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Discussion Starter · #1 ·
I have a 99 sable with dohc 24v. It was idling very rough and dying so I was told to replace the MAF sensor. I did this and it did not help. I found a very large vacuum leak on the hose that I believe comes for the PCV valve. It was a formed 180 degree about 3/8" ID hose. I replaced it with a piece of hose that I had laying around (without kinks) Took it for about a twenty minute drive with plenty of stops and it ran and idled great. Went to drive it the next day and although it now idles great sometimes when you go to accelerate nothing is there. It doesn't die it just doesn't respond. I cant find any more vacuum leaks, I cleaned the ICV. I was thinking maybe a new PCV but from what Ive been reading here most of it's posts seem to be about rough idling not accelerating. Replacing that vacuum line was a real pain and I wonder if I could have got some gunk or debris into the intake.

Any advice or help is greatly appreciated
Thanks

Edit: I also replaced the fuel filter
 

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QUOTE (pdxsable @ May 23 2010, 10:30 PM) index.php?act=findpost&pid=806398
I have a 99 sable with dohc 24v. It was idling very rough and dying so I was told to replace the MAF sensor. I did this and it did not help. I found a very large vacuum leak on the hose that I believe comes for the PCV valve. It was a formed 180 degree about 3/8" ID hose. I replaced it with a piece of hose that I had laying around (without kinks) Took it for about a twenty minute drive with plenty of stops and it ran and idled great. Went to drive it the next day and although it now idles great sometimes when you go to accelerate nothing is there. It doesn't die it just doesn't respond. I cant find any more vacuum leaks, I cleaned the ICV. I was thinking maybe a new PCV but from what Ive been reading here most of it's posts seem to be about rough idling not accelerating. Replacing that vacuum line was a real pain and I wonder if I could have got some gunk or debris into the intake.

Any advice or help is greatly appreciated
Thanks

Edit: I also replaced the fuel filter[/b]
It might be your trottle might be off, did you check that?
 

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Discussion Starter · #4 ·
QUOTE (caseitman @ May 24 2010, 07:43 AM) index.php?act=findpost&pid=806489
QUOTE (pdxsable @ May 23 2010, 10:30 PM) index.php?act=findpost&pid=806398
I have a 99 sable with dohc 24v. It was idling very rough and dying so I was told to replace the MAF sensor. I did this and it did not help. I found a very large vacuum leak on the hose that I believe comes for the PCV valve. It was a formed 180 degree about 3/8" ID hose. I replaced it with a piece of hose that I had laying around (without kinks) Took it for about a twenty minute drive with plenty of stops and it ran and idled great. Went to drive it the next day and although it now idles great sometimes when you go to accelerate nothing is there. It doesn't die it just doesn't respond. I cant find any more vacuum leaks, I cleaned the ICV. I was thinking maybe a new PCV but from what Ive been reading here most of it's posts seem to be about rough idling not accelerating. Replacing that vacuum line was a real pain and I wonder if I could have got some gunk or debris into the intake.

Any advice or help is greatly appreciated
Thanks

Edit: I also replaced the fuel filter[/b]
It might be your trottle might be off, did you check that?
[/b][/quote]

Thanks for the reply. How would I go about checking that?
 

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Discussion Starter · #5 ·
I just pulled off my throttle body to access the pcv and I had a lot of carbon build up. Ive cleaned it up and I'm hoping this might be the problem.

Does anyone know if this could possibly be the problem? I don't want to close everything up if I may need to do something else.
 

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Discussion Starter · #6 ·
I had to wait for the wife to get home with my car yesterday so I could go get the pcv valve. I decided to button it up and see if all of the carbon in the intake was the problem. It wasn't.

I was wondering if it could be my egr sensor. Does anyone know if my check engine light would come on if it was the sensor?

Does the fact that my check engine light does not come on rule anything out?

I also noticed that it is only happening when accelerating from very low speeds or complete stops.
 

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Check the IMRC linkage. The bushings get brittle, crack, and fall out prevent the bank 2 butterfly secondaries from operating. The engine can be very sluggish and idle may be rough when bank 2 gets stuck open. This may not set a code. These are located on the lower intake manifold, directly underneath the throttle body, very near the 180 bend tube you replaced. A small 5" horizontal silver rod links the two banks together.

EGR may be the problem. You can test it's function. With the engine idling, disconnect the green vacuum tube from the top of the EGR valve. There should be no vacuum (you should not hear hissing from the tube). If you do hear hissing, the EGV solenoid is not functioning correctly. Test the EGR valve by applying vacuum. A small hose and suction by mouth works. The engine should stumble or die if the EGR is working correctly when vacuum is applied. Idle should smooth out when vacuum is released.
 

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Discussion Starter · #8 ·
QUOTE (spridget @ May 25 2010, 07:13 AM) index.php?act=findpost&pid=806773
Check the IMRC linkage. The bushings get brittle, crack, and fall out prevent the bank 2 butterfly secondaries from operating. The engine can be very sluggish and idle may be rough when bank 2 gets stuck open. This may not set a code. These are located on the lower intake manifold, directly underneath the throttle body, very near the 180 bend tube you replaced. A small 5" horizontal silver rod links the two banks together.

EGR may be the problem. You can test it's function. With the engine idling, disconnect the green vacuum tube from the top of the EGR valve. There should be no vacuum (you should not hear hissing from the tube). If you do hear hissing, the EGV solenoid is not functioning correctly. Test the EGR valve by applying vacuum. A small hose and suction by mouth works. The engine should stumble or die if the EGR is working correctly when vacuum is applied. Idle should smooth out when vacuum is released.[/b]
Thanks for the response. I will check those as soon as it stops raining. I had the egr off yesterday and sucked on it and it did move but I will test it while running,

One thing I noticed is a small cable that is next to the rod on the throttle body that opens the main butterfly . The cable has some slack in it. Not so much that it doesnt move but some.
 

