1987 Ford Crown Victoria has fluctuating idle???

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  #1  
Old 07-05-03, 06:41 AM
braincambre500
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1987 Ford Crown Victoria has fluctuating idle???

Hello all,

About 4 months ago, my 1987 Ford Crown Victoria/5.0 Liter, goes to a high idle...then to a low idle...then to a high idle....then back to a low idle...it keeps repeating this sequence. It goes high for about 1 or 2 seconds, then goes low (regular idle) for about another 2
seconds or so.

It keeps doing this until the engine eventually goes toooo low...then just
stops running.

Although when I drive it for about 10 minutes or so, and then come up to a
stop sign....it does not do this...until about 2 minutes or so...
then it starts repeating its' high and low idle.

A few people at auto zone said to replace this and that...but I wanted to let this
forum know...before I start changing things out.

Any help in this would be commended.

P.S. I have brand new sparks plugs, and once on the highway and driving in twon,
their is no miss at all. It is just when I stop the car and either in DRIVE or PARK...
while the engine is running, it begins to do that repetitious cycle of idle high and
then going low.

Any help in this would be very much appreciated, as I try to keep the car up and
running...as best I can.

Again, thank you all for your time in reading my request!

Sincerely,

Patrick Cambre
 
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  #2  
Old 07-05-03, 10:15 AM
morlock
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It sounds like it could be your TPS (Throttle Positioning Sensor) Has a problem like that with my cadilaac and my vw, worth a look.
 
  #3  
Old 07-05-03, 12:14 PM
Joe_F
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Fluctuating idle on a Ford MFI 5.0 like that:

1) Dirt in the throttle body---clean it with the Ford approved cleaner that the dealer has.

2) Vacuum leak--cracked or split lines, replace as needed.

3) Bad Idle air control valve---looks like a long cigar mounted on a triangular base. The likely cause of the problem.

Do #1 and #3 (checking #2) and the problem should go away. Any parts store will stock an IAC for this vehicle. Bring the old one with you so the ID #s on it can be matched to the new one.
 
  #4  
Old 07-05-03, 07:40 PM
braincambre500
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Thank you all for respoding,

I will go ahead and check all those things out that y'all have mentioned. I will get back with y'all tomorrow.

Thanks again for the splendid advice!

...your friend, Patrick
 
  #5  
Old 07-05-03, 10:55 PM
Joe_F
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Thumbs up

Let us know what you find.
 
  #6  
Old 07-06-03, 01:04 PM
braincambre500
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Hello Sir Joe...Patrick here...

Hello Joe,

Yes, I took off my rubber attachment from the plenum. Then I
bought carburator cleaner from Auto Zone. I then sprayed and clean the air intake on the plenum as best I could. I repeadly spray and sprayed, until I use about 1/2 the can. It seems that it was a little carboned up...but I got it very clean now...as far as my eyes could see.

No change...engine still idled up and down.

I then checked all my vacumn hoses, but could never find a broken one, or any that was dis-connected.

I then tried to find the Idle Air Control Valve, but I am having a hard time in finding it. Please look at the attachment and let me know where it is...in regard to the picture.

I will be awaiting your reply.

When you do let me know where the value is...in relation to the picture...can I also take it off and clean it. And also, if I can not do this...how can I check to see if it is bad or not...Auto Zone said that once they sell me one...I cannot return it...as it is classified as an 'electrical device'...and they don't accept returns on any electrical items.

Yes, thank you once again for helping me out. I have a digital camera and can take pictures of anything you want me to...in regards to the engine area.

I will be here all week corresponding...if need be...to clarify the culprit.

I noticed that when I raise my throttle adjusting screw...to make the engine run a little higher...that the problem goes away...but then I am concerned of the engine racing tooooo high.

I will check the forum periodically today.

...your friend, Patrick
 
  #7  
Old 07-06-03, 01:15 PM
braincambre500
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Hello again Sir Joe...

Hello Joe,

I uploaded the picture (attachment), but I did not see it, when I
went back to this forum. I will try attaching it again.

Sincerely,

Patrick

P.S. If for some reason you do not see it in this post, please let me know how to let you see the picture of my engine...in relation to finding the air valve. I can e-mail it to you...just send me a personal e-mail, and then I will then send you the picture.
My e-mail address is...

[email protected]
 
  #8  
Old 07-06-03, 01:21 PM
Joe_F
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A couple ways you can see one:

1) Go to www.kemparts.com and do the catalog lookup for an Idle Air Control Valve for your car. It will return a part # and optionally, a photo. Then you'll see what I'm talking about.

2) If looking at the engine, the valve is on the throttle body, on the right side of the car, to the back as I recall on a 5.0 like that, has a cylindrical look to it, with a plug, bu the base is triangular shaped. You will see "9F715" in the part # on the barrel end of it. Did the person at Autozone show one in stock they had so you'd know what you are looking for?

