i gotta lsv (hense the name eghatchlsv) with a b16head... now it starts up and runs good and i burnt out my 1st set of spark plugs and thought ok maybe it was bad gas burnin them so i filled up with a fresh tank and ran thru it and filled up again and ran thru it... and changed the plugs so this way i have fresh gas and new plugs... but they still keep burnin out... not sure why but im thinkin my timing could be off a little bit or my air:fuel is off could i b rite???? i wanna kno all the possible things it could be, so is there anything else that could be causing this to happen...

o and the plugs got like a chalky black burnt look to it........

 

Your description is contradictory. I think you have confused 'burnin out' with the plugs looking black, but 'burning out' gives more the impression (to people who know something about engines) that the pugs would have melted electrodes and / or overheated porcelain insulators. This is typically characterised by the insulator appearing very white, and or blistered or otherwise not 'normal', in fact the opposite of appearing black (normal plugs should look light tan to darker brown, or perhaps some shade of grey, depending on the fuel being used).

Black "chalky" looking plugs (would more commonly be describes as being 'sooty') is a sign that the engine may be running very rich (i.e. too much fuel). I assume the 'out' part of "burning out" means that they have stopped sparking properly and the engine won't run or runs roughly, which is caused by the carbon build up on the plugs being an easier path to ground for the electric pulse than jumping the gap is (i.e. instead of jumping the plug gap to earth and making a spark the electricity 'escapes' to earth via the carbon build up on the outside of the insulator and doesn't make a spark, a kind of short circuit).

Another cause of spark plug 'fouling' (which is what we're discussing with the carbon build up) is the plugs being too 'cold', meaning that those particular plugs may have the wrong 'heat range' for your engine and physically run too cold in operation, and any carbon cannot burn off and builds up. In this case you would need plugs of a hotter heat range.

You have to be careful though, if you go to a plug that is too hot in range it will run at a physically higher temperature in operation and can cause problems that can damage your engine (i.e. 'pre-ignition' of the air fuel mix due to the plug glowing red hot).

Causes of rich running are going te be either that the air filter is blocked up with crap, or that the ECU is telling the injectors to inject too much fuel. If the filter is reasonably clean then you need to find someone who can diagnose and fix the cause of the overly rich injection. This could be some faulty sensor, the engine running cold and thus in 'start up' mode with a rich mixture (you do have an operational thermostat fitted don't you?), or it could be that the ECU needs reprogramming to suit your modified engine set up (a good idea in any case with any substantial modification from stock).

A change to a hotter plug may fix the symptom of the problem, i.e. allow the plugs to remain clean and sparking, but if the heat range of the plugs is actually correct and the real problem is the injection, then fitting hotter plugs may be a little dangerous to your engines health (i.e. risk pre-ignition).

Modified by johnlear at 3:15 AM 1/31/2008


Modified by johnlear at 3:19 AM 1/31/2008