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New Build - Engine doesn't start


cb4798

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Sometimes just a second pair of eyes is needed. Where abouts are you? There might be a local member nearby who can take a look.

Agreed. This is a staggeringly powerful approach to finding and fixing faults. See also medicine.

Jonathan

PS: Always worth testing those voltages at rest and "cranking"...

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Being a 140, you don't need the lead, hence not many owners have one, but it's does tell you exactly what's going on, so if you have access to one it's the perfect fault finding tool.  It's a MBE CAN USB lead, from SBD Motorsport, which is no cheap at £117, the software is just a download.   A standard OBD lead does not read the information from the MBE ECU, so your a bit stuck to the source of this lead.   Finally the lead could be used to map your MBE ECU but the Caterham supplied ECU is locked down, only a few know the codes needed to bypass theses locks. 

Hope this helps

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Thanks ChrisC - Looks like SBD are away until the 2nd so I will investigate that if the other suggestions fail. I have some time off tomorrow so will try the above first. If that fails, i'll connect SBD

RS2000, I took out a spark lead, connected it to another spark plug and touched it against the casing while turning the engine over. I couldn't see it sparking.

 

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I know you said you can see oil pressure registering, but when you put the key to position 2 in the ignition, do the needles on the speedo and Rev gauge "do a little dance"?

I ask as:

Whilst on the Isle of Man 2013 tour I suffered a breakdown where by the engine just stopped and would not restart.  Whilst a lot of fellow 7 people had the bonnet off and clambered over (and under) the car, I noticed that when we put the key in the ignition a turned it to position 2, the needles on the speedo and Rev guage weren't doing their customary shimmy (that on my Sigma 150) they have always done or making the noise they make whilst the needle dance is occurring.

A call to Kevin at Caterham South revealed that the ECU has to be able to "see" some of the instruments (he didn't elaborate as to which ones) and if it can't see them, it won't send a signal to the spark plugs to fire.

Once the fuse was replaced and the cause of the fuse blowing was found (failed wheel speed sensor) all was well again.

I appreciate the above is probably not the cause or cure, but I thought I'd post it for just in case!

Mike

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Do you have an earth lead from the engine to the engine mount? - if so check the tightness , if you have a second earth to the bulkhead by the battery, check that too.

Also, try starting by jump starting it from a tin top. You have plenty of fuel by my experience.

good luck

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Hi All,

I spent a couple of hours going over the car, pulled off the crank sensor and reattached it, added another wire from the battery to an earth point on the bulk head, checked under the dash for any loose wires, pulled out all the wiring that I tucked away to get to the main ecu plug and reconnected it, pulled off the inertia switch and reconnected it. No joy.

Mike, They flicker very slightly, but not much more than that.

I'm in the Kenley/Caterham area so if anyone is local and thinks they might be able to help or has a ecu lead, it'll be appreciated.

Chris

 

 

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Hi Chris,

I had trouble starting my Sigma 140. It would sound like it was trying to start but would never actually keep going when I let go of the starter. I found that if I gave it just a little throttle then it would start. It was a balancing act as too little or too much and it wouldn't start. Once started it ran pretty rough.

The problem was eventually sorted by Caterham doing a remap when it went for its final inspection.

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Hi Chris

The following is generic as I don't have any experience of the Sigma but lots with an old 16 valve Vx with a modern MBE 9A4 ECU, which I believe is what you have in the Sigma.  Yours may not be badged 9A4 but it's probably very similar electronically.  You can't get at the map as Caterham have locked all but authorised persons out, but you should be able to read what's going on sufficiently to do a bit of diagnosis, using a CAN adapter and Easimap running on a PC.

From your first post It sounds as though you have fuel pressure.  The pump will run for about 2 seconds after ignition switch on and then cut out and run again when you crank it.  This is  safety measure so that if you stall the engine in an accident, fuel doesn't continue to flow. 

When first fuelled, or after a long time standing idle, the fuel can take a while to come through, although you must have primed the system by now!  Have you pulled out any of the plugs to see if they're wet?  You may have fuel pressure but if the injectors aren't being driven by the ECU, it won't start.  As said above, I don't know the Sigma setup but MBE Easimap 6, with the right user permissions, has an injector test mode which enables you to run the injectors so you can hear whether they're opening (they 'tick').

