172 running on 3 cylinders

[mdm]

need a bit of help here lads,

got a 172 2001, problem is she running on 3 cylinders, number 2 has died, she has a coil pack, so far i've fired a new set of plugs in her, swapped the plugs leads around, swapped injectors around, checked she's firing all injectors, swapped plug lead 2 and 3 on the coil pack to see if it was the coil pack.

none of the above has changed anything, she still won't run on Number 2, the engine light is on but when driving she will flash it. also she sounds like a scobby. hope to read the codes tomorrow, but is there anything i'm missing or do you any ideas

help would be much appreciated

 

[CuppyDean]

You tried new HT leads?

 

[mdm]

i've swapped the leads about and it still stays with cylinder 2

 

[CuppyDean]

My guess is a faulty injector, you need to check them to see if there working, do the basic tests first then if that fails you need to do a compression test

 

[mdm]

i swapped injector 1 and 2 over and the problem still stayed with cylinder number 2, i know she firing the injectors as i pulled the top half of the inlet manifold of and turned her over, you can see the fuel spraying from each injector

the funny thing is this morning while driving her she would run on all 4 for about 2 or 3 seconds.

 

[CuppyDean]

Strange one, and non of the leads are faulty and the coil pack you tried out was fine also?

 

[mdm]

well i swapped the plug lead from plug 2 onto coil for cylinder 3 and visa versa for plug onto cylinder 2, given that they run wasted spark. the problem still stayed with cylinder number 2, i'm know thinking mechanical, may be a dropped valve

 

[CuppyDean]

Compression test next then

 

[Soot1e]

If it was a dropped valve there would be some horrible noise. Compression test may show up low pressure on that cylinder. then you'll be looking at cream crackered rings, stuck valve etc. Is there fuel coming out of the fuel rail and into injector no.2 ?
Did you get sparks from no 2 when you swapped the coilpack and ht lead around?

 

[mdm]

fuel is coming out of the injector and into cylinder 2, yea when i pull the ht lead off 2 she is arking. the thing is i'm running out of idea's i've changed / swapped everything to do with cylinder number 2.

 

[mdm]

everything electrical i mean, ie i'm getting a spark and fuel.

 

[CuppyDean]

Sounds more mechanical now which unfortunately means £££

 

[Soot1e]

You sure you have the leads going to the correct cylinders ? after all that swapping around you may have 2 leads reversed. If ok then it will be compression test or a visit to someone with a fault reader.

 

[Neal 182]

when your looking at cylinder 2 which one are you going for as renaults run number 1 at the fly wheel end other than that compression check

 

[mdm]

2nd from the gearbox side. ht leads are on the right way.

 

[Soot1e]

2nd from the gearbox side. ht leads are on the right way.

Yep, Thats how they number, just like Jaguars. Sorry mate can't help anymore, you've done all you can, except the fault reader.

 

[jamesd1263]

Bent valve? My mk1 done this

 

[Laine_16v]

Youve ruled out injectors, spark plugs, HT leads, and the coil pack. By the process of ilimination it must be mechanical and therefore expensive to fix

Whip the coil pack loom plug off. Crank the car over, does the cranking sound irregular?

 

[Tom@JMS]

You've missed the possibility of it being nothing but a mere lambda sensor, it may sound odd, but its a very real possibility.

Only sensible way is to read the code, sort what it shows.

 

[thegusset]

my car did this it had a broken wire just at the first lambda sensor bit of soldering and was fixed thank fcuk

 

[Huffski]

Glad I have read this I have the exact same problem but on cylinder 3 I have tried everything of the above too I plugged it in and I said Injection circuit open cylinder 3. Not sure what to try next maybe the lambda sensor.

 

[ND04]

I had the same problem turned out to be a corroded wire i took the car to an auto electrition they found and sorted the problem might be worth getting one to have a look did'nt cost that much either