SC chimaera non starter after break down

SC chimaera non starter after break down

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Discussion

nigegas

Original Poster:

284 posts

159 months

Sunday 22nd May 2016
quotequote all
Broke down last Sunday as I was heading down to TVR south west open day first time in 3 years
Pulled away from a roundabout heading towards m32 car just cut out tried to restart turned over fine
But would not fire nothing
The car is a 4 ltr SC and it's running a Canems ecu, coil packs ect
Checked so far
Fuel pump primes ok
Fuel pipe of and fuel is there when primed and cranking
Checked ecu status red light on with ignition on turns green when cranking
Compression test done seems ok
There is a spark at the plugs but it doesn't look great to me ?
Battery checked and ok
Checked all pipes are on SC
Plugs were a bit black looking
Any advice where to check next guys
Nige.

Matthew Poxon

5,329 posts

174 months

Sunday 22nd May 2016
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Sounds like you have covered the basics, next I would get a laptop with the ECU software on and connect to see if there are any anomalies there.

phazed

21,844 posts

205 months

Sunday 22nd May 2016
quotequote all
Spark always looked weak. If you can see a spark at all then it is more than likely okay .

KateV8

448 posts

153 months

Sunday 22nd May 2016
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I had Canems once and it let me down with a failed crank sensor, symptoms as you describe. Use the software to look for a lack of output.

QBee

21,009 posts

145 months

Sunday 22nd May 2016
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KateV8 said:
I had Canems once and it let me down with a failed crank sensor, symptoms as you describe. Use the software to look for a lack of output.
I had this on a Saab, the evening before flying off on holiday at 6am. Luckily I was too lazy to walk 800 yards to the newsagents. Car failed outside the shop. Symptoms exactly as described. Sensor was diagnosed by the Saab computer, changed and problem sorted.

Hansoplast

570 posts

161 months

Monday 23rd May 2016
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The same with my Mercedes SLK 320.
Feeler gets hot and cold many times so wiring and sealing becomes brittle and breaks.

Easy to fix.
Good luck.

Hans

QBee

21,009 posts

145 months

Monday 23rd May 2016
quotequote all
Thinking about it, my Merc ML had the same crank sensor failure, with the same result, Christmas 2014. Started off by not starting when hot (leave it an hour, then it worked), and then failed totally.
My daily Audi was also dead for those two weeks with electrical problems.
So my only reliable, working car for the whole of that Christmas was.......yes, you guessed, my TVR!!

Pupp

12,244 posts

273 months

Monday 23rd May 2016
quotequote all
Doesn't the green light on the ECU with engine indicate the crank sensor is reading ok? Does on an Emerald...

I'd treat it to some new plugs

nigegas

Original Poster:

284 posts

159 months

Monday 23rd May 2016
quotequote all
Pupp said:
Doesn't the green light on the ECU with engine indicate the crank sensor is reading ok? Does on an Emerald...

I'd treat it to some new plugs
Yes I get a red light on with ignition
And a green light when cranking from the
ECU
But nothing all very strange but I will try
A new set of plugs there on the way
Nige.

ChimpOnGas

9,637 posts

180 months

Monday 23rd May 2016
quotequote all
The front panel on all Canems ECUs are fitted with a twin colour status LED, this can be useful for a variety of diagnostic tasks. When power is applied to the ECU (ignition on), the LED should turn red. This indicates that the ECU has a voltage supply and it is simply waiting for a crank sensor signal.

When the engine is turned over on the starter motor, the LED should turn green. A green light indicates that the ECU has detected a crank sensor signal and has successfully located top dead centre of the engine.

It is expected that the LED may oscillate occasionally between red and green whilst cranking, but it is
important that this is not the case once the engine is running. A status LED which flickers to red when the engine is running indicates that the ECU has lost the position of TDC and is therefore unable to inject fuel or fire the ignition.

