help with data

[stonefish]

could anyone look at this run and comment..problem is seems to be running on 3 cylinders under load mountain chip and large exhaust fitted to 1995 s2....changed coil pack and was ok for about 3 days then same problem...coolant also leaking due to problem with head gasket recently changed...but pressure still building up in cooling system.and has leaked on new coil pack but all dry now..is there anything in elanscan data that shows a problem ???? thanks for help in advance

jeff

[lotuska]

Just had a quick look, you seem to be getting readings from the knock sensor, I think that this might mean that your ignition timing is incorrect.

Suggest you check the base timing and then retry before going any further.

[GeoffSmith]

Hello Jeff. Glad you got the interface working.

I've onlyu had a quick look but there is something strange about these results - you appear to be getting >300bhp (at less than 5000 RPM) from somewhere, which is obviously rather high.

I take it you weren't doing 130MPH (at 3000 RPM) either, so my first guess is that the VSS signal is wrong. I don't think it has a significant impact on the engine running so perhaps you're getting noisy signals at the ECU. I'll take another look over the weekend and I've asked ESM to take a look.

Geoff

PS did you reconnect the earth connection on the coil pack? A bad earth can give erroneous readings.

[ESM]

I agree with Geoff - the VSS looks very suspect. If you look at a graph of speed against RPM you see lines each with a slope reflecting of the gearing ratios. If you compare two similar cars the slopes should be roughly the same (unless someone fits monster truck tyres). I plotted the data above (blue) and a random log (black) and you can see that the slopes are around a factor of two different! The noise on the data looks higher too.

[GeoffSmith]

Thanks Alan.

[stonefish]

thanks geoff ans esm following advice have fited new vss (which comes out of a vauxhall calibra) and the data looks a bit more normal now...not going 130 mph on front garden...still missfiring under load...could this be the high knock count?? and also lack of power?? killamanjaro chip fitted with large exhaust...any ideas why missing under load??? ignition?? timing??? injectors??? only went for a quick spin arond the block...hope this may give you enough data..and thanks for your time.

jeff



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new vss.ecu.zip --------------------------------------------------------------------------------

[ESM]

The knock is certainly excessive. There are several possibles I'm afraid...

1) Timing - its a quick easy check so I'd tackle that first
2) Temperature sensors - they seem ok but in morning (so its cooled overnight) check CTS and MAT readings agree (before you start it up) and that they are consistent with the ambient temperature
3) Mixture - the oxygen sensor isn't showing any extreme issues in the log but it might have drifted in calibration giving you a lean mixture. You could unplug it and see if it runs any better (might put the ECU into limp home mode, which wouldn't be helpful though). Don't leave it unplugged for too long unless it proves the sensor is duff - oxygen sensors don't like it.
4) Sticky injector - perhaps one cylinder is getting mis-fuelled which will confuse the engine management so that none of the cylinders is fuelled correctly. Try some injector cleaner in the fuel.

That's all I can think of for now...

[stonefish]

hi esm,
followed your advice and disconected the oxygen sensor and the car ran ok without missfiring only got 0.5 boost though and check light came on...does this mean the oxygen sensor is knackered???
log attatched
jeff

[Gazza]

Jeff

You have PM

Gazza

[GeoffSmith]

Jeff,

Sorry but I must have overlooked this. Dapinky had a similar issue with terrible knocking on an SE and it turned out to be the base timing - check the Wiki. It is imperative that this is correct, because otherwise the engine is not operating anywhere near where the ECU thinks it is!

Geoff

[rip]

I should be scanning Rushing's Elan at the weekend and he suspects a faulty coil pack.
I seem to recall ESM (or possibly Geoff) correctly diagnosing this from a scan posted some time ago.

What signs should I be looking for please?

[max and andy]

When we where at Donington Enright gave us a paperclip and instructions in a little plastic bag. When we got home i looked for the connector that you touch the clip on. I thought the connector was the one coming off the ECU box. But it wasn't. At the time we had other problems to sort out. So i put it somewhere really safe as i new it was important. The trouble is i cant remember the safe place. We are taking the car to Lakeside Engineering in the morning. For a bit of work and a service. Will they need to know about the paperclip trick or will they already know? What does the clip do and where do you stick it? Andy

[DaveB]

Lakeside will know...

...while you are there, ask Max (not you!) or Tim to show you where the plug is and which holes to stick your clip into!

DaveB