Running On 5 Cylinders

[ToF]

Hey guys,

Long story short, my car was running on 5 cylinders yesterday after driving for 30 minutes. It has done this a couple of times already but I want to fix it now. This morning I went to start it and it was running on 6 therefore its pretty clear that it is a heat problem!

Now I know something is dieing once its hot but what could it be?

a. Coilpacks

b. Ignitor pack

c. CAS?? (Would it have anything to do with this at all?? Maybe someone who is more knowledgable could enlighten me? )

I would replace one by one until it fixes it as everyone does but I don't have money .

So could anyone please narrowdown the list for me?

Thanks all

[Col-GTSX]

Spark plugs...

Common problem with old plugs...

[ToF]

Spark plugs...

Common problem with old plugs...

WTF? Are you serious it's that simple?

Because I don't want to get new plugs and then the same thing happens and I foul up the plugs again. :

[Col-GTSX]

If it occurs because of heat and you have not done the plug for a while and its only just started happening you will find its a cracked plug...

Coil packs can be a possibility or the harness to the coil packs but 90% chance its just ya plugs...

Buy a full set of copper ones if you dint have much money they will cost ya about $5 each from super cheap...

Gap then to about 0.8mm if you have standard coil packs and bob's ya uncle.

[Col-GTSX]

On a side note... If it were you CAS the engine would not run at all...

They dont miss one cylinder...

[ToF]

On a side note... If it were you CAS the engine would not run at all...

They dont miss one cylinder...

Thanks for confirming that.

Also I checked the spark plug I thought wasn't firing yesterday and it wasn't cracked, but I'll try your suggestion first since it's the cheapest

Edited April 17, 2006 by ToF

[Col-GTSX]

Its most certainlly the cheapest...

Dont forget you can get the spark plugs in a six pack and save about 5-6 bucks... So find the ones ya want and if they dont have any 6 packs ask a staff member...

Last time i bought copper plugs i got a free one from super cheap...

Now i use iridium so i dont need plugs for anout 50,000km's or more... LOL

Once ya plugs are in (dont forget to gap em down to 0.8mm if u got standard coil packs) dont over tighten them. Check to see that the contact in the bottom of the coil packs is still spring'y as they need to cntact the top of the plug to get maximum spark.

If this does not help your situation then do a search on glueing you coil packs... But i reckon 90% chance its the plugs...

[ToF]

Now i use iridium so i dont need plugs for anout 50,000km's or more... LOL

If this does not help your situation then do a search on glueing you coil packs... But i reckon 90% chance its the plugs...

Yer the current plugs I got are iridiums but they were from the previous owner and I don't know how old they are.... could be 100,000km old for all I know LOL (didn't bother to change them when I serviced it after I bought it).

I was thinking about glueing the coilpacks as well as getting new spark plugs as well so I'll have a search for that thread... but won't the glue just melt under the heat? I'll be using Sikaflex 221 (I think?).

Also to add more info, I just went to move my car so it's still cold, but it started on 6 then suddenly cut to 5 and then back to 6 and then 5, kept doing that a couple times for 10 seconds then just stayed on 5. This was while it was pretty cold... so yer.

Bloody cars!!!

[Col-GTSX]

Sounds a whole lot like a cracked plug...

You will see straight away...

[blind_elk]

Do you know which cylinder is "switching off" when it runs on 5?

The ignitor modules are almost famous for breaking down with heat and age.

I'm pretty certain a cracked plug will always cause problems (hot or cold).

[ToF]

Do you know which cylinder is "switching off" when it runs on 5?

The ignitor modules are almost famous for breaking down with heat and age.

I'm pretty certain a cracked plug will always cause problems (hot or cold).

I was thinking the same thing but it's kind of hard to check with the cover there. I might chop it and then check it.

Any idea how much a 2nd hand or new ignitor module would cost roughly (if it is the cause)?

[ToF]

I'm about to go get new spark plugs even though my old ones weren't cracked or anything but I decided to test resistance in my coilpacks and they all read 1.3 ohms :

According the manual they should be 0.6-0.9... Anyone think 1.3 is still OK?

Edited April 18, 2006 by ToF

[Col-GTSX]

What did the plugs look like...

Was one a bit darker than the others...

[ToF]

Not really, all similar condition - lots of carbon build up but not excessive amounts, I reckon they are OK.

What do you think about my coilpacks? I mean 1.3 isn't impressive but would the fact that I got that value mean that my coilpacks are OK?