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Discussion Starter · #9 ·
The IMRC bushings look good I also applied suction to the egr and it cut out. Next step is changing the PCV as soon as I get a molded hose but I don't think that is the problem. I cant get past the fact that this happened after fixing the bad vacuum line. I cant find anything I may have damaged.

On the back side of the throttle body is some type of controller that I removed so I could see vacuum lines better. Is that something I could have damaged or reinstalled incorrectly? Sorry that I dont know what it's called but it has wires running to it.
 

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Could the "controller" be the IAC valve? Metal cylinder, 2 wires, attached to TB with 2 8 mm bolts? If that is it, was the gasket intact? Any chance some gunk fell into it?
 

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Discussion Starter · #11 ·
QUOTE (Jeff K @ May 25 2010, 11:22 AM) index.php?act=findpost&pid=806818
Could the "controller" be the IAC valve? Metal cylinder, 2 wires, attached to TB with 2 8 mm bolts? If that is it, was the gasket intact? Any chance some gunk fell into it?[/b]
I believe the IAC valve is the manifold itself. This is on the throttle body and it looks like it controls the butterfly or is triggered by the butterfly.
 

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Discussion Starter · #12 ·
I decided to go for another test drive today to see if I could get more info on when exactly my problems occur. It took several tries to get it to stay running. This was the first time that happened. I replaced the pcv with no change. I think it may be time to take it to the shop.
 

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Discussion Starter · #14 ·
QUOTE (spridget @ May 25 2010, 03:21 PM) index.php?act=findpost&pid=806871
The sensor on the throttle body is the TPS (throttle position sensor). The car may not run well if the TPS is damaged or disconnected.[/b]
I am pretty sure I didn't damage it I was mostly wondering if the opening is shaped kinda like an hourglass and it fits onto something in the throttle body that looks like a standard screw bit. I don't think anything fell out but I want to make sure
 

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Correct. The TPS has was looks like an hour glass shape that fits over a tab (flat head screw driver tip shape) on the TB. The TPS is spring loaded. When it's installed, the spring needs to be preloaded a tiny bit. The sensor is delicate, and if it's not installed correctly, and over rotated, it will fail. Or, if it's not preloaded, the TPS will always read low and the engine will not run correctly.
 

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Discussion Starter · #16 ·
QUOTE (spridget @ May 26 2010, 09:00 AM) index.php?act=findpost&pid=807016
Correct. The TPS has was looks like an hour glass shape that fits over a tab (flat head screw driver tip shape) on the TB. The TPS is spring loaded. When it's installed, the spring needs to be preloaded a tiny bit. The sensor is delicate, and if it's not installed correctly, and over rotated, it will fail. Or, if it's not preloaded, the TPS will always read low and the engine will not run correctly.[/b]
Thanks for the reply. I was just hoping that I might have done some damage to it, at least then I would have something to fix or replace. I may be wrong but I think my problem has to be something I did while finding and repairing the vacuum leak.
 

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Discussion Starter · #18 ·
Tested my fuel pressure this morning. With the key on I had 30psi and with the engine running I had about 32psi. From what Ive read I think that's ok. I had trouble keeping it running and every time I fingered the throttle it wanted to cut out until I got it running good. Another thing I noticed was whenever the IMRC kicked in at about 4000 rpms ( I think that's what it's called from an earlier post) the engine kind of pulsed. I'm not sure how to described it but it was like an up and down kind of rev. Not to the point of dying but noticable.

Thanks for any advice or help. Ive been reading the hell out of this forum for the last few days and I'm running out of things to try.
 

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QUOTE (pdxsable @ May 28 2010, 10:48 AM) index.php?act=findpost&pid=807434
Any help would be greatly appreciated[/b]
It is beginning to sound as though you have a combination of issues.

The lack of acceleration may be the IMRC itself. On the Contour they are prone to electronic failure because of heat issues and in some cases the internal gears fail or the cable binds and prevents the IMRC from opening the secondaries. To test the Contour I would simply rev the engine to above 4k rpm while watching the linkage for the secondaries. If the linkage doesn't move, there's an IMRC problem. Is there a different test for the 3L ?

The rough idle is likely an air leak. I'm not very familiar with the Taurus Duratec for '99, but have a great deal of experience with the Contour Duratec. I'll assume the applications are quite similar.
  • Since you did work on the engine, check the accordian tube for cracks in the pleats (sometimes difficult to see) and the tubes going to it. The front valve cover vent tube runs behind the water pump pully on the Contour and is occasionally a culprit here. Should be similar for the '99 Taurus Duratec.
  • The Contour was also known to develop intake manifold gasket leaks after engine work because leaning on or resting against the manifold would induce cracking in the old & brittle gasket material. There is a test for leaks there by use of a spray can, but I forget what spray was used. Don't want to use anything flamable as this is done with engine running, so maybe somebody could help me out here... Additionally, (** CAUTION ** YOU MUST BE CAREFUL not to strip the aluminum lower manifold and/or aluminum heads. Torque specs are in INCH Pounds, not ft-lbs) just snugging down the intake manifold bolts would sometimes solve the problem - at least temporarily.
  • Finally, check the brake booster vacuum tube. There should be a good seal at the booster and the tube should obviously be free from cracks. There are sometimes plastic elbows that connected to the intake manifold that can crack or break.
 
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