3.0L Missing...AGAIN
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From: torrance
3.0L Missing...AGAIN
This getting ridiculous... or at least frustrating. Took some time off from the wifes Escape to work on the old Ranhero. The Escape has a recurring engine miss and it is doing it again.
I have changed plugs, swapped COP's around and chased down the bad one and replaced it. It did fine for a couple of days but has now been doing the same thing for about 2 weeks now. Problem is, the reader won't give me any codes. Just said No DTC's reported. I can feel the miss and the gas mileage is down to about 12 mpg or so, so you just know something is wrong.
Cleaned the MAF sensor to no avail, except that cured the problem for a couple of days. Would the computer not read a bad DPSE sensor? Would a vacuum leak at the upper intake seals cause this but not cause a code to be thrown? I thought the damn computers read EVERYTHING!
I much prefer working on my two Falcons but they do not use nearly as much gas as the Escape is right now (due to limited or no driving) so I have to get this miss thing figured out but do not know what to look at next. I have run all kinds of injector cleaner through several tanks but that has not helped either. And besides, the computer would read that...right?
Thanks,
Chuck
I have changed plugs, swapped COP's around and chased down the bad one and replaced it. It did fine for a couple of days but has now been doing the same thing for about 2 weeks now. Problem is, the reader won't give me any codes. Just said No DTC's reported. I can feel the miss and the gas mileage is down to about 12 mpg or so, so you just know something is wrong.
Cleaned the MAF sensor to no avail, except that cured the problem for a couple of days. Would the computer not read a bad DPSE sensor? Would a vacuum leak at the upper intake seals cause this but not cause a code to be thrown? I thought the damn computers read EVERYTHING!
I much prefer working on my two Falcons but they do not use nearly as much gas as the Escape is right now (due to limited or no driving) so I have to get this miss thing figured out but do not know what to look at next. I have run all kinds of injector cleaner through several tanks but that has not helped either. And besides, the computer would read that...right?
Thanks,
Chuck
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From: St. Peter
I actually just read a TSB this weekend on the escape. It appears that if it doesnt have a spark plug with the date code 5A stamped on it you need to replace all 6 plugs, 6 coils, and the PCM. The TSB indicated that the spark plugs can cause an RF interferance that damages the PCM, and then the coils.
The escape that was in our shop had a cyl 4 misfire, and P0351-P0356. I can think of another reason why all 6 cyls would have a coil ciruct problems.
The escape that was in our shop had a cyl 4 misfire, and P0351-P0356. I can think of another reason why all 6 cyls would have a coil ciruct problems.
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From: torrance
I actually just read a TSB this weekend on the escape. It appears that if it doesnt have a spark plug with the date code 5A stamped on it you need to replace all 6 plugs, 6 coils, and the PCM. The TSB indicated that the spark plugs can cause an RF interferance that damages the PCM, and then the coils.
The escape that was in our shop had a cyl 4 misfire, and P0351-P0356. I can think of another reason why all 6 cyls would have a coil ciruct problems.
The escape that was in our shop had a cyl 4 misfire, and P0351-P0356. I can think of another reason why all 6 cyls would have a coil ciruct problems.
Interesting information and I thank you for that.
Chuck
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From: torrance
COP Testing Tool
Have any of you guys used this tool for testing COP's? I am wondering how the hell you get to the back coil overs to test with the motor running if you have to remove the upper intake to get to the COP's!
Waekon WAE76562 Coil Over Plug Quick Probe - VS | Spark Testers
Chuck
Waekon WAE76562 Coil Over Plug Quick Probe - VS | Spark Testers
Chuck
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From: St. Peter
I have a tool similar to that from waekon (PGI) and it works awesome. I would expect this tool to work just as well. And I agree, getting at the back COP's is near impossible w/out intake manifold removal. The next thing would be to check the voltage at the PCM connector, (actually check for switching ground). Then maybe look at the primary circut using a scope to see if the COP is working.
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From: torrance
3.0L Missing...AGAIN
I have a tool similar to that from waekon (PGI) and it works awesome. I would expect this tool to work just as well. And I agree, getting at the back COP's is near impossible w/out intake manifold removal. The next thing would be to check the voltage at the PCM connector, (actually check for switching ground). Then maybe look at the primary circut using a scope to see if the COP is working.
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From: St. Peter
You need a scope, and I believe by looking at the negative side of the primary circut you can see the coil charging/dischargin. here is a link
Primary Ignition (voltage)
Primary Ignition (voltage)
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Guy's, I hate to be a stick in the mud, but when it gets to the point of throwing parts at a rig to fix it. Then it maybe time to let the dealer have a crack. It maybe cheaper in the long run. I know you like to work on falcons and the old school stuff as I do, but this new stuff can be above our paygrade and it's made that way on purpose to protrct emissions tampering to a large extent. It could even be some sensor that isn't showing up on your scanner, who knows?
