Missfiring V8! HELP!!....anyone??

[JimsMowing]

As per the title. Today my car was not quite running right from early doors. but couldnt put my finger on it. I was running low on fuel and decided to wack in £40 to top it up nicely.

Got back home for half an hour before leaving for the gym. On starting it, it didnt sound right which manifested into a missfire. In the dark i have checked dizzy cap and all the leads, and the leads onto the plugs for a loose connection. I will have a look in more detail tomorrow afternoon after work but this only gives me a few hours before its dark and then setting off four a road trip Friday morning.

Can anyone give me some suggestions as to what may cause this and more importantly a process of elimination for areas to check?

Thanks in advance

Geoff

[Range Rover Blues]

Lordy, there's a question.

If you looked at it at night you would have seen any obvious arcing to earth from the HT ignition.  I'd suggest cleaning the dizzy cap though.

Low fuel, might have blocked an injector but the fuel filter should have picked anything up.

When Blue missfires, it's a valve :(  so a compression test is on the cards.

[JimsMowing]

Lordy, there's a question.

If you looked at it at night you would have seen any obvious arcing to earth from the HT ignition.  I'd suggest cleaning the dizzy cap though.

Low fuel, might have blocked an injector but the fuel filter should have picked anything up.

When Blue missfires, it's a valve :(  so a compression test is on the cards.

Sorted. Turns out that one of the HT leads had severed at the end where the carbon fibre is crimped into the silicon, which the clamps onto the tip of the spark plug. The leads in general were old, and a bit molten like when warm so decided to get a set of new Bosch leads. £31.50 from Halfrauds.  :twisted:

So all is tickety boo and i can do my road trip with a clear conscience that all is well....touch wood!  :D

P.S What did you mean when you said when blue missfires its a valve?

[Range Rover Blues]

P.S What did you mean when you said when blue missfires its a valve?

<---------
Blue AKA the Spanish Inquisition, our first RRC and the one that does MUD.

It's got a new coil, electronic ignition and now sprt a set of Magnecore leads and NGK IRiidum plugs.  But when it's been misfiring before it always coincides with a lack of compression somewhere and that has turned out on the 2 previous occasions to be a burned out exhaust valve.

Now it's doing it again (I swapped the engine last year for one that was supposed to be good) but I'm leaving it for now as I have a bigger engine and auto box to go in.

[JimsMowing]

[quote="Now it's doing it again (I swapped the engine last year for one that was supposed to be good) but I'm leaving it for now as I have a bigger engine and auto box to go in.[/quote]

 :lol:  So what lump have you got earmarked for "Blue" then? Something upwards of 5 litres per chance?  

[Range Rover Blues]

4.6 cross bolted RoverV8 and auto box.  Should be adequate for what I want :D

[JimsMowing]

Yeah that should do the job!! Is that basically the same engine as the TVR lump? 300bhp???

[Bulli]

i think tvr do an awful lot witht he heads and cams, but it should still have plenty of punch !

[Range Rover Blues]

The 4.6 is basically the P38 long engine fitted to a '93 LSE complete with new ECU, though the TVR engines were based on the Rover V8.

The 430HC was based on the 4.2 (4275) LSE engine but as Bulli suggested they had a bit of work on them.  My mate's got one and it's somewhere north of 300BHP, it's a very naughty car indeed :D

My LSE has a TVR bottom end in it, 5.0L.  Still doesn't sound as nice as his Chimera though.