Sorry, I was kinda freakin' out there, wasn't trying to be dissing nobody. Iskoos, you can bypass EGR totally just for testing just by unplugging and blocking off the hose that comes to valve itself. Then EGR can be totally weeded out as cause unless, UNLESS, the rare case of valve itself sticking open slightly and leaking. If you know anybody that can do, get someone to patch into O2 sensor(s) and check the output(s). You can do it with OBDII data loggers. Should be switching equal amount high and low around .5 volt at idle if sensors new and active. If switching way on one side more than other, or even locked in place, may show the problem. Lean (or vacuum leak) will hang down below .5 volt, rich is anything over .5 volt. Motor must be warmed up and in closed loop operation. Just because you changed an EGR part, don't assume that system is working, there are several parts to it that have to be right. My Focus sucked out the side of PCV hose after the valve and sensor showed .1 volt, locked, it would not jump back above .5 as required. That's when I started looking for the leak. If you got proper switching @ O2s, no vacuum leak.
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Does MAF sensor cause this? I am puzzled!!!
- Thread starter iskoos
- Start date
iskoos
CEG'er
The thing is my car is 95; it is OBD-I. And OBD-I diagnostic tool would still read the voltage from O2 sensor but I do not have such equipment. My O2 sensor was failed past January and I replaced it. So it should still be good under normal circumstances.
Can you explain yourself a bit more on testing the EGR valve? What should I expect when I remove the vacuum line from the EGR valve? I would like to test that valve out but don't know exactly how!..
Ray, Thanks for the explanation. Yes, I will do it on my driveway. So everything should be cool. But since the whole air intake assembly will be off, the car will idle at high rpm as I stated above because MAF sensor will be disconnected. All this will still make it difficult to locate the vacuum leak. I will first visually check as many stuff(hoses/plastics) as I can for any possible torn or crack. Then will consider using starter spray around the intake...
iskoos
CEG'er
RULED OUT THE MAF SENSOR!..
RULED OUT THE MAF SENSOR!..
I was right on my theory. It was NOT the MAF sensor. I found one at the autoparts store and bought it to test. I put it in and nothing changed. I then unplugged it, and the car didn't exhibit the problem because the idle rpm was high due to MAF being disconnected.
So I didn't find the actual problem maybe but I now know that the problem is NOT MAF sensor and moreover, I know that my MAF sensor is good
Back to vacuum leak chase...
RULED OUT THE MAF SENSOR!..
I was right on my theory. It was NOT the MAF sensor. I found one at the autoparts store and bought it to test. I put it in and nothing changed. I then unplugged it, and the car didn't exhibit the problem because the idle rpm was high due to MAF being disconnected.
So I didn't find the actual problem maybe but I now know that the problem is NOT MAF sensor and moreover, I know that my MAF sensor is good
Back to vacuum leak chase...
:laugh:
EGR vacuum test.
Modified test for EGR (per Ray and Steve):
(remove the green vacuum hose from the top, be careful as it is brittle, and apply a vacuum (attached a small hose and suck on itl) to see if the car stumbles while running. This indicates a properly operating EGR.
Does it work properly?
NO: The EGR valve is defective or the EGR passages are clogged. Check (and clean, if needed) the passages behind the Throttle Body. Purchase a TB gasket, and remove the air plenum (rubber accordion tube) then remove the TB. Clean the EGR passage (small cut-out in the outer edge of the TB's mating surface) really well, install a new gasket and re-attach the TB. If the passages are clear, the EGR valve is defective. While rare, they do fail.
YES: The EGR valve works and the passages are clear. The likely fault is the DPFE sensor or its sample hoses, followed by the EVR solenoid or the PCM. May also be caused by interconnecting vacuum lines or electrical connections.
DarkBlueZ
Hard-core CEG'er
I had the same problem. Check the vacuum hose on the back right side of the engine about half way done the back. Its a S shaped hose.
This is what mine looked like:
Check halfway down the back of the engine right below this spot.
Hope this helps.
-Jared
This is what mine looked like:
Check halfway down the back of the engine right below this spot.
Hope this helps.
-Jared
iskoos
CEG'er
Thank you guys!..
Really appreciate all your inputs.
Yes I did some extensive search on how to test the EGR valve this afternoon and I am now ready for it.
Sorry Tony when I came back to say that "I already figured it out..." you r post there waiting for me. Well, I had you paste it again but it shouldn't hurt, should it?
I will also check all the hoses between engine and firewall. Thanks for the heads up Jared.
I will post the result here...
Really appreciate all your inputs.
Yes I did some extensive search on how to test the EGR valve this afternoon and I am now ready for it.
Sorry Tony when I came back to say that "I already figured it out..." you r post there waiting for me. Well, I had you paste it again but it shouldn't hurt, should it?
I will also check all the hoses between engine and firewall. Thanks for the heads up Jared.
I will post the result here...
iskoos
CEG'er
Weekend!..
Weekend!..
Hey Guys,
Couple days past and I am still trying to find the problem. I pretty much checked all the vacuum hoses between the engine and firewall.
There are basically two vacuum hoses coming out of the back of the upper intake manifold.
