P0300 p0301 p0302
06-10-2016, 04:20 PM
#31
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It's been 150 miles with no codes or CELs. Just had a smog check.
I've been having an issue with my catch can setup, causing excessive crankcase pressure. Small amount of oil was blowing out the oil filler cap. I wondered if there might be a correlation, so I read this thread again, checking the dates of my first flashing CEL/misfire codes. My problems in this thread started while I was still in phase 1 of testing, before I had the issue with the crankcase pressure. And I passed the smog check before I corrected the pressure problem. So no correlation.
I've been having an issue with my catch can setup, causing excessive crankcase pressure. Small amount of oil was blowing out the oil filler cap. I wondered if there might be a correlation, so I read this thread again, checking the dates of my first flashing CEL/misfire codes. My problems in this thread started while I was still in phase 1 of testing, before I had the issue with the crankcase pressure. And I passed the smog check before I corrected the pressure problem. So no correlation.
12-16-2017, 10:14 AM
#32
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Well, the P0300 P0301 P0302 issue has started again. Once or twice a month over the past 2 months. Driving just over 70 miles a day. Since moving the coil packs and changing the spark plugs didn't seem to change the codes, I don't think those are the source of the codes.
While making a new thread about catch cans, I came across a post I had made in February, 2016. In it, I mention
I've only had the fuel pressure code the one time(I think, memory ain't the best, certainly haven't had it since then). I cannot recall what the specific code was.
Also, when I change the oil, the oil level is good. When I check the oil level at a later date, say, months later, the oil level is high. I've seen threads that say this is normal. But it could also be the HPFP leaking fuel into the crankcase.
While making a new thread about catch cans, I came across a post I had made in February, 2016. In it, I mention
Also, when I change the oil, the oil level is good. When I check the oil level at a later date, say, months later, the oil level is high. I've seen threads that say this is normal. But it could also be the HPFP leaking fuel into the crankcase.
12-16-2017, 10:38 AM
#33
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Does the oil smell like fuel?
Have you run Seafoam thru the oil ?
Could the misfire codes be loose connections?
Sometimes the simple things get overlooked while our imagination looks for a bigger picture problem, think about how many think it’s the ECM or BCM when it’s usally a loose fuse or relay or ground wire.
When was the last time you cleaned the throttle body? Or ZmAF ?
These can all cause a misfire.
Have you run Seafoam thru the oil ?
Could the misfire codes be loose connections?
Sometimes the simple things get overlooked while our imagination looks for a bigger picture problem, think about how many think it’s the ECM or BCM when it’s usally a loose fuse or relay or ground wire.
When was the last time you cleaned the throttle body? Or ZmAF ?
These can all cause a misfire.
12-16-2017, 11:46 AM
#34
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Does the oil smell like fuel? Maybe, hard to say. It's stronger than the new oil I have. It's been a long time since I've huffed gasoline vapors 
Have you run Seafoam thru the oil ? No, never.
Could the misfire codes be loose connections? If you mean at the coil packs, they are snapped in tight. Moving the coil packs to different cylinders didn't change the code.
Sometimes the simple things get overlooked while our imagination looks for a bigger picture problem, think about how many think it’s the ECM or BCM when it’s usally a loose fuse or relay or ground wire.
When was the last time you cleaned the throttle body? Or ZmAF ? When the valves were coked, and I removed the manifold. But it really wasn't dirty even then. Have never cleaned the MAF. It looked clean last time I looked.
These can all cause a misfire.
I'm certainly not ready to buy a new HPFP, this happens so infrequently, it's going to be hard to nail down. I just had forgotten about the fuel pressure code, thought it might be relevant.
But really, it seems to be NOT plugs or coils. If it were a bad electrical connection, I would expect to see it more frequently. So at this point, I'm leaning towards a fuel issue.
Ugh, I hope it's not injectors or fuel rail, I'd have to remove the intake manifold again! Well, that would allow me to make a progress report on the intake valves.
Hmmm, another commonality is this: The last few times it has set the CEL have been at the same location, slight downslope, coasting in gear, right before the parking lot at work.
Have you run Seafoam thru the oil ? No, never.
Could the misfire codes be loose connections? If you mean at the coil packs, they are snapped in tight. Moving the coil packs to different cylinders didn't change the code.
