Help ASAP - Running problem

[philthy]

Need help with this from experts, picked up car last week and there was not a single problem until last night-

The car (tuned 172) was missing a beat at lows revs when hot and cold, then it started to misfire on tickover(with loud bangs)

After misfiring it started to run on 2 cylinders when I got it going. It then ran perfect on 4 cylinders for about a mile.

After that it wouldnt start right almost always running on 2. Now it wont start everytime and when it does it either misfires or runs on 2 cyclinders then dies.

I got it started earlier but the revs shot up to 4k and stayed there. Now it wont even fire up

The car has Omex ECU, it is almost like it has reset itself and lost its mapping.
It has had new coil pack/spark plugs/leads in the last 10k miles.

Anyone have any ideas?!?

 

[LegoHead]

sorry not an answer, but a question. How can you tell if it is two cylinders?

 

[deviltronics]

try disconnecting the battery for 30 mins, this will reset the ecu to its original state (most do anyway), if it has picked up a problem the ecu should clear it.

thats just a wee guess, could be anything.

 

[philthy]

sounds like a motocross, wont accelerate and vibrates a lot

Il give that a try laters, i had it disconnected for 5 mins but didnt help

 

[LegoHead]

sounds like a motocross, wont accelerate and vibrates a lot

sounds like mine from cold, always goes after about a minute of driving.

 

[Obelix]

I would start with the obvious. Plugs,leads,coil. I know you said they were fairly new but you never know. Next thoughts..
tdc sensor
Idle control valve/throttle body (but I'm not sure this would cause a misfire)
Check the obvious first.
It soulds like it could be an electrical insulation breakdown somewhere.
Most likely coil/leads.
Good luck

 

[philthy]

Il need to check the coil properly, would it make the running as irratic as this?
Only way to check the sensors is to plug it in yea?
The leads are magencor and as new, checked them tonight.

 

[philthy]

After research Im guessing it could either be Lambda sensor (dnt know which one) or coil pack.

Someone must have seen this before?

 

[philthy]

After a call to GDI they say spark plugs, changing them tomo

 

[BexKTR]

could also be idle control valve which this car has on it... if it rev'd could be stuck for some reason.. worth checking also...

 

[ditz]

if it runs on 2 its pretty much gaurenteed to be either coil pack or a map problem.

 

[Peperami]

Had this a few months ago (albeit with standard tb) and i think yoz had it once before.

Throttle body was clogged up and needed cleaning out.

But does sound like it could be the coil too!

Maybe its a combo of a few things?

 

[philthy]

I just cleaned the throttle body, ICV, and changed the plugs, It started first time and ran perfect.. need to take it for a spin though.

 

[Peperami]

Let us know how it runs mate.

 

[philthy]

Well ran well for 15miles, then it all started again...

It goes down 2 cyclinders and backfires at low revs.... stick the boot down and it clears and flys through the revs.

Answers on a postcard before I stick a bomb under it....

 

[Peperami]

Mines doing this now feels like the throttle is getting stuck?

 

[philthy]

hmm yea a bit, its like the air and/or fuel is blocked

Has your car got an aftermarket ecu?

I think im going to have to take it to get the map checked out, feels like it has places its under or over fuelling

 

[Peperami]

Nope, standard ecu but carbon cannister removed. I thought this was causing it, but others with it removed havnt noticed this, and it ran fine for ages in its current state of tune.

Will keep an eye on this thread to see if you can find the root of the problem mate.

When yours sticks does it smell of petrol?

 

[philthy]

I did cleant he throttle body with carb cleaner and it was fine for a while, I migth try it again tomo but do it thoroughly.

Its running optimax with decat so smells most of the time anyway.

Im going to make some calls to remappers in my area to see if it sounds like its the problem also

 

[chris2006]

Is that correct if you disconnect the batt for 30 mins it restores to default?

 

[Fred@BTM]

no

 

[philthy]

Its stinking of petrol now, and running as bad as ever. No power at all

Got it booked in for mapping check on wednesday. GDI kindly offered to do it for free but I am 400miles from them... doh.

Fred, have you not had this problem before?

 

[mini-valver]

Fuel pump relay? Regulator blocked? Sounds more on the ignition side of things though TBH....

 

[philthy]

tried the relays, seem fine. Its not blocked as it stinks of fuel when it doesnt fire on all 4, so fuel is getting there just not igniting!

car is sitting waiting for a new coil pack coming, if its not this im fucked

stoddie very kindly came over to look at it for an hour, he hasnt a clue what it is either.

 

[Fred@BTM]

so its running on 2?

check the wires to the coil pack (its 3 wires for the omex) IIRC

are all the wires to the injectors ok?

does the engine note change if you disconnect each injector in turn with the engine running?

 

[philthy]

yea checked the injectors, all seemed fine.

By wires you mean the 3 going the connector on the coilpack?

Its starts on 2 so cant change much other than stall when leads are disconnected. Thats if it stays running for long enough to check.

To add confusion it was running well for 15miles after I changed the spark plugs, then progressively got worse as it went on to the point where it wont start, starts on 4 after been sitting for a day then goes down to 2 after 1-2 mins running when it heats up.

 

[Fred@BTM]

no idea!

HT leads arcing out?

earth straps ok?

so its got fuel to all 4, but no spark

 

[ja.jack]

That Omex sounds more trouble than it's worth. If I was to get grunty cams I'd just go for the re-mapped standard ecu. Ca'nt be much power diff', and a whole lot cheaper.

 

[Fred@BTM]

correct jack, but when you run different throttle body/ies its a must

 

[philthy]

will check the earth straps tonight, where should I look specifically?

If its not the coilpack, next stop is new leads.

Thing is, the coil pack is pretty new and the leads are magnecor.

 

[Fred@BTM]

oh dear then

earth straps are from the box to the passenger side chassis leg and the back of the box to somewhere (can't remember)

 

[ja.jack]

Yea, Fred, on Andy's web it says 197bhp and 180ft/lbs. just with cams. That would be fine, I'm not greedy. Hope he's not telling porkies. lol

 

[Fred@BTM]

i'm sure you'll be the first to let him know if your car doesn't make the power quoted

 

[ja.jack]

You aint shitting . lol

 

[rory182]

you buy Stoddies car Phil? Or Taylors? Or someone else altogether?

 

[Fred@BTM]

do a compression test just for good measure, it maybe something else entirely

 

[MarkM]

I doubt it is the map. The maps either in there or it isnt.

Sounds similar to the problems with the missus' Fiesta which was coil pack. Electrical IMO.

 

[drhowser]

Well ran well for 15miles, then it all started again...

It goes down 2 cyclinders and backfires at low revs.... stick the boot down and it clears and flys through the revs.

Answers on a postcard before I stick a bomb under it....

i had a faulty throttle which was a lot like that, i got lights too. although with the omex, i'm guessing you wont? but anyway a new throttle from renault solved everything (and lightened my wallet no end too!)

 

[ja.jack]

Seems strange how after fitting an Omex system, other components go on strike, as if they were expressing their displeasure at the usurpation of their pal, the original ecu. lol

 

[philthy]

Stoddies car rory.

The throttle is cable though and I cleaned it out thoroughly, how else can it go wrong?

The omex has been on the car for over a year now ja.jack, I dont think its got anything to do with that.

We will see if it is the coilpack tomo Mark.M.

Question- would the coilpack be worse effected if it was warm as it seems thats when it runs the worst