I'm finding conflicting info in the Ford manual about if there is a paper gasket or "O" ring type of seal between the upper intake and fuel rail. On AllDataDIY.com it says that there is a "O" ring seal but a hyperlink from "fuel Rail" shows a gasket.

Did they go from a paper gasket to a "O" ring seal somewhere along the line? I can see a paper gasket between the fuel rail and lower intake and somewhere I read(can't find it now) that a paper gasket isn't required between the fuel rail and the upper intake because it uses "O" rings.

 

I found the reference in the TSB that a paper gasket isn't required between the fuel rail and the upper intake.

 

Ken, are you lurking about?

About my System Lean Bank1/2 on my 97 Ranger 4.0L. I've always looked for vacuum leaks but never found any but ran a vacuum check which show a few inches low only. I spray some quick start around the upper intake to fuel rail area and the engine reved up! I check the nuts on the upper intake and two were loose but that didn't help my problem. I drove to the dealer and bought the gasket under the fuel rail and the "O" ring style seals for the upper intake too. There is a TSB on that gasket but I thought that the problem would have shown up already, wrong!!

I got the upper intake off now and the gasket is broken and sucked inside the front two ports on the passenger side. It was sucking in some major unmetered air!

Don't think that I posted it here but I did install another PCM because I was getting other goofy codes like IAC overspeed, #1 misfire and ignition coil malfunction. That's where the gasket was broken, #1 intake port! Since the new PCM, it took much longer for pending/hard codes to appear, there is some changes with this PCM so it wasn't a total loss.

 

I was away for a bit. That's great news, glad to see you tracked it down, that was a tough one to find. I never saw that TSB, do you have the number. What changes do you see with the new PCM? How's the truck doing now, running good, any codes.

 

[updated:LAST EDITED ON 01-Apr-02 AT 09:28 PM (EST)]Ken:

Yep, it's 98-6-8 and they say only 1.9 hrs. to do that job. I'd like to see somebody do that in two hours!

I got it running today and it idles soooo smooth now. the worst part was trying to get the EGR tube back seated with all the seal rings in the upper intake! I may have to adjust the idle but it ain't no big thing.

Although the book refers to the idle adjusting procedure being in the book, I never seen it. I got it from a contact at Ford Racing/High Performance Div. Do you know the proper procedure? I can list it here if you want?

It's probably just the fix but not the PCM but the Short Term Fuel Trims at idle don't shoot to 43%. This PCM does have a different number but the only thing I seen before the fix was that it just took a lot longer to pop a code, if fact I thought that I had fixed it by retightening the upper intake nuts.

I still have issues with the EZ Link scanner and I'm not letting up on AutoXray. Somebody seen my posts in the OBDII.COM forum and asking if I like to beta-test a Ford version of their PC based software when it's ready. Why of course!

I forgot! No codes so far, runs great!!!

 

Ken:

Here's the Idle Speed Set-up Procedure:


These steps must be performed in sequence!!

1. Get engine to operating temperature.

2. Disconnect IAC (Idle Air Control) Motor. If engine stalls, turn throttle stop screw in one full turn and restart.

3. Set idel using throttle stop. Idel speed will vary depending upon modifications made to the engine. Set to where you are comfortable with idle speed.

4. Set TPS (Throttle Position Sensor) anywhere from .96 to .99 volts. This is done by loosening the mounting screws and lightly rotating TPS. If you can not obtain the desired range, you may need to make the mounting holes slightly larger. This can be done by drilling them.

5. Stop engine. Disconnect negative terminal battery cable for 15-20 minutes. You may wish to tap the brakes or turn the headlight on or off a few times as this will help to ensure that you have purged any remaining electrical current from the vehicle. This will reset the computer to factory defaults.

6. Reconnect IAC Motor.

7. Reconnect battery cable to negative terminal.

8. Restart engine.

The only part is, how do you get to the contacts? A friend says that he uses paper clips somehow. My scanner reads that voltage althogh it's about .02v low compared to the two digital VOM I have.

