HELP LUMPY ENGINE AND OVER REVVING

[BGP]

Hi One and All,

I would be exceptionally grateful for any help, I have been through the forum and can’t find anything to describe exactly what the problem is.

Basically, the car (M100) has been stored in my garage for the last 6 months, so I though it about time to give it a bit of a run. Although the battery was flat, I gave it a jump start and it fired up first time. I then kept the engine running on tick-over (very smoothly as normal) when I gave it a clean.

Unfortunately after about 10 mins, the engine suddenly and very quickly cut out. I then tried to restart the car, on about the 10th attempt the engine started but appeared exceptionally lumpy as if it was only firing on 2 cylinders, there was also loads of smoke coming out of the back, which smelt very much of unburned petrol. Eventually the engine cut out again.

I left the car for about 1 hr and came back to it, this time it started first time firing on all 4 cylinders with no smoke; however, this time the engine started over revving to about 4000 RPM for no reason.

I left the car again for about 1 hr and this time it started normally with all 4 cylinders and no smoke; however, after 10 mins the engine cut out. When I eventually managed to restart it, I experienced the same symptoms as before (exceptionally lumpy as if it was only firing on 2 cylinders, there was also loads of smoke).

I switched off the engine and returned to the car 1 hr later and it started fine, but after 10 mins stopped again.

I am now lost as to what is wrong, can anyone help

Cheers

[ashm]

Hmm... systems that change state after the car's been running for a few minutes or gets up to temperature...?
- coolant temperature sensor
- O2 Sensor

either could perhaps cause overfuelling due to bad reading?

Adam

[Brit-Car-Nut]

Hmm... systems that change state after the car's been running for a few minutes or gets up to temperature...?
- coolant temperature sensor
- O2 Sensor

either could perhaps cause overfuelling due to bad reading?

Adam

Also possibly a bad fuel pressure regulator.

[whippit]

mine does the same from time to time, fires on two or three, runs like a bag of spanners for ten minuets ,
cleaned the tps , changed the cts a lot better but not 100% , it does throw the odd back fire in to scare the be-jesus out off me

[DeanG]

I had something like that. Finally after years I found it was an intermittent bad injector. It overheated the driver which would kill the second injector. This over fueling also ate the catalytic converter. Good luck.