Attempts stall, Idle Pulses 600-800 rpms, horrible MPG

[uzzo2]

6. Ignition COILS - (Old ones test out fine, but NEW lower resistance Accel coils installed anyway.)

did you do this, how did it come out?

[searcherrr]

Working in these threads right now:
Re: Bad fuel pump? 95 3.8L 158k miles
http://www.automotiveforums.com/vbul...03#post5893703

Re: Bad coil pack symptoms
http://www.automotiveforums.com/vbul...62#post5893762

[searcherrr]

Originally Posted by uzzo2

My vote is still for the RPG through the back window
Don't dread taking off the cowl, it's a lot easier than it looks, i can have mine off in about 15 minutes. Take off the windshield wipers and the antenna, several screws, then unplug the wiper motor and just pull it all out together, easy cheezy, good luck!

If the problem is still there after I get it back from the shop I'll pull the cowl and so a thorough vacuum line inspection.

RPG sounds like a lot more fun.

[searcherrr]

Items done IN BOLD:

1. Remove cowl and Inspect for vacuum leaks.

2. While cowl is off - Inspect for bad grounds.

3. FPR

4. TPS - Original and in nearly constant motion; wear item

5. IAC - I have a new one installed, but the problem at idle behaves like a bad IAC.

6. Ignition COILS - (Old ones test out fine, but NEW lower resistance Accel coils installed anyway.)

7. ICM

8. Camshaft position sensor w/ New Synchro - Since synchro installed there is a rattling/clicking/tapping sound from it.

9. Crankshaft position sensor


The bottom of the list:
10. MAS - Used/New cleaned MAS is installed. Still looks good; no codes. May clean again and swap in another to see, but this is a doubtful cause to me at this point.

11. O2 sensors; though no codes; are originals from at least 1 previously overheated cat

12. Fuel Pump - Have yet to test PSI with new pump. Will tomorrow.

13. Alternator - Though multiple tests show it as good, my shop told me Thursday its bad. I don't know why and wasn't given any details on this, but $350 parts/labor later I have a new alternator and I'm not even sure I believe I needed it.

[wiswind]

#8, I would ask the shop to look into the rattle sound from the synchro....it should be quiet.

[searcherrr]

IAC
I looked into vacuum lines this weekend and put together a makeshift vacuum testing rig today. Well, I found a couple of things. I didn't remove the cowl and just eyeballed where everything coming off the intake plenum was and following it all with my hands to where I couldn't see I felt if it was plugged in all the way. Some weren't, but I doubt they were leaking cause they were mostly plugged on well.

I put the air compressor on at about 17lbs and connected it to the air pipe right behind where the maf sensor goes so that I'd be testing from the pipe to the throttle body and beyond.

What did I get? BIG TIME ..... BIG TIME .... BIG TIME AIR coming out of the IAC itself. I removed the IAC cover and cupped the IAC with my hand and then removed it (repeated several times) so that I could hear the air leak sound changing to confirm it was at the IAC and sure enough this brand new IAC has been broken from Day 1. It did this on the old engine prior to the new engine install too, but it wasn't nearly as noticeable on the old engine for some reason.

The IAC on there is from NAPA, which my trusted shop swears by. Hoping that I could see some difference in the way my RPMs behave when I turn the steering wheel and when the fans cut off, I very tightly wound some electrical tape around the IAC where I think its leaking (at the metal joint part; where the pintle electrical portion inserts into the valve opening portion) and unfortunately I saw no difference in the way the RPMs behaved. The IAC electrics could be blown out too, so it may be more than a leak from the IAC.... perhaps the old alternator is the culprit.

Does anyone know what the knob on the side of the IAC does?

Today I'm going to let the shop know the results of my vac leak test and IAC thing and see if they'll give me my money back because I really want to get an OEM one. I told them from day 1 it wasn't acting right, right after I got the van back from the new engine installation.

What aggravates me after all this time is that I was the one who had to do the vacuum leak down test whereas I've asked them to do it several times and they always must've thought it wasn't necessary and didn't do it.

HOPE: I have none. I am happy I've identified the IAC as a problem, but I am not waving the "war is over" flag until I try a new OEM IAC out first.

