Not Firing On Cylinders 2 And 3

[WALDO 1]

Hi again

 

The saga of my 1.6 CTI continues.... I originally started a forum relating to Tachymetric relays which which also embraced the subject of ' no power at injectors'. After investigation a melt down in one of the wiring looms appeared to be the problem. After reconnecting the wires the car started and all seemed well enough. I didn't run it for long without the AFM etc but after putting it back together it became clear that it was only firing on 2 cylinders..no.s 1 an 4. It starts first time and doesn't actually sound too bad. I have changed the ECU (to no avail) even though I couldn't see how that would affect only 2 cylinders? I was minded of Anthony's comments in another forum regarding Haynes wiring diagram and their accuracy and looking at their wiring diagrams I cant see how this problem could happen. I am led to believe these injectors are powered in pairs. The Haynes wiring diagram looks as if they (injectors) are wired in series? This problem has to be linked to the original wiring problem but after much deliberation cant see a logical troubleshooting route?

 

With the engine running there was 12v either side of the injector connections on cylinders 2 and 3 and although that didn't seem right to me from what I have read that may not be a bad thing?

 

 

That said I am not sure what to do next and would appreciate any comments. There is a good blue spark at all 4 spark plugs etc., plenty of fuel . Again it is injector related but I have only managed to solve half the problem. Other than stripping back more wires is there anything I have missed?

 

Thanks

[dcc 855]

Rotor cap, rotor, king lead, plugs, leads, air filter, fuel filter, fpr, fuel pump, ecu temp sensor, afm, crap fuel.

[toolie72 67 1 Cars]

Try swapping injectors round but not their wiring? That should prove if injectors or wirings at fault ie if 2&3 start firing you know it's not wiring

I actually thought all 4 injectors fired at same time? Dunno

[welshpug 1,661]

they certainly are batch fire on jetronic.

[WALDO 1]

Hi again

 

Thanks for your comments. It has got me thinking. maybe I should invest in a couple of noid lights or even a couple of injectors and replace the two non working ones. There is a spark plug firing sequence so maybe there is a fuel injection sequence to mirror the spark plug firing sequence? toolie72 made a good point regarding swapping the injectors around which gave me the idea of buying a couple more.. What I wasn't clear about was why not the wiring other than for maybe that reason? It would be easy to remove an injector connection from say injector 1 to injector 2 and vice versa. I think they would reach across? Can you see any danger in doing that? I could then remove the spark plug connector to see which cylinder was working? Either way I do need to be sure as i can that it is a wiring problem if possible? I was reading on the internet that loots of car injectors are powered in pairs maybe not the 205 though?

 

Thanks again and regards

[jackherer 543]

There is a spark plug firing sequence so maybe there is a fuel injection sequence to mirror the spark plug firing sequence?

No, as stated above they are batch fire, i.e. they all fire together in one batch. If you follow the injector wiring back in the loom you'll find they are ultimately spliced together.

[WALDO 1]

Hi again and thanks for your comments.

 

Yes... fire in a batch of four rather than a batch 2 and 2. That is consistent with the Haynes wiring diagram/s. With that in mind I changed over the connectors on the injectors on cylinders 1 and 2 and sure enough cylinder 1 still fired and cylinder 2 still didn't. The engine started and ran as if nothing had been changed. Removal of the number 1 cylinder spark plug connector caused the engine to stall. This would appear to show that it isn't a wiring problem and all connector leads are benefiting from the grounding pulse from the ECU? This would indicate that it is in fact the injectors on both cylinders 2 an 3 have failed? I suppose I feel unlucky that two injectors have seemingly failed at the same time and wonder if this may have contributed to the original wiring failure? It was a very simple test inspired by comments for which I am grateful. My plan now is to buy a couple of injectors and swap them over for the doubtful ones and report back. This may take some time so please bear with me.

 

Thanks again

Edited June 9, 2016 by WALDO

[toolie72 67 1 Cars]

I took 8 injectors to a local engine reconditioner (nothing fancy with the place) and got 4 good ones back

All had varying degrees of crap-they all fed fuel but as I say got the best 4 cleaned out and that's about 5 years ago now and my cars my daily so it's done the miles since

They test them anyway so might be cheaper than shelling out for new ones (or no history eBay ones)

In my experience if you look sad, ask their professional advice (use those words) they'll be more than happy to help you

[Anthony 1,003]

Have you compression tested the engine to rule out HG failure between cylinders 2 and 3? Seen that happen before now.

[steve@cornwall 100]

Hah you had the manifold off at all ? What has been done since it last ran properly?

[Telf 224 2 Cars]

Alan,

 

As I stated last time you asked about the injectors you really need to check the wiring 100%. As Jackherer mentions they are all spliced together at a point in the loom just under the inlet manifold. If you have a break here or a short you wont spot it easily.

 

Bite the bullet and take the manifold off. Clean and check all the wiring, look at the splices, use the wiring diagram and bell out the lines- as in use a multimeter to test continuity and ensure you have no shorts to earth. the wiring is basic and just requires a few hours to clean test and be 100% certain its ok.

[Telf 224 2 Cars]

you can get your injectors cleaned and sorted by this bloke:

 

http://mrinjectoruk.co.uk/

 

he sorted mine- have seen his set up- good and knows his stuff

[WALDO 1]

Hi again

 

Sorry for the delay in getting back to the forum but was away until last night. Thanks for everyone's comments. I had ordered some injectors with unknown history before I went away which I now have. I was thinking of buying an overhaul kit and/or using Mr injector as suggested and have sent an e-mail seeking advice on both. My plan was to visually test the injectors whilst still attached to the fuel rail. I have noted Anthony's comment regarding a (presumed) blown head gasket but feel in all the circumstances that the injectors are the main suspects and think I should change them first. Following Telf's advice along with a few others on the forum I have decided to remove the Inlet manifold if I can. I have ordered today a new gasket and I have removed 5 nuts from around the manifold but it doesn't seem to want to move (like most other things on this car). Does anyone have any tips for safe removal as I haven't be able to find much on this topic?

 

Thanks again

[Anthony 1,003]

If it's never been removed before, there may still be the brace on the underside of the manifold holding it in place.

 

The gasket will hold it even with the nuts removed though and potentially need a bit of vigour to break the seal.

[WALDO 1]

Hi again

 

Thanks for that. As far I know, having owned the car for 25 plus years it hasn't had the inlet manifold removed before. I have done all my own servicing and repairs etc., so can't see why it should ever had needed to come off? I think that part of the difficulty i have sometimes apart from access and visibility is that nothing has been removed for a long time. I will try and have a look underneath it and see if i can see any kind of brace etc.

 

Thanks again and regards

[WALDO 1]

Hi again

 

I removed the fuel rail and injectors with the manifold in place in the end. I used a 17mm spanner to ease the injectors out. The pintle caps tend to be pushed off by the rubber seals sticking onto the manifold, having been in that situation for so long. I replaced the seals and the caps along with the two centre injectors. I tested them before refitting by using some kitchen towel whilst cranking the engine a few times. There was an even 'spray' of fuel from each of the 4 injectors which when reassembled means that the car now finally runs on 4 cylinders. I have put a full can of petrol system cleaner in with a full tank of new petrol and hope that I have no more problems for the time being. I am not sure what caused the failure of the two original injectors although I did have something of a short circuit meltdown.

 

Thanks again for the interest shown and the comments made all of which directly or indirectly helped me overcome the problem.

 

Regards