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Hi Guys. I'm new here and have posted in the newbie forum with an introduction. I'm not a mechanic and I am female, but I love my Cougar and have owned this car for about 10 years. I have a 97 XR7 with the 4.6L. I was wondering if maybe I describe my car's problem, I could get some suggestions as to what it might be.

My car is having some trouble idling upon starting it in the cold. It is intermittent and only does it when its cold, but not always. What happens is this, I turn my key on, everything appears to be normal, I turn her over and unless I give her some gas she will die. So what I have been doing to get her going is I hold on the gas just slightly to keep the rpms around 1000. After a few minutes of warming up, the engine makes a very soft "boof" sound and then all of a sudden she revs a bit and then idles normally. A couple of times this just hasn't worked and I let her die & restart and then after another try or two she will then start to idle.

I was having the same issue last winter, and took my car in and my mechanic could fine nothing wrong. I thought maybe it was a vacuum leak. Now I'm thinking I either have a sticky valve or maybe not firing all cylinders. I tried a can of seafoam about two weeks ago, and it doesn't seem to have helped. Other than this idling problem, the engine runs and sounds fantastic.

Any thoughts or suggestions would be greatly appreciated and I am happy to answer any questions.

Thank you!
 

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Look for vacuum leaks - all our cars this age have had them. Once you are sure you have no more vacuum leaks, I'd be looking at the idle speed control valve.

You mention you suspect it's misfiring - does it run rough even when you hold the gas when it's cold?
 

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I will have them look for vacuum leaks. I don't think I have a way to do that myself. Last winter when I took it in for the same problem, my mechanic didn't find anything wrong. I'm taking it to a new place this time. Is the idle speed control valve something I can check myself?

It does not run rough, really ever. It did when it was -6 F on Monday, but just during the first couple tries getting it started. It was so cold I don't think my car really knew what to do. And then I realized on Tuesday that 20 degrees feels a heck of a lot better than -6!

Its that soft "boof" sound that really has me perplexed. I hold it around 1000 rpms, and upon the "boof" it will rev up to about 1500 for a tick and then go back to its normal idle of about 800. It just really sounds like something is coming unstuck and like it gets a little burst of gas. It is so strange.

The only other reason I thought maybe it was misfiring is because I haven't put new plugs in it in probably, I don't even know how many years if I ever did. If I did, I bought the more expensive plugs. I think they were $10 or $12 a piece. Its been so long I really don't remember. That is bad, I know. Do I need new plugs & wires if its not misfiring, just because they are old? Now I'm really starting to feel bad! But I've been on a super tight budget for a while now & my mechanic usually tells me everything is fine.

The check engine light is always on, but he said it was my catalytic converter, and unless I wanted to spend a bunch of money, to just not worry about it. He said he would disconnect it for me, but I said to just let be on all the time.
 

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I will have them look for vacuum leaks. I don't think I have a way to do that myself. Last winter when I took it in for the same problem, my mechanic didn't find anything wrong. I'm taking it to a new place this time. Is the idle speed control valve something I can check myself?

It does not run rough, really ever. It did when it was -6 F on Monday, but just during the first couple tries getting it started. It was so cold I don't think my car really knew what to do. And then I realized on Tuesday that 20 degrees feels a heck of a lot better than -6!

Its that soft "boof" sound that really has me perplexed. I hold it around 1000 rpms, and upon the "boof" it will rev up to about 1500 for a tick and then go back to its normal idle of about 800. It just really sounds like something is coming unstuck and like it gets a little burst of gas. It is so strange.

The only other reason I thought maybe it was misfiring is because I haven't put new plugs in it in probably, I don't even know how many years if I ever did. If I did, I bought the more expensive plugs. I think they were $10 or $12 a piece. Its been so long I really don't remember. That is bad, I know. Do I need new plugs & wires if its not misfiring, just because they are old? Now I'm really starting to feel bad! But I've been on a super tight budget for a while now & my mechanic usually tells me everything is fine.

The check engine light is always on, but he said it was my catalytic converter, and unless I wanted to spend a bunch of money, to just not worry about it. He said he would disconnect it for me, but I said to just let be on all the time.
That 'boof' sound sounds like to me like the idle control (IAC) valve sticking. There really is no way to test it other than just stick another known good one on. It's really easy to change and you can do it yourself - two bolts, an electrical plug and a big air hose stuck on it.

Oh, by the way, if you put a good one on, start your car, and it doesn't want to idle right immediately - DON'T get discouraged! It takes a little running time for the computer to learn the new IAC valve sometimes.

 

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You can also clean the Idle Air Control Valve using Throttle Body Cleaner. Take the car to an auto parts store and have them read the check engine light. Get printouts of the codes and let us know what they are. Some codes could be several different things that could trigger them and not automatically the most expensive thing.
 

