4 Cylinder don`t work

Larosto · Post by **Larosto** » Thu Aug 06, 2009 5:01 am

Hello,
`ve got a difficult problem: I ran my car, and everything was ok, like always. Then, after a week it didn`t start again. I renewed the sparks, and the car started only on 4 cylinders. It didn`t start with choke, and so I gave full throttle and then four cylinders worked. The cylinder Nr 1, 7, 4 and 6 don`t work (Isaw it after looking at the sparks again, the sparks of these cylinders looked like new, the others were black).
I looked at the compression, it was about 9 bars at all 8 cylinders.
Then I removed the air filters to look at the carbs (I have fitted two SU HIF 44) and it seemed to me that they were working both, because the pistons were going up and down, and I saw the fuel spraying in the inlet manifold.
Any ideas why the four cylinders doen`t work?

regards
Horst

map1275 · Post by **map1275** » Thu Aug 06, 2009 7:46 am

Start again with basics, in a little more logical order.

Are you getting spark at the end of each ignition lead?

If it is the cylinders stated, spray some aerosol solvent directly into the throat of the right carburettor. Brake clean, Carb clean, Aerostart...
All the cylinders you listed are fed by one carb.

Turn the key and see if it will run on all eight (or more than four) for a moment.

The carburettor piston will lift with manifold vacuum. But this doesn't mean that fuel is being delivered.

Mrs Bingham · Post by **Mrs Bingham** » Thu Aug 06, 2009 8:52 am

If you have clean sparkplugs on the non firing cylinders are they soaked in petrol? Have you checked the firing order?

It should be 1 8 4 3 6 5 7 2

The left bank is 1 3 5 7

The right bank is 2 4 6 8

And the distributer turns clockwise with number 1 sparkplug lead pointing towards 5 o'clock or towards the left hand headlight.

Good luck...

primsil · Post by **primsil** » Thu Aug 06, 2009 8:15 pm

the cylinders you say are not working are fed off one carb, the others off the other carb so looks like a carb problem. Are the carbs balanced, that is what the problem sounds like, one is not allowing enough fuel through at idle.

doggreen10 · Post by **doggreen10** » Thu Aug 06, 2009 8:43 pm

IF YOU GO BY MRS BINGHAM YOU WILL HAVE 2 No 2 CYLINDERS AND NO No 3

Larosto · Post by **Larosto** » Fri Aug 07, 2009 5:00 am

Hi,

thank you for all the answers. `think the problem is solved. If I run the car on LPG, it works as good as always. So I think the carb of the left bank was overfilled with fuel, and so the sparks couldn`t fire. Something had "hanged up" when I was running on LPG for a longer time (3000 km). `will try to go on fuel again this weekend and hope for the best....

Horst

5988 · Post by **5988** » Mon Aug 10, 2009 7:27 pm

probably the needle valve is stuck (or the flot isnt floating so it floods the carb)
will need the float chamber off to check

Larosto · Post by **Larosto** » Sat Sep 05, 2009 9:52 am

Hi,

before I forget it: The seal from the choke (O-ring) of the left carb was to old and to hard. So, the carb was overfilled with fuel. New seal fitted, problem solved.

Thanks for the help.

Horst