inline 6 165 hp not firing

[mabshire]

I have a l6 and clyinder #4 is not firing...<br />I took the spark plug wire off and could not get an arc. I switched the wires, sparkplug, distributor, rotor, points, and condencer and none of these worked. <br />The #4 is the only one that is not firing, every once in a while it fires once. It does not matter what the speed is..<br />And the compression is 120 across the board<br /><br /><br />can anyone help?

 

[Don S]

Re: inline 6 165 hp not firing

I'm assuming when you said distributor, you meant distributor CAP ?????? If not, did you change the cap?<br />A couple of other things to check would be the distributor shaft bushings and the shaft. Also do a vacuum check a leak could cause only one cylinder to missfire.<br />Regarding your compression check. On engines that old, I find it hard to beleive the compression is that even. Did you do the test properly.<br /><br /> Compression Test service bulletin

 

[mabshire]

Re: inline 6 165 hp not firing

Yes, I met the distributor cap...<br />And the engine was just bored out..<br />The distributor has no vacuum..<br />There is just no firing getting from the distributor to the sparkplug

 

[FreeBeeTony]

Re: inline 6 165 hp not firing

How are the lobes on the cam in the distributor?<br />I have an IL6 and installed a Petronix Kit.......works great.

 

[mabshire]

Re: inline 6 165 hp not firing

The lobs on the cam are good... the cam is one month old...<br /><br />the only thing left for the electrical parts is the distributor... I just find it funny that it only does it to the #4 cylinder and not any of the others

 

[FreeBeeTony]

Re: inline 6 165 hp not firing

I meant the lobes on the cam in the distributor....not the camshaft. Maybe 1 is worn and not opening the points when it should?

 

[Don S]

Re: inline 6 165 hp not firing

I didn't mean vacuum on the distributor, I mean on the engine. A vacuum leak can cause on cylinder not to fire.

 

[Fishermark]

Re: inline 6 165 hp not firing

Don - if a leak affected the compression in some way, (a stuck valve, or whatever) I can see a cylinder not "firing" in the sense that there would be a "misfire" or skip in the running of the engine. But a leak wouldn't have anything to do with a spark plug not "sparking." Or am I "missing" something myself?

 

[Don S]

Re: inline 6 165 hp not firing

Good point Fishmark........I read it wrong, thought he said he was getting spark at the plug. <br /><br />Disregard the Vacuum leak idea.<br /><br />That does narrow it down though. If no spark, and the plug, wire, cap, and rotor have been replaced, and the compression is good, the only thing left that could affect only 1 cylinder is the cam in the distributor not opening the points for that cylinder.

 

[mabshire]

Re: inline 6 165 hp not firing

Well it was the Distributor... <br />there was play in it left and right...<br />enough play that you can open and close the points...<br />It is running good now...<br /><br />Thanks

 

[trog100]

Re: inline 6 165 hp not firing

i love nit-picking.. he he.. but to miss on just the one it would need to be a combination of things.. play in the shaft plus worn lobe.. or play in the shaft plus bent shaft.. and probably points set to close as well..<br /><br />simple play in the shaft would cause intermittent misses and not just be confined to the one..<br /><br />just for those into the art of diagnostics.. he he<br /><br />glad u have it fixed.. thats the main thing..<br /><br />trog100

 

[hoot]

Re: inline 6 165 hp not firing

thanks for closure on the problem. sometimes we never know what was done for a solution.

 

[Don S]

Re: inline 6 165 hp not firing

Trust me trog, it doesn't have to be a combination of things. Just the worn shaft will do it in real life situations. Rather you can explain it or not.

 

[trog100]

Re: inline 6 165 hp not firing

yes.. its possible don.. praps not seemingly likely but certainly possible..<br /><br />trog100

 

[Don S]

Re: inline 6 165 hp not firing

I know it's possible, it's happened to me a couple of times. Only on in line 4 and 6 cylinder engines, but it's happened.