 

Now I see the TSB, the name was the problem. Some of those things are a real PIA to get seated, been there. I looked in my manual and didn't see a procedure for idle speed adjustment. I'll have to look at your other post on the scanner. Glad to hear it's running good.

 

>Ken:
>
>Here's the Idle Speed Set-up Procedure:
>
>
>These steps must be performed in sequence!!
>
>1. Get engine to operating temperature.
>
>2. Disconnect IAC (Idle Air Control) Motor. If engine
>stalls, turn throttle stop screw in one full turn and
>restart.
>
>3. Set idel using throttle stop. Idel speed will vary
>depending upon modifications made to the engine. Set to
>where you are comfortable with idle speed.
>
>4. Set TPS (Throttle Position Sensor) anywhere from .96 to
>.99 volts. This is done by loosening the mounting screws and
>lightly rotating TPS. If you can not obtain the desired
>range, you may need to make the mounting holes slightly
>larger. This can be done by drilling them.
>
>5. Stop engine. Disconnect negative terminal battery cable
>for 15-20 minutes. You may wish to tap the brakes or turn
>the headlight on or off a few times as this will help to
>ensure that you have purged any remaining electrical current
>from the vehicle. This will reset the computer to factory
>defaults.
>
>6. Reconnect IAC Motor.
>
>7. Reconnect battery cable to negative terminal.
>
>8. Restart engine.
>
>The only part is, how do you get to the contacts? A friend
>says that he uses paper clips somehow. My scanner reads
>that voltage althogh it's about .02v low compared to the two
>digital VOM I have.

I have seen a procedure similar to this for older vehicles, specifically the 89 2.9l Ranger but it doesn't require the TSP adjustment. I do remember that some of the older ones did require this adjustment. I wouldn't think the TPS adjustment would be required for the newer ones since they use a ratch system. This is were the PCM determines the lowest voltage at start-up and uses that value as closed throttle.

 

Ken:

I got that info from a guy at Ford's Racing Div. and they admit to be stuck in pre OBD-II engines!

I connect my scanner to a 2002 Ranger 4.0L and it's TP voltage was over 1v. The suggests that there is a procedure in the PCM, etc. manual for setting the idle but like I said, I never found one!

I replaced my TP because it had dead spots in it but I couldn't even come close to getting that less than 1v. Even after opening the holes up a bit, I'm idling at about 835rpms, a bit under specs, I barely got under .99v. The higher you go the more the holes are off!

 

>Ken:
>
>I got that info from a guy at Ford's Racing Div. and they
>admit to be stuck in pre OBD-II engines!
>
>I connect my scanner to a 2002 Ranger 4.0L and it's TP
>voltage was over 1v. The suggests that there is a procedure
>in the PCM, etc. manual for setting the idle but like I
>said, I never found one!
>
>I replaced my TP because it had dead spots in it but I
>couldn't even come close to getting that less than 1v. Even
>after opening the holes up a bit, I'm idling at about
>835rpms, a bit under specs, I barely got under .99v. The
>higher you go the more the holes are off!

I'll look to see if I can find any infoamtion on TPS voltage but I don't think it matters on our trucks since the PCM determines minimum voltage at start up. I'll have to see what my 3.0 idles at.

 

In my manual, under pinpoint tests, DH, pre-diagnostic, it has a chart for the TSP voltage 0.95@ closed throttle to 4.65@ WOT. I looked through the PPTs and also saw some references to the closed voltage being as low as 0.49 and being OK.

 

Ken;

That sounds like just about anything is correct and that idle set-up procedure is for older vehicles.

One other thing I notice. In the manual, I think that it's section 6a, it lists different readings at warm idle, two speeds and maybe WOT. It shows the IAC percentage at warm idle as being 20-35% duty cycle. I couldn't understand that because my engine was idling at 1400-1800rpms at that time before the gasket repair was within those limits! That didn't look correct to me. So, now that it's fixed. I get 0-1% duty cycle at warm idle and I guess if I popped the connector off the IAC, the rpms would hardly drop at all which is the way to check it, right out of the book! Very strange!!