Technical Injection removal.

[SoulPower]

Hi all,

Need a hand removing the fuel rail/injection system on my 1.2 8v mk2 to test a misfire and possibly replace one of the fuel injectors if need be.

I can see they are on tourqe head bolts? I'm expecting to lose a little fuel on removal but I'm just wondering if there is a detailed guide on any of this that someone could link me to? or any advice for the do's and don't's when carrying out the task.

Also, easy or hard job in general?

Thanks ff.

 

[fingers99]

Injectors are probably the last place to look for a misfire -- check the leads,plugs, coil packs first (do the old start it up in the dark, bonnet open, see any blue flashes, trick).

Easy enough job, but how are you going to test them? Remember that a blocked injector will generally stay open longer..........

There is usually a pressure release thingy on the end of the fuel rail.

 

[SoulPower]

Injectors are probably the last place to look for a misfire -- check the leads,plugs, coil packs first (do the old start it up in the dark, bonnet open, see any blue flashes, trick).

Easy enough job, but how are you going to test them? Remember that a blocked injector will generally stay open longer..........

There is usually a pressure release thingy on the end of the fuel rail.

brand new leads and spark plugs, plus I noticed I broke one of the injectors near the cambelt end (the plastic peice where the yellow plug sits on for the wiring) when replacing plugs.

was just going to see if the mis fire follows the individual injector or if it was the wiring.

No idea what the flash trick is lol.

 

[fingers99]

You look for blue flashes from the ignition system. Any indicate a HT leak, so fix that, no misfire. Darkness helps!

Torx fastners on the fuel rail. If you've broken the injector, you'll need a new one (expensive!) or get one from the scrappy.

 

[SoulPower]

You look for blue flashes from the ignition system. Any indicate a HT leak, so fix that, no misfire. Darkness helps!

Torx fastners on the fuel rail. If you've broken the injector, you'll need a new one (expensive!) or get one from the scrappy.

I've been quoted £144 on one, however I can get one from a 16v engine for £20. Any thoughts on going second hand? thanks

 

[fingers99]

Just get a s/h one, but not from a 16v engine (it's sure to be an injector ith higher capacity and -- at the very least -- will make that cylinder run rich). £144 for a new one is OTT anyway, but I doubt you'll pick up a new one for less than £80.

what is the part number of the injector (should be on the side here the electrical connector plugs in, something like IWP **** -- here the *represents a number).

 

[SoulPower]

Just get a s/h one, but not from a 16v engine (it's sure to be an injector ith higher capacity and -- at the very least -- will make that cylinder run rich). £144 for a new one is OTT anyway, but I doubt you'll pick up a new one for less than £80.

what is the part number of the injector (should be on the side here the electrical connector plugs in, something like IWP **** -- here the *represents a number).

I'll have a look for that code possibly tomorrow but i'm meant to be with the girlfriend shopping for crimbo and that :\ and gets dark early, but ill see what i can do cos needs to be done at the end of the day, haven't had my car for a while now lol.

 

[fingers99]

If you can find a breaker with a 8v 1242 you'll probably pick up the lot for £20, rail included -- there's no real call for them.

 

[beau]

is it misfiring on 1 or 2 cylinders?

 

[SoulPower]

is it misfiring on 1 or 2 cylinders?

Just 1 matey, far left one near the cam belt end on the 8vs.

@Fingers: That sounds promising then, I'll see what I can see!

What do you roughly think the reliability of a s/h injector will be ? Thanks

 

[fingers99]

Should be fine -- if it were a race car you might get them tested and matched, but for road use in a standard car they should be fine. And, then, your existing injectors are s/h!

Just make sure they're all the same injector and all 8v.

 

[pooroldcodger]

Since having the clutch replaced this week, we've got an intermittent mis fire, when cold. Some days fine, next day not. This morning car was missing, struggling for power, and injection light came on at the same time as the problem. When the problem stopped, the light went off etc. I don't have a code reader. Where should I start looking? Is it feasible that there could be any link between the clutch job and this new problem?

 

[fingers99]

You'd get better -- and more -- replies if you didn't thread hijack! But it's difficult to see an obvious connection unless someone didn't replace the earth lead on the gearbox properly. Go find it, coat with vaseline, tighen up.

You might try the old "start the car up at night, lift the bonnet, look for blue flashes" trick to see if the misfire is related to the coils, plugs, leads, etc.

 

[pooroldcodger]

You'd get better -- and more -- replies if you didn't thread hijack! But it's difficult to see an obvious connection unless someone didn't replace the earth lead on the gearbox properly. Go find it, coat with vaseline, tighen up.

You might try the old "start the car up at night, lift the bonnet, look for blue flashes" trick to see if the misfire is related to the coils, plugs, leads, etc.

Sorry Mr Fingers. I'm a dab hand at writing an old fashioned letter, but the do's and dont's of these forums are a bit of a mystery! I just thought that the topic seemed similar to my train of thought. Didn't intend to do the "wrong" thing.
Anyway, I satrted the process of elimination today, and changed plugs and air filter. I noticed that 2 of the plugs had a brown line around (sign of arcing?) plus some signs of moisture as well. All plug electrodes quite white as well. I don't know if that's good or not.
I did not know about thye earth connection, so I will check that out as soon as possible.
Thank you.

 

[fingers99]

No big deal, but it's best to start a new thread, otherwise you find that only people ho have been looking at the existing thread will see it.

 

[SoulPower]

for road use in a standard car they should be fine. And, then, your existing injectors are s/h!

Just make sure they're all the same injector and all 8v.

Right ok good stuff, so when I loosen up the fuel rail, Do i literally just take out the injector needed? Will there be a continous flow of fuel pumping out if the engine is off, with ignition also off? I assume no? But is there any tips to stop fuel going everywhere anyway?

Thanks

 

[fingers99]

There's often a pressure release thing on the end of the fuel rail. Otherwise, take the fuel filler cap off and wear goggles just in case.

Injectors are held in to the fuel rail by a clip, so once you've go the rail off, pop the clip off and pull them straight out -- don't be too brutal as they can snap, usually in the same place as your old one!

 

[SoulPower]

There's often a pressure release thing on the end of the fuel rail. Otherwise, take the fuel filler cap off and wear goggles just in case.

Injectors are held in to the fuel rail by a clip, so once you've go the rail off, pop the clip off and pull them straight out -- don't be too brutal as they can snap, usually in the same place as your old one!

ah I see, I've looked at the rail had a tug, but can't remember how to remove the yellow wiring clips? It was dark but do I just simply pull them off?

And also do I need to remove anything else to get to the injectors/ remove the fuel rail thanks

 

[fingers99]

There's a wire clip thingy you press in to release the electrical connectors -- get it right and there should be no resistance.

There are metal clips which need to be eased out with a screwdriver which hold the injectors themselves to the fuel rail.

Will be similar to this:

 

[DaveMcT]

DO NOT FORCE ANYTHING. If the clip or connector wont pop off easily you are doing it wrong. The clips however slides off and are easily sprained. You may need to get new ones. New rubber seals are also a good idea.