Discussion
Hi All, looking for some help before calling the pro's in, went out on Sunday in the V8S, a nice 20 mile round trip to Haslemere and back to Petersfield, ( I was giving it a bit of earole https://www.pistonheads.com/gassing/imgs/12.gif ) as had an ice cream for the missus...FYI not driving cone in one hand , it was in a small takeaway cup) 3 miles from home on the return the car starts to misfire and backfire then looses power and grinds to a halt, now recovered and back ingrate at home, there's plenty of fuel and a spark, will spin over and try to fire with no luck will also occasionally backfire out of the exhaust but no actual start. Its always been reliable and nothings been fiddled with since December last year
Any ideas ?
Any ideas ?
Hi GreenV8S, when I broke down I did think that I had possibly run out of fuel, despite having put some in and the fuel gauge registering ( never been accurate) so put in another 10 litres but no difference, basic test strong spark from the king lead , can hear the pump activating , removed all the plugs and these are showing quite wet.
Hi GreenV8S, when I broke down I did think that I had possibly run out of fuel, despite having put some in and the fuel gauge registering ( never been accurate) so put in another 10 litres but no difference, basic test strong spark from the king lead , can hear the pump activating , removed all the plugs and these are showing quite wet.
Think I may have found the problem....when checking for a spark at the plugs , altough there was one it seemed erratic so popped the distributor cap off to check the rotor & cap for tracking and found I could rotate the rotor arm ...pretty are that's not right !, can feel a little resistance when rotating almost as if the teeth on the drive gear have been stripped , will think about removing it tomorrow, has anyone else come across a similar issue ?
Think I may have found the problem....when checking for a spark at the plugs , altough there was one it seemed erratic so popped the distributor cap off to check the rotor & cap for tracking and found I could rotate the rotor arm ...pretty are that's not right !, can feel a little resistance when rotating almost as if the teeth on the drive gear have been stripped , will think about removing it tomorrow, has anyone else come across a similar issue ?
Potential point of failure are the rotor arm breaking so it spins on the upper shaft, the mechanical advance falling apart, the drive gear coming unpinned from the lower shaft, the drive gear failing.
The last three seem extremely unlikely to me, and the last one would also mean no oil pump drive.
I suggest you start by removing the rotor arm and see if the upper shaft rotates, then work down until you find the problem.
Avoid removing the dizzy from the front cover if you can, because getting the right gear alignment and base timing is quite fiddly.
The last three seem extremely unlikely to me, and the last one would also mean no oil pump drive.
I suggest you start by removing the rotor arm and see if the upper shaft rotates, then work down until you find the problem.
Avoid removing the dizzy from the front cover if you can, because getting the right gear alignment and base timing is quite fiddly.
Hi Guys, thanks for the advice , have send a message to V8 engine appreciation on FB now just awaiting approval. Further investigation earlier today removed RA and I can definatly rotate dizzy drive in either direction easily 360 degrees, I decided to pop out all plugs , Cap off and see if oil pressure would show while cranking, after a good 20-30 second no OP on guage but rotor turning ! Have checked and drive now seems fully engaged (I'm a little confused), think I'll set static at 6BTDC on compression stroke No1 cyl and see where rotor points, will hold off removing dizzy just in case any of the V8 Engine guys have any thoughts....her who must be obeyed just rolled her eyes saying "well you did want something to fiddle with"...
TOMPERRELLI said:
Have checked and drive now seems fully engaged
The symptoms suggest you have a mechanical failure within the dizzy. The drive gear is attached to the shaft with a rollpin. If the pin has sheared the broken remains might still be enough to turn the dizzy, but of course the timing will be random. I've never seen a mechanical advance unit fail, but if it did that might also fail in a way that jams enough to produce some drive sometimes. Again, timing may be random.I believe you're at the point where you'll need to remove and repair/replace the dizzy. The location of the fault will probably become obvious at this point. If it's a failed pin, that's an easy quick fix. Otherwise expect to replace the dizzy. Mine was a 35DLMB ('limb') distributor. Most of the aftermarket RV8 specialists will sell replacement distributors. If you fit a non-OEM one, expect to get an ignition amplifier too which will need wiring in.
You'll need to get the orientation of the dizzy body and the rotor arm correct when you reinstall it. It will help massively if you position the crank on #1 TDC, scribe matching reference markes on the dizzy body and front cover, and mark the orientation of the rotor arm on the dizzy. If you replace the dizzy, try to transcribe the reference marks to get the replacement as close as possible to the same orientation.
Note that the rotor arm is driven through a skew gear which will cause it to turn as you withdraw it. Mark the position of the arm when installed, and also when it has been removed. If you position the rotor arm in the 'removed' position and install it, the arm should turn back to the 'installed' position.
Obviously you'll also need to set the static timing afterwards.
A little update...Hi Guys, Thank you, just removed the dizzy, drive gear is fine ....but the gear on the cam is stripped !!!, I did say I wanted to tinker !!!Looks like Im going to be busy for a bit....I will change both gears any way, looking at the history the engine did have a cam, follows and water pump etc change in 2017 has done about 5000 miles since, hey ho ....part of life's rich tapestry, just need to source the bits now
Gassing Station | S Series | Top of Page | What's New | My Stuff