Thread: 3.5L running on 5cylinders! please explain??

hey phil, i think you don't have an ignition problem, more an injector problem
----if it's an injected engine?
so now shoot that theory down and tell me its carburetted!
otherwise i have no idea,
but a couple of things_
has it got points or a hall effect dizzy -maybe a clearance problem with the rotor plate thing.
if you remove one of the crook leads from a plug and fit a loose plug in the lead you should see a spark at the plug gap with the plug resting on a metal part of the engine, if so then check the injector.
happy hunting

Id be lookin at the dizzy to cam timing as it sounds like its out of wack get cyl 1 to top dead on compression stroke this is best done with rocker covrs off so you can watch the rockers on NO 8 to determine top dead at NO 1 then make sure the dizzy is in the right possy before removing the dizzy cap mark the side of the dizzy with a marker to show were NO 1 lead is pluged in try mark as close to the center line of the lead then remove the dizzy cap and see if the rotor is pointing at your mark as id say with the symtoms you discribed the rotor wont be pointing at the mark with the engin at top dead on NO 1

I was going to suggest a dud carbie, but that should effect four cylinders, not 3...

Discowhite,
Mark the TDC (0) mark on the crank pulley, put a timing light (Strobe) on #1 cyl plug lead, passenger side front of block, disconnect the vacuum hose from dissy and plug, start engine and let idle, point strobe at crank pulley and see where and if lead (plug) is firing, if you cant see the timing mark you have your plug leads on incorrectly. You have to establish where #1 is in the distibutor and mark the side of the body (Dissy that is), when you place the dissy cap back on mark the plug lead post that it lines up with, that will be #1. Following the Firing order and travelling in the direction of rotation of the rotor button put the next lead in the firing order and so on, remember that the cylinders are numbered 1357 on the passenger side with 1 at the front and 2468 on the drivers side with #2 at the front, try that first and if it don't work get back to us. I know you are using a dissy cap and leads from a runner, but someone may have timed your dissy with #1 in a different position, Regards Frank.

Originally Posted by harry

so now shoot that theory down and tell me its carburetted!

Originally Posted by discowhite

1982 RRC 175cd strommies.

are you getting spark at the plugs on the cylinders that arent firing......?

I know this may sound stupid, but how is the air valve on one of the carbys? I know from experience that you can start a 3.5 on one carby. Having a stuck needle would account for no fuel on half of the engine. ( Trace the inlet manifold runners....) and make sure the inlet manifold is up to scratch - lack of vacuum is also a problem sometimes (A vac leak on one side....?)

Originally Posted by langy

I know this may sound stupid, but how is the air valve on one of the carbys? I know from experience that you can start a 3.5 on one carby. Having a stuck needle would account for no fuel on half of the engine. ( Trace the inlet manifold runners....) and make sure the inlet manifold is up to scratch - lack of vacuum is also a problem sometimes (A vac leak on one side....?)

2 on one side and one on the other, Regards Frank.