Re: [DML] Back on track! (update)

[srubano@xxxx]

The Plugs, Cap, rotor and wires are all new. The heads were rebuilt 
along with rebuilding the engine myself. I guess the only thing I can 
think of at this point is that the Valve lash is off on one of the 
valves....I'll have to recheck those (which I was about to do 
actually). The oil is new and so are the tensioners and timing 
chains. Oh and to answer your question it backfires out the tail 
pipe...but not a "bang" more of a hesitation "popping" noise. It 
sounds like it's happening on one cylinder...looks like it's time to 
break out the old leak down tester to test the compression of each 
cylinder. Thanks.

Steve

--- In dmcnews@xxxx, Heydudetoo@xxxx wrote:
> Steve;
> When your engine backfires, is it through the intake or out the 
tail pipe? 
> An engine that back fires has either an intake or an exhaust 
valve 
> open when the gas mixture for that cylinder explores. Carbon 
buildup in the 
> engine can stay hot enough to light off gas mixer at the wrong time 
or the 
> plug can receive fire at the wrong time. Valves must both (intake 
& exhaust) 
> be closed tight when the mixture explores or you will get a 
backfire. 
> The most likely thing is carbon in a plug, fire jumping 
inside the 
> rotor cap,( bad plug wires cause this) or a weak / broken valve 
spring.
> Pull a couple of plugs, are they carboned up? (black build 
up around 
> the tip) If so, put in 6 new ones of the correct rating. The wrong 
heat 
> range lets them run to cool to burn off the carbon and you get 
build up and 
> back fires.
> No carbon on the plugs, pull the rotor cap and check for blacken 
lines inside 
> the cap.
> Normally jumping fire will blacken this area. If there are black 
lines 
> inside the cap replace the cap, rotor and plug wires.
> A weak valve spring will give you backfires at high RPM, a broken 
one will 
> give you Lots of backfires.
> I believe this engine uses oil pressure to keep tension on the 
timing chains, 
> how is your oil?
> Anyway, just my two cents.
> Jerry
> Vin# 4890
> 
> 
> [Non-text portions of this message have been removed]