Is this considered a VACUUM Leak?

[iskoos]

have you checked the IAC valve?

Replaced Already.
I stated everything I have done so far in my 2nd or 3rd post on the first page of this thread.

 

[iskoos]

I do think that amc49 and striker2 are almost on the same track but there is some misunderstanding.

striker2, first you sounded like exhaust gases in the combustion chamber doesn't affect a/f ratio and you sounded like it wouldn't cause a bad idle.

I then stated that adding extra mass whether burnable(like air) or unburnable(exhaust) will take up space and thus a/f ratio will be affected(so the idle quality). And I think amc49 agreed with me on this one.

Then you came and explained that PCM can determine how much of this gas is burnable air through MAF sensor and how much of it is NOT thus PCM would reduce the fuel in the mixture to maintain 14.7:1 ratio.
That's makes sense really!.. And I agree with you but this doesn't explain that we shouldn't see a bad idle if EGR leak occurs.
So say for example You replace half of the air volume with some burned gases and cut the fuel amount by half, you still have the same 14.7/1 ratio NO problem here!.. But there is also bunch of useless gas in the combustion chamber so we cannot expect the engine run at the same quality just because 14.7:1 ratio is maintained.
And I think you agreed with us on this one too. Correct me if I am mistaken.

So at the end we all agree that introducing exhaust gases into combustion chamber(at idle where the a/f mixture is very sensitive) should reduce the idle quality and possible cause a bad idle even if PCM is able to maintain 14.7:1 ratio.

This is the theory part...


Now...
amc49, I 100% agree with you on your approach to a problem. I should just BE SURE NOT guess here.
My theory on EGR leak is somehow a guess unfortunately/ And this is based on eliminating some other factors(all stated in post #7 of this thread). And especially per EGR valve suck test. When I did the suck test(when I apply vacuum to EGR valve at idle), I realized that the stumble on the engine is very similar to what's happening to me at idle. So it wouldn't surprize me if my problem is actually a leaky EGR valve. But again this is just a guess. To eliminate this (TO BE SURE) I have two options,

1) I will either remove and check (possibly replace) the EGR valve which is not very easy when looking at how it is mounted.

OR

2) Just like you said, plug it all(because we know that engine doesn't need EGR to run properly) and see if the idle improves.

I would love to go with the option #2 here but I just don't know how to plug the EGR between the valve and intake.
I would really appreciate if you can show me a method to do that. It would save me from doing lots of unnecessary work.

How do I do that on Zetec engine? How would I plug the system between the valve and intake?

Thanks so much

 

[striker2]

i actually stated this in my first post:

at idle, if the EGR is flowing, it may dilute it enough that you dont get a good burn and the engine stumbles slightly.

so i have been stating all along that it will effect idle.

removing the EGR valve on the zetec is actually quite simple. remove the intake so you can see the valve. then use either an open ended wrench large enough or an adjustable wrench and remove the pipe from the valve. after that just remove 2 bolts holding the EGR to the pipe that goes to the intake manifold and remove the valve.

i did state that the EGR valve doesnt normally go bad or have problems on the zetec, but that doesnt mean they cant. also, if the EGR valve was stuck open and leaking you would always have problems at idle, not just sometimes. also, the lack of an EGR code makes me believe it probably isnt an EGR problem.

one thing to try doing, if you have access, is to hook up a scanner and see what your long term fuel trim (LTFT) is. if its trying to richen it up then you likely do have a vacuum leak or a bad FPR (mine went bad on my zetec, was only getting about 20PSI instead of 40). as amc49 said, pull the vacuum lines and plug all 3 ports. then run the engine and see if it still stumbles.

 

[iskoos]

i actually stated this in my first post:
so i have been stating all along that it will effect idle.

removing the EGR valve on the zetec is actually quite simple. remove the intake so you can see the valve. then use either an open ended wrench large enough or an adjustable wrench and remove the pipe from the valve. after that just remove 2 bolts holding the EGR to the pipe that goes to the intake manifold and remove the valve.

i did state that the EGR valve doesnt normally go bad or have problems on the zetec, but that doesnt mean they cant. also, if the EGR valve was stuck open and leaking you would always have problems at idle, not just sometimes. also, the lack of an EGR code makes me believe it probably isnt an EGR problem.

one thing to try doing, if you have access, is to hook up a scanner and see what your long term fuel trim (LTFT) is. if its trying to richen it up then you likely do have a vacuum leak or a bad FPR (mine went bad on my zetec, was only getting about 20PSI instead of 40). as amc49 said, pull the vacuum lines and plug all 3 ports. then run the engine and see if it still stumbles.