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The IAC is probably having issues due to vacuum leaks; cleaning or replacing it might help a bit, but it's still not the problem.

There's a thread, let me see if I can find it...

This isn't too bad:

http://forums.tccoa.com/showthread.php?t=112503
 

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Discussion Starter #7
Hey Rick! Thank you for the diagram! I agree with you about the boof sounding like a sticking valve, I just had no idea what kind of valve it might be. I did locate the IAC valve and it looks pretty easy to remove, but with my luck I'd probably break something else in the process. I don't have a different one to put on and a new one is about $50, so I'm just going to have them check it out or clean it at the shop on Wednesday (no doubt they will recommend putting on a new one?). Also, right now its just too warm for the problem to appear I think. It usually only does it when its below freezing.

So I got my codes read today. Here are the results:

1. Trouble code: p0401
Code Definition: Insufficient EGR Flow Detected

2. Trouble code: p0430
Code Definition: Catalyst system efficiency below threshold (Bank 2)

I hope those aren't super serious. I am so glad I found this forum!!!
 

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If you do replace the IAC, I'd only suggest using a Motorcraft brand unit. The others have a less than stellar reliability/longevity record. RockAuto or Amazon will typically have the best prices around.
 

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You can check that pipe that goes across the engine, right in front of the IAC. On my car, I found that the connection was loose fitting on both ends. Where it plugs into the plastic intake, I wrapped it with electrical tape to make a tighter seal. At the other end, I tried to seal it with duct tape. It was almost like the pipe wasn't long enough. When I pushed it in tight at one end, it would pull out at the other end.

I had to do the cats on my 3.8 a few years ago. Money was tight. I went with aftermarket for about $400, both cats. Saved a ton of money! Even my own mechanic ( who is a friend ) wanted $1100. I had Midas install it and they had to drill and tap the O2 sensor on the passenger side, cost about $180 to install. It has passed the e-test for the last 4 years!
 

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Discussion Starter #10
If you do replace the IAC, I'd only suggest using a Motorcraft brand unit. The others have a less than stellar reliability/longevity record. RockAuto or Amazon will typically have the best prices around.
Thanks for mentioning this Rod! I did look into it and seems other brands have problems much more frequently (like idling at way too high rmps). Since the motorcraft brand IAC is way more expensive though and the thing doesn't give me any problem except when its just really cold (like 25 F or below), I might just try having them clean it and put it back on, or maybe I can try doing it myself (not sure if I am brave enough, yeah I'm not). The one that is on there is definitely still working pretty fine for the most part, so maybe I shouldn't worry about it too much for now? I will definitely have them check for vaccum leaks of course. But I think if there are any they are only coming up when its cold. I guess my biggest problem right now is I am on a super tight budget and cannot spend money that I don't absolutley have to.
 

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You can check that pipe that goes across the engine, right in front of the IAC. On my car, I found that the connection was loose fitting on both ends. Where it plugs into the plastic intake, I wrapped it with electrical tape to make a tighter seal. At the other end, I tried to seal it with duct tape. It was almost like the pipe wasn't long enough. When I pushed it in tight at one end, it would pull out at the other end.

I had to do the cats on my 3.8 a few years ago. Money was tight. I went with aftermarket for about $400, both cats. Saved a ton of money! Even my own mechanic ( who is a friend ) wanted $1100. I had Midas install it and they had to drill and tap the O2 sensor on the passenger side, cost about $180 to install. It has passed the e-test for the last 4 years!
Looks like there are two airlines I can check, the one that goes from intake into the iac and the one from the intake to the valve cover.

I'm not sure which one you had to have replaced but that seems pretty pricey! And what Midas did sounds pretty scary!
 

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it's good to have friends who are welders when it come to catalytic converter problems :)

Also, "insufficient EGR flow" can be the result of a broken vacuum line, either leading to the EGR solenoid, or to the EGR valve itself, or even somewhere else. I had this exact code and this was my particular problem, yours might be similar. It (a vacuum leak) can also easily be the reason for your idle issues. It is absolutely imperative that you have absolutely no vacuum leaks anywhere, during any time, because even though the car's computer can accomodate for leaks while it is running, start-up procedures are not quite as adaptive as one would hope so, in terms of interventions done by the computer to compensate for mechanical problems that result in idle fluctuations immediately after start-up.
 

