Misfire again

[Martin R]

Im back with another problem on Lizs S2 Elan. Its a bit of a tale but here goes.
I posted awhile ago about it having a misfire on WOT always at about 3K RPM.
It went away after i had a bit of a tighten up on the exhaust system and all seemed well.

It came back with a vengance about 2 weeks ago.
I took the car to a MLOC rolling road day last weekend to try and get a few clues as to the cause.

It was put on the machine and the diagnosis was as follows.
All electrics, spark, coils OK.
The operator reckoned the car is massivly overfueling. So much so he could not get a accurate reading.

At this i decided to remove the Everest chip to rule this out. The problem was still about the same.

The car has now developed the mother of all misfires at start up and any revs and is virtually undrivable.
Removing the chip has actually made it worse.
Ive done the paper clip test and all is normal.
Ive also removed the plugs and they are correctly gapped but black with soot.

Any ideas as to a way forward TIA.

[Specky]

This sounds like the injector misfire fom Brazil, now where's that thread..

check the resistance...springs to mind

TTFN

[Specky]

Here it is

viewtopic.php?f=37&t=14086&

TTFN

[Martin R]

I will check the injector resistance at the weekend and report back

[Enright]

My money's on the Coolant Temp Sensor.

[Martin R]

My money's on the Coolant Temp Sensor.

Neil, thanks for that as well. Would this have shown up on the paper clip test though ?
Its flashing 12 on the test all the time.

Edit, i will check the resistance of the sensor against this

http://wikilec.9600.org/index.php/Coola ... _%28CTS%29

and report back.

[Paul.P]

The car sounds just like Gary's did when his CTS went !

[dapinky]

IIRC CTS faults DON'T show up on paperclip or elanscan (but the elanscan data can be interpreted to detect a fault).

I may be in a position to lend a CTS (if I can find my spare one in the garage) to see if it helps.

[Paul.P]

IIRC CTS faults DON'T show up on paperclip or elanscan (but the elanscan data can be interpreted to detect a fault).

Dave, please correct me if i'm wrong, but doesn't fault code 14 & 15 relate to coolant temperature being to low or high which would/could indicate faulty sensor

[dapinky]

Paul,

I'm far from an expert in these things, and you could well be right....

....I think what I meant to say is that there is no specific 'flag' for a CTS failure (or am i wrong with that one?), but that someone who knows what they're on about (Smiffy) can look at the results and have a good guess that the CTS is knackered......


....this is going from memory of previous threads where the gurus threw in the correct information, (and the phone calls i made when mine went tits up!!!!)

[GeoffSmith]

CTS - Pound to a pinch of s**t.

It won't set a flag unless it reads open or closed circuit (absolute zero or hotter than the sun) but if it's reading a consistently low temperature, then the mixture will be highly enriched. An ElanScan run will confirm.

[Martin R]

Todays really dim question Ive pulled the plug off the top of the CTS. As it only has the one connection i presume you read the resistance between that and the sensor body ? Is this correct ? If it is the CTS is open circuit. More thoughts please.

[Enright]

Wrong one. That will be the feed to the temperature gauge.
The CTS is nicely buried (in the same lump of aluminium) much closer to the head underneath the CAS, and it definitely has 2 terminals.

[Martin R]

I should not be let out on my own at times.

[Martin R]

6270 Ohms hmm any thoughts on this ?

[GeoffSmith]

Looks about right - try warming it.

[Martin R]

With the car warmed up to just under the normal running temp ie 1/4 on the temp guage it reads 295 ohms. It took a bit of warming up as its missing very badly.

[Martin R]

The readings would suggest to me the CTS is working OK. Do you agree ? Also would an Elan scan on the car throw anymore light on the problem ? Im seriously scratching my head for the next course of action.

[Specky]

Did you check the injectors?

TTFN

[Martin R]

The injectors appear to be reading Ok. For future reference.

1 - 1.7 Ohms
2 - 1.8 Ohms
3 - 1.7 Ohms
4 - 1.7 Ohms