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engine misfire or stumble - help
Paul (Notts) - 13/3/09 at 06:21 PM

Ideas needed…

The car has been running really well recently until last night I ventured out to the local Westfield meet. After a few second the car seemed to misfire or more accurately stumble. Seems worst when you try to accelerate.

Car is running EDIS 8 and a Webber 5000 carb.


Plan of action for Saturday includes

1 checking the VR sensor mounting
2 plugs
3 leads
4 wiring to edis and coils and megajolj.

What else could be the problem. Just gets on my nerves as it was running so well and the it pulls a moody.

Paul


flak monkey - 13/3/09 at 06:24 PM

Is your fuel tank breather blocked?


Paul (Notts) - 13/3/09 at 06:30 PM

good idea!!!!

[Edited on 13/3/09 by Paul (Notts)]


big_wasa - 13/3/09 at 06:32 PM

fuel filter blockage ?


rusty nuts - 13/3/09 at 06:40 PM

Could the carb be flooding? Could cause your problems , whip a plug out and check colour. Check for air leaks? Quick squirt of WD40 around the carb base, manifold etc.


wrigglypig - 13/3/09 at 06:58 PM

when you get it started from cold , quickly feel the headers near the head the should all get warm evenly, cold ones mean they aint firing, it will be a start for you, Let us know how you get on

Kev


Paul (Notts) - 13/3/09 at 07:09 PM

If you just let it idle then its fine, and will rev in neutral ok. Only seems to be a problem under load.


Bigheppy - 13/3/09 at 07:27 PM

Could it be running on the edis limp home mode.


handyandy - 13/3/09 at 07:27 PM

either an air leak or plug lead breaking down,
imo.

andy


britishtrident - 13/3/09 at 08:23 PM

If the air temp was cold it could have been carb icing, however generally.

If the engine was previously running well --- if it hiccups under load it is fuel related, a misfire under load tends to be ignition.

If the loss of power happens two or three seconds after giving the engine throttle the problem is between the float chamber and the tank. --- start by checking the fuel line ines are clear from the pump back to the tank -- be way to do this is remove the filler cap, disconnect the pipe at the pump inlet and blow back to the tank with a foot pump --- if it is clear you will hear lots of bubbles i the tank.

Then disconnect at carb inlet and fuel pump outlet and blow back from the carb end to the pump.

Remove the float chamber lid check for signs of water in the fuel and check the carb float valve is clear.

Check all the cab jets are clear and the accelerator pump is working.


Paul (Notts) - 13/3/09 at 08:39 PM

Defiantly more of a hiccup than a misfire so will have a good look at the fuelling.

Thanks for that

Paul


Paul (Notts) - 14/3/09 at 04:44 PM

cleaned fuel pump filter and then cleaned carb. reset float heights.

also moved any ignition lead that was close to rocker cover.


now runs better than ever.

thanks for the advice.

Paul