P0171/4 code issue, tried to fix

[dtpatt21]

Help!

I've been getting the lean codes, CEL, etc.

I ordered the parts to do this fix a while back. I just got around to doing the project. I changed the upper intake plenum gasket-the 6 individual ones, new isolator bolts, new valve cover and new pcv valve. It still idles like crap. I undid what I did and reinstalled it thinking I might have screwed up a gasket or something and same thing. I've double checked all my vacuum lines, etc.

Any suggestions on what to do/check? I pretty much followed this site to the t:
http://leckemby.net/windstar/windstar01.html

[12Ounce]

Did you swap out the seals and gaskets between the lower intake and the heads/block? Its rare, but they do fail.

[dtpatt21]

No, I didn't swap out the gasket that's below the lower intake...

[dtpatt21]

help! what should I do/check next? replace the lower intake gasket?

[12Ounce]

Well, first I would plug off the vacuum tap that feeds the vacuum manifold on the firewall ... and also the hose that feeds the brake booster. Then see if the engine runs better or not. The idea is to make sure some vacuum leak away from the engine is not getting to ya.

After you are pretty sure the vacuum system is pretty sound, then I would consider removing the lower manifold. It ain't a big deal ... but the first time you do it, it seems like one.

BTW, what year model are you working on ? If not '99 or later ... forget all I've said.

[dtpatt21]

It's a 2002. So, the hose that comes off the throttle body back to the fire wall, plug it on the motor side and the one coming off the brake booster? What will this isolate?

[12Ounce]

All the ac/heat door motors and controls, etc. ... and of course, the brake booster ... which can be a sleeper.

[dtpatt21]

I plugged those two big vacuum lines and it still is idling crappy. Lower IM gasket?

[12Ounce]

Well, if you are pretty sure you've eliminated all the hoses ... and PCV hose included ... my next guess would be the "lowers".

Do your research first. You will find plenty on-line. Bolts should be tightened in sequence. Invest in a 1/4" beam torque wrench if you don't already have one.

Be prepared to do some extra things ... draining/replacing coolant. Cleaning injector inlets. Replacing IMRC link retainers. Etc, etc.

[Airjer_]

You can also carefully spray carb cleaner around the intake to see if there is a change in idle. If there is than you have found the source of your vacuum leak.

You did check to see if the MAF sensor is clean?

[12Ounce]

Good point about the MAF sensor.

What after the lower gaskets and seals if the leak persists? Well, the engine front cover and the oil pan are possibles .... You may want to check just to make sure these bolts are not loose now.

[dtpatt21]

k, thx for the suggestions. would starter fluid work as well as carb cleaner?

i'll try cleaning the maf, I haven't done that yet. any suggestionS?

[dtpatt21]

ok, an update.

I cleaned the maf, no change. however, when i hit the accelerator really quickly, there's a loud suction noise and then it goes away. it's very instantaneous. just a suction sound then gone. what could that be? I've check every friggen vacuum line. i sprayed carb cleaner, nothing.......help!

[12Ounce]

Make sure the front cover and oil pan are not loose. Are the links in place on the IMRC actuator?

[dtpatt21]

where is the IMRC actuator?

The front cover, as in the front valve cover? I'll double check that.

I'll also double check the oil pan.