So this happened...
10-27-2019, 09:51 PM
#46
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I forgot to add when I also have all new O2 sensors.
I'll try and get some data in the next couple of days.
I'll try and get some data in the next couple of days.
10-27-2019, 10:30 PM
#47
napolean Your RKAT is negative so you are running rich
You say you changed your MAF>> Aftermarket or genuine Bosch?
Have you changed your wideband O2 sensors? They control your fueling and set the tone for closed loop operation when running thru the MAF
Do you have a stock intake >>when pulling the lower boost hose from turbo to IC on the drivers side is there any oil present?
You say you changed your MAF>> Aftermarket or genuine Bosch?
Have you changed your wideband O2 sensors? They control your fueling and set the tone for closed loop operation when running thru the MAF
Do you have a stock intake >>when pulling the lower boost hose from turbo to IC on the drivers side is there any oil present?
MAF is genuine Bosch. Original and replacement give the same issues.
I haven't changed the wideband O2s, but my misfire problems are on open loop.
Anyway am I running way to rich? It is less than 1%, I figured that is within normal range?
10-29-2019, 03:33 PM
#48
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Everything is stock. I have seen an oily residue on turbo to IC, but nothing like drops of oil or blue smoke on startup.
MAF is genuine Bosch. Original and replacement give the same issues.
I haven't changed the wideband O2s, but my misfire problems are on open loop.
Anyway am I running way to rich? It is less than 1%, I figured that is within normal range?
MAF is genuine Bosch. Original and replacement give the same issues.
I haven't changed the wideband O2s, but my misfire problems are on open loop.
Anyway am I running way to rich? It is less than 1%, I figured that is within normal range?
10-30-2019, 07:48 PM
#50
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Does the diagnostic let you see the volume of each individual injector?
10-30-2019, 10:33 PM
#52
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That is disappointing.
The OBD2 system design was supposed to eliminate these sort of mysteries.
You have eliminate an ingniton problem. If it was throttle body I would think there would be random misfires on all cylinders, not just the same two or three.
What are you thinking of doing next? For me it is pointing to some sort of injector issue on cold start or another possibility is that some engine oil or coolant is making its way into those cylinders as the engine cools, a head gasket leak. Have you done compression/leak down test?
The OBD2 system design was supposed to eliminate these sort of mysteries.
You have eliminate an ingniton problem. If it was throttle body I would think there would be random misfires on all cylinders, not just the same two or three.
What are you thinking of doing next? For me it is pointing to some sort of injector issue on cold start or another possibility is that some engine oil or coolant is making its way into those cylinders as the engine cools, a head gasket leak. Have you done compression/leak down test?
10-30-2019, 10:46 PM
#53
That is disappointing.
The OBD2 system design was supposed to eliminate these sort of mysteries.
You have eliminate an ingniton problem. If it was throttle body I would think there would be random misfires on all cylinders, not just the same two or three.
What are you thinking of doing next? For me it is pointing to some sort of injector issue on cold start or another possibility is that some engine oil or coolant is making its way into those cylinders as the engine cools, a head gasket leak. Have you done compression/leak down test?
The OBD2 system design was supposed to eliminate these sort of mysteries.
You have eliminate an ingniton problem. If it was throttle body I would think there would be random misfires on all cylinders, not just the same two or three.
What are you thinking of doing next? For me it is pointing to some sort of injector issue on cold start or another possibility is that some engine oil or coolant is making its way into those cylinders as the engine cools, a head gasket leak. Have you done compression/leak down test?
- Headgasket has crossed my mind. But again why would the two of them fail at the same time? The car has not been in range 2 over rev range. I have 10 range 2s which happened apparently 700h ago (way before my time).
- Injectors, again why would 2 go bad at once? I would not be opposed to swapping some around, but I have heard that you virtually have to drop the engine to do so...….also if I unplug the MAF and start the car, I never see any misfires. (this points to me to a mapping/wrong mixture)
- Ignition: Coils and plugs have been eliminated by swapping stuff around and both are now. As a desperation move, I could reinstall the original coils (which worked fine when I removed them) and try a different brand plug. However the Bosch FR6 LDC is a tried and proven plug.
