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        General >> Problems >> 2-3 missing under load
        
(Message started by: ro284 on Dec 4^th, 2011, 5:39pm)

Title: 2-3 missing under load
Post by ro284 on Dec 4^th, 2011, 5:39pm

2-3 missing under load.holding back, and reluctant to rev, ive checked plugs, (4 electrode bosch,) coils seem ok, will do compression test tomorow, but it had a new head 12 months ago, when i start it in the morning i will see if there is a cold exhaust manifold as it warms up, any ideas please?
Thanks Bob

Title: Re: 2-3 missing under load
Post by lleewar on Dec 4^th, 2011, 11:36pm

Have you cleaned the maf. Causes all sorts of running problems.

Title: Re: 2-3 missing under load
Post by ro284 on Dec 5^th, 2011, 11:02am

Thanks lleewar, i disconnected the maf, still had problem, no difference, have cleaned it recently, i thought i would test the coils by swapping them over first i noticed that the front coil would keep the engine firing on pistons 2 and 3. however the rear coil would not run on pistons 1 and 4, so i swapped the coils over to see if any difference, and only the front coil would run the engine on 2 and 3, (not smoothly of course!) but continuously, i suspect it,s a coil. in the meantime the speedo had shot right round the clock and stuck pointing down! what have i done? Also anyone got a 2-3 coil they could sell me,
cheers Bob

Title: Re: 2-3 missing under load
Post by ro284 on Dec 5^th, 2011, 4:05pm

Just a bit to add re-symptoms, the tick-over is fine, and the car will cruse along nicely with no throttle, it is only when you press the throttle, it starts to get lumpy and stutter, i think it may be a coil pack, going by the previous symptoms and tests, but then it may be an injector or two, or something else, so any thoughts appreciated, thanks Bob

Title: Re: 2-3 missing under load
Post by martin_rowe on Dec 5^th, 2011, 5:16pm

Coils, plugs, the 2 HT leads, wiring to the coils. Any or all would be a starting point, wiring often gets a bit ropey right back to the bulkhead.

Title: Re: 2-3 missing under load
Post by 5stud on Dec 5^th, 2011, 5:16pm

have you had a good look at your top loom. you have a pm

Title: Re: 2-3 missing under load
Post by lleewar on Dec 5^th, 2011, 7:33pm

Bob, I have some coil packs available if you need them :). Just to let you know, I had the same problem. Car ran perfectly even on cruise until I pressed the accelerator. A cleaned maf and a change of coils cured it. Like yours, they must have been breaking down on load. Lee

Title: Re: 2-3 missing under load
Post by lleewar on Dec 5^th, 2011, 7:35pm

As 5stud say's, check the top loom for breakages.

Title: Re: 2-3 missing under load
Post by Mike H on Dec 6^th, 2011, 1:27pm

on 12/05/11 at 19:33:29, lleewar wrote:

they must have been breaking down on load. Lee

That makes sense 'cause need more Voltage at the plugs when the gas pressure in the combustion chambers goes up.

In case you haven't yet check the spark plugs gaps, they can unobtrusively wear out, in that the electrode(s) can be eaten away to nothing but still work. Until that is they don't want to any more ;D

Title: Re: 2-3 missing under load
Post by Stixy on Dec 6^th, 2011, 2:26pm

Have you tried taking the vac pipe off the egr valve ? to stop the egr operating

Title: Re: 2-3 missing under load
Post by ro284 on Dec 7^th, 2011, 6:11pm

Thanks for replies guys, i have checked the top loom, no problems that i can see, also unplugged egr valve, no difference there. I agree with Mike H, as the car revs freely on all cylinders and only plays up under load, unfortunately i have had to struggle on and drive the car about a bit, (with difficulty and very high petrol use!) because my 12 valve is not taxed or insured yet, Still i have a couple of coils on order now, so hopefully that will do the trick,
however i still have a speedo that has swung right round since i have been fiddling about with the wires on the head, i have tapped the clear plastic and the needle flipped about an inch back but swung back to the wrong position again, is the speedo driven from the camshaft of auto box ? please, Thanks Bob

Title: Re: 2-3 missing under load
Post by Tompion on Dec 7^th, 2011, 9:43pm

Try an instrument reset:
http://www.fordscorpio.co.uk/instreset.htm

Turn on the ignition (no need to start it), press and hold the odometer trip button until the display changes. Turn off the ignition, when you turn it back on the needles will flick round & hopefully the speedo will return.
If it has got trapped the wrong side of the lower ledge repeat the procedure but give the top of the dash a thump when the rev counter needle has swung to the right (as it’s about to return), with any luck the speedo needle will jump the ledge and return.

Title: Re: 2-3 missing under load
Post by ro284 on Dec 8^th, 2011, 9:55am

Brilliant, that did the trick! thanks again Tompion,
Bob

Title: Re: 2-3 missing under load
Post by ro284 on Dec 9^th, 2011, 2:19pm

All ok now yipee! Huge thumbs up to Lee, Got my coil packs today as he said i would.(well packaged) Thanks again buddy.
it was the pack i thought it was, so what i learned from testing was that the engine would not run on pistons 2 & 3 with one coil, but it would run on 2-3 with the other, so a gathered that if i changed the front coil with a good one it would run, which it did. Nice to have the car back, i have had 31 to a gallon on this car, but for a few days only 17!
Cheers all for all help and advice, Bob

Title: Re: 2-3 missing under load
Post by Mike H on Dec 9^th, 2011, 2:41pm

Congratulations! Well diagnosed peeps http://livinginthepast-audioweb.co.uk/images/misc/th_thumbsup.gif

Title: Re: 2-3 missing under load
Post by lleewar on Dec 9^th, 2011, 6:57pm

Glad to help and to hear your back on the road Bob. Cheers Lee ;) ;)