A few minor engine issues (zetec)

[Tj-zetec]

I've found over the last few weeks the old girl is a little rough on cold starts. Even on hot days.
Mostly rough, lumpy idle but i can't quite tell if it's missing. It's only at idle though, given some throttle it behaves itself.

And just recently it's developed a bit of a flat spot at low rpm and doesn't really pull until the revs get up around 3-3500 rpm.

It's due for a service, which i usually do myself but obviously i can really only change fluids and filters.
Is it worth, after servicing it, taking it somewhere that does computer tuning and diagnostics?? there's a place up the road from me that i hear good things about but i wanted your opinions first.

[BlackLS]

Have you replaced a fuel pump yet?

How many K's has it does.

May also be an oxygen sensor.

[Tj-zetec]

just on 140,000.

No i haven't done a fuel pump. it's only at idle where it had problems, wouldn't a pump affect engine uptake at any revs??
It doesn't seem to starve for fuel, just runs lumpy

[Mullett]

Start from the top:

New sparkplugs
New fuel filter
New air filter

Then:
Coilpacks
Fuel Pressure reg
Catalytic converter
Crank angle sensor

Computer diagnostics is a pretty loose term, but if they've got the right gear they'll be able to tell you if something's stuffed. I'd suggest a dyno tune (if someone in your area can do them). You'll get more power/economy and it'll tell you straight out if there's a problem with your Air Fuel Ratio (which is quite likely what's causing the flatspot).

-RM

[Fast Eddie]

Quote: "Doesn't really pull until the revs get up around 3-3,500 rpm" Ha, that's a familiar feeling and its something that doesn't worry me but mine's an auto though.

I can recommend someone who can dyno your Focus. P.M. if you like and I can find out for sure whether they'd be willing to help you out. Might even put my LR on the dyno too.

Can you recall if you'd had "E.C.U. Edits" programmed into it within the first year or so of ownership?

[eXtremist]

Run some "Subaru Upper Engine Cleaner" through your engine.

Its said to be the best upper engine cleaner when compared to things like carby cleaner etc..

[Tj-zetec]

hmm interesting.
It had platinum plugs go in about a year ago, maybe 15000 ks.
I've got a k+n filter which is in desperate need of a clean but it's too cold and damp to do it when i get home from work so i'll hit that on the weekend otherwise it'll never dry.
I did, however pick the dead bugs and wipe some of the grime off it and turned it around (it gets real grubby on the side where the snorkel enters the air-box) and that seemed to help.

It'll get new filters and fluids soon.
the upper engine cleaner sounds interesting. what is it, an additive or a flush of some sort.

edit* oh and it had better not be the cat converter, otherwise lambros at HiTech is gonna get a nasty phone call.. hehe.