an armoured box and the wiring is all black (and loomed in as well as possible).

Of course if it is an amateur install then it is a lot easier to trace!

 

If the immob and wiring loom are all supplied intact by Caterham, then I suggest you get them to explain how it works before switching on again.

I'll be very surprised if you haven't cooked it! ☹️

[myothercarsa2cv]

Yep, CC are busy today trying to figure out what I do to the car to make it want to break all the time!!!

Pop them an email, try direct to one of the aftersales team or technical bods. They may be able to help, and are always very helpful when I've emailed them. They're a good bunch

 

John

_________________________

 

Bugsy: '82 2cv6 (Back on the road!!! 😬)

Talloulah: '08 1.6K Classic (Grubby )

[Ben Fung]

Mike sounds like you were right. The immobiliser was supplied intact by Caterham so I've no idea how it was setup - I believe it was a vendor install so possibly not even CC installed it.

 

Having spoke to CC they seem perplexed about the behaviour too and think it may be a back to base replacement of the immobiliser. This means I won't get the joy of hearing it come to life for the first time after my efforts building the thing.

 

So unless I want to trailer it back and forth, just to hear it running in my own garage for jollies, the first time I'm likely to see it running is probably post SVA.

 

Absolutely gutted!