A flickering status LED can indicate a defective crank sensor arrangement, electrical interference or poor earth connections to the ECU itself... so you should check this carefully.

Remember it doesn't matter if its on the most sophisticated engine management system in the world or the most basic of carburetors, the engine is still just an engine, and engines naturally only want to do one thing, run!

As long as you have fuel of a mixture that's not insanely rich or lean, and as long as you have a spark occurring reasonably close to when it should in the cycle.... your engine will run!

Its back to basics... do you have fuel & do you have spark?

And in your case.... does the red light on the ECU turn green when you crank the engine?

Good luck with it thumbup

nigegas

Original Poster:

284 posts

159 months

Monday 23rd May 2016
quotequote all
ChimpOnGas said:
The front panel on all Canems ECUs are fitted with a twin colour status LED, this can be useful for a variety of diagnostic tasks. When power is applied to the ECU (ignition on), the LED should turn red. This indicates that the ECU has a voltage supply and it is simply waiting for a crank sensor signal.

When the engine is turned over on the starter motor, the LED should turn green. A green light indicates that the ECU has detected a crank sensor signal and has successfully located top dead centre of the engine.

It is expected that the LED may oscillate occasionally between red and green whilst cranking, but it is
important that this is not the case once the engine is running. A status LED which flickers to red when the engine is running indicates that the ECU has lost the position of TDC and is therefore unable to inject fuel or fire the ignition.

A flickering status LED can indicate a defective crank sensor arrangement, electrical interference or poor earth connections to the ECU itself... so you should check this carefully.

Remember it doesn't matter if its on the most sophisticated engine management system in the world or the most basic of carburetors, the engine is still just an engine, and engines naturally only want to do one thing, run!

As long as you have fuel of a mixture that's not insanely rich or lean, and as long as you have a spark occurring reasonably close to when it should in the cycle.... your engine will run!

Its back to basics... do you have fuel & do you have spark?

And in your case.... does the red light on the ECU turn green when you crank the engine?

Good luck with it thumbup
Hi Dave
Yes all the above u have mentioned seem to be working spark at plugs fuel to the rail and a red light on and a solid green
Light when cranking I think the only thing I can check now is fuel pressure at the fuel rail to eliminate the fuel regulator
And new plugs
Nige.

ChimpOnGas

9,637 posts

180 months

Monday 23rd May 2016
quotequote all
nigegas said:
Hi Dave
Yes all the above u have mentioned seem to be working spark at plugs fuel to the rail and a red light on and a solid green
Light when cranking I think the only thing I can check now is fuel pressure at the fuel rail to eliminate the fuel regulator
And new plugs
Nige.
Ok Nige, personally I can't see all 8 spark plugs giving out at the same time.

And before suspecting the FPR keep in mind hearing the 3 second priming pulse of the fuel pump when you first turn the key on (before cranking), is not any kind of proof the fuel pump is actually running when you're cranking.

And when cranking there's that much noise you'll never hear the fuel pump. Are you 100% sure the pump is running when your actually trying to start the car?

Pupp

12,244 posts

273 months

Monday 23rd May 2016
quotequote all
According to the OP, the car was running but stopped and would not re-start - the plugs are black apparently (why will need to be ascertained).

If the fuel pump primes, then there will be residual pressure in the rail even if the pump is not running after the priming phase. If the injectors are firing (well worth checking the common +ve feed to both banks back to the relay in the footwell), then if there is an adequate spark the engine will at least fire (even if not continue to run) on being cranked. The fact it is doing nothing indicates to me the fouling on the plugs is defeating the spark hence the suggestion of replacing them...

What plugs are they and how was the car being driven? As an SC car, it may have 8s in it; they may well have cold fouled if the car has been toodled around for too long (etc)

drlloyd

145 posts

194 months

Tuesday 24th May 2016
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+1 for replacing the spark plugs. We have seen this type of problem on more than 1 occasion - with fouled spark plugs preventing a V8 engine from starting, hard to believe but true. smile