-One goes to fuel pressure regulator. Checked it. It is in good shape no cracks or any sign of wear.
-Another one goes to EVR selenoid to control the EGR valve when needed. Removed and checked the hose. Absolutely no problem!.. Also Checked the hose that comes out of EVR selenoid and goes to EGR valve. No problem at all. They were in really good shape that it would just be a waste of time to replace them.
-Two vacuum hoses between the DPFE sensor and upper and lower venturi also looking good.
-There was however one vacuum hose that was in bad shape. I would brittle when I squeeze it. It comes out from the right back of the engine block about half way down(just like where youngkidwithnomoney points out on the picture) and goes around the back of engine to the other side of the car and plugs on a somthing looks like a switch(right around alternator; power steering resevoir). The hose was so bad but NOT cracked. I however took aout and replace it today. But I know it won't fix anything.
I also tested the EGR valve. I used the suck test and everything came up the way described. When I applied enough vacuum to EGR valve, the engine stumbled really bad and almost died.
I also bought a new DPFE sensor and EVR selenoid just to rule them out. Replaced both of them and nothing changed. So I know there is no problem with either one.
When I removed the the hose from EGR valve, I checked it with my thumb and there was no vacuum on the hose which is alright because vacuum opens the EGR valve and EGR valve is not supposed to be open during idle. So all this tells me that things looking alright...
Well now I am about to hit the wall here. Should I still take the EGR valve out and inspet it? It doesn't seem easy to take it out and it seems to be working. Could there still be a problem with that valve. Because the stumbling idle symptoms are very similare to what happened when I applied vacuum to EGR valve!..
Any more ideas!..
P.S. Youngkidwithnomoney, Man I looked it the section you described and found no hose in "S" shape. Everything I checked in that area looks alright...
Weekend!..
Hey Guys,
Couple days past and I am still trying to find the problem. I pretty much checked all the vacuum hoses between the engine and firewall.
There are basically two vacuum hoses coming out of the back of the upper intake manifold.
-One goes to fuel pressure regulator. Checked it. It is in good shape no cracks or any sign of wear.
-Another one goes to EVR selenoid to control the EGR valve when needed. Removed and checked the hose. Absolutely no problem!.. Also Checked the hose that comes out of EVR selenoid and goes to EGR valve. No problem at all. They were in really good shape that it would just be a waste of time to replace them.
-Two vacuum hoses between the DPFE sensor and upper and lower venturi also looking good.
-There was however one vacuum hose that was in bad shape. I would brittle when I squeeze it. It comes out from the right back of the engine block about half way down(just like where youngkidwithnomoney points out on the picture) and goes around the back of engine to the other side of the car and plugs on a somthing looks like a switch(right around alternator; power steering resevoir). The hose was so bad but NOT cracked. I however took aout and replace it today. But I know it won't fix anything.
I also tested the EGR valve. I used the suck test and everything came up the way described. When I applied enough vacuum to EGR valve, the engine stumbled really bad and almost died.
I also bought a new DPFE sensor and EVR selenoid just to rule them out. Replaced both of them and nothing changed. So I know there is no problem with either one.
When I removed the the hose from EGR valve, I checked it with my thumb and there was no vacuum on the hose which is alright because vacuum opens the EGR valve and EGR valve is not supposed to be open during idle. So all this tells me that things looking alright...
Well now I am about to hit the wall here. Should I still take the EGR valve out and inspet it? It doesn't seem easy to take it out and it seems to be working. Could there still be a problem with that valve. Because the stumbling idle symptoms are very similare to what happened when I applied vacuum to EGR valve!..
Any more ideas!..
P.S. Youngkidwithnomoney, Man I looked it the section you described and found no hose in "S" shape. Everything I checked in that area looks alright...
riffraff4201969
CEG'er
Ray is the man...
Ray is the man...
[His alternator replacement how-to was the first time he saved my ass.] and the vast majority of the other advice/how-to's on here are solid. I know I have personally saved a significant amount of money [many thousands of dollars] on repair bills and learned a lot about the, once mysterious, inner workings of my car. It also has had the upside of extending the life of car that I love and have grown very attached to. A feeling that's apparently common among CSVT owners.
If you think it might help resolve your idle issues I can give you the symptom/diagnostic flow chart for a slow/low idle from alldata. PM me and I'll send you the info.
Ray is the man...
[His alternator replacement how-to was the first time he saved my ass.] and the vast majority of the other advice/how-to's on here are solid. I know I have personally saved a significant amount of money [many thousands of dollars] on repair bills and learned a lot about the, once mysterious, inner workings of my car. It also has had the upside of extending the life of car that I love and have grown very attached to. A feeling that's apparently common among CSVT owners.
If you think it might help resolve your idle issues I can give you the symptom/diagnostic flow chart for a slow/low idle from alldata. PM me and I'll send you the info.
iskoos
CEG'er
My car has been fixed!..
My car has been fixed!..
Please see the new thread under "My Contour has been FIXED" to read the end of the year-long story...
My car has been fixed!..
Please see the new thread under "My Contour has been FIXED" to read the end of the year-long story...