Porsche Enthusiasts Club Forum

I now have a misfire problem, Grrr this car..... it started quite slow and minor a couple of weeks ago and just got worse, I have put a new Dizzy and rotor on which made it better for about a day but still not right, now its worse again and doesn't get better.

I have been out there tonight and while running poked the leads around with a piece of wood to see if there was any arking, I know it's very dry and hot but I didn't see anything and the engine rythum didn't seem to change.

Does anyone know the correct firing order, as far as I can gather it is from the top left 4 2 3 1 is that right?

Is there anyone local to me here on the Wirral CH45 that can maybe borrow me a coil or leads to elminate them please before I go and spend more money trying to work out what it could be.

Thanks.

Firing order is 1 3 4 2 - One (ie 1) being your first plug closest to the front of car. Check that the plug HT leads are connected into the dizzy cap in the correct order...

Once you have the leads in the correct order and it still misfires, like running on three cylinders, pull out one HT lead at the spark plug and see if the engine keeps running. If one fails to stall the engine, it likely that that 'one' is not firing: bad plug or broken HT lead.

If that doesn't work, I would suspect the coil unit. Most engine coils are the same - find a decent basic one from a friend and test. Then replace with a Bosch unit or similar...

Dave

Hi Dave, I think I have them in that order but I'm confused as to were the 1 and 3 should be, I currently have them on the bottom with 1 being on the right if you are looking straight at the dizzy cap, so its like this:

4 2
3 1

is this right?

Hi. I've just checked the distributor cap on my 2.5N/A and the HT leads are connected in the order you are showing. Having seen engines with the HT leads connected incorrectly and considering there are only 4 HT leads (of which two would have to be incorrectly connected) I'd be very surprised if the car would run at all if you had them incorrectly connected. It would just bang and pop and refuse to start. It sounds to me like you've disturbed something when working on the leads or your new ignition components have a fault. It is pretty easy to damage an HT lead if you are pulling them off the distributor cap for example. I think you need to take a systematic approach and work through the system with a multimeter. It will take a while but otherwise you are just shooting in the dark.

Good luck

Matt

Pull your plugs and check to see what they are like. If 1 is black, etc, obviously a problem with that cylinder. If they all loook bad, could be fuel pressure regulator, etc that may be on the way out.
Alasdair

All very valid points. With regards to pulling spark plugs, I would look for a 'wet one', which would confirm a non spark to that cylinder, when the other ones are 'dry'. The other scenario is a blocked/failed fuel injector possibly?

Dave
CT

Hi Guys, thanks for the replies. Most helpful to me indeed.

It went in on Friday (Yesturday) for the clutch and I have asked them to look at the misfire although they did tell me that I also need a Fly sensor and a clutch slave clyninder which they showed me last night at the garage so hopefully i'll get it back Monday all okay (please please).

I also need two gear box mounts but they can be done at a later date, they are still in place. I have saved this car from the race track as the previous owner I am sure was preparing it for the track as the calipers were green and the trim had toggle swtichs fitted, it also has a short shift gear change fitted (which i do like and will be keeping) but overall think who ever has been working on the car before i got it was mashing it up for the track.

Plus I bought it for my son! (currently 16 yrs old) Last Dec (2015) and since then have had it, resprayed in orginal colour, complete wiring loomed fitted, change of trim and carpets from brown to black, two front metal wings, front bumper, bezel, front lights, rear tail light, two engine mounts, shocks all round, discs (pre-drilled) and pads all round plus a rear caliper, gone through 2 sets of script door handles, I really hate fitting them, also had the cambelt, balance belt done, oil change, spark plugs in (feb 2016) new air filter (cone) central locking, alarm etc, plus old tape player cassette (awsome, and I can put any CD on to tape) and I think that's it plus the clutch of course!

By the time my son is 17 and passes his test, he'll simply walk to me, take the keys and say cheers Dad and drive off in a practically new 34 year old car that hopefully looks awsome! And I'll have to get myself a £500 ford to drive round in as I'll be broke by that time!

But a promise is a promise and I am a man of my word, lucky for my Son. What I have learn't is next time when I take my son to a Porsche day at Brooklands in Surrey I'll keep my mouth shut and not tell me that Porsche made an everday car for the everyday man that he could go to work in and should we come across one cheap enough I'll get it for him and we can do it up ready for him ready for when he can drive, that was six years ago!

It will be very hard to hand it over........................Maybe I just won't!

What a great Dad you are, can you adopt me

It'll be more heart breaking after he has his first in it. You might want to consider getting him a half decent running driving 924 for when he passes his test, if he keeps that straight for 2yrs hand over the shiny one then.

Hi

Wow to insure that for a 17 year old will cost many many thousands....

When my son passed his test at 17 he said to me... Dad can i get a 928 ?...I said sure as long as YOU can afford to insure it...he said no problem, went on his computer and told me sadly that he found one company who WOULD insure him (third party only) at a cost of £25,500 ...

So he bought a Corsa lol ..even that at 17 just passed test was £1700 ...

All the best Brett

You'll be suprised to know that from 18 yrs old they can get there are insurance compaines who do provide cheaper insure for them under the classic polices.

Little does he know that he will need to be rich to insure it when he is 17 but I did promise to provide him with inusre just the car, so my work is done here

He won't be having his first in it unless its a non fault because he know if it's his fault he need not bother coming back............ plus I'm not going through all of this with a 924!

Well, the clutch is done and wow what a difference, however the garage said they could not tell that there was a misfire however since getting it back it is still there so I tried a used coil but that was still the same so fitted a new set of leads and put my coil back on but still the same, it had new plugs in Feb and a new dme relay in may so what do I do next, any suggestions as I cant locate were the ecu should be to look at that, does mine even have a ecu?

Chuck the plugs in the bin, get a new set, sounds like one is breaking down

Think your right as I took then out again this afternoon to check them and number too has pretty burnt away so I shall get a new set tomorrow and gap them as the current seemed to be gapped wrong.

I'll let you know tomorrow how it goes, thanks.

Hi David -

Your woes continue! Spark plugs should last many miles but a few of yours haven't...

I am still erring on the side of a duff injector - if one is injecting more fuel than the required amount, it will certainly do damage to that corresponding plug cell, causing a misfire and subsequent damage to the plug.

When getting a decent set of spark plugs, just open the box and fit them - gapping is not necessary - just fit and play.

Another option is to get the cam belt checked and it's appropriate timing...

If that helps -

Dave
CT