View Full Version : Bad engine running
I've developed a bit of a problem with my saloon (1.2 carb). Started and ran perfectly this morning, but after i slowed down from the dual carriageway it started running really badly. Under about 2000 revs it'll stall, and if i give it some pedal/choke to keep the revs up it just drops until it dies.
Driving along at slow speed the engine feels really lumpy, almost like its trying to stall all the time. When it does stall though, it restarts ok but still doesn't run well. Temperature is staying between just out of the blue and under quater mark (as per usual), so its not the carb icing up, or the engine overheating. I've had a look under the bonnet and there's no sign of skank in the water, the level hasn't dropped, and the oil is nice and clean though so its not like the head gasket has gone pop.
Anyone have any idea what could be causing this? Or how to fix it?!?!
2litreturbo
11-03-04, 11:57 AM
just because the engine is warm doesn't mean there is no carb icing. I'm not saying that is the reason but dont rule it out. Obvioulsy if it is a sunny day then that wont be the reason!
Yeah, well it wasn't sunny but it wasn't exactly cold - i've been to work in much colder weather and not had a problem, thats why i didn't think it was that :?
2litreturbo
11-03-04, 12:18 PM
have you got an oil pressure gauge? have a look and see what that says.
Nope (well i have on some GTE dials, i just haven't put them in yet :lol: )
2litreturbo
11-03-04, 12:47 PM
may be something to do with that but not 100% sure. haven;t experienced that problem
sounds like you have sucked up some shite into your carb from the tank. try gettin some carb cleaner and blow it all through.
2litreturbo
11-03-04, 02:12 PM
plugs might need a clean.
thanks guys, i'm just about to finish work so i'll let u know how it is when (IF!) i get home lol
my mini did this....
run on choke and lower it abit at a time till the car keeps idling at the lowest amount of choke.....leave it running awhile and it should run peachy again.
(choke full, leave running, abit less, abit less etc etc.....)
Giving plugs a clean and check there spark/contacts might help too
it got me home in one piece, didn't seem to be running too bad at all going home, but its not idling at all. Its ok with a little bit of choke tho. I'll take a look at the plugs and HT leads in a minute, i've got some spare lying around so might swap them over and see if it helps.
Snowface
11-03-04, 06:25 PM
it can be as sunny as hell on a Winters day, doesn't mean its going to be warm though.
(think of ski slopes in Austria, they so sunny u need glasses/goggles and u don't see the snow melting now do you?)
I'd say Carb icing was the problem.
nova_rally
11-03-04, 06:40 PM
Carb Icing is caused by water in the carb freezing over the jets right?
Never suffered with it myself (using old black box air filter but no hot air intake) amd nor has my mate who runs a K&N. Could the fact that we both regularly use carb cleaner in the petrol to get rid of water have anything to do with it?
Alan
Snowface
11-03-04, 08:32 PM
water shouldn't be in the carb at all. Its the cold air that freezes the fuel i think when its mixed.
what about redex? is that any good?
sounds kinder familier this problem that Road_knight is having. Mine does similiar in the mornings. Right bitch
Well i've just driven it back from chard in heavy snow, and it's been ok (well not perfect, its still a little twitchy when idling but nothing a bit of choke couldn't fix). So it doesn't look like cold outside temperature was an issue. Didn't get a chance to check the plugs and what not, i'll see if its any better tomorrow.
nova_rally
12-03-04, 09:07 AM
Petrol Freezes at about -57 degrees C!!
Alan
ok, its not any better today! Wouldn't even start this morning. Engine was turning over, but not starting. As far as i know the battery is fine. Didn't want to risk bump starting it in case i got halfway to work and it died!
So had to take the hatch today which means paying for parking :evil: lol...
my 1.3 sr acted in this way also. whats annoying is that there are so many factors that can affect it your never sure what to blame, but i think mine was def worse in the winter months.
it always had a problem with low oil pressure so reckon its somthing to do with that.. not quite sure if low oil pressure would cause this to happen but its the only theory i could come up with.
Would poor oil pressure at the lifters cause this errattic engine behaviour?(If the valves weren't opening prop etc)
i eventually got rid of it to a mate and then the engine blew a few weeks later! the bearings were shagged and he kept running it for as long as poss and then snapped a rod!
then the engine blew a few weeks later!
ok now i'm worried!!
Is there any way to check the oil pressure? as i've only got the 3 gauge dials on at the moment.
Snowface
12-03-04, 06:26 PM
Petrol Freezes at about -57 degrees C!!
Alan
yes but when mixed with air in the carb it forms a vapour that freezes i think.
U say its water? How is water meant to get in the carb? It shouldn't be there if it is. Is their a hose pipe connected to it? lol
Engines + water = total engine faliure (water is uncompressable so when piston rises it will fail badly).
(and don't go 'Oh what about water injection', that is different, controlled)
U say its water? How is water meant to get in the carb? It shouldn't be there if it is. Is their a hose pipe connected to it? lol
I was meaning water in the head, i.e. head cracked or gasket blown - in all the other times i've seen that happen the water level has either dropped or filled with white skank (where its mixed with the oil) so thats what i checked first!! But its all ok.
Gonna give the car a quick service either monday or tuesday and change oil, filter, plugs, and check distributor and leads.
nova_rally
12-03-04, 07:00 PM
Water in Petrol (through knackered filter) or it comes through your air filter. The atmoshpere is made up of water and it will go through. Doesn't help if you start pulling the air filter off your car in damp weather etc. I've been doing so this last week and only now has the car started cutting out. when driving. If your experiencing bad running make sure that that litle plastic pipe coming out of the base of the carb is either blocked up or connected to your black box filter. Let it suck air and your car will run awfully.
Water in the engine won't make slightext bit of difference as your pistons don't touch the head at all, there is always a gap so water isn't a problem in the bores and is a product of combustion anyway.
Alan
2litreturbo
12-03-04, 09:02 PM
carb icing happens when moisture in the air condenses and freezes, not the petrol,
Also, you say water isn't compressible and your right. But if water went into the engine it would imediately turn to steam anyway and water vapoour is compressible as it is a gas.
Snowface
13-03-04, 12:52 PM
so why is it diesel engines totally fukc up when water gets sucked up the exhaust into the cylinders?
2litreturbo
13-03-04, 06:09 PM
so why is it diesel engines totally fukc up when water gets sucked up the exhaust into the cylinders?
because it happens when the engine is cold and the engine does not get hot as quick as petrol engines because it relys on compression not ignition
Snowface
13-03-04, 08:27 PM
i didn't really get what ur saying.
Diesel engines run under much higher compression (20:1 or higher) and as a result they got warmer quicker, thats why they have larger radiators than petrol cars and are also built stronger (heavier).
Diesel can suck water up wether they are cold or hot and mess up engine.
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