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MG MGF Technical - hesitation on acceleration

Actually got my MGF back on the road today after its stood outside unused since last July.

I have periodically started it and allowed it to warm up, but thats pretty much it as its not been legal to use on the road.

I have noticed today that it starts first time, ticks over great and runs pretty well, that is until you put your foot down anyway. then it feels like its hesitating. It does this in all gears and is most prominent around the 2500 to 3500 rev band. It runs fine on a trailing throttle or at a constant speed.

Any ideas?

It was fully serviced approx 300 miles before it was laid up as it had new head gasket, water pump, radiator etc.

Thanks,
John

John Collins

John,

sounds like a problem with the connection of any sensor.
May be MAP sensor.

What engine is it ? VVC ? or standard ?
What is the engine idle speed ? More the 1000 revs ?
Dieter

Hi,

its a standard 1.8 engine, it idles at around 900rpm, I guess you are right, probably a dry connector somewhere, I'll run it this week to work and back and see if it improves, and then have a good look at weekend.

John
John Collins

A weak spark could give those symptoms, so worth checking the distributor cap & rotor arm, and possibly taking each plug out in turn and checking for a healthy spark. If it's a MEMS3 engine with coil packs, these sometimes don't like long periods of infrequent activity. But as Dieter suggests, poor connection on a sensor can also produce a variety of symptoms so well worth pulling each connector off and sluicing with electrical contact spray.
bandit

Yes, but a poor sensor or crappy sensor connection usually also results in fail save mode with high idle at 1200 revs and more ?
Doesn't it?

So the investigating the ignition route seams sound.
Plugs, coils etc. as suggested.
Dieter

Thanks for info, maybe I should have also said that the petrol level in the tank was minimal, I've put £20 of fuel in and given it a good run, all seems fine now, I'd forgotten how good an mgf is to drive and I had thought of selling it and even bought a replacement, but am now having 2nd thoughts!

John

John Collins

This thread was discussed between 03/03/2009 and 04/03/2009

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