Thread: D1 running rough

Originally Posted by discojim

Hi all,
I know this has been brought up before (and i have read all the posts) but my D1 is not running real well. Firstly i have replaced the plugs, leads, cap and the button but it still runs rough. At idle it feels like it is missing, once you get over about 2000rpm it is not as bad but you can still feel it. I usualy run the D1 on premium but i ran 1 tank of normal and the problem has only just started.

Help

Doug

Imlet manifold gasket? If misfire disappears under load it is a likely. Run some water along the edge of the manifold against the heads.Or listen with a piece of hose to your ear for hissing noise.

The other thing to do is give it a compression check ... If this comes up trumps, then you can start working towards other suspects ....

Mike

As suggested a compression check can indicate a mechanical problem in valve train, head integrity or a bad cylinder but if the engine has only recently developed this rough running I would say more likely a fuel, spark or ignition issue.

1 tank of ulp won,t make it run any different unless your v8 is highly modified with plenty of advance above say 10 deg...

work methodically on one system at a time eg fuel or ignition

some things to check along with your haynes manual

air cleaner element clean? fuel filter? fuel pressure 2.5bar 36psi?
distributor air gap (non ferrous feeler gauge}
idle air valve & hoses clean & no holes(air leaks)
no 1 cylinder at tdc comp stroke to check timing mark
crankcase breather system needs to be clean for good idle
correct plugs & heat range hard to beat ngk bpr5
HT leads correct between cap & plugs can't beat magnicore leads
coil & amplifier modlue output & connections ok

just to name a few

Thanks to all that supplied answers. It turned out to be a dogey plug! all good now!

Cheers

Doug

Originally Posted by discojim

turned out to be a dogey plug!

You said that you installed new plugs ... But one was dodgy ... What was the brand & serial number on it??

Haha names please...WE WANT NAMES!!!

Would it have been a Champion plug?

Twas a NGK plug. Bloody thing!

Doug