pongle

Hi guys,

Been trying to debug an interesting problem on my 96 Escort 1.6 16V Zetec EFi. A few weeks ago it started to intermittently loose power when driving a long and idle quite roughly. Over the course of about 30 miles the problem got more frequent, until now it does it continuously.

Normally the engine idles around 1,000 RPM, but now it sits at 500.

I replaced the HT leads to no avail and checked the spark plugs, finding that they are all sparking but cylinders 1 & 4 have black tips.

The garage, after having the car for over two weeks, claims to have tried replacing the ignition coil and cleaning out the injectors with no change, but that the compression was low on one of the cylinders. I rescued the car back from them and did a few more experiments myself.

Flushed the engine oil, just in case it was stuck lifters, no change.

On the compression test I performed all of the cylinders were identical.

When I disconnect each fuel injector in turn, cylinders 1 & 4 had no effect on the running of the engine, 2 & 3 caused the engine to run even more roughly.

None of the vacuum hoses show any leaks.

I am suspicious that the ignition coil is still faulty (one secondary goes to 1 & 4, the other to 2 & 3), so I may replace it again.

Anyone else have any ideas?

Cheers,
Tim

tabetha

Almost defo the coil at fault, esp the way the fault crept up like it did, as you say the coli is paired 1+4, 2+3, unless it is a wiring fault to that side of the coil, do you have any mates who's coil you could just try ?
Even when a plug sparks in air doesn't mean it will when fitted as it is under pressure which needs more lecky to jump a gap.
Short of some mysterious failing of 1+4 injector I would concentrate on the coil/supply, injectors could if wanted to rule out be swapped with 2+3 to see if problem shifts, but needfs sorting asap as it will kill the cat in no time.
tabetha

pongle

OK, excellent. New coil on order. Fortunately I don't have to drive it around, so damage is limited to the test runs. Good idea for the injectors. My next step was going to be to pull 1 and 4 to see if they were producing anything (easy to get to, whereas 2 & 3 are under the inlet manifold...)

AstoN_B

iTrader: (1)

sounds quite similar to problem im still having. mine goes away on anything over 1/4 throttle. Im starting to suspect throttle position sensor.

pongle

Interesting. I wonder if it's getting enough air... Anyway, mine won't go over 2k RPM while driving, no matter the throttle setting, so probably not the same thing

AstoN_B

iTrader: (1)

^^ id get it plugged in mate, sounds like Limited Operation Strategy (limp home mode)

should mean the car is aware of the fault and should tell you when fault reader is plugged in.

Mine isnt in limp home mode yet still isnt right i wish it could talk!