The bubble on the PCV hose? Vacuum leaks suck (figuratively and literally); are you testing with pressure?
SOLVED: Another misfire chasing threads (2008 express van)
- Thread starter Tonyv__
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
OP
OP
Tonyv__
Full Access Member
Yeah it’s a smoke machine. But the smoke is so light I used windex to confirm the location
Got it. Fix the hose and see if it makes a difference. Maybe keep smokin' to see if you find anything else.
OP
OP
Tonyv__
Full Access Member
Just ordered a replacement on RA. Should be here this week
will keep this post updated until I find the culprit. Too stubborn to take it to the dealer like I said I would
Tonyrodz
Resident Resident
Hopefully that was the issue.
OP
OP
Tonyv__
Full Access Member
So the vacuum lines didn’t fix the problem ( unless there’s more leaks I cannot find). Took the valve cover off today and looked at the rockers and springs. Everything looks tight and the rockers all seem to move up and down as the engine rotates. Learned how to read my live data and saw that my long term fuel trim was 10.9 on the high side. Also read that the intake gaskets are prone to fail and cause misfires so I ordered some gaskets and plan to tackle that this week. Does anyone know if I have to remove and replace the gasket on the valley pan as well (where the knock sensors are) ?
also ordered myself a scope to look inside the cylinder walls while I’m at at.
also ordered myself a scope to look inside the cylinder walls while I’m at at.
Are your LT fuel trims that high on both banks? Or is this one bank only?
Watch your STFTs at idle and note both banks. Then run it up to 2K rpm and see if the STFTs change much.
OP
OP
Tonyv__
Full Access Member
This is at idle. Running temp 189 I’ll try it again tomorrow
what also confuses me now is bank 2 is cylinders 2 4 6 8 I believe my misfire is on the other side (bank 1)
Attachments
It doesn't seem to be in closed loop yet, but it should be based on your coolant temp. It looks like the upstream sensors aren't working yet, unless the STFTs are changing off of "0," but a steady '0' is suspect.
The passenger (B2) LTFTs indicated that the ECM is adding much more fuel on that side than the driver's side. I suspect the vacuum leak, if it's the cause, is on that side. You could also have a mechanically stuck injector with one cylinder pushing just air. Eric O just did a video on one:
Can you get a graph or number values of the B1S1 and B2S1 O₂ voltages? They should be jumping between 0.1 and 0.9 V.
The passenger (B2) LTFTs indicated that the ECM is adding much more fuel on that side than the driver's side. I suspect the vacuum leak, if it's the cause, is on that side. You could also have a mechanically stuck injector with one cylinder pushing just air. Eric O just did a video on one:
Can you get a graph or number values of the B1S1 and B2S1 O₂ voltages? They should be jumping between 0.1 and 0.9 V.
Last edited:
OP
OP
Tonyv__
Full Access Member
I posted the entire live data from just idling…
a couple weeks ago I swapped the fuel injector from 7 to 8. Nothing changed. Would that rule out a stuck injector?