POSITIVE BATTERY CABLE TO FUSE BOX -
Also, I have stumbled across something pretty stupid. The Positive battery cable that goes to the fuse box seems to have a crappy connection to the battery despite my best efforts with the wrong tools to recrimp a new end on it. I was plucking/tapping on it while under the hood and found the under hood light would flicker on/off at some points in sync with my tapping. So I have to recrimp it "the right way" and hope the connection is better, though since the battery doesn't move (its secure) and neither does the cable during operation I doubt this was a big deal.... but its also disturbing that mere tapping on it can flicker the hood light too. I guess I have to invest in a crimping tool and find out where/who sells the GOOD crimping stuff cause the stuff I've seen at Wal-mart and/or Autozone usually isn't that great.

[wiswind]

I looked up 1995 3.8L windstar on rockauto's website.
Under "fuel/air" all the way down, Throttle body Gasket, they list several gaskets.
Felpro # 71216 is the one for the IAC

I would try getting that and installing it.
If it does not solve anything....it is a wopping 62 cents.
I would try to locate it at a local auto part store, unless you have something else to order.
Cheapest shipping for just that 1 part to my house is $7.40

[searcherrr]

I didn't mean to insinuate that it was coming from the IAC gasket. Its coming from the IAC casing itself. AIR just shoots out of there and I can feel it very liberally. I'd call it a major vac leak... definitely not tiny enough to make a hiss or a squeaky noise.... just "foof" air sound rushing out. Makes all the sense in the world to me now because as the IAC tries to adjust it has an air hole right there inside itself.

In any case a new IAC with a new gasket is on order. If idle doesn't stabilize this time (I will pull the battery cable for 5> minutes to clear learned values) I'll do another vac test and if air comes from the same area then we know we're probably dealing with air coming out of the throttle body somewhere near the IAC.

[tripletdaddy]

Progress! And a very interesting discovery. Super mega A++ for effort and stick-tuitiveness!! Not having a clear picture in my mind of the location of the leak on the IAC, it does seem reasonable that it shouldn't leak with your pressure test as that would indicate there is unmeasured intake air and a vacuum leak. I wonder why there aren't any codes for the unmeasured air from the IAC leak.

NAPA supposedly warranties parts for lifetime, but of course not all of them. I was surprised when I asked if they do have LLT warranty on parts. Turns out, NAPA or Carquest or a heavy truck parts supplier may be the best place for a higher end wire connector. You probably don't feel like replacing the whole wire assembly, though some here are strong advocates of not using some inferior clamp connectors and instead using a prefab wire with the right ends on it like or better than OEM. I think what is on it is two or more wires crimped together at the battery clamp, so replacing it may be not reasonable. You may consider getting a copper lug and solder it to the end of the wire.

There are some much more expensive wire connectors at good hardware stores, Home Depot, Lowes, and some auto parts stores. They aren't your typical connector. I'm not sure they even crimp on. I think they screw on maybe like a compression type connection and the wire end is encapsulated to prevent corrosion. It might be called GRIPPS, but don't quote me on that.

[wiswind]

I would check into what it would cost for a new wire....might be less fuss and not expensive.
If it is a high current wire...and has been loose for some time, the copper wire inside the connector could be chared and/or corroded.

[searcherrr]

Autozone - They have Tsunami brand lugs/connectors that have an allen wrench screw to compress the wire down inside the gold plated lug. It was 6 bucks. The other positive wire is crimped pretty good already so instead of making the 2 consistent I'm opting to leave it alone (experience teaches me that gleaming smile). So I'll have one gold n shiney one going to the fuse box and a regular copper lug to the starter.

I also bought a heavy duty pliers/clipper and basically I'm just gonna clip a bit off the cable and put the fresh end in the tsunami lug. I'm still debating on opening the pliers/clipper (pricey) instead of using some big ass garden shears.

I think I'd prefer the crimping method if I could get a crimper that would do it right, but the kind of crimper I'd want to get will cost at least $25 and it'll rarely be used. Reason I'd prefer the crimp method is it leaves no space inside the lug whereas the allen screw down type leaves some space on either side of the cable I think, but I have to try it out first. If it doesn't lose the signal when I move it around afterwards that'll be fine with me.

[searcherrr]

Originally Posted by wiswind

I would check into what it would cost for a new wire....might be less fuss and not expensive.
If it is a high current wire...and has been loose for some time, the copper wire inside the connector could be chared and/or corroded.

