Help Camshaft or electrics?

[Revchimp]

Hopefully someone may have an answer. The Chimp has behaved well for almost a year, but on return from Manchester in august got what appeared slight misfire under load, take her up slowly and it was ok, been through the ignition &done all the obvious stuff ignition wise.Plugs cap rotar arm leads and ignition module all replaced Car now with friendly and trusted local garage who have also been scratching heads, result suggesting not ignition but cam /cam followers...
Symptoms were sound like a machine gun going off from what inside sounds like near side when accelerating hard and under load sy 3000RPM +
Any suggestions?

[jamienshelly]

I had that on Tuesday and it was the 100 amp fuse on the chassis, but I doubt your battery would have powered everything since August as it won't be charging, it may be your coil or the amplifier breaking down or even the king lead from the coil or even the TPS,
If it was the cam, then the fault would have slowly shown itself and not fine one day then knackered the next (unless something has broken),
Good luck with finding the fault and keep posting the sequence of testing etc so we may be able to help some more.
Just had a thought, it was mentioned in a previous post about the air filter trunking, they can collapse and cause hesitation too.

Edited by jamienshelly on Friday 27th September 12:46

[Revchimp]

Jamien
Cheers for that, strange thing is all electrics have been replaced with new parts, and engine runs, ticks over fine even drives ok (ish) but have noticed a lack of oomph of late. Much head scratching going on at the moment, Monday may well reveal problems meantime missing the opportunity of a fine weekend and an autumn blast ( b***er!)

[jamienshelly]

Check the air intakes, if they are ok then check the T.P.S, as if this goes wrong it is giving false information to the ecu on the throttle opening, Im sure someone will be along shortly and give you some precise information that is easy to follow.

[Revchimp]

Cheers for that,
this seems a sensible way forward especially as the fault happened after some really good runs and at the M6 toll booth when (Like a kid) I treated it as a starting grid against a rather attractive blonde in a BMW z4.... ( I won despite misfire)and it got me home no problem just damned annoying. Anyway will pass info on to friendly mechanics and see what transpires. given we have gone through all other obvious routes its got to be a goer before I lay out £££££!

[jojackson4]

Ingnshion timeing ?
Is your advance and retard ok inc pipe to plenom

[Bassfiend229hp]

Plug leads arcing to the exhausts? Have you checked the boots are all intact? I had similar symptoms and that's what my problem was - no.8 boot had cracked and under load was arcing to the exhaust manifold - cured with new plug lead.

Phil

[bsdnazz]

I had an irritating miss-fire, especially under load and 3,000 RPM, fixed by replacing the spark plug extenders.

The car and I are much happier now!

[L1OFF]

bsdnazz said:

I had an irritating miss-fire, especially under load and 3,000 RPM, fixed by replacing the spark plug extenders.

The car and I are much happier now!

I had the same sympton with my Griff 400, diagnosed as a cam (well known specialist) but fixed by replacing the plug extenders (2 were high resistance).

[Revchimp]

L1 off wrote:-I had the same sympton with my Griff 400, diagnosed as a cam (well known specialist) but fixed by replacing the plug extenders (2 were high resistance).

Cheers L1off,

This makes me feel slightly better, although garage claim they have connected the leads directly to plugs and no improvement... so we still scratch our heads. We await further diagnosis or misdiagnosis only up side is its out of MOT and the weather is bad otherwise ....

[Revchimp]

Up Date 12:10 Wed

Just had the dreaded phone call, apparently garage has consulted another engineer ( Roger Evans) and he has diagnosed little ends sound as though they are shot!!! Any comments or ideas gratefully received- meanwhile off for a serious bout of cursing and gnashing of teeth and purchase a lottery ticket in hope...!