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And it goes on
dave - 20/7/10 at 10:26 PM

Got the car assembled again tonight started it up and low n behold still the same problem as before. Idle is very rough black smoke and the odd flame from exhaust pipe. Checked all the leads by fitting a spark plug and turning the engine over all ok. I did notice that plug 4 is dry and new where as the other 3 are a bit sooty. I should add the engine is MX5 1.6
PLease help.

jollygreengiant - 20/7/10 at 10:28 PM

have you checked the valve clearances on the offending cylinder?

rayward - 20/7/10 at 10:36 PM

black smoke is too much fuel, are you using the original MX-5 injectors/ECU/Fuel Pump ?

have you done a compression Test ?

Ray

dave - 20/7/10 at 10:40 PM

Yes using all of the above but haven't done a comp test yet.

chris mason - 21/7/10 at 06:27 AM

It sounds like an issue i come across a month or so ago, on a car at Road Runner Racing.
Did you used Sheilded wire for the Airflow meter? if not the interference will be your problem.
Replace the wire which should be sheilded and it will be fine.

The interference causes the car to overfuel in a big way, loads of black smoke and runs like a pig.

If you need to know which wire it is let me know and dig out the wiring info i'd produced.

Only needs to be earthed at the ecu end.

Not sure how the dry injector 4 plays in this though.

Chris

[Edited on 21/7/10 by chris mason]

Bumble - 21/7/10 at 06:38 AM

Hi Dave,
Very similar issues to that which I had a week or so ago (diff engine setup though). See previous thread links.
HTH,
Matt
http://www.locostbuilders.co.uk/viewthread.php?tid=139241

http://www.locostbuilders.co.uk/viewthread.php?tid=139356

ed1801 - 21/7/10 at 07:08 AM

Is your temperature sensor connected and working, otherwise it thinks it is very cold and fuels accordingly.

l0rd - 21/7/10 at 08:31 AM

quote:
Originally posted by ed1801
Is your temperature sensor connected and working, otherwise it thinks it is very cold and fuels accordingly.


+1

MX5 had that problem. Another problem when i was taking the loom apart from one was that loads of cables were shot at the terminals.

clairetoo - 21/7/10 at 06:21 PM

Have you tried disconnecting the injector on number four ? It sounds very much like a bad connection , or stuck injector - at tickover from cold the plugs will be a bit black and sooty anyways .

dave - 21/7/10 at 10:24 PM

Thanks for the replies still have the problem, i was advised to use a LED to check if power is going to the injectors (everytime the injector gets power from the ecu the led should light) well it does on 1 & 2 but stops after 5 seconds on 3 & 4. Could be a faulty ecu