3) Do not touch the idle screw. The idle is computer controlled. Turning it will not fix the problem.

Let us know what you've found based on what I've given here.
 
  #9  
Old 07-06-03, 02:58 PM
braincambre500
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Hello again Sir Joe...Patrick here

Hello Joe,

I just got back from Auto Zone and the manager showed me
where the Idle Air Control Valve was on the '87 Ford Crown Victoria.

Yes, you are right, it does look like a fat cigar...about 8 or so inches long, extending towards the driver's side front fender. It also has an electrical harness attached to the very end of it. I did not see any part numbers on it...as the manager said...it might very well be located on the bottom side of the value.

I also noticed, on top of the throttle body, the adjustment for the idle screw...BUT I DEFINATELY WILL LEAVE THAT ALONE...AS YOU SAY!

So I asked the manager...what could I do...to know that the value is bad...since I cannot exchange it back, if that is not the problem...he said I could take the device off and clean the insides...in which he said...there are flaps inside...that move up and down.

I told him that I would check with you...as far as what to do next.

So there you have it...I know what the Idle Air Control Valve looks like now...so tell me my next step Sir Joe.

I will check periodically for your reply at this forum.

Sincerely,

Patrick
 
  #10  
Old 07-06-03, 04:30 PM
Joe_F
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Try cleaning the valve as suggested. See if things improve. If not, replace the valve.

Use some WD40 and an old toothbrush and try to work any dirt/carbon loose and flush it out. See if it works OK now. If better, but not 100%, change the valve.

Tell us what you find.
 
  #11  
Old 07-06-03, 06:44 PM
braincambre500
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Update Sir Joe...

Hello Joe,

I took the value and cleaned it GOOD!

I then replace it back, but when I was doing that, I noticed on the firewall...a harness of about 5 vacumn tubes...and the bottom tube was NOT THERE. I looked further down behind the engine and noticed a unsecured vacumn tube. I then grabbed it and put it back, where it looked like it was suppose to go.

I then started the engine, but the engine had NO CHANGE.

I then took the vacumn tube that I put on...and took it off...and then capped off the vacumn connection.

The engine then seemed to calm down...

That is the situation as of now...I took it for a test drive and
everything seems to be running fine. I do not have that up and down idle any more.

Your thoughts on this is certainly NEEDED.

Sincerely,

Patrick
 
  #12  
Old 07-07-03, 03:09 AM
Joe_F
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Ah, yes a vacuum leak .

You'll need a good vacuum diagram of where everything goes. You can try to use the one under the hood, but I suggest you try Autolibrary.org below for a better one, or hit the local library for any books they may have.

Failing that, an Alldata.com subscription for $25 should give you the needed diagram.
 
  #13  
Old 07-07-03, 11:14 AM
braincambre500
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Monday morning, Sir Joe...

Hello Joe,

Yes, thank you for suggesting that I acquire a vacumn layout of the car. I had tried to go to http://autolibrary.org but I was not allowed to enter the site. I wonder why?

My next bet would then have to be the library...I will do that.

I want to thank you very much for sticking with me through all of this...and you DID help. If you had never advised me to take off the valve and clean it, I would have never spotted that vacumn harness..with one hose un-attached.

Thank you again for the splendid help.

...and do have a very rewarding week, my friend!

...your friend, Patrick
 
  #14  
Old 07-07-03, 11:20 AM
Joe_F
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Patrick:

Use the link in my signature file.
 
  #15  
Old 07-07-03, 01:26 PM
braincambre500
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Hello again Sir Joe...

Hello Sir Joe,

Yes, I went to your signature file, and clicked on the LINK. Although I did have a HAYNES Auto Repair Manual I bought from Auto Zone some time back, and it does have the vacumn routing. I will check also on the car for that too.

I want to let you know, that also, for some strange reason, the car worked fine after I plugged up that open vacumn line, but when I started it this morning...it was back to the same thing.

So I am back where I started...what I will do is this...I will look real good at where ALL the vacumn hoses go. Then I will get back with you.

I want to say this also...it might help you a little more in understanding my culprit.

The car was given to me by a dear friend, who finally bought a new car.

I have been using it for about one year now, and it always had a burnt oil smell, when it came time to turn the engine off. I noticed that the was a puddle of oil, right around the distributor shaft....so I finally went to Auto Zone and bought that 'rubber O-ring' that fits on the shaft...assuming that was the culprit. Well, it worked...and now the car has not been leaking oil in that area.

Although, when I took out the distributor shaft and put the new o-ring on it, I messed up the orientation of the splines that go back.

