Engine dies when taking off from standstill

[Alan and Liz]

My 'six' is a CR P.I., with Bosch fuel pump and Revington PRV. All else is pretty standard. When taking off from standstill, with revs at about 1000 rpm, my engine sometimes loses all power and dies on me. If I am quick with the clutch and feather back on the throttle I can sometimes pick up the power and get away. If I set off with more revs and slip the clutch somewhat this problem never occurs. There are no obvious air leaks. This problem seems to occur irrespective of engine temperature. Any ideas please?

[Graze]

Hi Alan and Liz,

 

Welcome

 

Does it ever falter at any other time, over bumps, under hard acceleration etc some more info might help to refine the cause although I suspect fuel or timing not electrics from what you have said.

 

How old, what condition is the metering unit? Injectors? Is it running rich? Choking on acceleration?

 

Any other symptoms

 

Graze

Edited June 8, 2015 by Graze

[barkerwilliams]

Alan & Liz,

 

Sounds a rather like an issue I had with idling / butterflies not being fully synchronised. Without the air manifold / plenum fitted at tickover I could fully block off each cylinder in turn with palm of hand over the six individual rubber connector pipes, about four cylinders made little difference, but two cylinders killed the engine instantly.

 

Without load the engine was essentially ticking over on two cylinders and without enough revs to bring in the other cylinders the car could not pull away and would stall. I needed butterflies re-bushing and new throttle linkage.

 

At least mine was simple to diagnose.

 

 

Alan

Edited June 9, 2015 by barkerwilliams

[Peter Cobbold]

Hi Alan an Liz,

Welcome to the forum.

As Alan says first try synchronising the butterflies.

If they are OK then check the ingnition timing. It should be set to 12 BTDC static.

Peter

[Alan and Liz]

Thanks for the replies so far, everybody.

 

In reply to 'Graze' I have found a loose connection to the earth from the fuel pump which I discovered once the car had ground to an ignominious halt on a run earlier this week. Prior to this week the problem only manifested itself on pulling away, until the engine began misbehaving and then dying when going well, so I'm not sure as yet if this is a solution. The engine, however, has always pulled well when subjected to enthusiastic acceleration. I suspect, however, that the engine may be running rich so will be checking out spark plug colour following a good run, later this week. As regards the metering unit, this car is fairly new to me and there are no receipts for a recon or new metering unit, so suspect that this is original and hence has 85k under its belt. The injector spray patterns are good, though.

 

In reply to 'Alan', the problem is one of the engine dying through lack of pick-up and lack of power rather than stalling under applied load. However, I will follow your suggestion of checking out the butterfly linkages and of closing off the inlets.

 

In reply to 'Peter', I will follow your suggestion to check the ignition timing (and auto-advance) first. I have just bought new points and a red rotor arm from the 'Distributor Doctor' but, following the time-held edict of checking and changing only one item at a time, and in sequence, and following through each check and change to see what difference this made, I get the feeling that it may be a while before I get round to fitting these!

 

Many thanks, all, for your suggestions so far. Please keep them coming. I'll keep you posted on my progress.

[grumpy2]

How does the car drive at low revs? Ie will it hold steady at 30mph in 4th (is that abou 50kmph?). If not then definayely start by checking the air flow through the butterflies at idle and light throttle.