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it's good to have friends who are welders when it come to catalytic converter problems :)

Also, "insufficient EGR flow" can be the result of a broken vacuum line, either leading to the EGR solenoid, or to the EGR valve itself, or even somewhere else. I had this exact code and this was my particular problem, yours might be similar. It (a vacuum leak) can also easily be the reason for your idle issues. It is absolutely imperative that you have absolutely no vacuum leaks anywhere, during any time, because even though the car's computer can accomodate for leaks while it is running, start-up procedures are not quite as adaptive as one would hope so, in terms of interventions done by the computer to compensate for mechanical problems that result in idle fluctuations immediately after start-up.
Thank you so much for your reply. All of you guys are really great and I thank you for your time and the knowledge that you share. I'm sure they will check for vacuum leaks, and hopefully, if there are any, that is the problem. But we will see. I'm dropping it off in the afternoon so they can see how it starts in the morning. It is not going to be cold really, so I'm sure it will start up just fine. Hopefully some checking & some cleaning will do the trick. Along with other normal maintenance items, I'm thinking a good place to start will also be new plugs & wires. I haven't gotten new ones on my car in I don't know how long, 8 years maybe, if I have ever done it in the 10 years I've owned the car! Is that bad? I would have thought my regular guy would have said something if he really thought I needed it. Pretty sure I am not misfiring though.
 

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Good Luck

wow, my car has the exact same problem since like 3 years now, but mine does it every time that i start it cold.. i have replaced all vacuum lines according to this guide

http://www.mn12tech.com/vacuum-hose-replacement.php

Also I replaced the IAC valve 4 times, 1 was new the brand was TOMCO. 1 used from another bird, 1 from a crown victoria, 1 from a grand marquis.

what i do now its like I am the idler on my car lol when i star it up i quickly rev up a little the engine to maintain it on 1100 - 1200 RPM for a little while... but if i let it go the engine quickly goes down to like 400 - 500 RPM and if its really cold it dies.

Once the engine its warm the engine operates normally and this affects nothing on performance but i think it affects fuel mileage

I am really hoping that you find the solution to this problem because its really stressing for me as you saw all that I have done
I do too get the exact same code for the EGR flow so i think that this is what is causing this.... (considering that they changed the DPFE sensor or something like that in a ford dealership when i took the car there to check that problem.... i think i just threw all that money to the garbage because it did nothing for the car)

so good luck and please post something if you find the solution to this

THANKS!!!
 

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wow, my car has the exact same problem since like 3 years now, but mine does it every time that i start it cold.. i have replaced all vacuum lines according to this guide

http://www.mn12tech.com/vacuum-hose-replacement.php

Also I replaced the IAC valve 4 times, 1 was new the brand was TOMCO. 1 used from another bird, 1 from a crown victoria, 1 from a grand marquis.

what i do now its like I am the idler on my car lol when i star it up i quickly rev up a little the engine to maintain it on 1100 - 1200 RPM for a little while... but if i let it go the engine quickly goes down to like 400 - 500 RPM and if its really cold it dies.

Once the engine its warm the engine operates normally and this affects nothing on performance but i think it affects fuel mileage

I am really hoping that you find the solution to this problem because its really stressing for me as you saw all that I have done
I do too get the exact same code for the EGR flow so i think that this is what is causing this.... (considering that they changed the DPFE sensor or something like that in a ford dealership when i took the car there to check that problem.... i think i just threw all that money to the garbage because it did nothing for the car)

so good luck and please post something if you find the solution to this

THANKS!!!
Unplug the electrical connector from the Mass Airflow Sensor. Then start the car. The computer will use backup tables to meter the fuel flow, based on throttle position and RPM. If it runs or idles better than it did before, you need to clean the Mass Airflow Sensor. I drove my car around for a year like that. Fuel mileage was not affected much at all, that I could see. The check engine light will come on and you will need to fix that before you get E-test, if applicable where you are.
 

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i would almost bet the EGR valve is toast with that code, i had the same one not too long ago and that's what it was. pretty common ford problem, not just on Tbirds/cougars. yeah still check for vacuum leaks of course, but at least the EGR valve is a simple swap if all else fails. only costs around $30-40

sooooo easy on the 96+ intake, its the big round silver disk looking thing just above and to the right of the IAC in that picture, an 1"1/8 wrench, and two 10mm bolts and she comes right off in the driveway, i put a BWD one in place and its been working fine for a few months now.

definitely check out http://www.mn12tech.com/vacuum-hose-replacement.php its awesome! any part store should have bulk vacuum hose in the right size and it doesn't take too much effort to swap out everything. hardest ones are of course behind the fender well and under the bumper skirt on the charcoal canister.

the cat code however... yeah, unless you want to swap out the whole 3 cat assembly for quite a chunk of change, (or go with a custom mandrelbent duel exhaust :p ) your mechanic was right, just ignore it. as long as the exhaust is still flowing it shouldn't effect the run-ability of the car too much.

plus just because your a girl doesn't mean you cant get greasy :D don't be intimidated by it, get some simple ratchet sets, screw drivers, and wrenches then have at it. its pretty simple once you start taking stuff apart, just don't forget how it goes back together. whats the worst you could do, break something? men do that too ya know :tongue:

oh and tie up the hair! nothing worse then getting a pony tail stuck in a creeper... or worse in the fan belt! :mad:
 

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If it really is an EGR no flow on a 96 or 97, unbolt the egr as above, and look into the hole it bolts into.