I should've went with that idea to begin with. I went outside tonight to replace the IAC and put a new lug on the fuse box battery cable at the battery side and found that after I cut back about 1.5" of the cable that it looked like it'd gone a few rounds with some lava. So with 10 minutes left till Autozone closed I rushed over there and got a new cable and some red electrical tape since they apparently only sell black cables. huh. I threw in a nice new roll of blue shop towels too.

Replacing the fuse box battery cable was surprisingly easy as Ford thought of this when building the fuse box. When you push a lil tab to the side the end of the box slides up allowing access to the 2 nuts that hold on the heavy voltage cables (1 goes to battery and other to alternator). You also have to release 2 tabs on the side of the fuse box itself to raise the box up a lil bit so you can get a driver/socket behind the box. I wedged a screwdriver handle under the fuse box to hold it up while I operated on it.

After that I resistance tested from the alternator positive lead terminal to the positive lead on the battery cable and got a 0.00 resistance where prior I believe it was showing above 1, which ain't good.

Replaced IAC with new gasket.

Both old IAC and new IAC resistance test around 9.4-9.6 ohms which is within the 6 to 13 ohm allowance according to what I was lucky to find in the Ford Cd-Rom...... but the old IAC is leaking air right?

Well...... I thought so. I have to say my constitution is pretty low right now, but maybe there is a glimmer of hope here by the results. The results are that the problem is now worse. Yes, worse..... the "near stall" does seem worse.

So to wrap up.....

Summary of Results:

Replaced thought to be leaking air IAC

Replaced fuse box battery cable

Whistling - There is from time to time a whistling noise (or was at first) when you first turn the wheel slightly left or right. The other day after I taped the old IAC where I thought it was leaking after I shut off the engine there was a very long whining/whistling/squealing noise AFTER the engine was off and finally wound down like letting air out of a balloon.

Near stall issue is now worse

Engine intake vacuum - Now shows in the middle of the green area at idle whereas in past was borderline in the red zone.

Fuel Pressure - Oddly enough fuel pressure is now LOWER at 2000rpms or above, at 26psi since the new fuel pump installed. At idle it is at 28psi which is actually just like the old pump and worse for PSI at acceleration. At key flick (no engine on) pressure gets up to around 37-38psi and holds when you turn it off for at least 5 minutes.

Does this mean I have leaky injectors (or no, because pressure holds at key flick)? Cause thats the only thing not replaced yet on the fuel system. -----OR----- because I know I obviously still have a vacuum leak is fuel pressure being affected negatively?

Since new fuel pump my in town mileage has dropped to about 8mpg.


Action Plan:
Air was coming from somewhere near the throttle body for sure during the vac leak test. I was positive it was the IAC, but that has to be wrong since the van is still showing near stall signs and they are worse. They are either worse because the new IAC is working better than the old one OR the new positive battery fuse box cable is providing less resistance.

Tomorrow I will proceed with another vac leak test and try to better isolate where the leak is coming from. I'm very discouraged cause this is having me look towards the throttle body which isn't a cheap replacement (I think).

[garync1]

Hey.. If its a vac leak near the throttle body take a propane torch. Turn the gas on.. But of course don't light it.. LOL Just hold the unlit propane torch around the area were it may be leaking and see if the engine idles better or smooths out...I done this before and man does it help.. Of course the mechanic that taught me this died in an explosion...Naaaa! He is still alive. Just kidding. Now the type torch i am speaking of is also use in plumbing to solder pipes..

[searcherrr]

What is the knob for on the side of the IAC?

For whatever reason I've identified on my old and new IAC that air comes out of that spot. Whats the deal with that? Is that how its supposed to be?

[searcherrr]

Having tested 2 IACs and both leaking from the same spot I did an internet search and on another Ford using the same or similar IAC with a knob on the side it turns out this isn't a knob after all. Its some type of check-valve vent for when the throttle plate slams shut... so in other words its only supposed to let air OUT and only under a certain condition involving the throttle plate..... therefore detecting leaking air from it during a leak test doesn't show me anything.

Unless I can seal this vent or make an IAC block off plate there doesn't seem to be a way to leak test this setup "well". The plate would have to be made of hard steel so that it could be locked down well with the IAC mount bolts.

I can't believe the tightening torque for the IAC is listed as 71 - 101 ft lbs!!! WOW! I have a torque wrench, but I don't have a 8mm socket that deep. I hope I've got the thing tightened good enough.

Right now what I really need to know is what the IAC voltage should be.