The MGF Register Forums

My MGF 1.8 16v has an erratic fault. She runs well, then starts to loose power, you can change down the engine picks up then dies again. I have changed plugs and coils to no avail. Any ideas.

How old are the plug leads? They can break down after time.

New plugs and coils fitted. Problem is she eventually stops but you can restart immediately although the problem will still be there.

Welcome to the Forum ~ hope to see you at an event soon.

Blocked fuel filter?

Have just purchased new fuel and air filter to try. Might remove sensors I can get to and clean as well! Hope to come to meet some time.

Hi and welcome to the forum.

James

Has your car an OBD socket on the fuse board under the steering wheel? If it has it might be worth checking for any fault codes. I have a basic one which connects to my tablet. If you're local I'm happy to see if there's any codes registered.

nigelandjo wrote:Has your car an OBD socket on the fuse board under the steering wheel? If it has it might be worth checking for any fault codes. I have a basic one which connects to my tablet. If you're local I'm happy to see if there's any codes registered.

All models have an OBD style socket there. However only MEMS 3 cars (basically mk2 onwards) are OBD2 compliant, earlier cars need a specialist reader.

However reading the ECU is a good idea.

A 1.6 litre in an MGF will be MEMS3, so an EOBD reader will work fine. If fault codes are stored, this will be very useful - but often only codes related to a misfire are present and not necessarily very illuminating...

Are these problems only when the engine is warm? Anything that seems to precipitate the problem? Anything that seems to make it better? How did it start, and has it been getting worse?

Now having fitted; plugs, HT leads, coil packs, air filter, fuel filter and cleaned two sensors in water,problem still there, in fact worse. Car kangaroos then will eventually stop. Can then restart immediately but problem may or may not be there. I have listened to the fuel pump when running rough then clearing and it sounds the same! Am going to have it tested but not much hope. Any thought mechanical (fuel) or electrical.
Car is 2001 MGF 1.8 16v. Thanks

Clogged cat?

All sounds very odd, I don't suppose it could be anything to do with needing to reset the throttle position sensor or a clogged Idle air control valve? Sounds like it's worse than the symptoms of those things but you seem to have tried everything else

Is your throttle cable caught on anything, is it fed into the right clips on the manifold and is it twisted at any point along its length?

Assuming it's MEMS3 ( you mention coil packs ) could it possibly be the camshaft position sensor failing?

This is the one that sits in the camshaft cover, or perhaps the plug that connects to it.

Konighaus wrote:Now having fitted; plugs, HT leads, coil packs, air filter, fuel filter and cleaned two sensors in water,problem still there, in fact worse. Car kangaroos then will eventually stop. Can then restart immediately but problem may or may not be there. I have listened to the fuel pump when running rough then clearing and it sounds the same! Am going to have it tested but not much hope. Any thought mechanical (fuel) or electrical.
Car is 2001 MGF 1.8 16v. Thanks

2001 will be MEMS3. Get it on a fault code reader (plenty around - my favourite is the pscan as it can access all the car's ECUs, not just MEMS ) which will helpfully provide you with some clues...

I have now fitted a new camshaft sensor with no effect. Disconnected battery overnight to see if that worked, would that clear a fault on the system or do I need to take it back to garage to clear? Secondly would a failed LAMDA sensor cause erratic running and engine to stop, and with no warning lights. Once stopped restart immediately. It does smell like it is getting hot could it be a failed catalytic converter! However the fact it runs really well when the fault is not there is the worry. Looking more like the crusher is coming!!

Fitted new LAMDA sensor plus new cat. converter, still same problem and nothing coming up on computer! Eventually fitted new O2 front sensor and hey presto problem solved. Thank you all for your comments, hope my experience might help someone else for a lot less money!

Konighaus wrote:Fitted new LAMDA sensor plus new cat. converter, still same problem and nothing coming up on computer! Eventually fitted new O2 front sensor and hey presto problem solved. Thank you all for your comments, hope my experience might help someone else for a lot less money!

Glad to hear you solved the problem. Hope to see you at an event in the region sometime.

Thanks for the update, pleased it's sorted.