Intermittent revving

[Rfc1drew]

Hi all
I put fresh fuel in the car today and she starts and idles grand. When I rev the engine it's on and off and not steady. I have had the carbs off and put new gaskets in and oil in the top for the damper.

[stevejgreen]

Re: Intermittent revving

Are we talking a TC 1.8 engine?
Have you checked for induction leaks on the vacuum side? It sounds as though you are getting a burst of fuel and then the vacuum is insufficient to hold the pistons up?
Are both float chambers set the same and both carbs getting fuel? The carbs are siamesed, if one carb is not delivering fuel, it will rob the other of vacuum.

[Rfc1drew]

Re: Intermittent revving

Hi it's the 2.0 vitesse engine with strombergs on it. Have checked fuel flow and seems OK. Has an electric pump fitted and electronic ignition

[stevejgreen]

Re: Intermittent revving

Hi it's the 2.0 vitesse engine with strombergs on it. Have checked fuel flow and seems OK. Has an electric pump fitted and electronic ignition

That will be one for Ben then, Strombergs are not my strong point. My guess he is away for the weekend.

[philcoyle]

Re: Intermittent revving

Check your vacuum pipe from manifold to servo just in case the servo has an air leak, clamp it off and start the engine, that's one test out of the way.

[fouter]

Re: Intermittent revving

Hi,
I had a similar problem years ago which turned out to be a rip in the rubber diaphram in the carb might be worth checking.
Not sure if this is what you meant as the gasket replacement though.
Best Regards
Graham

[djj_engineer]

Re: Intermittent revving

I had my Strombergs rebuilt by Burlen Su Spares the spindles were very sloppy and there was not tick-over. But the effect was constant not an intermittent reving. I sound like there may be a surge in fuel. How much fuel is pumped by the Electric pump?

[b_caswell]

Re: Intermittent revving

I would suspect an air leak some where on the intake system. Fuel problems normally cause the engine to misfire not surge.
Check that you have not got the gasket between the air filter and the carb up side down blocking the small equalisation vent next to the bolt holes.

As Graham says check the carb diaphragm's first then if you have the emission valve check that diaphragm. Or as Phil says isolate the servo. Also try Isolating the vacuum advance pipe as there is another diaphragm at the distributor. It could be if this one is leaking its altering the timing.

[Rfc1drew]

Re: Intermittent revving

hi all and thanks for the replys, had the tops off the carbs and the rubbers were fine. Then looked at the dizzy and could see the cables moving under load. A wee black cable had a split due to the little clamp holding it not letting it move, soldered it up and runs sweet.