were to start running rough

[harvey]

Hi to all this is only my second post so please be gentle, I am not a techie but I am enthusiastic, After recently purchasing my elan se turbo, I went to the yorkshire dales last week and drove for about 500 fantastic miles, the car did not miss a beat and was great fun.

On my return it developed a misfire at about 4-5000 rpm, so i went to investigate the next day and it had dissapeared, however it later appeared again but this time the engine was running really rough, I have readf many threads, inclding wastegate sticking, ignition coils etc and dont really know were to start, I have managed to do the paperclip test and that gave a reading consistantly of twelve.
Is there any way of testing the coil pack? I did look at the wastegate wiggle but backed down when i realised with my chunky great fingers i would stuggle to remove and replace the bottom bolt, is it possible to free the wastegate by moving the actuater rod while in situ ie with grips or something? any help where to strat will be greatly appreciated as I intend to keep this car a s a summer Toy for the foreseable future, and feel if I get to know the mechanics of it myself this will save me having to fork out large amounts of money to local garages who may or may not know what they aare working on.
many thanks
Harvey

[madbilly]

Hi Harvey,
If it's misfiring it's likely to be ignition related rather than wastegate. Spare coils, baseplates, HT leads and sparkplugs are all available but rather than replacing them all it's better to test things and only replace if they appear faulty, otherwise you can end up spending lots of money and still having the problem. The engine management manual (available for download on this website, just ask for the login details on the literature part of the forum) describes the ways you can test various things.

I'd start with the spark plugs - check the gap and see if they spark.
Then check the HT leads (with the engine running, if you hold them and you feel a shock then they need replacing, but this is not a good thing to do if you've got a dodgy heart).
Measure the coil resistances (one circuit should be a few ohms, the other several thousand, do a forum search for details).
Test the EST circuit (see the manual).
Remove the CAS assembly (mark where it lines up with the adjustment bracket first so you can set the timing back to how it was when you replace it) and inspect the sensors for dirt etc. Also check the locating pin in the shaft of the sensor to make sure it's central (again do a search for details, pics, etc).

I hope that helps you get started. I had a very similar problem and I thought I'd cured it but it has occassionally come back recently, though not seriously. I'm still fault-finding!

Cheers,
Will

[harvey]

Thanks Will, Your information was exactly what i wanted to hear from a fellow owner who has had similar problems, however the misfire now seems to have settled down and i am back to the original fault which is,,, Starts and runs smoothly, take her down the road and start to increase the revs up to about 4000 rpm the boost goes up to around .5 then as soon as i increase the revs it misfires and will not boost any more, this is a little intermittant but as soon as i drop the revs it behaves normally, could this be a Turbo fault? or wastegate, I have checked the plugs so far and will probably replace the leads next as they are probably still the original ones.

Harvey

[madbilly]

I think what you're describing may be boost creep leading to overboost and fuel cut but I (don't think) I've ever experienced that so can't really give you any guidance. Getting the wastegate moving freely is a good start, but after that it may depend on whether your car's got any mods (exhaust, chip are the main culprits I think) as to what else needs to be checked/adjusted.

I'm out of my depth here, anyone else got any suggestions?

[harvey]

I am going to check the wastegate is free next and then take it from there, I am pretty sure the car is standard as the last owner had the car for ten years and I have a mountain of history with it, will make a post when done, thank you for your support.
Harvey

[superbad]

Sounds like coils, but check the timing too. Depending on how weak it is, a weak spark can cause a misfire (rough running), or just poor combustion at high boost/revs. Doesn't sound like you have a sticking wastegate or overboost. In my experience this car is very sensitive to ignition system issues. Personally I would replace the plugs, wires, and coils unless you know they have been done recently. Even changing the plug gap from 1mm to 0.8mm has a very noticeable effect on the way the car runs.

[harvey]

great news finally got round to changing the coils today and hey presto she is running sweeeet now, thanks for all your help happy new year to everyone.