Low RPM misfire

[Patrick Bateman]

My code reader has identified a misfire on cylinder 3 but curious if the symptoms here can point towards anything in particular before I take it to a garage-

• Revs with no issue when in neutral only (no load)
• Obviously misfires when trying to accelerate in any gear at low revs- happens from cold and once up to temperature
• Once above approx. 3000 RPM there is no obvious misfire and the car accelerates as normal in any gear. Can rev all the way to the limiter with no issue.

Any likely culprits with those particular symptoms?

 

[photo_ed]

Sounds like it could be an injector on the way out. A fairly common issue and an easy fix.

 

[Oracle]

17 year old car

£350 will cover all the proper original supplier parts.

4 x Magneti Marelli injectors.

2 x Bosch Lamda sensors

4 x NGK spark plugs

1 x Valeo coil pack

1 x set of Champion/ Beru HT leads.

Top to lower inlet gasket & O ring.

No more problems, assuming compressions are good.

 

[Patrick Bateman]

Would need to double check when the plugs and leads were changed, reckon about 2017 off the top of my head. All injectors and the pre-cat O2 sensor were changed 4 years ago.

 

[Oracle]

Cam cover oil leak into the spark plug well?

 

[Patrick Bateman]

Plugs, leads and coil pack all replaced, apparently running fine. Went to pick it up tonight and when the mechanic went to get the car it was misfiring constantly now- but on cylinder 2 now, not 3.

I'll see how it runs tomorrow but is the fact that a different cylinder is now misfiring suggesting anything or ruling anything out?

If it had returned but on the same cylinder I'd be less worried. All 4 injectors were replaced 4 years ago.

 

[Oracle]

Can we be certain that all involved are numbering the cylinders correctly as 1, gearbox end, and 4, cambelt end?

 

[Patrick Bateman]

This was going by my own code reader and the garage's. Both said the same cylinder.

 

[jimmybrown]

I had similar a few years back. Replaced coil pack, injectors, lamba sensor none worked. Eventually tracked down the (I think it's called this) MAF sensor, the one at the top of the engine. It had a very slight split in the plug rubber and cost about a tenner to fix!

 

[Oracle]

An air leak is a possibility, so replace the O ring between upper & lower inlet manifolds.

 

[Oracle]

Injector feeds from the ECU are cylinder 1 pin 59, 2 pin 90, 3 pin 60, 4 pin 89.

Separate connectors & 90 pin ECU connector and spray with industrial strength switch cleaner.

Injectors should read 14.7 ohm resistance.

Stick to E5 petrol.

 

[Patrick Bateman]

Is that o-ring definitely the only seal/gasket worth checking at this point? Away to order it and want to check there's nothing else worth a shout initially.

 

[Oracle]

Is that o-ring definitely the only seal/gasket worth checking at this point? Away to order it and want to check there's nothing else worth a shout initially.

8200052311 metal gasket, fitted with HMP grease both sides.

While the top manifold is off, pull the plugs again and run a compression check.

No compression, no bang.

 

[Patrick Bateman]

Are you meaning a different part when you say metal gasket? You've listed the o-ring part number there as per the photo you posted further back.

 

[Oracle]

Are you meaning a different part when you say metal gasket? You've listed the o-ring part number there as per the photo you posted further back.

My apology for the error, I had too many part numbers on the same piece of paper.

7700114203 for the metal gasket.

Renault Clio 172 182 Inlet Manifold Gasket - Renault Parts Direct

Renault Clio 172 182 Inlet Manifold Gasket - Renault Parts Direct - Renault Parts Direct is a web based service from our authorised Renault dealer.

renaultpartsdirect.co.uk

The O rings for the air temp & MAP sensors are not supplied individually, so you will need to source them from a workshop assortment

box.

 

[Patrick Bateman]

No luck with the garage. They've done a load of fault finding, swapping injectors, compression check etc. and can't find anything. They hadn't replaced the o-ring I supplied though, despite me asking to change it and the owner is becoming a cheeky prick so they can get fucked from now on.

Feeling a trip to SWR in Stirling.

At the end of the day it went in with an intermittent misfire on cylinder 3 and after all the work has a constant misfire on cylinder 2 so something has bloody changed.

 

[mhj360]

Any progress on this issue @Patrick Bateman? Mine also seems to have developed a similar issue, low rpm (~2k rpm) misfire on cylinder 2, stutters on acceleration in gear, but as far as I can tell it only happens from cold start and disappears when warmed up.

Would be great if I can pinpoint an easy fix before throwing money at the entire fuel/ignition system.

 

[Patrick Bateman]

SWR were busier than expected so it's booked in for 11th July. No change for now and it's parked up doing bugger all.

 

[Patrick Bateman]

FML SWR are saying it's the Beru ignition leads I originally supplied!

 

[Oracle]

FML SWR are saying it's the Beru ignition leads I originally supplied!

I would be extremely surprised if there was a quality problem with BERU leads.

Have they been damaged by poor fitment ?.