It took me all day to push up the number #1 cylinder and then aligned my rotor with the #1 marking. It was a hit and miss, because I didn't know if I was 180 degrees out of line. But I FINALLY got the car to start, and run fine.

But ever since that day, the car started having that high and low idle. I MUST HAVE re-arranged something, in my procedure of putting the new 0-ring on the distributor shaft. I still am not satisfied that I 'stabbed' the distributor correctly...although the car runs fine on the road. It is just that 'high and low' idle I get all the time.

I wanted to let you know this...as I should have said this from the beginning.

It might very well give you a deeper in-sight to where my culprit is still lying.

I have a digital camera, and I will take a picture of the 'small' picture in the HAYNES book of the vacumn routing. I will then print it out, and start looking at ALL my lines.

Do please respond back to me, should anything else come up in your mind...know that you know the 'whole' story of the Crown Victoria.

I thank you once again, my friend, for sticking with me on this matter.

I know that if you let things go on a car, they could very well start affecting other things...and I want to try and nip this in the bud as early as I can.

Sincerely,


Patrick Cambre
 
  #16  
Old 07-07-03, 01:48 PM
Joe_F
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I would change the IAC. Check all those vacuum lines very, very closely. Spray some WD40 around the area. (Not too much, it's messy).

If the idle picks up when you do, you still have a vacuum leak.

I do still suspect the IAC valve, especially if you said it was gummed up.
 
  #17  
Old 07-07-03, 02:33 PM
knuckles
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Did you disconnect the SPOUT connector when you reset the ignition timing?

If not, the base timing is off & the computer is trying to compensate, which will cause a 'hunting' idle such as you describe.

Disconnect the SPOUT connector & check base timing. It should be 10 BTDC. If it is out by more than 2 either way, re-set it to 10. Install the SPOUT connector, then disconnect the battery NEGATIVE cable for a few minutes to clear the computer's Keep Alive Memory.

Drive the car for 20 minutes or so under varying conditions & let us know what happens.
 
  #18  
Old 07-07-03, 03:26 PM
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Join Date: Apr 2002
Location: Pittsburgh,Pa
Posts: 2,417
I'm not sure you have this but you may want to look under the pcv grommet and see if a metal filter is in there.Hard to get at but they get plugged and cause your problems and can cause oil leaks.
 
  #19  
Old 07-07-03, 07:21 PM
braincambre500
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Good afternoon Joe...

Hello Joe,

I read all your posts and this is what I have to say.

I did not disconnect the SPOUT connector when I redid the ignition timing. I do not even know what the SPOUT connector does, much less know where it is under the hood. Do let me know that.

I know recall, after I had changed out the distributor shaft o-ring, that I needed a timing light, to adjust the engine to 10 degrees BTDC...although when I finally put the timing light on the marks...THAT IS WHEN I NOTICED THE ENGINE GOING HIGH AND LOW...AND I COULD NOT GET A STEADY READING ON THE TIMING LIGHT...IT KEPT GOING FROM 10 DEGREES BTDC TO ALL THE WAY TO 30 DEGRESS BTDC....BACK AND FORTH WITHIN SECONDS. SO THEN, I JUST LISTENED TO THE ENGINE AND TURNED THE DISTRIBUTOR SHAFT TO THE BEST POSITION I COULD FIND...THAT IS...BY JUST LISTENING TO THE ENGINE.

So, that is probably what happen. I did not reset the computer, by taking the positive lead off the battery for a few minutes...and I also did not disconnect the SPOUT connector.

Also, concerning the PVC...there IS a metal filter under it. Before I had gotten the car from my dear friend...I would forever clean this steel meshed filter every couple of months for him...like you said...because a backup pressure was building up. I eventually took the filter out completely...and then just put back the PVC valve. So there is no filter in there anymore....but my idle NEVER did do the up and down motion back at that time...after I had taken out the filter. The idle, as I recall even clearer, starting doing that when I began to re-time my engine , after changing the o-ring out on the distributor shaft.

So, I will do this....I will again try and re-time the engine...although I will take the positive lead off the battery for about 5 minutes and also disconnect the SPOUT connector and then begin.

But please tell me, when I am re-timing the engine, but about the SPOUT connector. You say that I need to disconnect it from the engine. Does it have an electrical hookup or is there a vacumn line attached to it...that I have to take off? And please tell me where that device would be on the engine...thank you.

Yes, it seems that we are getting closer to the problem...now it looks like I timed it wrong...that is...by not dis-connecting the SPOUT connector....and by not letting the computer re-set itself...by not disconnecting the + lead to the battery for a few minutes.

I will go ahead and do the timing procedure tomorrow. Just reply back to me and let me know the procedure in timing it 'right' this time. Id want to make sure my timing procedure will be correct. I will wait for your reply before I re-time the engine.

