Misfire

[LukeVTR]

The car seems to be misfiring from the exhaust when its in idle and when i turn the car on. Also noticed the petrol seems to be being used quicker than normal and the engine management light came on today for about 5 seconds then went out.

Is all this due to a sensor or coil pack?

The following has been changed/done - spark plugs, tappets adjusted, head gasket, inlet gaskets

[saxosxi]

could be coil pack or lambda sensor could be aload of things, have you changed plug or leads recently???

[LukeVTR]

Changed the plugs recently and leads were changed before the head gasket was done so they are new.

[Lozza_vtr]

When i had a misfire on mine, i plugged it in to the diagnosis and it was a lambda fault. Changed it and sorted the misfire.

[LukeVTR]

Would it be worth cleaning and spraying the sensors with wd40? Bloke who did my head gasket jet washed the engine to clean the oil off.

Also, where is the lambda sensor on a mk1 vtr?

[saxosxi]

could do mate and if you pop up your bonnet look to the front, near the fan yourl see the top of your manifold the lambda sensor is located on that be a wire coming off it too!!

[LukeVTR]

The engine management light has started coming on more often now, it comes on for about 5 seconds then goes off and after driving for a bit longer will come on again.

[Anders0n]

The engine management light has started coming on more often now, it comes on for about 5 seconds then goes off and after driving for a bit longer will come on again.

Sounds like your lambda sensor then, cleaning it with wd40 won't do anything, you'll need a new one.

[Mark51]

tbh mate its going to be quicker and probably cheaper in the long run if you just get it plugged into a diagnositc machine. this should be about £20.

you could end up spending more on guessing at what it is rather than getting it diagnosed striaght away

[LukeVTR]

Its booked in for a diagnostic check thursday.

[guvna]

Would a faulty Lambda always throw up an error on the ecu, or can they play up without you noticing it on the dash?

[ox45]

mine was same and ended up being the coil pack, had a diag done but it never showed up

[ox45]

Changed the plugs recently and leads were changed before the head gasket was done so they are new.

do vtr's have plug leads??? just wondering as mine has cassette type c.p

[LukeVTR]

Done a diagnostic check today and it showed 2 faults - mixture and 02 sensor, was told the lambda sensor is making the mixture fault show up so ive ordered a lambda sensor.

Edit - I hope it isnt my coil pack, ive got quite a good deal on the lambda anyway £33 delivered.

[LukeVTR]

Ive changed the lambda and its still misfiring. The diagnostic said it was the sensor and the engine management light hasnt come on so looks like that problem is fixed. Is has to be coil pack now surely?

[Rhea21]

my car is still misfireing after having to diagnostics changed what it said but still happening, let me know how you get on, starting to think mine is the coil pack aswell!

[LukeVTR]

my car is still misfireing after having to diagnostics changed what it said but still happening, let me know how you get on, starting to think mine is the coil pack aswell! someone has said the coil pack fault didnt show up on the diagnostic ive never changed it either so must be

[LukeVTR]

Seems like it got worse today it feels like its pulling back in most gears and at idle the exhaust sounds like its misfiring loads. Also noticed that rattling noise could a faulty coil pack cause a rattling sort of noise (from the sparks) if it was misfiring under acceleration?

[Rhea21]

does your misfire all the time as if i can manage to drive and not lift my foot off the accelerator for to long mine doesnt misfire so everytime i stop at traffic lights i have to keep revving my car!

[LukeVTR]

I can drive it but if i stop in traffic the revs start dropping then going back up and you can feel the car shaking from underneath and the exhaust is making the noise it does when it misfires. If i put my foot down in gears it feels like its pulling back then opens itself up and gets faster but that is when the rattling starts.

[LukeVTR]

The problem i had with it misfiring when putting your foot down has now been fixed, turned out to be the timing belt was 2 teeth out.

My idle seems to have calmed down but its still playing up a little is there a good chance its the coolant temp sensor causing it?. The car idles at around 500 when the engine is warm but plays up every now and again and drops revs then goes back up (isn't stalling)

[evans1089]

The problem i had with it misfiring when putting your foot down has now been fixed, turned out to be the timing belt was 2 teeth out.

My idle seems to have calmed down but its still playing up a little is there a good chance its the coolant temp sensor causing it?. The car idles at around 500 when the engine is warm but plays up every now and again and drops revs then goes back up (isn't stalling)

How did you sort it then? with the timing belt?

[LukeVTR]

Garage sorted it.

When its idling it isn't as noticeable as it was but it still happens randomly, ive read a few threads on people having problems with their icv and coolant temp sensor so would the random idling be to do with one of those?

[evans1089]

i had the exact same problem, and still do mate,i increase the idle on the idle control valve to about 1200 rpm, and it stopped it stalling at lights or stood still!

Now i just need to sort the mis firing! :(

[LukeVTR]

Ive read a few threads and it seems to be the coolant temp sensor causing it on most.

[evans1089]

Ive read a few threads and it seems to be the coolant temp sensor causing it on most.

and which ones that mate?

[LukeVTR]

The green plug on the side of your engine, for the mk1 saxo anyway

[LukeVTR]

The problem i had with it misfiring when putting your foot down has now been fixed, turned out to be the timing belt was 2 teeth out.

My idle seems to have calmed down but its still playing up a little is there a good chance its the coolant temp sensor causing it?. The car idles at around 500 when the engine is warm but plays up every now and again and drops revs then goes back up (isn't stalling) and sounds like its missing a little on idle

Does anyone have an idea what is causing this? Would a loose part of the exhaust cause this or is it a sensor?

[evans1089]

increase the idle, i did it to stop if stalling, just need to stop it misfiring now :(