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From: St. Peter
We first need to figure out why you do not have any DTC's with a misfire. What kind of code reader are you using? Also wendell is right, if you take it to a dealership (or any shop with a scan tool) they will be able to read all your codes, present or in the history. Also they will be able to monitor the fuel trims, and see what is going on from that aspect.
I am in no way suggesting throwing a PCM, 6 coils, and 6 spark plugs at it without first figuring out the date codes on the spark plugs and getting any DTC's from the PCM.
I am in no way suggesting throwing a PCM, 6 coils, and 6 spark plugs at it without first figuring out the date codes on the spark plugs and getting any DTC's from the PCM.
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From: torrance
The reader is a CanOBD2. Just to check the PCM, today I unplugged the MAF connector and it did throw a code for that so at least I know the PCM is working.
It has 6 new plugs and one new COP that was suspect due to the codes changing cylinders when I switched the COP's around. Ran fine for a day or so then acted up again. I have another COP in the drawer but can't get a code again for misfire so don't know where to place it.
Cleaned the MAF again yesterday, real well, started it up and no miss. Then this morning when I started it up it started missing right away. Once warm it was fine until I turned on the A/C.
Don't know if it's my imagination or not but it also felt as though it wasn't shifting right which, if I recall my Google searches, could be related to either the throttle position sensor or crankshaft sensor.
It has 6 new plugs and one new COP that was suspect due to the codes changing cylinders when I switched the COP's around. Ran fine for a day or so then acted up again. I have another COP in the drawer but can't get a code again for misfire so don't know where to place it.
Cleaned the MAF again yesterday, real well, started it up and no miss. Then this morning when I started it up it started missing right away. Once warm it was fine until I turned on the A/C.
Don't know if it's my imagination or not but it also felt as though it wasn't shifting right which, if I recall my Google searches, could be related to either the throttle position sensor or crankshaft sensor.
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From: St. Peter
Well, in any case if there isnt a signal from the crank, or the TPS is out of range, you should be getting a code. It is just strange given your symptoms that the check engine light is not on. Usually it will be on within a few misfires. Thats why it would be nice if you had a genisys to check the fuel trims. Also sometimes it will take a few drive cycles to trigger a light. But it seems to me that you have driven it enough.
Even a mass airflow sensor will set a low/high frequency or some sort of code. However I guess I have seen it (especially on nissans) where a dirty MAF will actually cause the tranny to shift like garbage, and the whole car not to run right, even without a check engine light.
Unfortunatly I really dont know where to start with this.
I guess first you can test to see which cyl is misfiring by pulling the front 3 coils off of the spark plug with it running. Do it 1 by 1 (make sure to give the spark some place to go by grounding the coil somewhere). And whichever coil you unhook that does not change engine RPM would be your problem cyl. Then just hope it is on the front three.
Even a mass airflow sensor will set a low/high frequency or some sort of code. However I guess I have seen it (especially on nissans) where a dirty MAF will actually cause the tranny to shift like garbage, and the whole car not to run right, even without a check engine light.
Unfortunatly I really dont know where to start with this.
I guess first you can test to see which cyl is misfiring by pulling the front 3 coils off of the spark plug with it running. Do it 1 by 1 (make sure to give the spark some place to go by grounding the coil somewhere). And whichever coil you unhook that does not change engine RPM would be your problem cyl. Then just hope it is on the front three.
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From: Central Coast of CA
Have any of you guys used this tool for testing COP's? I am wondering how the hell you get to the back coil overs to test with the motor running if you have to remove the upper intake to get to the COP's!
Waekon WAE76562 Coil Over Plug Quick Probe - VS | Spark Testers
Chuck
Waekon WAE76562 Coil Over Plug Quick Probe - VS | Spark Testers
Chuck
You know you now have three good ones on the number one bank, and you can check the number two bank since you took the back one's and put them up front.
Stewart
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From: torrance
Chuck, remove the plastic cover and test the number 4, 5, and 6 cylinder COP. If all three of those coils check out ok, swap them with the number 1, 2, and 3, cylinder coils.
You know you now have three good ones on the number one bank, and you can check the number two bank since you took the back one's and put them up front.
Stewart
You know you now have three good ones on the number one bank, and you can check the number two bank since you took the back one's and put them up front.
Stewart
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From: Central Coast of CA
I just had to replace a coil on my daughters Escape.
The bad coil was on the number 1 cylinder, so the intake (as you know) had to be removed. Well, I didn't have to take it all the way off to get to it. I was able to cheat the COP out after loosening the intake and getting some cheater space.
Unfotunately, the dealership didn't have any in stock and had to order one. So, I took one of the good ones from the number 2 bank and replaced the bad coil with a good one, and put the bad one on the number 6 cylinder, so I wouldn't have to loosen the intake again.
This also allowed me to make sure the COP was indeed bad, because it should set a new DTC for whichever cylinder I place the coil on.
It did. It set a new DTC for the number 6 cylinder, so I just popped it off and put the new one on when the dealership got the coil in.
After doing that, it was kind of a no brainer for me to see a solution to your dilemma.
Stewart