You don't appear to have a spark but sometimes this can be difficult to see.  Can you borrow a timing light, either the in-line or clamp-on (Snap-On) type which will show whether you have a spark on each plug when you crank the engine.

As the pump's running, you would appear to have power to the ECU so I would check positively for a spark and injector operation.  If neither are working it would indicate either a wiring or crank sensor fault or even a faulty ECU.  I would pay serious attention to all the earths, e.g. battery to chassis, chassis to engine block, and all the 'star' points where numbers of black wires are gathered together.  Make sure that they're clear of any paint.

Check also that all relevant relays are properly seated.  It's possible that one of the relay socket female spade connectors has been pushed back into it's housing and isn't making a connection.

Does your wiring loom have a connector or unterminated wires that come from the ECU connector to attach a CAN adapter and PC?  If not you either need an in-line adapter for the ECU connector or break into the loom ECU plug and attach a couple of wires.  Not hard to do but considerable care needed?

Hopefully you've fixed it already but, if not, try some of the above and let us know what you find.

Paul

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Can you borrow a timing light, either the in-line or clamp-on (Snap-On) type which will show whether you have a spark on each plug when you crank the engine.

I didn't know that clamp-on testers existed. Difficulty in testing the HT side has sparked a lot of discussions recently, and there may be others who are currently suffering. 

What's the cheapest that that you would consider buying... and are there kind Members who would lend one?

Thanks

Jonathan

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Morning Jonathan

I bought a SnapOn on eBay for about £100 and it's been invaluable, mostly on older classics rather than 7.  Crock leads to the battery and a clamp that clips around an HT lead, usually #1 plug for timing purposes but can be used to test each individually.  Push buttons to adjust lamp timing to align the timing marks to tdc, and read off advance/retard from digital display.  Simples.  Similar to http://www.ebay.co.uk/itm/SNAP-ON-TIMING-GUN-LIGHT-MT1261A-/161523658371?pt=LH_DefaultDomain_3&hash=item259b8f6e83 this.

Also gives revs although this needs to be interpreted with wasted spark coils.

I also have an in-line strobe light that I bought about 50 years ago *laugh* but it's not much good for connecting to plugs buried 4" in the head.

I'm happy to take it where needed, so long as it's not too far.  Prefer not to lend - been there, done that, lost stuff or had broken.

Paul

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@cb4798 - I don't know where you are but I've got a Gunson Advance Xenon Timing Light that's of the clip-on variety, picks up the current pulse down the HT cable when simply clipped around it. Nothing too fancy but will certainly tell you if you're sparking.

I only used it once; when my spare engine was immitating an artillery canon and throwing fireballs out of it's exhaust when I first tried to start it, it showed me the timing was so far out that I realised the coil pack connections were reversed!

It's not doing a lot of good sitting on my shelf. You're welcome to borrow it if you want. You may want to update the location in your profile as at the moment nobody has a clue whether you're close enough to help *scratchchin*

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From Dave Andrews (might help)

What to check if you have no Spark at the Plugs

Although there are many sensors that can fail, there are very few that will stop the spark, most will simply cause incorrect adjustments to the fuelling or timing.

If you are getting no spark then either you have a very low battery, a wiring fault, a faulty CPS or a faulty ECU .

 

A faulty TPS or MAP sensor will not stop the spark, in fact the ECU will still fire the coils with no TPS connected or with a bad MAP signal.

 

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Chris,
 
Although I have offered nothing constructive to assist, your plight has the whole families concern.  My wife constantly asks how this is going and I have to advise the updates are getting thin (your thread rates above 'Neighbours' at present).  Don't let it beat you Chris, take heart, this has got to have a happy ending eventually.
 
If only for the sake of my marriage, what's the latest?
 
Rgds, Anxious of Bexleyheath
 

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Never mind that, I've got £10 riding on "Crank Position Sensor" at 7-2 with Ladbrokes, and £20 on "dodgy battery" at evens with Betfred.

Couldn't you find an accumulator?

I can't stand the tension much more.

Very good, but it may need to be higher...

:-)

Jonathan

PS: Is this a convenient hook for ceiiinosssttuv?

Jonathan

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