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'o4 Streetka Running Rough On 98 Octane?


DELRIO
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Have recently had coil pack, leads, plugs and battery replaced as engine management light came on and diagnostic said 'cylinder 2 misfire'

However its still running rough, esp at low revs, n im now thinkin rather than misfiring its a fuel or injector prob?

Iv always used standard 95 unleaded but recently decided to 'splash out' on a couple of tanks of 98. Could thos be the culprit???

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To be honest if your getting a misfire, I would say your looking more at either a bad injector, seal or possibly a bad plug connection.

Is it only on 98 octane that it fails, or is it constant?

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As James has already mentioned, possible injector trouble or maybe even a burnt valve

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Brilliant guys thanks for the input, really appreciated.

Have eliminated the 98 octane possibility as am now running on a fresh tank of 95 and the problem is constant. PLUS engine mgmt light is now back on and problem is worse than ever!

Some other info:

The problem is defo worse when the engine is hotter or has been running for a while.

When engine is cold it will rev smoothly in neutral but after a run on the motorway it will even misfire in neutral if i rev it.

One mechanic has suggested that even tho the leads have been replaced and are brand new, they might be the cause of the problem as they arnt genuine ford ones and may be arcing out.

A mate had suggested maybe the Mass Air Flow sensor may be faulty?

Im also wondering if it could be causing a problem that i have used two different viscosity oils? (5,30 and 10,40)

Taking it to a different garage tomo for them to plug in their diagnostics computer and hear their thoughts on the matter.

The saga continues!

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ALL SORTED!!!

Turns out the new leads had been fitted without the plastic end caps being removed!

They are on the end of the leads that connect to the plugs and are marked 'remove before use' but this had been overlooked and so the leads were arcing out and not clipped in place properly.

Such a relief to have figured it out.

So anyone in Torbay with car trouble I can now highly recommend Neil at Parkside Garage, Magdalene Lane, torquay, 01803 316002

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Lmao, well thank goodness it was a cheap and easy fix!!

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Yea fingers crossed for some trouble free motoring from the Diva for a while lol

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Yea fingers crossed for some trouble free motoring from the Diva for a while lol

Who fitted the leads then? Lol

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A guy at another garage who to be fair was really helpful and took the car at very short notice last week. I rang him earlier with an update on the saga and just to let him know to keep an eye out for those plastic caps in future. He seemed genuinely grateful for the heads up!

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An excellent result, glad to be of service!

Now, I wonder how much that would have cost if you went to Ford :D :P

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  • 2 months later...

saga part 2



all was well ... for a couple of months and its just started playing up again :/



could be due to the fact that i bought cheap aftermarket parts rather than genuine ford ones?



ford want £100 just for a set of leads whereas the non-genuine ones were only £25.



think im gona try find a set of genuine ones on eBay before i splash out £100 just incase its not actually the leads causing the problem.



extra info: yesterday she was driving fine until i got on the motorway then started to misfire and engine light came on.


so i pulled over for about ten mins, check lead connections n when i drove on she was fine!


drove to destination using A roads instead of motorway, no probs.


after an hour or so at destination (so engine had cooled down) i go to drive home and she is misfiring even in neutral when i rev.


so kinda back to square 1 with this one???



input from anyone greatly appreciated :)

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Have you got any error codes?

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cheers for reply!

havnt had it plugged into a diagnostic yet but id put money on it saying its a cylinder misfire again because its the exact same symptoms.

jus reading thru some other posts and someone with the same prob had their EGR valve replaced. however, it doesnt actualy say if it resolved the prob.

what are your thoughts on that? and on the gen/non-gen parts theory?

Del

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ps last time (2 months ago) on one diagnostic it said cylinder 2 misfire and on another garages diagnostic it said cylinder 4 misfire

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ok after more research im pretty sure its either

1 car doesn like the non gen leads

2 car doesn like the non gen coil pack

3 one of the new plugs is misfiring.

ideally id like not to have to buy genuine ford leads AND coil pack so which one should i try first?

also if it is one of the plugs not working properly how do i find out which one?

does each plug interact with a different cylinder?

cheers

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Try reducing the spark plug gap to 1.0mm

Do you know what plugs are fitted ?

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i dont know what plugs are fitted but probably cheap ones that the garage got from the same place as they got the coil pack n leads from.

have got some prices from ford:

set of plugs £28

set of leads £120

coil pack £160

gona start with plugs first n hope that sorts it before moving to the more expensive stuff.

fingers crossed!

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update: after finding out that ford parts are made by Bosch and can be sourced much cheaper online I returned the £28 set of plugs i had bought and low and behold the car is running absolutely fine.

plus the engine mgmt light has turned itself off!?! i dint even think that was possible without a diagnostic tool being plugged in to reset the light???

anyway while she is running fine im gona sit tight n hope for the best. if she starts missing again i"ll buy some Bosch plugs on eBay and get them fitted.

if the problem then persists i have found an online breakers who will suply a genuine, tested coil pack and leads set for £15 including delivery with a 3 month warranty!

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Yeah the eml is only present when by he issue is present or the car thinks there is a potential issue. If the issue was as it appears to be the plugs, replacing them with the correct set stops the error code and stops the error and so no light is needed. The error code would be hidden or grayed out and would be ignored by the ECU unless parameters reflect the error is back.

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ok that makes sense ... BUT I didn replace the plugs!

I returned the expensive plugs to Ford and on the way to buying some Bosch ones the light went out and the car started running perfectly. mystery!?!

defo some kinds little electrical gremlin goin on tho cos even tho she is runnin fine atm, the alarm beeps sometimes when i unlock the central locking (never did this for the first 3 years of owning the car) and also sometimes there is a delay in my dash lights coming on when i turn on my headlights. oh and my heated seats dodnt work but i just assumed that was a fuse?

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Sounds like the ht leads if not the coil pack...?

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  • 2 weeks later...

update:

problem came back worse than ever so ...

had my after market ht leads and coil pack replaced today with second hand genuine ford ones. no improvement, still misfiring badly n runnning like !Removed!.

diagnostic tool then gives us an error code saying there is an injector error.

so i start shopping around for injectors.

but before i buy one i have a brain wave. if iv got an intermittent faulty injector maybe its just dirty?

so i stick a full bottle of redex into a frsh tank of fuel and ... it seems to have done the trick!

but im not counting my chickens just yet.

we'll see how she drives for a few days and if theres still a misfire here n there ill have a new injector fitted too.

but so far so good :)

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