If it's completely clogged, as I have seen, the easy fix I've seen people do is to push the plug of material into the intake with a screwdriver.

Don't do that. :)

A shopvac on the egr port while holding the TB open works, without randomly running a slug of gunk thru your engine.

You may have to work at it with carb cleaner; if it's really gunked up, OR if you have a 94/95, pull the TB and clean it.

If you have a 94/95 and need to clean the egr passages, do a pi swap instead, it's less labor. :)

Also, there is a disc welded into the EGR pipe between the two ports for the sensor; it can clog.

Any of these clogs are a sign of an engine that has been run on old/cheap oil.

:)
 

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Discussion Starter #18
wow, my car has the exact same problem since like 3 years now, but mine does it every time that i start it cold.. i have replaced all vacuum lines according to this guide

http://www.mn12tech.com/vacuum-hose-replacement.php

Also I replaced the IAC valve 4 times, 1 was new the brand was TOMCO. 1 used from another bird, 1 from a crown victoria, 1 from a grand marquis.

what i do now its like I am the idler on my car lol when i star it up i quickly rev up a little the engine to maintain it on 1100 - 1200 RPM for a little while... but if i let it go the engine quickly goes down to like 400 - 500 RPM and if its really cold it dies.

Once the engine its warm the engine operates normally and this affects nothing on performance but i think it affects fuel mileage

I am really hoping that you find the solution to this problem because its really stressing for me as you saw all that I have done
I do too get the exact same code for the EGR flow so i think that this is what is causing this.... (considering that they changed the DPFE sensor or something like that in a ford dealership when i took the car there to check that problem.... i think i just threw all that money to the garbage because it did nothing for the car)

so good luck and please post something if you find the solution to this

THANKS!!!
Well it was only 3 degrees this morning and my car started up just fine! I had to kind of wait until it got really cold again to give it a good try. Seems a good cleaning of the EGR passages and the throttle body (not sure what all that entails) hopefully has done the trick. Also my check engine light is now off and running very good on regular 87 octane fuel. Yay! So I was really pleased with the guys at the shop I took it to. They were more interested in making sure I was happy than trying to tell me that a bunch of stuff needed to be replaced. They were happy with taking baby steps with me and trying the simplest fixes first. And for that I am grateful. They did tell me that if my engine light comes back on or if I get the p0401 (or maybe it was a p0420) that maybe I would need something done with the DPFE.

Also, when I filled up my car, I calculated that I had been getting 14 mpg (UGH!). But I do let my car run a lot more in the winter, especially now that I wait with my kid at the bus stop & let my car run. So it is probably not really that bad. I usually do get around 23-24 in more normal conditions. 25-26 on a really good day.

And thank you to nall_one for your response too, I don't mind getting a little greasy ha! My daily driver in college was a 69 Austin Healey Sprite that took constant care & upgrades. My friend who rebuilt the trans for me, when both of us worked together we could have the engine & trans out, any of a multitude of problems fixed and then back in in about two hours. There's something to be said about a car with no brain LOL. But it was a tiny tiny little engine and a transmission you could carry like a baby. Little dual carbs, they were so cute and required tuning about once a week that I did myself. Oh those were the days LOL.

There's a saying about British cars, and I suppose the same might apply to some of our beloved MN12's and that is "If there isn't any oil under it, there isn't any oil IN it."
 

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And thank you to nall_one for your response too, I don't mind getting a little greasy ha! My daily driver in college was a 69 Austin Healey Sprite that took constant care & upgrades. My friend who rebuilt the trans for me, when both of us worked together we could have the engine & trans out, any of a multitude of problems fixed and then back in in about two hours. There's something to be said about a car with no brain LOL. But it was a tiny tiny little engine and a transmission you could carry like a baby. Little dual carbs, they were so cute and required tuning about once a week that I did myself. Oh those were the days LOL.

There's a saying about British cars, and I suppose the same might apply to some of our beloved MN12's and that is "If there isn't any oil under it, there isn't any oil IN it."
My father used to own an Austin Healey .. wish I still had it, those are worth quite a bit more $ now - although very tempermental cars, I still have a tool to adjust the dual carbs.

The saying about british cars is about the Land Rover / Range rovers .. notorious for leaking oil - biggest reason I hate working on them although they are easy and aside from the head gasket / block cylinder sleeve issues, they are fairly decent. If your 4.6 is leaking oil, its time to replace the lower coolant adapter gasket - if its a 3.8, chances are you have a cracked pan from the motor mounts going bad.
 
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