3.9 rover v8 rebuild

fisherb · Post by **fisherb** » Tue Nov 06, 2007 1:53 pm

Having recently invested just short of a grand in my v8 engine, including a piper rp4 cam I cant seem to get it to rum correctly again, it backfires and misfires almost constantly, however every now and again for a few seconds it will run lovely.
This obvouisly sounds like a stupid loose wire, however I've been over them all and cant find one.
When going through the ignition checks when I check for a voltage between the battery live and the coil negative I'm gettin 12.8 volts. It says there shouldn't be one but doesnt tell me what to do if there is!!

Can anyone help as I'm not really enjoying riding my push bike around,
Thanks in advance

ChrisJC · Post by **ChrisJC** » Tue Nov 06, 2007 3:25 pm

More info required -
What ignition system are you running?
What fuel system are you running?

Chris.

fisherb · Post by **fisherb** » Tue Nov 06, 2007 3:28 pm

sorry, should have thought about that!
Hotwire injection, running lpg and petrol, doesn't seem to have any bearing on the running which one I use though.
Ignition system is coil and dizzy with 2 ign amps on it which where installed with the lpg kit

ChrisJC · Post by **ChrisJC** » Tue Nov 06, 2007 4:40 pm

So it's a standard Rover ignition system with one of these igntion timing adjuster thingys to alter the timing for LPG running?

I would try just wiring up the ignition as Mr. Rover intended and see if that helps. The little ignition timing adjustment boxes have a reputation for being less than brilliant.....

Chris.

disco-v8 · Post by **disco-v8** » Wed Nov 07, 2007 1:16 am

im having sort of the same problem with mine at the moment but mine is popping through the airbox

what got me more intrested was you say your running the piper RP4 cam from RPI, the same cam im using......

just thinking that maybe its the cam to blame as its got a very late opening of the valves of only 18 degrees, and every other cam ive seen on the market is above 22 degrees, so could be this....

heres a video of mine tell me if yours is the same

http://uk.youtube.com/watch?v=nF0abjWwbu8

ChrisJC · Post by **ChrisJC** » Wed Nov 07, 2007 8:29 am

I'm using the RPI Torquemax cam (which might be the same one) on my 4.6, and it runs beautifully. Standard ignition and twin SU's. OMVL R90/E vapouriser and twin mixers.

Chris.