sudden bad running
Discussion
On my way to work this morning on the M5 and suddenly the car starts to act like its got a fuel starvation problem - juddering and 'hiccuping' slow down and notice it really smells of petrol. Limped into work with all gauges showing normal, it will start but runs very roughly with loads of unburnt fuel pumping out the exhaust. no signs of head gasket failure but I did notice the swirlpot was steaming a little although as I said the temp gauge never went above 90. I have tried disconnecting the TP makes no difference. I'm a bit stuck as I don't have any tools with me to whip the plugs out... any suggestions please.
what GreenV8S said...
The symptoms do sound similar to what mine was doing a while back. Perhaps the ECU has switched into LOS mode because some sensor's output is out of range ? This will richen the mix up and make the thing stink of petrol.
Possibilities:
Could be Engine Coolant Sensor - check connections. These are about 12 quid from Ford IIRC.
Could be the Idle Speed Control Valve - can be cleaned.
Could be the Air Flow Meter (the top one) - Whip the air filter off (when you have some tools !) and check that the heated wire and its housing has not become gunked up. A bit of carb cleaner and careful use of a cotton bud works wonders here.
Could be something else less obvious than the above - any mates with a Ford EEC IV ECU Interrogator ?
The symptoms do sound similar to what mine was doing a while back. Perhaps the ECU has switched into LOS mode because some sensor's output is out of range ? This will richen the mix up and make the thing stink of petrol.
Possibilities:
Could be Engine Coolant Sensor - check connections. These are about 12 quid from Ford IIRC.
Could be the Idle Speed Control Valve - can be cleaned.
Could be the Air Flow Meter (the top one) - Whip the air filter off (when you have some tools !) and check that the heated wire and its housing has not become gunked up. A bit of carb cleaner and careful use of a cotton bud works wonders here.
Could be something else less obvious than the above - any mates with a Ford EEC IV ECU Interrogator ?
I'm having a problem a bit like this too, although I can smell petrol on start up and it takes a couple of goes before it starts cleanly and there's a definate smell of petrol just after starting which then disappears.
Once running it's fine, but something I wouldn't mind people's opinion of...
Cheers!
Once running it's fine, but something I wouldn't mind people's opinion of...
Cheers!
Got hold of some tools and checked the ignition - fine. I've got a dastek unichip fitted and when this was disconnected the car ran better up to 2500rpm when it starts to backfire in the exhaust really badly reconnect the unichip and the fuel pump now refuses to work!!!!!!! time for the AA I think.
wonderland said:
I'm having a problem a bit like this too, although I can smell petrol on start up and it takes a couple of goes before it starts cleanly and there's a definate smell of petrol just after starting which then disappears.
Once running it's fine, but something I wouldn't mind people's opinion of...
Cheers!
If it's not sparking to start for a couple of turns before it catches, then it's pumping fuel-air mix through the valves and out the exhaust, so you'll smell petrol, especially if you reverse out of your drive into the petrol cloud!
Nothing to worry about in itself, but best if the car starts on the key - probably ignition system contacts etc...
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