I will glue my coilpacks and clean the contacts tomorrow and then see how it goes but if it still happens I guess I'm left with the ignitor module right?

[Col-GTSX]

Yeah pretty much...

I think you would be best off replacing the plugs anyways...

Could be cracked bakerlite and lack of contact to the tip of the plug. One plug should be dis coloured a bit due to the miss fire. I would say it could be the ignightor but its un likelly... I have had this problem many times before wit many skylines and its always been either plugs or coil packs...

When i say coil packs 9 times out of 10 its just dirty or the springs have lost tention and are spark jumping to the tip of the plug....

Try a set of plugs or at least test resistance on all of them, re-gap them to 0.8mm and try it out... Also clean up all the coil packs tips and check the springs...

Ignightor is very un likelly...

[ToF]

Yeah pretty much...

I think you would be best off replacing the plugs anyways...

Could be cracked bakerlite and lack of contact to the tip of the plug. One plug should be dis coloured a bit due to the miss fire. I would say it could be the ignightor but its un likelly... I have had this problem many times before wit many skylines and its always been either plugs or coil packs...

When i say coil packs 9 times out of 10 its just dirty or the springs have lost tention and are spark jumping to the tip of the plug....

Try a set of plugs or at least test resistance on all of them, re-gap them to 0.8mm and try it out... Also clean up all the coil packs tips and check the springs...

Ignightor is very un likelly...

Yer I did get new plugs. And I am going to clean and glue my coilpacks tomorrow but as I said I already checked the resistance on all the coilpacks and it turned out 1.3ohms.

[BOVed]

I had this problem not long ago thought my whole engine was cactus after grumbling and sooking for a bit and looking at how much it would cost me to put in a new engine I decided to pull the plugs and when I did I found no1 was not just cracked or loose the plug itself was fine but the thread in the haed was gone!!!!! when i lifted the coil the plug just came out!!! whatha?the dodgy arse mechanics who serviced the car when I bought it mustve stripped the thread partialy and just jammed it back in and not bothered to tell me

and when on high boost the pressures popped what was left of the thread out : so stated lookingfor a new head to get it machined new gaskets head studs etc etc... lots of dosh for a small job, then I found these things on google called timesert inserts for replacing threads, they use them in planes etc not a helicoil by the way and come with the tools to tap the new thread etc, I removed the air intake and conected a vacum set on blow with tape and sat another vacum on suck over the thread, then greased up the thread and slowly started tapping the new thread and I mean SLOWLYYYYYyyyyy! when the new thread for the insert was finished I conected a thin tube with tape to the top vacum and vacum the inside of the engine for like ten minutes then screwed in the new thread insert put anti seize on the plugs IMPORTANT!! then bung the plugs back in and roberts your fathers brother, the cars never run better :PBJ: everyone I went too to get this done said $2000-$2300 to get it done it cost me

TIMSERT INSERT PACK$260

TIMESERT INSERT$4

ANTISEIZE$12

4 hrs my time

I realise this may not be your problem just thought Id let you know because it saved me heaps

[Josh]

Hey bloke, I had a similar prob a little while ago.. car would start firing on 5, ran and sounded like shit..

drove around with my coil cover off, when it started messing up again i'd pull over and disconnect the coilpacks 1 by 1 until the idle didn't change.. took No.6 off and nothing happened, changed it out, haven't had the problem since and the car has received a huge thrashing after just competing in two consecutive days of drift comp... didn't miss a beat... coil was cheap too - $25..

[ToF]

OK an update.

So far I've glued up the coilpacks with Sikaflex and cut my coilpack cover so there's more ventilation. I've sanded/cleaned all the contacts on the ignitor module and coilpack cover to make the earth a bit better. I also have new copper plugs gapped at 0.8mm.

Now it started all good for about a minute but then it changed. Now when idling it will misfire (not sure if that is the right term?).

The car still runs alright but when I rev and hold it at 2000rpm and you can still hear it missing regularly (small pops in the exhaust - btw: this is not the pop from excess fuel). Basically it isn't fully dropping a cylinder but its sort of half misfiring it about once every second.

Tomorrow I might check which coilpack is misfiring but for now does anyone have any other theories on what else could be at fault?

Edited April 20, 2006 by ToF

[Josh]

Could be your ignitor module also....

I know what you mean by it not sounding like a fuel backfire - the car actually sounds like a WRX... and will drive like a peice of shit..