Injector tested, but how do I know its not the coil pack?

[daelo]

Hi guys,

Engines misfiring this morning with yellow engine light flasshing , I've sprayed some wd40 in coil pack contacts as thought it might be water from all this rain,no difference. Took the plenum off and checked the spark plugs ... from the left looking​ at engine bay

1 is fine , 2 and 3 appear a bit sooty, 4 looks OK.

I put everything back together and then unplugged injectors 1 by one...from the left,

1 engine wants to stall, 2 engine wants to stall but not so badly, 3 makes no difference to engine note, 4 engine wants to stall.

So i assume injector 3 is faulty as its not making a difference when disconnecting it, which is best to replace first, the coil pack or the injector?

Don't think the cars ever had a new coilpack but had new plugs and leads about 40k miles ago,cars on 130k ATM.

Advice please guys as this is my daily driver but I have managed to source a new injector for 58 plus vat Bosch item

 

[Dan@SJM]

Take the injector out and put it in cyl 4. Put cyl 4 in cyl 3. Do the same test and see if the misfire has moved.

 

[daelo]

OK so I managed to get 3 and 4 out with a lot of wiggling and without removing 1 or 2,question is how do I get them back in? Is there a special technique? I've tried pushing them back in but due to the size of the o ring looks like it might need quite a lot of force,should I take the whole rail off will that make it easier?

 

[MG cup]

Take everything off for ease (its not a big job) and use petroleum jelly ideally on the o rings and they will slide in. Check for any cracks on the o rings too while there out as a fuel leak is the last thing you want.

ps wd40 or even spit will suffice if your stuck.

 

[daelo]

Cheers, Managed to get them back in with a very small smear of LM grease (makes perfect sense tbh!!) So 3s now where 4 was ,its harder to tell the difference in the engines note now,not as discernable as before,so that point towards a faulty coil pack? Probably makes sense to replace that I reckon first?

Also disconnecting the it leads at the coil pack one by one , a couple of them arc really badly over the white trumpet bit(Andi think to any metal nearby),is this normal?

 

[MG cup]

Yeah that's normal for the arcing on the coil pack.

At your mileage I would think its more the injectors but it won't harm to remove and wire brush the spark plugs (replace with the correct NGK versions if necessary) and refit with some wd40 in all the leads and plugs etc then try your injector test again.

I had all my injectors ultrasonically cleaned on my last track cup which improved the running massively (it never misfired just didn't run clean before) but I also went through 3 sets of the correct NGK spark plugs in the 5 track days and 2000 miles I done.

 

[daelo]

Well no difference with a new coil pack so that I can tell,going to put the injectors back the way they were and start again I think

 

[daelo]

Going to pick up four new pfre6e's and see how I get along with those. In my haste to remove one of the injectors I managed to pull/snap off the electric contact so that warrants a new injector anyhow! Must be more careful next time!!

 

[daelo]

Replaced spark plugs, a little bit better but not perfect still. Can ht leads be the next problem? They don't seem to have any damage or cracking splitting what so ever. Now the car runs to an extent it's driveable is my best bet to find a garage with a clip machine? I really do hope it's not the injectors. This misfire has been coming and going for quite a few months now

If the injectors arnt the pproblem what else could it be, this is a terrible Monday!

 

[KevF182]

As has already been said, The issue is most likely to be injector(s).

When you did the test pulling the conections first time and confirmed cyl 3 was missing that was quite telling. I'd also bet that no 2 is on its way out/needing clleaning. You can test them for resistance, the correct value is somewhere between 14 - 15 ohms, if reads 1 then its had it. But even when they have not gone completely they can cause running problems. Since you've gone down the route of replacing things then you might as well just get the new injector on cyl 3 before trying clip.

By the way, what bosch injector did you source? You sure its the right one?

 

[KevF182]

http://www.ebay.co.uk/itm/Renault-C...o|Cars+Type:2.0+16V+Sport&hash=item46170fe9f5

This is what you want.

 

[daelo]

http://www.ebay.co.uk/itm/Renault-C...o|Cars+Type:2.0+16V+Sport&hash=item46170fe9f5

This is what you want.

That is exactly what I have enquired about to Kat@Renparts, waiting back on a response for 3 of those injectors. I assume they will work fine with a bosch(over priced ... maybe @ £70) injector I had to get today?

Tomorrow I'm going to brim her up on the way to work and put some STP injector cleaner, see if that makes things better. It's an odd one really, if I keep revs and about 2000 (or 3000 etc... or even idle) I can hear a light pop pop pop every half second or so , so I'm still thinking it'll be a injector problem (130k injectors can't be fault free surely, let alone deposits, I've never had them cleaned or run cleaner through them).

It's just all a ****load of money to be spending when it potentially needs a new cambelt in 5000 miles or so :S

 

[KevF182]

I would have just bought one injector before doing anything else, personally, but you've not doen any harm renewing plugs and coil (assuming the coil is the correct valeo one). I am puzzled why you've put a bosch injector on. I cannot imagine it will be exactly the same spec. as the correct IWP042's. I would want all four the same.

 

[daelo]

In regards to the injector, got the part number from this site, cross checked with Renault which matched up, then local motor factors who stated the bosch brand injector was the only one they did for that part number (8200207049).

In regards to the coil I went with the ecp ( http://www.eurocarparts.com/ecp/c/R...e751494d6acf324ca8eedc0bcff8bbbc114abb&000197 ) , the other one they have is the Bremi manufactured one (which is also the same as the local motorfactors matching ren part number substitute http://www.eurocarparts.com/ecp/c/R...b6389528a0fbc0088b20c87328f3cd68a9678b&000197 ), am I going to be harming my diagnosis by not using a valeo unit (which i assume is the Renault own stock one) ?

Having the idea of just buying the four injectors from ren parts (as above cheers) an then selling the bosch one as unused (to an extent of say 50 miles) and being done with it, needing my car as a daily and initially not being able to get off my driveway limited my buying power somewhat today

 

[KevF182]

Im not 100% a valeo one is Renault OE. So don't worry about that. Understand your options were limited, you got to get to work etc. keep your old one as well though, it was probably fine.

I don't have any experince of putting non-genuine injectors on, but I wouldn't want to missmatch brands myself. Does it look identical? I'd take the bosch one back to the factor and say its not right. Its not the same etc etc. They will be fine with that, it happens all the time.

 

[daelo]

Cheers kev, the only discernable difference is that body is mainly plastic and not metal ( exactly this one http://www.ebay.co.uk/itm/INJECTOR-...o|Cars+Type:2.0+16V+Sport&hash=item589bb01da2 )

Problem is I've fitted the the thing now, its probably going to be stinking of petrol lol! I'll consider my options (and if I'm feeling brave return the injector at the weekend to the factors, I'm sure there's some sale of goods act I could quote if things get hairy!) might ask for a deal on four of those injectors from Kat in anycase.

 

[KevF182]

Cheers kev, the only discernable difference is that body is mainly plastic and not metal ( exactly this one http://www.ebay.co.uk/itm/INJECTOR-...o|Cars+Type:2.0+16V+Sport&hash=item589bb01da2 )

It might be fine ? But it definately looks different, importantly the nozzle is a different shape although I cant tell if the orifices are the same, which is probably most crucial.