- A leak down and compression test would be something useful to do to eliminate a mechanical issue, but im not sure I have one.
I cleaned the throttle body. It was somewhat dirty, I was hopeful that was it, but that didn't resolve anything either.
Maybe I just need to try the original coils with some different brand plugs...……...
10-30-2019, 10:55 PM
#54
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To be honest im at a loss.
- Headgasket has crossed my mind. But again why would the two of them fail at the same time? The car has not been in range 2 over rev range. I have 10 range 2s which happened apparently 700h ago (way before my time).
- Injectors, again why would 2 go bad at once? I would not be opposed to swapping some around, but I have heard that you virtually have to drop the engine to do so...….also if I unplug the MAF and start the car, I never see any misfires. (this points to me to a mapping/wrong mixture)
- Ignition: Coils and plugs have been eliminated by swapping stuff around and both are now. As a desperation move, I could reinstall the original coils (which worked fine when I removed them) and try a different brand plug. However the Bosch FR6 LDC is a tried and proven plug.
- A leak down and compression test would be something useful to do to eliminate a mechanical issue, but im not sure I have one.
I cleaned the throttle body. It was somewhat dirty, I was hopeful that was it, but that didn't resolve anything either.
Maybe I just need to try the original coils with some different brand plugs...……...
- Headgasket has crossed my mind. But again why would the two of them fail at the same time? The car has not been in range 2 over rev range. I have 10 range 2s which happened apparently 700h ago (way before my time).
- Injectors, again why would 2 go bad at once? I would not be opposed to swapping some around, but I have heard that you virtually have to drop the engine to do so...….also if I unplug the MAF and start the car, I never see any misfires. (this points to me to a mapping/wrong mixture)
- Ignition: Coils and plugs have been eliminated by swapping stuff around and both are now. As a desperation move, I could reinstall the original coils (which worked fine when I removed them) and try a different brand plug. However the Bosch FR6 LDC is a tried and proven plug.
- A leak down and compression test would be something useful to do to eliminate a mechanical issue, but im not sure I have one.
I cleaned the throttle body. It was somewhat dirty, I was hopeful that was it, but that didn't resolve anything either.
Maybe I just need to try the original coils with some different brand plugs...……...
10-30-2019, 11:45 PM
#55
Nope, it started this year after winter hybernation. Coils and plugs were changed 2 years 2k miles before problems started (OEM 997 coils).
10-31-2019, 09:05 AM
#56
You say the problem goes away with MAF unplugged. Have you cleaned it or replaced it? These are usually simply issues. Def not head gaskets.
10-31-2019, 10:39 AM
#58
I agree with s65e90 try swapping the MAF again. Preferably with one from another car that is functioning correctly.
MAF was replaced with a brand new bosch unit,. same porsche numbers. Issues remain. Read outs look good on the MAF as well
The MAF often times gets blamed falsely due to the "unplug" experiment. Unplugging the MAF forces the ECU to go in a emergency predefined engine map, ignoring many sensors. MAF has been ruled out, and not to be snarky, it has been discussed 3x before in this topic.
10-31-2019, 10:54 AM
#59
You're not being snarky, it's hard to digest 4 pages. We could offer less advice?
In any event, what made the change to the colder plugs? Did you really need em? Why are you treating the car like it's got a carburetor when starting it? No need to hit the gas, and certainly no need to keep it at 2k to get heat in the cats. Did you ever reset the TB adaptation and clean it? Also puff of smoke at startup is normal as the engine is sideways.
In any event, what made the change to the colder plugs? Did you really need em? Why are you treating the car like it's got a carburetor when starting it? No need to hit the gas, and certainly no need to keep it at 2k to get heat in the cats. Did you ever reset the TB adaptation and clean it? Also puff of smoke at startup is normal as the engine is sideways.
10-31-2019, 11:05 AM
#60
In any event, what made the change to the colder plugs? Did you really need em? Why are you treating the car like it's got a carburetor when starting it? No need to hit the gas, and certainly no need to keep it at 2k to get heat in the cats. Did you ever reset the TB adaptation and clean it? Also puff of smoke at startup is normal as the engine is sideways.
The plugs are OEM replacements from Porsche according to the dealer catalog.