11 replies to this topic

[jime17]

Hi all.

Got my 998 auto 1990 standard set up started after 6 months idle.

Changed air filter plugs. Leads. Adjusted points new dizzy cap.

Fired up after loads of cranking piggy backed off a running car with jump leads.

got it warm and was idling fine, but when i rev and let revs drop, it drops to a point where it can't keep running and it stalls.

The only way to rev it and keep it going when the revs drop is to slowly nurse it down to idle speed.

Any ideas?

[jime17]

Forgot to add. Petrol in tank has been there the 6 months the car has been garaged. Don't know if this is a problem.

[jime17]

Any takers? It ran ok before it's hibernation.

[jaydee]

First of all, put fresh fuel in the tank, after 6 months it wont be good.
You problem sounds like an air leak at the carb (check vauum pipes, breathers etc) or overfuelling.

[seancv1]

Might be worth checking the earth connections for the battery and the engine as well. ?

[tiger99]

As well as the above, assuming it is an SU carb, I would strongly suspect that the piston is sticking. Unscrew and remove the damper, take out the 2 or 3 screws and lift off the top, and take out the piston, taking care to avoid bending the needle. A very light polish with metal polish (NEVER anything coarser) around the edge of the piston and inside the cover (or sometimes just a good spray with WD-40, and wiping it off completely with a cloth, to remove muck), and a clean with petrol or other solvent of the inner tube and damper should get it all moving freely again. Refill with SU oil or 3 in 1 to just below the top of the inner tube before refitting the damper. Don't forget the spring! And, re-centre the jet so the needle is not rubbing (see Haynes) unless you have one of the spring loaded needle horrors of course.

Also, the centrifugal advance mechanism in the distributor could be sticking, but carb is far more likely. Check the distributor anyway, it only takes a minute. Twist the rotor arm (it will only move significantly in one direction). If it springs back when you release it, it is most likely ok.

Another possibility (and yes, it has happened to me, on two different cars, one a Mini) is that there is friction somewhere in the throttle mechanism, cable etc, so that it does not go right back tight against the adjusting screw when you think it has, but when you release the pedal from high revs, it goes back fully, and the idle speed adjustment is just too low, so it stalls.

[jime17]

Thank you chaps. I will try the above and report back. When the wife and kids allow me time.

[jime17]

Just re read the earth strap reply.

I had to jump it off my scenic because the 2 min of cranking without success was flattening the battery.

It just need a hand off of a diesel car battery with more CCA.

A would a poor earth cause the problem with the engine dying?

[KernowCooper]

Quote:A would a poor earth cause the problem with the engine dying? not unless you had no engine earth and it affected the ignition, If it cranks over one assumes the earth connection is ok.

Engines which are runing weak do have tendency to stall when you drop the revs, have you checked the intake manifold gasket and carb for air leaks with wd40?

[jime17]

Thanks kc

How would one check with wd 40?

[KernowCooper]

You have the engine idling and spray around the inlet manifold gasket to head and around the inlet to carb gasket, if it revs up there is a air leak at that point, also check the breather hose to carb is not split.

Edited by KernowCooper, 29 March 2013 - 01:12 AM.

[jime17]

Thanks. I'll report back