Thank you man. My answers in the same order:

1) I never removed the intake and that's the main reason why I don't want to remove the EGR if I don't need to. I can see the EGR clearly, removing shouldn't be a problem. There is just not enough room to use tools without removing the whole intake. If i remove the intake, I have to replace the gasket etc...

2) You are right. The stumbling doesn't occour constantly so there shouldn't be so much EGR flow at idle(if this is the problem). I am thinking if there is, it is just a bit not much.

3) No unfortunatley I don't have scanner to see the trim level. I thought of fuel pressure regulator but have no way of checking it.
I checked all the vacuum lines and didn't find any problem, but I guess it wouldn't hurt to plug all of them and run the engine.
But what are these 3 vacuum lines?

I have 2 lines coming out of the back of the intake:
1 directly goes to FPR, and the other one goes to EGR valve by way of EVR selenoid. The line comes from PCV doesn't go into plastic intake manifold. It connects to engine block on the middle left side behind the coil pack. And the line comes from EVAP canister connects to this line with a "T" as well.

So do you mean all these lines by "Unplug all 3 ports?"

I suppose I can do it but one of these lines is powering the FPR. Will the engine run properly without FPR?

 

[striker2]

1. you dont have to remove the intake manifold, just the intake tubing, no gaskets there.

2. it definitly wouldnt be much at all since its not constant.

3. what year is your car? on my 97 there were 3 ports on the back of the manifold, one went to the EGR solenoid, one went to the FPR, and one split. the split one went to the HVAC controls and the EVAP solenoid. the port on the side by the coil pack actually does go into the intake manifold, but it pulls the vacuum from all 4 intake ports right at the head. as you know this goes to the PCV and the EVAP canister. i was ignoring the PCV/EVAP line as i wouldnt pull that line since oil and fuel vapors travel through it normally (not to mention you would no longer have a way of removing any pressure from the crankcase).

you can check the FPR with a fuel pressure gauge. check it at idle and snap throttle. it should sit at ~40PSI at idle and should rise slightly when you snap the throttle. also, it wont hurt it to disconnect the vacuum line while checking for vacuum leaks.

 

[amc49]

Sorry, boys sometimes I get a little too terse. All I'm saying is that sometimes the computerized f/a ratio is not all there is to the problem. That's what I meant by EFFECTIVE f/a, if the motor doesn't like it who really cares what the ratio is? Sorry about the multiple post also, sometimes I think of something else a few seconds later, there's all kinds of garbage banging around in this head. Like this one: nitrogen will not stay inert, once combustion temp gets high enough, some of it converts to NOx. I certainly could care less about post count or whatever, not important to me at all. I gotta '98 model with the VCT instead of EGR, but I certainly didn't think it was that hard to remove valve. In vacuum lines don't forget one that goes to power brake reservoir, also, yank PCV, it won't hurt at all, cars before 1968 dumped the fumes into the air, you can do it for a test. If you want a vent yank the oil fill cap, let it vent there. Didn't someone mention code 335 earlier? That's for EGR pressure sensor, right?

 

[striker2]

Sorry, boys sometimes I get a little too terse. All I'm saying is that sometimes the computerized f/a ratio is not all there is to the problem. That's what I meant by EFFECTIVE f/a, if the motor doesn't like it who really cares what the ratio is?

True

Sorry about the multiple post also, sometimes I think of something else a few seconds later, there's all kinds of garbage banging around in this head.

thats why there is an edit button on your posts

Like this one: nitrogen will not stay inert, once combustion temp gets high enough, some of it converts to NOX.

combustion temps only get high enough if the engine is running lean too much. obviously running lean means there are extra O2 molecules running around to join with the nitrogen to create NOX.

