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Engine stutters at low revs
Posted: Sun May 17, 2015 8:02 pm
by robmurray
My 2000 Coupe is in pretty good shape and runs well but it stutters when pulling away. It occurs at about 1500rpm. You either have to blip the throttle to clear it or drive through it with the car kangarooing until it clears. Feels like fuel rather than ignition. Any theories?
Thanks
Rob
Re: Engine stutters at low revs
Posted: Mon May 18, 2015 8:30 am
by Stefan2000
I think in first place it's important to know for sure that your advance mechanism is working properly (especially around that rpm range which you could check with a timing light).
You should also make sure that the carburettors and jets are clean, float level correct, fuel pressure correct, that you have the correct idle jets and main jets and so on.
Did you check these things first and all seems to be within specs?
Re: Engine stutters at low revs
Posted: Mon May 18, 2015 9:58 pm
by robmurray
Hi there
Yes the bob weights are fine. Carbs have been stripped and cleaned plus set up. Assume jets are correct.
I'm assuming it is just a set up issue?
Rob
Re: Engine stutters at low revs
Posted: Sun May 24, 2015 10:01 pm
by Barnfind
Yo could see if the idle jets (any) is clogged. It could cause that kind of issue at low revs. Check also the advance timing, the weights could be stuck in open. Check that the level inside the carbs is correct. If the fuel pressure is too high, or the return line is blocked, it could over-enrichen the mixture, more evident at low speed..
How did it begin to happen? It could also be somethjing wrong in the engine, but it is less likely tan merely a setup problem.
Regards
Re: Engine stutters at low revs
Posted: Sun May 24, 2015 10:25 pm
by Dario
Hi, I had a similar problem and chased it down to the fact that the emulsion tubes on the main jets were slightly bent. This makes the jets not seat correctly. You can check this by either mounting the emulsion tubes on a drill and spinning them. Also, you can see if the seat correctly by going over the jets with a black felt marker and fitting the jets. When you remove them, you should see a clear circle where they were seated. If the circle is not complete, or not even, then it's not seating properly. I suppose my emulsion tubes got bent when someone overtightened them. This lets gas through and makes the transition from idle to full jets a bit rich.
Good luck, and remember to check the height of the floats and all the usual things.
Dario