Sometimes the simple things get overlooked while our imagination looks for a bigger picture problem, think about how many think it’s the ECM or BCM when it’s usally a loose fuse or relay or ground wire.
When was the last time you cleaned the throttle body? Or ZmAF ? When the valves were coked, and I removed the manifold. But it really wasn't dirty even then. Have never cleaned the MAF. It looked clean last time I looked.
These can all cause a misfire.
I'm certainly not ready to buy a new HPFP, this happens so infrequently, it's going to be hard to nail down. I just had forgotten about the fuel pressure code, thought it might be relevant.
But really, it seems to be NOT plugs or coils. If it were a bad electrical connection, I would expect to see it more frequently. So at this point, I'm leaning towards a fuel issue.
Ugh, I hope it's not injectors or fuel rail, I'd have to remove the intake manifold again! Well, that would allow me to make a progress report on the intake valves.
Hmmm, another commonality is this: The last few times it has set the CEL have been at the same location, slight downslope, coasting in gear, right before the parking lot at work.
12-16-2017, 12:00 PM
#35
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Hold the dripping dipstick in a flame, if it ignites it's gas.
Higher oil level is only "normal" when hot or parked on an incline.
I am betting on the HPFP, It is pretty sophisticated the way it regulates pressure. I think it is not reacting fast enough when you let off the pedal. So it is dumping fuel into the cylinders
We don't need another "blame the BCM" thread!
Higher oil level is only "normal" when hot or parked on an incline.
I am betting on the HPFP, It is pretty sophisticated the way it regulates pressure. I think it is not reacting fast enough when you let off the pedal. So it is dumping fuel into the cylinders
We don't need another "blame the BCM" thread!
12-16-2017, 12:03 PM
#36
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"The last few times it has set the CEL have been at the same location, slight downslope, coasting in gear, right before the parking lot at work"
That would be on trailing throttle - perhaps indicating it is running too lean?
That would be on trailing throttle - perhaps indicating it is running too lean?
12-16-2017, 12:13 PM
#38
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My understanding is that, when coasting in gear downhill, the fuel is supposed to pretty much shut off. Is this true?
It doesn't light up the CEL when doing the same down a longer, steeper downslope (1 mile, 7% grade)
It's so infrequent, not sure if evidence would show up on the spark plugs.
At least it's not flashing anymore.
It doesn't light up the CEL when doing the same down a longer, steeper downslope (1 mile, 7% grade)
It's so infrequent, not sure if evidence would show up on the spark plugs.
At least it's not flashing anymore.
12-16-2017, 07:26 PM
#40
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Yes, I did.
The oil on the dipstick doesn't burn, so I guess there is no fuel in the oil, so the HPFP is less suspect.
No Seafoam in the oil.
The connectors that snap into the coil packs are snapped in nicely. What other connections should I check? I'm gonna have to see if I can remember if I've messed with any connectors since just before this started.
Haven't messed with fuses, relays, or ground wires. The climate here is such that no corrosion forms on these.
I could try cleaning the MAF. I think if it were that, though, it wouldn't be just these same 2 cylinders every time. The throttle body is a real pain to get to, to clean it, or even just to inspect.
OK, looking back, this started shortly after removing the intake manifold, shell blasting, catch cans. So, I had several things disconnected. The throttle body had just been cleaned.
I guess I'll get some MAF cleaner, and some Seafoam for the gas tank(maybe the injectors are dirty, although I try to always use Top Tier Premium, usually Costco).
The oil on the dipstick doesn't burn, so I guess there is no fuel in the oil, so the HPFP is less suspect.
No Seafoam in the oil.
The connectors that snap into the coil packs are snapped in nicely. What other connections should I check? I'm gonna have to see if I can remember if I've messed with any connectors since just before this started.
Haven't messed with fuses, relays, or ground wires. The climate here is such that no corrosion forms on these.
I could try cleaning the MAF. I think if it were that, though, it wouldn't be just these same 2 cylinders every time. The throttle body is a real pain to get to, to clean it, or even just to inspect.
OK, looking back, this started shortly after removing the intake manifold, shell blasting, catch cans. So, I had several things disconnected. The throttle body had just been cleaned.
I guess I'll get some MAF cleaner, and some Seafoam for the gas tank(maybe the injectors are dirty, although I try to always use Top Tier Premium, usually Costco).