ZX5 engine stumble when stopped, help!

[pbfoot]

Any high mileage Focus owner should clean around the butterfly in the throttle body.Oil from the crankcase vent and the pcv system causes a sticky residue to form which causes the low idle, hard starting problem

[pumafeet10]

The car only has 80k, so not what would be considered high mileage at all, but throttle butterfly was cleaned when the AEM intake was installed and again yesterday, along with everything around the intake manifold area

[Grinder]

Hmmmm. Car ran fine until you put an intake on it. Now it runs like crap....... I dunno......maybe reinstall the factory airbox (after disconnecting the batt again) and see if your problem still persists.

If the car uses an airflow sensor to calculate fuel delivery and load, it would be important that the airflow through that sensor is capable of being properly sampled.

[pbfoot]

Have to say sounds like an intake leak.You should always check whatever work you just performed before suspecting anything else. You can spray a little wd-40 where the intake and head meet and if the idle goes up you found it. Disconnect battery for at least 15 minutes to reset and it should relearn within five minutes of driving.

[pumafeet10]

as stated a few times, i have checked over all rubber hoses, tb connections, maf connections, pcv and anything else that is located on the head on the engine, and nothing made any difference.

The only thing that i keep thinking it may be is the maf, as i stated before, i sprayed maf cleaner into the intake and it stalled after a second or two of spraying.

I sprayed with brake clean all over the outside of the intake with everything hooked up and nothing happened at all

Does the zetec engine have a iacv? i know on my honda civic that is a very common problem

Sadly i will need to but a new or used oem intake as i sold mine, but no big deal if i have to do that, but would like to get this working correctly first

[pumafeet10]

Still have a problem, actually was driving today, less then a quarter tank of fuel and the car stalled at lights twice! Which makes me think fuel system, maybe fuel pump?

[my_beautious_ZX3]

Did you (or previous owner) in the distant past replace your fuel pump with an older one from a junkyard?

The reason I ask is that a classic symptom of the recalled fuel pump in the early model Focii was just that - stalling at stoplights with quarter tank or less of fuel. It probably happened to me a half dozen times before the problem was correctly diagnosed.

The recall only affected vehicles mfg'd through the end of 2001 (mfg date, not model year), so your '03 wouldn't have wound up with a defective pump unless it received one from a junkyard or old inventory.

[pumafeet10]

We are the only owners of the car since new, but that still doesn't mean that it's not the fuel pump. I don't want to just waste money on replacing perfectly good parts but sometimes stuff just needs replaced

[my_beautious_ZX3]

during a normal start, a healthy pump will make a "whirring" sound for a few seconds. It is very obvious in a quiet garage if you turn the ignition key to its final detent without turning it all the way to starting.

Do you hear that sound when trying to re-start the car in its stalled condition?

[pumafeet10]

I know the sound, and it is very faint, and actually was listening for it on my drive today after it stalled once, when my civic pump primes, it's very noticeable, but on the focus it has always been very quiet