misfiring scooby

[jumping350]

As some of you used to have scoobies maybe can shed some light,

notorious misfiring problem on my Scooby, intermittent yesterday started it 5 times no problem then went to leave and misfiring on cylinder one and two.

when it starts normally there's spark to everything idles fine drives fine.

cleaned mad sensor,lamba reads below 1 at idle but gives over 1 when i press throttle then settles is that normal?

ive had maf,iacv,tps sensor suggested but i wouldn't of thought it would cause the car to misfire,

would crank sensor be cause?

really stumped on this one any help appreciated

[Ekona]

Swapped coil packs from the other side? Pulled the plugs to check for water ingress?

[Ebized]

Hope there is a Scooby expert on here who can help you.....he shrugs

[ilogikal1]

What MY is it, to start with?

[jumping350]

its a 51 plate bugeye, pulled plugs gaps are fine no odd residue around, plus when it runs normally theres is no misfire or anything so if it was faulty plug or lead would it not do this all the time? when it was misfiring at idle wiggled every wire i could but made no difference to what was happening at the time

only code im getting is misfire cylinder 1&2

plus Knock sensor, however knock sensor has been like this for a few months and its intermittent also,this hasnt effected the drive of the car once.

 

Quickly went and turned it over before I went to work and its back to normal again

any thoughts

Edited October 6, 2013 by jumping350

[ilogikal1]

Did you test the MAF when you cleaned it? Easiest way to do this is simply unplug it with the engine running, if the engine stalls the MAF's fine, if the engine still runs then it's dead.

 

My next port of call would be to test the coil pack, as suggested by Ekona.

[ilogikal1]

Just seen your edit, intermittent knock sensor is usually a faulty connection on the sensor itself.

[350zedd]

Insulation could be breaking down on the plug leads / coil.

Do a visual check in the dark to see if you can detect any blue sparks arcing to earth

[jumping350]

yeah ive wiggled the knock sensor before and the lights gone out so I know that problem I have another sensor anyway to go in,

interesting you say that about the maf I will try that, would this not flag up on ecu?? and is it detremental enough to cause a misfire in the engine?

[ilogikal1]

The only other thing that's not been mentioned so far is the NPS, this tends to leave misfire codes.

 

The ECU will learn to compensate for a MAF if it's dead, and IIRC correctly it doesn't usually get flagged by the ECU (certainly not on the classics at least). It can cause a misfire if the ECU's over/under compensating for the measured air flow.

Edited October 6, 2013 by ilogikal1

[jumping350]

yeah i asked about this to the garage as well and they didnt seem to think this was the problem, thats the one on top of the gearbox isnt it??

I might just buy every sensor at this rate

[ilogikal1]

Yes, it's on top of the gearbox.

 

Scoobynet might be able to give you some better advice than me and help to narrow it down, maybe even save you a few sensors.

[jumping350]

thanks for your help ilogikal...ive been trawling all over surrey scoobies, scooby net, scooby world, scooby everything all have the problems not one has posted a conclusion or less than 10 solutions in one thread

Its quite funny in 2 hours on here I have had more responses/replies and gathered the same and more information than 4 days worth on the scooby forums

Should have posted it on here first!! but testament to how a good a forum this is

il rechec the maf and crank sensor and report back

Edited October 6, 2013 by jumping350

[ilogikal1]

No problem mate, let us know how you get on - maybe go and add the solution to all those other threads when it's sorted too.

[jumping350]

After 2days of wiggling everything and waiting for it to misfire again, turns out to be a dodgy connector on coil pack , bit of a clean and bobs your uncle...least its not expensive and get 4 more days with zed before it goes away (again) for winter lol cheers for help money saved is going on some suspension me thinks

[jumping350]

Ok still misfiring when i wiggle connector it seems to sort it out sometimes, sometimes when i let go of connector its goes back to 2 cylinders, connector looks fine not damaged or corroded would this def be coilpack side that's dodgy or connector side? Is this normal when a coilpack is on way out

[Richie-B]

Have you checked for codes?

[jumping350]

Yeah no codes come up

[ilogikal1]

Still having the problem?

 

Have you tried swapping the coil packs over? If the problem swaps sides too it's the coil, otherwise it's the connection.

 

Failing that, get your multimeter out. IIRC, resistance should be between 0.63-0.77 Ohms across the terminals.

[jumping350]

Thanks buddy,looks like ive got a pattern coilpack so that could be the problem just got a genuine Subaru one so when it happens again in going to swap over and see if that solves it,hope its not the connector doesn't look like it comes apart at all