Hello all.


Yesterday I filled my panda up £30 quid in. Was fine for about 10 mins until I stopped at lights on a hill. I first noticed the engine popping as though there was a misfire, then when amber came on I got ready to set off and the engine cut out and would not start. I eventually got it started but it sounded like it was running on 3 or cylinders. There is also a strong smell of petrol, she's running a little better now but misfires, there is a definite popping sound coming from the exhaust and a lack of power.


Now I have changed the coils, leads and plugs, cleaned the throttle body and it was running fine until I filled her up. Prior to this, I have been getting flat spots and dipping revs at idle after giving gas. Just seems strange that this has happened before on a full tank.

Has anyone had anything like this before?. I have read and looked and found similar stuff but nothing definitive.

A missfire on one cylinder will cause the ECU to add more fuel so it runs rich and make the problem even worse.

Basically the unfired power strokes put unused oxygen down the exhaust. The O2 sensor sees that and the ECU thinks it's running weak so adds more fuel.

You need to unplug and refit the spark plug leads one by one. The one(s) which makes no difference is the faulty one. As you have at least one not firing, removing any of the others will probably stop the engine.

Just done that now and it's defo running on all 4s again but it is popping when reving the engine. I got it up to running temp (temp at which the dipping idle and flatspotsstart.) But I am unable to take her on the road atm as I am only on prvisional and our lass isnt here.


Seems to be a lot better though, I also tightened the throttle cable as it appeared quite loose.


See what happens tonigh when I get picked up from work.


Cheers.

Was the fuel you used your “Normal” stuff and from the same garage you buy from? Sometimes (But rarely) if you buy from a fuel station that has a low turn over! It can be stale. Try going to a different one and see what happens.

I’d be inclined to run a cleaner through the system. Many in the market, some work and most do not. Better ones as BG44K and Wynn’s formula Gold. This can be purchased for around the £10 if you know where to look. Might be worth a try considering all the other things you’ve done so far...

Yeah it was from a garage, quite a busy one as well. I'll grab a cleaner and run it through again at some point.


See how it goes tonight. It seems to be back to normal but the issue is so intermittent. Usually the car runs fine until about 10-15 mins later it'll play silly buggers and start doing the dippy rev thing.

It could the fill-up caused the problem.. fuel doesn't go stale as much as gets contaminated so the fuel system cleaner route is worth a go.

You'll only know it's "fixed" for sure if you can syphon out the fuel that's in there now and fill up from a different garage.

I would try e.g. Shell or Tesco and put in £20 of their 99-ROM/Optimax since that might solve the problem... and when you fill it up next time, if the problem comes back then you'll know that a higher octane fuel doesn't cause the problem, which would be significant in finding out what does.

If you have a lumpy idle and a misfire and your ignition components are new, then the only thing it can be is the fuel injection or the Throttle Position Sensor (TPS).

I dunno how many injectors you have.. but it's worth getting them checked, either via OBDC (error messages stored in the ECU) or by taking the beast to an injection specialist who can measure the output of each one. You can DIY it by getting hold of a spare injector (second-hand would do) and fitting it in each position in turn to weed out any that isn't performing properly.

TPS could be gummed up so the car doesn't know it's supposed to be idling or revving but this is probably less likely than a duff injector so maybe one for later.


Ralf S.

The throttle position sensor is a sliding contact potentiometer which can wear over time.


Getting the error codes is the least costly way forwards.