I gotta '98 model with the VCT instead of EGR, but I certainly didn't think it was that hard to remove valve. In vacuum lines don't forget one that goes to power brake reservoir, also, yank PCV, it won't hurt at all, cars before 1968 dumped the fumes into the air, you can do it for a test. If you want a vent yank the oil fill cap, let it vent there.

cars before 68 had a special shaped tube that when air passed over it created a vacuum to pull the gases out of the crankcase. you can pull the PCV line for testing at idle but i would nit drive very far without it. on an old engine you likely will have significant blow-by and with no good way to vent those gases, pressure will build up in the crankcase. i would not pull the oil fill cap as you will get oil everywhere as there is a cam lobe right beneath the cap. (accidently left the cap off once and started driving, under hood was not pretty after that)

Didn't someone mention code 335 earlier? That's for EGR pressure sensor, right?

i looked back and aparantly he did, i must have missed it. however, 335 (O) EGR feedback signal is/was out of range. which means the DPFE is sensor is likely shot and if the EGR is indeed leaking exhaust into the intake could be why there is no code for excessive flow.

 

[iskoos]

1. you dont have to remove the intake manifold, just the intake tubing, no gaskets there.

I will try if I get to that level. I know the manifold doesn't need to be removed but there is not enough room to loosen the bolt comes from cat. and connects to EGR valve from bottom. I will look at it again this weekend. But as far as I remember, there was not enough room to use a wrench here. That's why I was trying to see if it would be possible to plug the line between EGR and manifold. If I can do it without removing EGR, I will know for sure. Removing EGR and knowing that it actually doesn't have any leak won't be fun after all the work...

3. what year is your car? on my 97 there were 3 ports on the back of the manifold, one went to the EGR solenoid, one went to the FPR, and one split. the split one went to the HVAC controls and the EVAP solenoid. the port on the side by the coil pack actually does go into the intake manifold, but it pulls the vacuum from all 4 intake ports right at the head. as you know this goes to the PCV and the EVAP canister. i was ignoring the PCV/EVAP line as i wouldnt pull that line since oil and fuel vapors travel through it normally (not to mention you would no longer have a way of removing any pressure from the crankcase).

Mine is 95 Contour GL Automatic. They made few changes between years. As I said I have the same two ports like you; One goes to EGR selenoid (Manual calls it EVR selenoid for some reason), ant the other one goes to FPR. On my model year they combined the line coming from PCV and from EVAP selenoid with a "T" and this one goes to port on the side. And according to you that port pulls vacuum from 4 intake ports which is not hard to believe.
So you are saying it is OKAY to plug all THESE 3 AT THE SAME TIME AND RUN THE ENGINE????
If so I will do it. It is not difficult.

you can check the FPR with a fuel pressure gauge. check it at idle and snap throttle. it should sit at ~40PSI at idle and should rise slightly when you snap the throttle. also, it wont hurt it to disconnect the vacuum line while checking for vacuum leaks.

Gotta get a pressure gauge for that. But I can get it. It would be a good garage tool.

As far as the code I am getting 335. Yes it refers to DPFE sensor but I replaced it along with EGR selenoid. Its NOT it. I wish I could get excessive EGR flow code. I would feel more confident of the possible EGR leak in that case. But 335 is absolutely the only code I have.

 

[iskoos]

Sorry, boys sometimes I get a little too terse. All I'm saying is that sometimes the computerized f/a ratio is not all there is to the problem. That's what I meant by EFFECTIVE f/a, if the motor doesn't like it who really cares what the ratio is? Sorry about the multiple post also, sometimes I think of something else a few seconds later, there's all kinds of garbage banging around in this head.

You didn't do anything to apologize amc. You shared your thoughts and it is appreciated.
I would also appreciate if you could explain one more time how you plug the pipe coming from EGR and going to intake.
You mentioned earlier that a thin metal can be used. Have you done it before? Can I do it on my Zetec engine?

