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MG MGF Technical - 'Stuttering' 1.8i at 1500-2000 rpm
|If anyone has any ideas...|
My 1.8i has started 'stuttering' occasionally at around 1500-2500 revs when pulling away in 3&4 gear. It is momentary and stops after 2 or 3 'hiccups.' Otherwise it's running fine...
Any idea what this could be? The car has done 70000 miles near enough...
|Stab in the dark says|
1) MEMS throttle position sensor fault - Press go pedal to the floor rapidly five times with ignition lights on but engine not running
2) MEMS throttle position sensor fault - dirty POT, replace throttle with Trophy model (also enjoy extra power)
3) MEMS fueling map fault - Don't know, probebly a trip to see the testbook
4) Sticky throttle - (unlightly, I think this only has an effect on trailing throttle) see 2
5) Leaky inlet manifold - usually caused by unconnected hoses, unlightly unless work has been done recently
Think I'll try the cheap option first and try and avoid that Testbook, which is guaranteed to be pricey...
|Only a guess but mine was misbehaving recently and I did the obvious things.|
Turned out to be none of these. Instead it was the leads. After changing these and half a can of injector cleaner down its snout it was like a new car.
|Good point, it could well be the ignition system...|
Do you have trouble starting and is the problem under heavy acceleration, these are pointers which would point to ignition problems (not enough spark for the gap)
Anyways it is probebly worth replacing
the plugs (have done over 20k miles)
the leads (may have done up to 70k miles)
and posibily the distributer/rotor arm if they look worn/black.
Don't try to clean the rotor arm or cap as the matalic deposits will be helping the spark.
|Hmmm.... it is under heavy-ish aceleration that the problem manifests itself more often than not. |
Just checked the paperwork and can't see that the leads have been changed for some time, if at all - so, this could be the answer?
Thanks for your suggestions...
|The ignition system seems a likely culprit Chris - I've been having similar problems with my '96 F, despite having changed the leads about 6 months ago.|
I've replaced the rotor arm and dizzy cap, and things seem to be much better - no more kangarooing :o) Amazingly, despite a FMGSH, the date stamp on the rotor arm stated Oct 95: the whole system is the one that originally came with the car when it was first built!!! According to Dr Dave, rotors/ dizzy caps over 4 years old are prone to malfunctioning.
I reckon this ought to be the first port of call: the parts are all cheap, and very accessible once the engine bay cover is removed.
|Ps. Buy decent leads, Rovers are pretty well pathetic. magnecore seem to be the standard replacement item. I tried to get Splitfire but they don't seem to do them for the K series.|
Sorry I forgot to mention to give the coil a good spray with damp start. It is at the rear bottom side of the engine. Pretty silly place to put it since we are turning into a tropical monsoon climate.
This thread was discussed on 03/04/2002
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