Author Topic: CS 6/1 fuel pump  (Read 2086 times)


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CS 6/1 fuel pump
« on: April 03, 2020, 05:55:56 PM »
Hi guys I know this question has been asked many times before I'm struggling to get my cs to start
I can get fuel up to the cylinder I get lots of white smoke  timming gas been considered and have spent ages trying to get the spill test right no matter how I adjust I still get fuel leaking
Is there any way I can test my pump  to see if it's completely worn ?
Many thanks


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Re: CS 6/1 fuel pump
« Reply #1 on: April 03, 2020, 11:06:40 PM »
Hi Steve

The first thing to consider is 'What has happened since the CS last ran?' it might save a lot of time....

White smoke leans towards the fact that fuel is getting into the cylinder somehow.

Are you sure you are timing it to TDC on the power stroke?

First thing would be to listen for the injector 'creaking' as the pump delivers the diesel.

You should be able to hear this noise (or something like it, a squeak or a muffled ping) every SECOND revolution as you crank the motor by hand with the decompressor holding the exhaust valve open.

Even with my well shot hearing it's very evident!

If it's not there are several possibilities,

No, or insufficient, fuel reaching the pump,

Pump is worn and unable to overcome the injector,

injector pipe is blocked.

Injector is worn and is incapable of holding pressure and 'popping'

Injector is blocked.

Pump timing is incorrect and the follower (on the injection pump cam) is not lifting enough to operate the pump. Very unlikely unless you've had the thing in bits, but check the lock nut under the IP, if it's slack search the forum for IP timing or post up and I'll go through it, be careful, raising the follower too much and cranking the motor over will trash the IP in one revolution.

If you are happy that there is a good flow of fuel, under pressure, to the pump then pull the injector, crank the motor and check that fuel is pumping out of the top of the pipe, no fuel indicates lack of fuel, a blockage in the line (You've established there's fuel through the pump with the 'spill' test) or a terribly worn pump.

If there's fuel reconnect the injector to it's feed pipe outside the head, bleed the line, retighten the nut, crank the motor and watch the spray.

No spray, could be lack of fuel, air in system, blocked injector or weak pump. Loosen the nut connecting the injector to it's pipe, bleed fuel until there's no bubbles of air appearing, try again.

If there's still no spray take the injector down to the local specialist and get it tested, same course if the spray is not an even fan or if it's a dribble or drip.

This is the cheapest option, if the shop can overhaul your injector (I'm not up to date with UK prices, but around £40 would be my guess) then repeat the above test with the refurbished injector. should it still not 'pop' and you've bled the injector pipe then the pump is the No1 suspect...

Rebuilding the pump yourself is fairly straight forward, if you can source a new element, check the online prices for an element and a new pump, before getting a quote from the local repair shop.

Should you have a good spray pattern and a healthy 'creak' from the injector, with the injector out of the head, then it's either lack of compression, check the inlet and exhaust valve clearances, or timing.

To check the timing is somewhere close remove the rocker cover and with the decompressor engaged, turn the engine over until the exhaust valve closes and the inlet opens. put an index finger on one valve cap and a forefinger (of the same hand!) on the the other. rock the flywheel back and forth (with the other hand!) until you find the mid point where they change over, that should be very close to TDC, prior to the ignition stroke.

Mark the flywheel  at TDC (If you want a little more accuracy rig a temporary pointer to the edge of the flywheel) the 'creak' from the IP should be just before the mark when you rotate the flywheel in the CORRECT direction, when the two valves are 'rocking'

If this don't help then worn rings / bore or badly seated valve (s) and lack of compression may well be the problem.

It's a bit hard to tell from your post but there should be enough here to get you going in one direction or another.

It's now just before midnight, here at the bottom of France, I've had a few glasses of wine -perks of being locked down in an empty B&B with a decent wine cellar - there's nothing I want to watch on the TV, and I've thoroughly enjoyed the mental exercise, working through your problem. I'm sure others on here will chime in and if I've missed anything obvious they'll point it out.

Please post up any and all results, we're all going to be in this state for a few weeks yet!


Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.


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Re: CS 6/1 fuel pump
« Reply #2 on: April 04, 2020, 12:53:23 AM »
Stef.  Great diagnostic essay.  We should put it in the WOK

FWIW I have several times lately just bought a new indian pump + injector + line cos they're cheap and an instant solution

I'm inclined to drop the old pump in an icecream container of INOX to soak for a year or tow and promise myself "I'll get back to that one"

(put 'em on the Retirement To-do List lol)


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Re: CS 6/1 fuel pump
« Reply #3 on: April 04, 2020, 02:45:03 PM »
Hi Mike and Stef, and Steve

Nice wiki. In addition to Stef, he said all step by step, take a look at my thread to see - in pics - what Stef said! here: https://listerengine.com/smf/index.php?topic=8320.msg102965#msg102965

Cheers, and stay safe.
By order of firing up:
Bernard 18A - 1968 (mama's water pump - year of my birth)
Petter PAZ1 - Jun 1967, 3HP, sn 416xxxx
Petter PAZ1 - Nov 1979, 3HP, sn 425xxxx
Lister 12/2 - 12651227, the pearl!
Deutz MAH 914, 1952 - Zündfix in chamber and go (7Mai2023).


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Re: CS 6/1 fuel pump
« Reply #4 on: April 05, 2020, 11:51:13 AM »
Thanks guys for all your helpful advice I will give it another try Monday as we're all on lockdown and I will keep you all posted on the results