2.9 Fuel Injectors (maybe)

[TMRnoV]

Hi All, Car (S2 2.9) is only running on 5 cylinders, I have changed the dizzy cap, HT leads, rotor arm and plugs, no change still on 5 only, what should the next step be ? fuel injector ? and if so anyone got a part number or source ?

Cheers

Tim

[GadgeS3C]

Obvious question - but are you getting a spark on all cylinders?

[mep12345]

Tim, I have said before I have a lot of spares you can borrow for diagnosis. Drop me an email on [e-mail] and ill send you my contact details. I assume you are close to Plymouth given your last post. The spares I hold includes a full set of injectors

I also have fault code reader that may help

Hth

Mark

[Barkychoc]

Pretty sure they fire in 2 banks of 3 - ie 3 injectors fire at once so if you determine which you can swap a plug from a working cylinder to your duff one to see if it fires.

[mep12345]

Barkychoc said:

Pretty sure they fire in 2 banks of 3 - ie 3 injectors fire at once so if you determine which you can swap a plug from a working cylinder to your duff one to see if it fires.

I might be wrong but as they fire into each chamber individually I'd be surprised if they fird together. By chamber I mean induction chamber not cylinder. If they fired together in banks then the fuel would have settling time on two cylinders before being drawn into cylinder. I think the bank firing may have been the 2.8 engine with the earlier fuel injection system and a very differrnt induction set up. I await to be corrected as I am working on my assumptions from current engi e rebuild where the induction system has just been reassembled.

[Stew Mc]

GadgeS3C said:

Obvious question - but are you getting a spark on all cylinders?

Would second this.
IMHO start with the basics. Find out which cylinder is down using insulated pliers, engine idling and pull off and refit one plug lead at a time. Presume you don't have a catalyst? If so probably not recommended but if it is down on a cylinder, any damage to the cat has more than likely been done.

The offending cylinder will show itself as the idle will not change when the lead is removed.
Once you find the offending cylinder have you got a spark and fuel to it? If spark and fuel are OK, I would move on to a compression check. Not aware of these engines burning valves but they are old now and a tight tappet could have caused a problem.
If you are not happy doing the above, find someone who is local and can help. I would not jump in too deep until spark, fuel and compression's are known.
Cheers, Stew.

[TMRnoV]

Hi and thanks for the suggestions, and thanks Mark I will drop you an e-mail, actually hoped I'd you see last night at the Corn Mill but understand from the other guys that your not around during the week.

Anyway it's cylinder number 4 that's not firing, after fitting new leads, plugs, cap and rotor arm surely it can only be that cylinders injector that's faulty, I'd be very unlucky to buy a faulty cap, unless of course it's the distributor ?

Other than that the only the other thing is low compression, feel the need to buy a tester coming on.

Tim

[phillpot]

mep12345 said:

I might be wrong

Think you are






So, definately No. 4 ?

Have you pulled plug lead off and briefly run engine with a spare (one of the old) spark plug plugged in and resting on the engine ? does it spark?
Alternatively push a screwdriver into the lead and hold near (1-2mm) to a good earth (the plenum) should be a good blue spark ?

If you now take plug out it should be wet, bone dry would suggest no petrol reaching that cylinder

Injectors are obviously electrically operated, is the connection good ? if cable long enough swap plug with cyl. five, does misfire move to 5 or stay on 4?

this is what I would do, others may have different ideas good luck!

[mep12345]

phillpot said:

mep12345 said:

I might be wrong

Think you are

Mmmm must be that the timing of injection isn't that sensitive to timing and can deal with small "settling" time in induction chamber. As I said working from assumptions with no books here as away from home.


Tim, also have in line spark testers you can borrow to prove spark as Mike above mentions

[phillpot]

mep12345 said:

Tim, also have in line spark testers you can borrow to prove spark as Mike above mentions

Or just grab hold of the lead, if you go "ow ow ow ow " you've got a spark

[mep12345]

phillpot said:

Or just grab hold of the lead, if you go "ow ow ow ow " you've got a spark

[TMRnoV]

OK thanks chaps, I have checked the spark at number 4 and that is good (used old plug and marigolds) the plug in number 4 is dry so no fuel, can we say categorically that it's an injector at fault?

Tim

[phillpot]

phillpot said:

Injectors are electrically operated, is the connection good ? if cable long enough swap injector plug with cyl. five, does misfire move to 5 or stay on 4?

[jwoffshore]

It could be a faulty injector, or it could be a break in the wire or poor/dirty connector. Have you checked you are getting 12V pulses from the plug to that injector? Simplest would be an old style voltmeter with a needle. You'll see the meter jump a little, but it won't ever read 12V because the pulse is too brief.

[Simon says]

Very easy to diagnosis a faulty injector while the motor is running (idling) run a long screwdriver from the inj body to your ear (crude stethoscope) and you will hear it clicking away (no you don't need a trained ear) if the car as spent any amount of time with the fuel rail dry/laid up then sticking can happen and frequently does on older injectors with a bit of gum/varnish around the pintel area I have fitted s/hand engines that have spent long periods with dry fuel rails/injectors and had maybe 1 or 2 inj's stuck closed (no clicking) sometimes freed with a couple of taps with a small spanner on the steel body while the engine is running to bring them back to life again although if they have got this bad I would strongly recommend getting them all ultrasonically serviced anyway the Ford 2.9 Cologne is batch/bank fired injection not sequential as suggested earlier good point by Philpot about swapping inj plugs over to diagnosis duff cylinder/fault

Edited by Simon says on Wednesday 10th October 22:00

[phillpot]

Simon says said:

I would strongly recommend getting them all ultrasonically serviced anyway

I had a set serviced by www.injectortune.co.uk , didn't have a problem but was doing fair bit of work on engine so was a case of "while they're out"

[Simon says]

phillpot said:

Simon says said:

I would strongly recommend getting them all ultrasonically serviced anyway

I had a set serviced by www.injectortune.co.uk , didn't have a problem but was doing fair bit of work on engine so was a case of "while they're out"

Very wise the flow chart before and after always makes interesting viewing too

[mep12345]

Tim if you want them serviced there is a place in cattedown that does the job. £15 to test and another £10 if service needed. Per injector. Not sure how that is for price but had them quote for me recently and the guy advised me not to bother given my symptoms so turned down work he could have easily had-normally a good sign. They do the lot in a day too. Can't remember name but have details at home, they are in the old Lucas building

[TMRnoV]

Thanks for all of the advice/help guys but I have sourced some new injectors (6) and they should be delivered tomorrow, taking the plenum and throttle body to be soda blasted as well (I know it doesn't contribute to the poor running but they will look nicer )

Probably get the old injectors serviced as well, always good to have spares.

Tim

[phillpot]

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