Yet another question albeit related to the spark plug threads

[I.Mupferit]

Is it possible to have the scenario of 1 injector supplying more fuel than it should, maybe because it might not shut off properly due to a speck of dirt perhaps? I am just trying to get to the bottom of an annoying plug fouling issue I have which mainly seems to affect 1 plug.

 

If I drive like my hair is on fire and bounce it off the rev limiter going up through the gears, it will clear the misfire and be fine for a while but always, after running at town speeds for a while, it will return. Being able to clear it this way eliminates HT leads and coil I think, besides, I have changed these and the problem is still there.

 

I have only got hold of the hotter plugs today so haven't tried them yet but I don't fully understand why only 1 plug (the same one every time) is much more affected than the others unless maybe that cylinder is getting too much fuel.

 

Does this sound like a plausible explanation?

 

Maybe I'll swap a couple of injectors over and see if the misfire moves with it.

 

I'm just trying to make sense of this and it helps to rationalise it by tapping other peoples experiences.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

 

Edited by - Brent Chiswick on 22 May 2008 08:14:58

[Molecular--Bob]

Does your ECU allow for individual fuel trims on the injectors. Might be worth looking at these to see if you have one of you cylinders trimmed up a little, unlikely but possible.

 

You can get injectors cleaned and flow tested for aroung 15quid each, which might be worthwhile before you start changing everything else.

 

Edited by - Molecular--Bob on 21 May 2008 14:43:21

[I.Mupferit]

I'm not 100% certain but I'm pretty sure the Emerald K3 doesn't allow for individual fuelling of each injector. Could be wrong though.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Stationary M25 Traveller]

There was a thread on here only days ago about a company on the Slyfield Ind Estate in Guildford that cleans injectors.

 

7 related photos

[I.Mupferit]

That was instigated by me asking. I hate not knowing why something behaves in the way it does hence me asking all kinds of seemingly unrelated questions in order to try and get to the bottom of this particular problem.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[ECR]

swap injector 1 to another poisition and see if the fault follows ...

[oilyhands]

The Emerald does allow individual fuel trims, I would see if you can monitor the exhaust temperature on each runner, it is often a good indication of how the cylinder is operating.

 

Oily

[I.Mupferit]

Good idea Dave, I'll get hold of something to read the temperature.

 

I was going to try that Roger but just wanted to establish if it is possible for injectors to overfuel, perhaps by remaining slightly open, as I try to rationalise reasons for this rather odd behaviour.

 

Other than this irritant, it is a stonking good engine so I really want to get it sorted so I can enjoy it to the max.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Mcalvert]

Brent - I saw in a London Maplins store this week that they were doing a laser-pointer temperature gun for £30, down from £50...

 

Michael.

[Pooh_R]

If you have access to an oscilloscope and current clamp, the movement of the injector pintles can be observed. Any timing differences between cylinders would be evident. (subtle leaks once the pintle close might not).

 

Pooh

 

 

[I.Mupferit]

I decided to swap a couple of injectors over last night to see if the plug sooting moves with it so hopefully that will eliminate one thing or the other. I didn't get a chance to go for a run last night but should be able to test it out tonight.

 

Thanks for all your suggestions.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Molecular--Bob]

Another concern is where the lambda probe is located on your car. Does it run on only one header or is it in the collector. If it is in the header for the duff injector your map may be out and you risk running lean on the good cylinders. If its in the collector you may still get slight leaning as a result of the over fueling in the duff cylinder, but less of a problem.

[I.Mupferit]

No lambda fitted.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Jason Plato]

as ECR said

 

simply try moving the injector and see if the problam moves 😶‍🌫️

 

Taffia rear gunner

 

[I.Mupferit]

As I said - I already have! 😶‍🌫️

 

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

 

Edited by - Brent Chiswick on 22 May 2008 09:34:12

[dannylt]

I doubt it will make any difference moving the injector, just that that cylinder is most marginal. If you replace all the plugs does it happen again? Having a poor starting enrichment map or some poorly mapped site can cause all these problems, as I've experienced several times. I think you're close to Track'n'Road - if so they have always managed to fix this problem for me. Of course, worth having your injectors cleaned if they never have been!