back to the project 96 3.8l rebuild

howdy again

i took some time off this project to get caught up with my life but now i am back at it.

this is a complete rebuild (rings bearings ect). it is to the point of running(badly). i have driven it about 200km so far and things are going downhill fast. even after finally getting the cam position sensor installed correctly (2 weeks to order one out of the states) it still have driveablility problems. 1/2 the time at idle it is fine (bit rough but not bad) and the other half the time it is barley running/stalling. when it goes rough it seems to last untill the engine works itself up to 1500+rpm then suddenly clears up and purrs like a kitty, smooth and powerfull. i have spent the last week on this problem. the codes i have been getting are 1537/1528(intake runners), 401 egr flow low,p1131 o2 sensors(still waiting for delivery from California on those),174 lean bank 2, 301,301,305 missfires (not the plugs (new double platninum) and new premium wires. the missfire combinations seem to change from day to day so it is not cylender specific problem.

what i have done so far is:

1. put in premium plugs and wires
2. changed the coil pack with one from the wreckers - no improvement
3. changed the maf sensor with one from the wreckers - no improvement
4. changed the ?? (egr bypass box sensor thingy)- no improvement
5. done the hokey pokey and turned myself around - no improvement
6. wired the dpef (vacumm butterfly valve thingys) closed with wire - no improvement (havent checked the codes since then but assume the codes for those will be gone)
7 replaced all plasitic vaccume lines with new rubber hoses - no improvenmt
8 changed the gaskets at the throttle body/air bypass - no improvement
9 sat cursing and swearing at this dam van for 30 mins - no improvement

things i have noticed tonight:

1. no vaccume getting to the egr valve itself. the line goes from the valve to a gizmo on the back side of the black intake thingy. the second line going into the gizmo does have vaccume so the problem is with it or the pcm?
2. no vaccume getting to the intake runners vacumme thingys. same deal as problem #1 so its beggingin to look more like a pcm issue?
3. noticed the air conditioning is on at all times the interior fan is on, no matter what setting. could this be related somehow or do these windstars always have the ac on? the vaccume is good to the control box inside as i can switch to floor/vent ect
4. after running the motor for a bit then turning it off, there is a tapping/clicking noice coming from the intake manifold area. is that just temp differential or could it be an air leak?

i think the egine will run much better once the egr vaccume issue is figured out.i dont seem to be loosing any oil or antifreeze and no noticable knocking from the motor (just the origonal rods,, might have to change them out later)

any ideas or suggestions on where to go from here??

thanks
gord :banghead:

My '96 3.8L A/C is working in all settings other than OFF, and VENT.

The IMRC vaccum and the EGR valve vaccum come from vaccum solenoids on the back of the upper intake manifold.
There is a vaccum solenoid for each.

The IMRC vaccum solenoid is on the passenger side-ish of the back of the upper intake manifold.

The EGR vaccum solenoid is on the driver side-ish of the back of the upper intake manifold.

There is also a vaccum solenoid on the firwall, on the driver side-ish.... This is for the charcoal Canister.

The important thing is, there should be a constant (when the engine is running) vaccum to the solenoid input.

The PCM sends a signal to the vaccum solenoid telling it to be open / closed.
The other vaccum line goes to the unit being controlled by the vaccum.

I would verify that the "IN" side of the solenoid has the constant vaccum source.
If not, that is likley the cause of the P0174 code that you mentioned, and a contributer to the engine not running right.

Also verify that the electrical connections are made to the vaccum solenoid.

There is a little "cap" on each vaccum solenoid.
Inside that cap is a little felt or foam filter.
I have seen a couple of posts about that filter getting clogged, preventing proper operation of the solenoid.

The fact that you can select the interior air flow away from the defrost (windshield) to the floor and vents indicates that you have those vaccum lines connected. That also comes off of the back of the upper intake manifold.

Concerning the ac operation: In my extended family of autos, there are two '97 Tracers. I was surprised to find that the ac ran "all the time", unless all ventilation is turned off. No ac "ON-OFF" button! Your model Windstar may be designed the same.

We pull the fuse during winter months.