 

[striker2]

check the wiring to the DPFE sensor. is the insulation cracked or peeling off anywhere? do you know if the car ever had the wiring harness replaced under the recall?

this is from my 97 ford CD:

With a 22 mm crowfoot wrench, completely loosen the EGR valve to exhaust manifold tube nut from EGR valve

 

[iskoos]

check the wiring to the DPFE sensor. is the insulation cracked or peeling off anywhere? do you know if the car ever had the wiring harness replaced under the recall?

I found out about the recall when my car was @ 103k and the dealer didn't fix it. Yes my wiring harness is not ig very good condition. There are cracks on the isulations. I fixed some of them with electrical tape but no way I can see everything under the hood. However, the ones that are on the firewall in pretty good shape. I did need to do anything for those including DPFE connector. The picture showing DPFE wiring is attached.

Thanks for the tip. I never thought about it. If I can find 22mm crowfoot style wrench, I may loosen it up. I will look into that seriously.

 

[SicSE]

Also, as an aside, I'm not so sure that codes just show up as soon as something goes wrong.

Some do, but many don't... it depends on the problem. Some issues need to be present when the PCM looks at them on at least 2 consecutive ignition cycles. Some need to occur X times during a certain time period, and some, (like a slight EGR leak at idle), will not throw a code at all, if the leak is slight enough to allow the DPFE voltage to stay within spec.

Witness the water temperature gauges that don't register accurately, I've put a laptop on both cars and the water temp does not move in a normal manner, Focus gauge will stay cold until around 170 then go to the middle quickly and stay there even when water temp is 235 degrees! Doesn't move into the red zone till like 250 (when commanded by PCM, there's the catch!), then it's all at once.

That's because most of the "sensors" used for the gauges on newer cars, are actually just switches. They're cheaper than the the thermistor-type sensors, AND they reduce customer complaints like "The temp needle goes a little past the half-way mark", or "The temp needle doesn't quite reach the half-way mark anymore". Definitely not the best thing for the performance-minded driver, but we are by far the minority in Ford's eyes.

 

[striker2]

I found out about the recall when my car was @ 103k and the dealer didn't fix it. Yes my wiring harness is not ig very good condition. There are cracks on the isulations. I fixed some of them with electrical tape but no way I can see everything under the hood. However, the ones that are on the firewall in pretty good shape. I did need to do anything for those including DPFE connector. The picture showing DPFE wiring is attached.

Thanks for the tip. I never thought about it. If I can find 22mm crowfoot style wrench, I may loosen it up. I will look into that seriously.

double check and make sure the hoses for the DPFE are on the correct ports. IIRC one should be "ref" (reference) and the other should be "in". the reference port needs to be hooked up to the line that comes after (closest to the EGR valve) the metering orifice in the EGR tube.

 

[iskoos]

double check and make sure the hoses for the DPFE are on the correct ports. IIRC one should be "ref" (reference) and the other should be "in". the reference port needs to be hooked up to the line that comes after (closest to the EGR valve) the metering orifice in the EGR tube.

I check that everytime I remove DPFE sensor. Ports are in different sizes on the sensor so are the vacuum hoses. So it is really difficult to connect them in the worng order. But if one tries hard, it is not impossible.
I am pretty confident that hoses are connected the way they were when I bought the car 9 years ago. But I will check it again.

 

[amc49]

I have blocked off EGR that way before. I used a piece of .009" aluminum, along with a gasket I made to replace the failed one. Block it at the point where EGR bolts to intake. Buy an open end wrench instead of crow's foot, I did and took a torch and heated up wrench and bent it to suit, saved $12. If you don't forget to cap the valve cover oil fill hole back up, it leaks very little, at least mine does AT IDLE. I don't get all this worry about crankcase pressure, engines have run just fine with it for 100 years, just don't block case from venting. The effects of pressure are only after LONGTERM. NO PCV valve on the planet will vent ALL of the pressure at higher rpm, that's why some of the residue ALWAYS gets in the PCV filter inside airbox. Also, how can lean make NOx if car is computer controlled? There should be no lean. But there's still an EGR valve......maybe someone should tell Ford, we could save them several million dollars in EGR parts. NOx is formed by COMBUSTION TEMPERATURE (2500 degrees or higher), which could be from lean but in a normal running car mostly the result of COMPRESSION RATIO.

 

[iskoos]

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...