timing belt job causes rich AFR? What have I broken this time?
#22
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yeah, I just don't trust that leak down tester. I slapped it on cyl's 1&2, and I can never get the same results twice. I'll have to see if I can borrow a good one from someone at work.
#23
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Had some time today to do a basic compression test. I have a cheapo HF gauge with the check valve up basically right by the gauge. I think it reads consistent, but i suspect it reads low. My warm dry comp was 125 PSI across the board. I did a wet test on cyl 1 just for giggles, and it bumped comp up to 135 PSI.
No sign of a single cylinder that's suddenly way off on compression. The mystery continues.
No sign of a single cylinder that's suddenly way off on compression. The mystery continues.
#24
Had some time today to do a basic compression test. I have a cheapo HF gauge with the check valve up basically right by the gauge. I think it reads consistent, but i suspect it reads low. My warm dry comp was 125 PSI across the board. I did a wet test on cyl 1 just for giggles, and it bumped comp up to 135 PSI.
No sign of a single cylinder that's suddenly way off on compression. The mystery continues.
No sign of a single cylinder that's suddenly way off on compression. The mystery continues.
#25
You refreshed the bottom end 5k miles ago and only get ~130psi compression? Is that hot or cold?
I have had a similar experience although mine was caused by swapping in a refurbished head 6 months after refreshing the bottom end. Rich AFR's, oil usage (does yours use oil?) but still drives well, compression of 180PSI and good leak down numbers. Turns out my rings never bedded in and it took putting a new head on it to show the weakness, it went from rich AFR's to massive amounts of blue smoke in about 4 weeks.
I have had a similar experience although mine was caused by swapping in a refurbished head 6 months after refreshing the bottom end. Rich AFR's, oil usage (does yours use oil?) but still drives well, compression of 180PSI and good leak down numbers. Turns out my rings never bedded in and it took putting a new head on it to show the weakness, it went from rich AFR's to massive amounts of blue smoke in about 4 weeks.
#26
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Bottom end has about 107k on it. Top end is a lightly refreshed junkyard head. I did a timing belt job to replace seals, and I suddenly lost a ton of VE. I've had to pull a lot of fuel From my map. I redid the timing belt job 2 more times trying to find a mechanical solution. I haven't figured out what went wrong.
#27
When you were replacing the VVT actuator did you happen to notice if the location dowel on the end of the intake cam was okay?Had a car come in once that was running, albeit with a nice lopey idle, and rich running issues. Traced it back to mechanical timing.
Eventually learned the previous shop gave that customer a similar story before handing the car to the customer, because they couldn't figure out what they'd done. The customer didn't relay this to me. Just dropped it off with "it doesn't run right". Anway, it looks like they'd held the exhaust cam with a BFwrench for torqueing the crank bolt, and it snapped the locator dowel on the exhaust cam. So you could line up the marks fine, but cam timing was whatever it felt like that day after crank up.
Eventually learned the previous shop gave that customer a similar story before handing the car to the customer, because they couldn't figure out what they'd done. The customer didn't relay this to me. Just dropped it off with "it doesn't run right". Anway, it looks like they'd held the exhaust cam with a BFwrench for torqueing the crank bolt, and it snapped the locator dowel on the exhaust cam. So you could line up the marks fine, but cam timing was whatever it felt like that day after crank up.