misfire

[Matt X2C]

my car has developed a misfire on cylinder 1 (nearest the oil filler cap) most likely due to having to drive through a massive puddle on sunday evening. I have already tried swapping spark plugs, and the same cylinder still misfires so i have narrowed it down to either the coil or the leads.

If it is the coil, would 2 cylinders misfire or only 1?

It seems it is only 1 unit but I am not sure in which way it would fail?

i think leads are the most likely cause.

 

[Steve]

Moisture in the Distributor cap is a very common cause of a misfire, but it wouldn't affect one cylinder, it may well one of the HV leads but this is unlikely to be moisture related. Why don't you label up the suspected one, swap them over and see if it misfires on a another cylinder.

 

[Matt X2C]

ok, it isn't spark plugs and it isn't leads.

called renault assistance to my home yesterday to look at the car and he said it was definately a coil. Picked up a coil from Renault today, thankfully Renault UK picked up the bill. Fitted it, and there is still a misfire.

gonna try resetting the ECU and trying it again but if not then its going to have to go to Renault. Got a horrible feeling that its gonna be a head gasket which ain't gonna cheap, unless its obvious that my mods didn't cause the damage.

how can the guys machine tell him its the coil when its not?

 

[DaveTrophy]

Sometimes, fault codes can be triggered by something else, kind of tricking the ECU.

Its hard to explain, but the ECU responds to information that it receives,if the ECU is not receiving the correct information, it will flag up a fault code like "sensor implausable signal", when in actual fact its not at fault, the fault is coming from else where. It brings on the Engine management light to warn you that something is wrong.

This is only an example but im guessing its something similar which will have brought up a coil fault?

Sorry if that doesnt make sense to you lol, i find it hard to explain things in words

Can you not swap your mods back to standard or have you got rid of the original parts? Could end up saving you a lot of money if as you say its the mods that are the cause...

 

[Matt X2C]

Sometimes, fault codes can be triggered by something else, kind of tricking the ECU.

Its hard to explain, but the ECU responds to information that it receives,if the ECU is not receiving the correct information, it will flag up a fault code like "sensor implausable signal", when in actual fact its not at fault, the fault is coming from else where. It brings on the Engine management light to warn you that something is wrong.

This is only an example but im guessing its something similar which will have brought up a coil fault?

Sorry if that doesnt make sense to you lol, i find it hard to explain things in words

Can you not swap your mods back to standard or have you got rid of the original parts? Could end up saving you a lot of money if as you say its the mods that are the cause...

i kind of know what you are getting at.

Mods could be transferred back to standard at an absolute must, but the exhaust took ages to put on due to renault's crappy standard 1 piece design, for some reason it wouldn't come out unless the rear axel was dropped.

plus its not my time, its my brothers, he fitted everything

 

[Steve]

Matt, you're the only person I know of that didn't cut the OE exhaust in half, it seemed a bit extreme to drop the rear axle out but you've now got an exhaust in one piece to put back for things like this. Good job.

Good luck with it, I don't think Renault would not cough up for a cylinder head because you've fitted a new cat back exhaust. Why don't you ask anonymously on Renaultsport about mods affecting warranty issue, before going to the trouble of converting it all back.

 

[Matt X2C]

Matt, you're the only person I know of that didn't cut the OE exhaust in half, it seemed a bit extreme to drop the rear axle out but you've now got an exhaust in one piece to put back for things like this. Good job

i nearly did cut it in half, I wanted it on so badly! :lol:

booked into renault next wednesday, but in the mean time got aa renault person coming to look at the car by 5 and if he can't diagnose anything different then it is being taken to renault tonight.

 

[Matt X2C]

its all fixed, another aa guy came round and stumbled across the problem.....the injector plug for cylinder 4 had come out...whether this was to do with water in the big puddle forcing it off, or it not being plugged in properly I do not know but I just took it out and its fast.

For the last couple of days my mums rounaround, an S13 200sx has been my runaround...its a 1.8 turbo with 170bhp and the trophy makes it feel so slow.

Im so happy!

 

[hoolio]

Good one

 

[7MAT]

Glad to hear your cars OK, you got that sorted quickly!

 

[TRL]

Wondered where you had gone.....thank God you came out of this one smiling.

 

[Matt X2C]

cheers guys....oh and now the lamba sensor is back in, there is no emissions light from the decat!

it really felt very fast and loud yesterday, I missed it so much!

Hopefully going to do an evening trackday at Brands in 2 weeks to make up for 3 days without the car!