Engine woes

[keith]

Hi,

I'm hoping one of the experts here can give me some help with a problem I'm having with my P5B which I acquired last October.

The cars start fairly well after turning over a few times with the choke in the right position. However after starting it will stall if I try to move off before the engine has warmed up, so I have to sit in the car for 5 minutes or so before going anywhere. Once its warm it goes OK on the flat but it seems to have no power behind it and tends to struggle up hills.

I've had it tuned and the points changed which made it slightly better. There is a slight blow in the exhaust manifold. Oil is OK as are the rest of the fluids. The car has not been converted for unleaded so I'm runing it on unleaded with an additive.

Its a lovely car, I've waited 30 years to own one, but this problem is taking the fun out of owning it. I wonder if I'm expecting too much from a 34 year old car but from reading this board and Take Five it seems that the car should go better than it does.

Can anyone offer advice or words of encouragement.

Many thanks,
Keith

[Deleted]

Its not necessary to use an additive thse engines will run easily on 95 Octane unleaded with up to 6 deg retard of the ignition back to TDC.

This will not affect the running in any event.

Assuming it has been tuned properly, as it sounds like it could be running weak, it could be fuel satrvation caused by worn pump/porous diaphram/blocked fule lines/filters. Not expensive to sort out either

It could also be due to sticky valves/lifters if the engine has not been run and even piston rings.

This may clear with more use and good blast down the motorway, or perhaps clear road if you doubt it will make it, often works wonders.

A compression check is well worth doing as is renewing the plugs and condenser and possibly the leads.

Its certainly not expecting too much from a 32 year old car - they will see off any modern Eurobox. Have confidence in it.

Do you know any history?

[Allan NZ P5b]

Stupid I know?
but you are not pushing the choke in straight after starting are you It will need choke for a few minutes after starting. This will mean it will appear to idle fast about 1200-1400 rpm untill you can push choke in.
Also if you push choke in too far while in park then engage reverse or drive the drag of the box/torque converter will initially slow engine enough to stall.
I start on choke About 1/2 as we are not that cold then engage Drive or Reverse then feather coke to happy point,then drive off. Then after 1-2 minutes move in to fast idle only position about 1/4 inch out to stop it stalling at lights then after about 3 minutes push all the way in. Obviously this time frame varies with ambiant temperature.
I know this seems obvious but lots of modern car drivers do not understand how the choke works or what it does.
Also state of tune is important and over here anyway most mechanics can't set the car up right unless you pay an experianced classic guy a lot of money.
In the end I bought timing light, carb balancer, and colour tune plug to set car up and once I had run through the settings as per book She runs like a dream. Starts 1st crank every time.

Regards and good luck.

[Phil Nottingham]

Good points - I have never had two V8's that start the same cold - some need churning over on full choke and quickly warm up others start first off and take ages to warm up.

Ambient tempearure/humidity also affects this as does the fitment of Electronic Ignition.

I would never trust tuners and always do it myself but I accept that some people cannot do this.

All the P5's /P5B's are dead easy to service and require few special tools provided the manual is followed to the letter.

Dwell Meter, strobe light and a cheap carb balancer are sufficient plus Torquewrench if dismantling anything

[RichardF]

The symptoms you describe are the same I experienced during my days in the RAF. One of the tactical fire engines just would not pull at all. After a strip down (having done all the usual other things), we found the cam lobes severely worn. One new camshaft later and it was a different vehicle and pulled away like the rest. After all other checks, this may be the one to go for.

RichardF

[Phil Nottingham]

The camshaft does wear on these engines but it is best to eliminate the easy and cheaply fixed problems first.

[Smallfry]

Thats true Phil, but you will never eliminate the small things IF the camshaft is worn.

If you can hear any noise at all from the valve gear, and if you cannot get the engine to run smoothly at idle right down to about 500 rpm, you will find that one or two of the cam lobes are worn out, and if this is the case, you will never get the engine to run nicely, no matter what you do to the ignition or carbs.

The other tendency for people to do is to try to lean the mixture out, in a vain effort to gain a little more economy. Any automatic car will stall when cold if you do it, and AllanNZ is right......there are not too many tuners, mechanics, call them what you will, who KNOW how to tune these old engines. Plenty about who THINK they know, but dont really have a clue.

[Phil Nottingham]

I actually meant eliminate "the possiblity" - its no use jumping in and pulling the engine apart to rectify what turnes out to be a faulty ignition coil.

You can pick up some bargains like this though as I bought a Mini for spares for beer money because the engine had shot it and was only firing on 3 cylinders.

On removing the tappet cover one of the lock nuts on the inlet tappet had loosed and the valve was not opening. This engine is still going 10 years later!

[Smallfry]

It must be an A series engine thing ?

It reminds me of an Austin 1100 my uncle used to have. One day it developed a fault, it would run OK when idling and when it was revved up, but when it was actually driven, it was completely gutless and would not do over 15 mph.

I remember my dad and my uncle in our garage.......points and condenser, check fuel feed then plugs cap and leads, valve clearances, more test drives, then head off, valves reground, new gaskets, Saturday until late and Sunday. Reassembled, and ta...ra.....no difference !

They didnt bother to check the air filter because it had only been replaced two weeks previously. It turned out that a whole large sheet of damp newspaper had been sucked into the air intake and completely wrapped itself round the filter, blocking off the airflow.

God only knows how it got in there, because the air inlet is only small, and is tucked down the back of the engine. But as you rightly say, you should always go methodically through the easy stuff first.

[keith]

Many thanks all for your input.

I've booked the car in for a service with my friendly P5B expert. Although some of the things I could have done myself (such as the electrics) I feel that checking the fuel system and compression are beyond me at the moment.

I'll let you know what the fault was.

Thanks again,
Keith