rover p6 v8 auto 1974

[classicalgreen]

had it a few months now. every time it goes out it breaks down!
working through issues. new leads. points .condensor. plugs. tyres... runs but with lumpiness. suspect coil ? ht leads? and fuel system need sorting.
sigh.. money pit at moment but hoping to try and get past that stage. clcck isnt working lol but least of worries. fuel gauge now fixed too . fuel pump worked on with new seals etc but suspect not up to task.
hell of an issue when cold. hot runs ok but lack of power? wondering if carbs need overhauling? more money and time ..soon be xmas .
otherwise body etc in decent nick.

[Luxobarge]

new leads. points .condensor. plugs.

Where did you get them from? There are loads of really crap ignition parts on the market, most of the big spares vendors sell them, and they are best used as paperweights, they're simply not fit for purpose.

There may be other suppliers of decent parts out there, but you'll be guaranteed good quality parts from this guy:

http://www.distributordoctor.com/

I'd start by making sure you have known good components in this department and go from there, particularly the points, condensor and rotor arm.

Cheers

[mach1rob]

Agreed, bin the points and condenser and fit an electronic kit to remove those issues once and for all, fit and forget. Get a red rotor arm if you can, no rivet to cause issues.

Setting up the carbs is worthwhile, getting the mixture right will help no end, worthwhile doing if you have issues when hot and cold, make sure the choke is operating correctly. An hour or twos tinkering could help no end, and plenty of tutorials around on You Tube etc if you're not sure.

[garethp6]

my p6 was doing it but it was the points and the condenser so i threw them in the bin and went electronic that does help i would check the fuel flow and have a look at the mixture. u wanna make sure yr getting a good spark and make sure the timming is right mine is a TDC just have to start right from the beining i would check the leads and that u got a spark check the timming then the mixture they are not to bad to play with good luck gareth

[classicalgreen]

been a while since i dropped by. update. car starts after lot of choke and cranking. having fitted new carb kits. fuel filters. pump serviced. electronic ignition etc.
runs badly until slightly warm when warm.starts easily and needs no or little choke. checked fuel flow from pump into container when cranking= loads. no over flow from carbs. checked fuel mixture with air flow meter on each carb ( no air cleaner) and colortune in each cylinder. so far so good.
no carried out compression yet ( about 4 degrees outside and unable to close garage door ) , assuming tappets are pumping up ? it ought to run sweetly .will recheck timing in month or so when weather improves? plus compression check. ( wet and dry) . slightly tappet ..so assuming it lilkely a few lifters not pumping fully and causing a misfire .lumpiness until warm.
while its sitting in a dry ( cold ) garage I am changing both front brake callipers and master cylinder as found fluid on floor .ggrrr
hopefully have car back on road after april 2015. as £££ isn't easy when retired and other half thinks i was mad to even buy it at huge cost. ( probably right there) front driver seat in 'ambler'? cloth is showing sign of the cushion falling apart.. suppose to eb expected for car 40 years old. sigh.
starting a saving fund after april too. hopefully het enough in kitty to get upgraded to power steering.. yes its Ok in a straight line.. you try three point turn with cars waiting..

[kstrutt1]

Sorry to say it but running lumpy even when carbs /ignition sorted and tappetty would point to a worn cam, to check you need to measure the lift at the rocker shaft, mine had one lobe almost worn away, in my tr7v8 the cam was pretty easy to change in the car, never done a p6 though.

[TerryG]

If you can get the crank pulley off, changing the cam on a rover v8 isn't overly difficult. You really, really do need to do a compression test though. If it is low on a wet test then knowing the rover v8, a worn cam and lifters is a distinct possibility or maybe a REALLY stretched timing chain.

[classicalgreen]

car only has under 38k from new so worn cam seems unlikely.. it is tappety when cold and runs rough etc when warm it gets quiter and settles down ,leading me to think its hydraulics tappets failing to pump up 'sticking; when cold . that would account for poor starting/run/idle when cold regardless of choke.
will do compressions around march. currently working on from brakes ( new callipers etc as won't release fully after applying) lack of use of mechnical parts can often give rise to issues.
oil pressure is higher than I would expect at hot idle ..so maybe a sticking oil pressure relief valve giving excess oil pressure to start with .. may also play a part with tappets..lest hope the old girl behaves later in year as hopefully can do a tad more than the 300 miles it covered last year ( issues plus bad weather-it never goes out in rain)

[kstrutt1]

Unfortunatelly the cam can wear very quickly particularly if the oil is not changed regularly or they are used for lots of short journeys.

Even if it is the case don't lose heart, as said above it's that difficult a job and the parts are not too expensive, just make sure you get set for a 3.5, after doing mine 3 times to try and get an oil pressure I found I had a 3.9 front cover gasket which has a extra hole allowing air into the pick up side of the pump.

A high oil pressure could be good news or it could mean the engine is choked with black sludge, have you had a look inside the cam cover yet is it clean?


Kevin

[TerryG]

The oil pump on pre-serpentine rover v8s is even when new, marginal. (the later ones prime better but the flow is still pants) I suspect that even though the car has only done 38k it has been started and run without being moved fairly often. 15psi+ at hot idle is good, below 10 means you have a problem.
There are other things that can cause similar side effects, the cam timing could be out or the timing chain stretched, the valves could be coked up, etc.
At least a compression test only takes 15 minutes and will give you an idea of where to look. Is there any reason for waiting 2 months before doing one?
It's not that your problem is definitely the cam, its that there is a good chance and without doing a compression test its not possible to rule it out or diagnose much further as you have already done the fuel and spark, assuming they are right there is only compression left.
lots of cranking could mean you are just waiting for the float bowls to fill, it could also mean the mixture is set wrong or that you have a weak spark. when you fitted electronic ignition did you swap the coil? In this temperature I would expect to need full choke.
How did you re-set your carbs after rebuilding them?
btw, if you do swap the cam, the one from a 3.9 will give you slightly longer duration and increase your power output a smidge.