Sincerely,

Patrick
 
  #20  
Old 07-08-03, 03:38 AM
Joe_F
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To my recollection, it's that plug at the distributor.

What Knuckles is saying in a nutshell is this: Unless you disconnect this connector, the computer is trying to "out do" you with your timing by "ear". It is sensing that the timing needs to be changed, so it's doing it. Disconnecting this connector during the timing procedure takes the computer out of the picture and makes it like timing an old fashioned car. It's imperative that you do this.

Try what Knuckles says and let us know what happens.
 
  #21  
Old 07-08-03, 11:32 AM
braincambre500
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Hello Sir Joe and Sir Knuckles...

Hello guys,

Well, I have to tell you HOW I FOUND THE CULPRIT!!!

I woke up this morning, read all the posts y'all have given me, and then I went to the car. I was looking for the SPOUT connector...there was only ONE LARGE electrical harness connected to the distributor...although from that...there was a two wire harnes...with a crossover plug. I then assumed this plug, should I unplug it, would have to be the SPOUT connector, as I have seen NO OTHER plug hooked up to the distributor.
I too the crossover plug off.

I then tuned the car right at 10 degrees BTDC. Then then took the positive connection off the battery for five minutes. I then re-started the car, and the 'high and low' idle came back.

Something then popped into my mind, thinking that, since I had taken that wire mess filter out of the car, which was underneath the PCV valve, the only thing that could be plugged up would be the PCV itself.

I then took off the PCV valve and started the engine. Although the engine idled higher then normal...THERE WAS NO HIGH AND LOW IN THE IDLE. I made sure, by letting the engine run a good five minutes!

I then took gasoline and cleaned out the PCV as best I could. I then put it back...
'
NO HIGH AND LOW IDLE ANYMORE!!!

I then went to Auto Zone and bought two new PCV valves.
Although the engine to too hot right now, to put the new value in, the car performed 'beuatiful' as I made my way to and from Auto Zone...which is about 3 miles away.

Well, well, well...it seems as though when one knows more of the whole story...the culprit is always lying around...it just has to be though off thoroughly...and by both of you helping me out...I probably would have never thought of the PCV valve...not until y'all had mentioned the wire mesh filter underneath the PCV value.

Boy, boy, boy..it is sure nice to hear the ole' Vic running like normal again. 'Cause when it is running good and normal, it is as quite as a sleeping baby!

One more thing I would like to ask, since I have gotten this far. Since I do not have an RPM gauge, what would be the best way to adjust and set the idle.

Again, my gratitude to you both. It is always a pleasure to know, that at this forum, there are people who are indeed concerning about others...especially when we never see each other face to face!

With utmost respect,

Patrick Cambre
 
  #22  
Old 07-08-03, 11:39 AM
Joe_F
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Thumbs up

Good job. Put the wire mesh filter back (any parts store will have it) and you can rent a tachometer/RPM analyzer from Autozone through their tool rental program. You can also find old engine analyzers/RPM gauges on Ebay for under $20.00, I see them there all the time.

Replace the PCV valve and the mesh filter and you should be OK at this point.

Good job once again. As mentioned it was a vacuum leak .
 
  #23  
Old 07-08-03, 11:49 AM
redneck
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I had a '86 mustang 5.0 do the same thing--only it would start the high low cycle, then run normal for days before doing it again--I tried all the above things and then some--ended up unloading the car--head mechanic at the Ford garage even said "It is the nature of the beast" Last Ford I ever owned. Glad yours worked out for you!
 
  #24  
Old 07-08-03, 02:33 PM
braincambre500
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Hello all...

Hello all,

Yes, I just got back from Auto Zonea and purchased 'two' PCV values, one for later...when it acts up again.

Although when I put the new PCB in line, and slightly adjusted the
engine idel a little lower, would you believe the same thing came back again.

I am beginning to think that, there is a 'crutial' stage when it DOES act up, when I slightly raise or lower the idleing screw on the engine. Although the engine is running slightly higher than normal, at least that is what my ears hear, the up and down motion of the engine is NOT there. But the minute I lower the engine, thinking of a right idle, the up and down motion appears again.

I again, remember, when my friend had the car, and he wanted to get it timed, so he brought it in a local shop (a good gualified shop that has been in my area for years)...but the head mechanic at the shop told him...it was time for a rebuilt engine or a new vehicle...he said that there were too many places where the engine was leaking oil/or leaking air...or at least that is what I recall.

Be it so, since the car was GIVEN to me...I guess I will just leave the idle slightly higher than normal.

Yes, many many things to look at...when something goes wrong!

Well, I am satisfied to know that the engine is still performing great, other then having to set to a low idle.

...your friend, Patrick

P.S. Thank you 'redneck' for your reply!
 
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