[lastminuteman]

Hi, hoping someone can point me in the right direction. My car missfires around 2k rpm and pulls strong 3k+. It gets worse when its raining and when its not raining the miss is only noticable when the engine is warm?

I pulled the spark plugs and 3 of them are running lean. Any ideas on where to start? Thanks in advance

 

[g4vvq1983]

Sounds like you want to put a new set of plugs in it, does it have HT leads?, cant remember the exact engine now...i would change plugs, leads and air filter, have a good look at the distributor cover if it has one and rotor arm...look for black lines inside and out on the cap ans rotor...sounds like ignition misfire under load...from Fred in Essex.

 

[lastminuteman]

If it was ignition misfire wouldnt the plugs be fouled with fuel and be a dark colour and not bright white, I stopped and pulled the plugs while it was missing? I did re-gap thd spark plugs didnt make a difference to the misfire?

Airfilter looks to be ok.

 

[g4vvq1983]

Hi there, well not always, you cant always go by what plugs look like, if they have done a lot of mileage or have black marks down the outside i would change them....ok on air filter, well you could go down the route of code tests etc..think you have to do a b with a papaerclip or dedicated code reader...i dont think it's EOBD...it might be...

Has it got distributor and plug leads on etc? Fred.

If it was ignition misfire wouldnt the plugs be fouled with fuel and be a dark colour and not bright white, I stopped and pulled the plugs while it was missing? I did re-gap thd spark plugs didnt make a difference to the misfire?

Airfilter looks to be ok.

 

[lastminuteman]

I think it does have a distributor and plug leads. When it misfires it also overheats so I do think its running lean, sometimes I can hear a whistle kind of sound too maybe an airleak is what I was thinking.

I spent more than I should have buying it, so not wanting to spend much trying to find the problem. The previous owner wired the fan to a switch instead of sorting it out. Also the heater only blows cold air not sure if thats related or not, the windscreen also fogs up with water and leaves an oily residue.

Ill try finding out if any codes have been stored in the morning. Cheers, Andrew

 

[g4vvq1983]

Hi Andrew, it definitely could have an air leak if you can hear a whistle..plug leads do fail quite a lot, they get breaks in them, if there is a distributor on the passengers side of the engine....you will see a brown or black cover with 4 or 5 black leads coming out of it that go to the plugs...caps and rotor arms can get damp and start tracking, that means Sparks jumping about where they shouldn't..

i would look around the servo hose and any vacuum hose for air leaks, usually if its the inlet manifold gasket it will run on 3 cylinders...if its an air leak it should whistle more at idle than revving....

I think the fan should run off a switch screwed into the radiator...prob wants a new switch...the heater, sounds like an air lock or the controls aren't working properly. i would turn the temp on hot and check both the heater hoses get hot, running, the matrix might want flushing out....

Usually the MIL light comes on when you get fault codes...but always exceptions...there are some U tube clips on checking for codes on Corsas..

from Fred in Essex.

 

[lastminuteman]

Just had a quick look and it has an ignition coil pack. I checked the secondary windings with a multimeter and one reads 5.48kohms and the other 5.45kohms. I tried squirting water around any vacuum hoses with water from a washing up liquid bottle and did not notice any drops in rpm or rough idling.

Checked plug leads with meter and seem to be ok, had a good look at filter and does need a new one, so guess next step is replace filter and plugs? Cheers

 

[g4vvq1983]

Hi there, well i think i would change the easy stuff first, afraid its a bit hit and miss, i wouldn't pay too much attention to HT resistance readings, probably not significant as long as there somewhere near, the primary resistance should be about 1 ohm or a bit less......

It sounds like it has a Wasted spark system on, that is a coil with 4 outlets where the lead push in, so no distributor. that being the case it should have a crank sensor on and possibly a cam sensor...still might be worth perusing a code test, i think the socket is on the right side of the steering column on that, in the fuse box??, i did have one years ago, that was a diesel with the Japanese Isusu engine in, i had that for 7 years, it never had a running fault and it never failed to start...mind you the one i have now Corsa C 1-0 litre year 2000 same...never had any problem so far with that...think had that about 6 years..that's petrol...

You done the right things testing the leads with an ohm meter they should have some resistance as there suppressed for radio interference...if they had a break in that would have told you....worst case sanario it could have an ECU fault...but you might want to look on U tube at the code test routine...

By the way what sort of fuel sytem does it have on, Carburetor, single point injection or multi point injection??

from Fred in Essex.

Just had a quick look and it has an ignition coil pack. I checked the secondary windings with a multimeter and one reads 5.48kohms and the other 5.45kohms. I tried squirting water around any vacuum hoses with water from a washing up liquid bottle and did not notice any drops in rpm or rough idling.

Checked plug leads with meter and seem to be ok, had a good look at filter and does need a new one, so guess next step is replace filter and plugs? Cheers

 

[lastminuteman]

It is single point injection I think, any idea which pins it is to short out, top right or left? And yes fuse box and connector is where you said.

Edit: Do you also know which pins on ignition pack is for the primary windings or will it be obvious when i go check Thank you

 

[g4vvq1983]

Hi there ok on single point injection...i poor connection on the injector can cause poor running or restricted jet prob isn't that but might be worth putting a can of additive in the fuel tank, you can but it from most garages....

Now the code test on yours most probably only covers the injection system and not the coil etc..but it seems there are only 4 terminals in the socket that actually have a metal terminal in them, all the other holes are blank, it looks like the two on the top right.....you get a paperclip and fold it into a U shape, put it in the top 2 holes that have metal in then turn the ignition on and count the flashes on the lamp...they tend to repeat over and over...you will prob get something like say 33, you will have to google it, it's not an EOBD generic code, it's vauxhalls own.....see link below.

I dont know which wires, on coil primary, but i think you only have 3 or 4, if you have 3 one is live with ignition on, plug off, so its between that terminal of the coil and the other 2 in turn, so it has one live in and two switching wires, or 2 primary winding, one for cylinders 1-4 and the other for 2 and 3...primary test with ohm mete hardly woeth doing unless their open circuit, if they are working there prob ok.....from Fred.

It is single point injection I think, any idea which pins it is to short out, top right or left? And yes fuse box and connector is where you said.

Edit: Do you also know which pins on ignition pack is for the primary windings or will it be obvious when i go check Thank you

 

[lastminuteman]

To update...changed plugs, changed leads (one was split should open my eyes a bit more lol) and now just changed coil pack. Still misfiring\hesitating :\, seems to only happen on light throttle under load?

 

[g4vvq1983]

Hi there i'm still around lol, if its got a distributor cover and a rotor arm i would change those, it sounds like it could be running lean, i presume its has a single point injection??, well whether it does or not, i would put some injector clean additive in the fuel tank, have a look round for vacuum leaks on inlet manifold, and hoses etc...can you do a code test on it?, i think on the B you have to short 2 of the pins on the socket with a paper clip and count the flashes of the MIL light, there are U tube clips to tell you how to do it....and check air filter is ok...it could be a dead pot on the throttle potentiometer if it has one...good luck from Fred in Essex.

To update...changed plugs, changed leads (one was split should open my eyes a bit more lol) and now just changed coil pack. Still misfiring\hesitating :\, seems to only happen on light throttle under load?