Misfiring Laguna

Please tell us if this is the late 96 engine with wasted spark, or more likely coil and distrubutor- if the latter then you have classic symptoms of HT leakage caused by either a cracked cap or knackered rotor arm.

Tim..

I've got the exact same problem with my 1996 Daewoo Nexia. Runs great and always starts first turn of the key but sometimes from cold it will chug and splutter like it's not firing on all 4 cylinders. It clears itself and runs perfect after a few moments driving. Changing plugs & leads has not made any difference but will try a new dizzy cap and rotor when I get round to it.

Fairly sure it's a wasted spark type - the coil(s?) is/are bolted to the side of the engine, just in front of the plugs and the HT leads run to there rather than the distributor cap. They don't look to have any obvious signs of cracking, but if they're suspect and an easy job to replace I'll pick up a couple from the local scrapyard. There's a plastic unit on the end of the camshaft where the dizzy cap would be - I'm guessing that on this model it's a sensor for the ECU.

Just to follow up my last post, it does have wasted spark ignition and the coils do seem to be suffering HT leakage, due to moisture - since dosing them liberally with WD40 on Sunday the engine hasn't misfired once. Suppose I'd better buy a new coil pack though... any suggestions for a cheap decent Renault parts supplier in the Leeds area appreciated!

Neither- go to German Swedish and FRENCH car parts.

Cant find the link at the moment, but a google will reveal it i'm sure,

Tim..

Try

They are roughly the same price for parts. They both have outlets in Leeds.

Pete

Thanks for the info.

Fitted new coils and leads the other day, started up and... exactly the same! Bugger :o( It seems to be more responsive when it's warmed up, don't know if that's a placebo effect though.

Bit odd as spraying WD40 on the coils seemed to solve the problem. Any more suggestions please anyone?

Have a look under the bonnet in the dark & see if there's anything visible when the engines running (the darker the better). Check the sparjk plug leads are routed right so they don't interfere with anything else, sacrifice a chicken & sprinkle the blood over the coil errrm ...

This sounds suspicious.... You have identified that one or both coils are leaking HT which is causing the misfire and that spraying WD40 water dispersing fluid on them stops the misfire, so I'd be more than slightly suspicious that the new coil is infact faulty...

Tim..

I'm beginning to wonder if the coils were only a part of the problem.

This morning when first started it ran like a bag of spanners as usual. Put my rigger gloves on and pulled each of the HT leads off in turn. No. 4 cylinder is the culprit but the lead produces a nice healthy spark to earth. No. 1 cylinder, off the same coil, is fine. Turned the engine off, left the car for a few minutes, came back, fired up, it ran OK.

The plugs are fairly new so I don't think it's them (no change from the old ones). Is it a sticking valve I wonder? Maybe a blocked oilway? If a lack of lubrication was the cause, wouldn't the problem get much worse over time? It's been about the same, intermittently, for about a year now. Think I'll try your suggestion involving the chicken :o)