I'm nesw to this site but have been on some Diesel forums before with a lot of success with fixes. So here is my dilema.
Info. 96 Windstar 3.8 144K miles.
Also note that I've had the luxury,at least for a couple of days of having an identical twin to compare and swap parts with.
Problem goes like so. Customer complains that the van stalls when turning. Well, found out that it requires a special scenario for this to happen. She goes to the store and pulls into a parking spot. Comes back out, starts it up and backs out. As you would usually do, she turns the wheel to go forward along with changing from Reverse to Drive and if she gives it a moderate or as I would call it 'Normal' amount of acceleration, plunk it dies. Only when the van is pretty well warmed up. Also, in my testing, I've noticed that while parked, engine idling and completely warmed up, if I snap the throttle the engine stumbles. This nearly every time. The IAC seems to just slightly over compensate for load such as going from park to reverse or drive. The donar van, same year same everything, runs perfectly (199K miles).
For what I've seen and done:
When I first started, LT FTRM% on bank 1 were running about 12% while LT FTRM on bank 2 were around 0%. I trouble shot for a vacuum and coolant leak and ended up replacing lower intake manifold gaskets as well as all upper intake seals. The EGR ports had already been cleaned out as well as the IAC had been recently replaced. When I got it back together, both LT FTRM's as well as ST FTRM's run at essentially 0%, fluctuating for driving conditions.
With the donar van, I've swapped IAC, EGR, DPFE sensor, all 4 O2 sensors, MAF and IAT sensors. Fuel pressure holds 31lbs until vacuum drops then it shoots up to 40lbs. Never see less than 31lbs. Swapped throttle bodies, which seemed to make the problem a little worse. Checked PCV valve and it's open. I've strapped the IMRC valves to their closed or idle position and thought I had it whooped until a few stops later. Ive replaced the powersteering pump because of loud growling, and as some of you have guessed, it still growls. The only times that I can kill it is related to having it in a faily tight turn. I have killed it a few times while turning the wheel sharply the then punching the gas. This little smiley
truely is how I feel. The IAC works seemingly well. Heavy load and snap of the throttle will shut it down. The donar van, with a lot of the old parts from this problem van will not die regardless of what I subject it to.
Sorry for the long post but I thought it might help to regurgitate all that I've done for the past 2 weeks. Please help!
Tim the toolman