Engine light, no fault code

[Ted]

Hi,

I'm having a problem for a while. Sometimes, after starting the engine, the engine light stays on and the iddle speed is high (between 1500 and 2000rpm).
And it will light off after few minuts, and iddle goes to 1000rpm. It does this when the engine is cool and when it's hot.
But I have no fault code when doing the paper clip test.
I fought it could be electric problem, but I've change coils (they were dead), spark leads (they were old) and sparks, and it's the same.
When the engine light is on, the engine speed is not limited to 4000rpm, but it seems that the engine is running strangly.
Does anyone have an idea?
I use SP98 gas. The exhaust smell strong gas, even when the engine is hot. It seems that it's running too rich. Would SP95 be better?

[Fredjohn]

Hi Ted

My engine runs fast when started from cold, but then calms down to c900/1000rpm. This is I believe relatively normal for ECU controlled auto choke engines: it allows the engine to warm up without stalling.

But the red light should go out once started, as seems to happen to yours.

I don't think you actually have a problem: if the red light goes out and revs drop to tickover speed (900/1000rpm) then that is OK.

Just check the tightness of your fan belt: it may be slipping a bit on start up.

I use SP95 not SP98 fuel: I don't believe there is any need to use SP98: it was designed as an "unleaded engine" from the beginning. Save your money!

Fredjohn

[dapinky]

Hi Ted,

Just a thought here, but Iwould suspect the Coolant Temperature Sensor - there are a few things you can try to see if it helps the diagnosis....

....Firstly, when the tickover is high, put the car into 'service mode' - it should tick over at 925rpm as there are no engine sensors affecting things at that stage.

If it drops, then it indicates that one of the sensors is causing the issue, if it doesn't, then it is possibly a fuelling issue.

If you have 'elanscan' all of this is a bit easier, but it can be done with a paperclip!

Check the wires to the CTS - try unplugging it and see if the idle speed changes (NOT in service mode) - if all of that happens, then the sensor is likely to be suspect, and a replacement is the best course of action - but don't buy a Lotus one (well, not an Elan one anyway! - the Esprit one is identical but half the price, and there are quite a few others out there which are identical, at about a tenner - or less)

[Ted]

Thanks,
The CTS had been changed for months. I will try the "service mode".
I have elanscan, I will try to make a scan with the problem.
One thing strange is that when I have the problem, when I press the throttel the engine speed quickly slow down before increasing, like misfire

[GeoffSmith]

Ted, you can read the stored error codes with ElanScan.

It sounds like it might be an air leak somewhere. I had a similar problem and it turned out to be the vacuum reservoir.

[Ted]

I'm really desapointed.
I'm having the problem each time I restart car after à short stop.
I tried elanscan, but my computer couldn't log. And when the engine light desappear elanscan logs. Elanscan and paperclip don't give me fault code.
I don't know what to do. Could it be the ecu that would be dead? I will Have my injectors cleaned, and FPR changed, but I don't think it will change anythink.
I'm upset with that car....