Rotational Velocity test
#1
#2
AE has the record feature, where you can save the data for later playback - and sharing on the forum.
I'd say you have a slight imbalance in #5, but #8 can be explained away with whatever CPS you're using. That's the part that bugs me about these fancy-schmancy sticks - it's a bear to get them in balance and keep them there. 3 PERDEL is not a disaster, but I can feel as little as 2 PERDEL.
What are your symptoms that had you looking at PERDELs? Rough idle? Is it intermittent?
I'd say you have a slight imbalance in #5, but #8 can be explained away with whatever CPS you're using. That's the part that bugs me about these fancy-schmancy sticks - it's a bear to get them in balance and keep them there. 3 PERDEL is not a disaster, but I can feel as little as 2 PERDEL.
What are your symptoms that had you looking at PERDELs? Rough idle? Is it intermittent?
#3
G'Day Tugs
Its been around 20000K,s since my engine build and Im getting intermittent blue smoke. It might be a big puff when I take off from sitting in traffic or a slight mix with the black when running hard. It might do it every time on one day then not at all the next. My first thought is valve stem seals but they were new on the build. My next step will be a compression test. Saying that I did the cap on the filler neck and it wont pop off.
Its been around 20000K,s since my engine build and Im getting intermittent blue smoke. It might be a big puff when I take off from sitting in traffic or a slight mix with the black when running hard. It might do it every time on one day then not at all the next. My first thought is valve stem seals but they were new on the build. My next step will be a compression test. Saying that I did the cap on the filler neck and it wont pop off.
#4
If you are so inclined, it can't hurt to check your injector bolt torque. A loose injector or a bad O-ring can give these symptoms - it's happened before. Are you getting any knocking sounds in the engine?
I take it that's 20K kilometers? 16K miles for us in the US. I've had sticks come loose as soon as 1000 kilometers.
I take it that's 20K kilometers? 16K miles for us in the US. I've had sticks come loose as soon as 1000 kilometers.
#7
Perdels is a common test of engine health. It can also be called rotational velocity or CCT, but the venacular is perdels. Perdels is short for percent delta, delta being the scientific term for change. Each cylinder adds to the rotation of the crank, and since a weak cylinder pushes the crank along a little less that the others, that change is measured and reported as a percentage. The test will show which cylinders have an issue, and then the cause needs to be determined. There are several recent threads on the subject, read around to learn more.
CDU - You sure it's throwing P0278? I see #5 slowing down, not #6. Is #8 a long lead injector? Agreed with Rich on checking torque on the injector bolts. If for no other reason than he's the demigod of loose injector bolts. Worth ohming the UVCH, maybe there's a burnt pin or other resistance. Also chafing under 42 pin connector, if you have not already addressed it.
And the pins for 5 and 8 are adjacent at the IDM, see image. Water intrusion and rodent nibbles come to mind.
CDU - You sure it's throwing P0278? I see #5 slowing down, not #6. Is #8 a long lead injector? Agreed with Rich on checking torque on the injector bolts. If for no other reason than he's the demigod of loose injector bolts. Worth ohming the UVCH, maybe there's a burnt pin or other resistance. Also chafing under 42 pin connector, if you have not already addressed it.
And the pins for 5 and 8 are adjacent at the IDM, see image. Water intrusion and rodent nibbles come to mind.
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#8
Great explanation, aawlberninf350 (It hurts my tongue when I say that), you left just one thing out: If you have a hot cylinder (more fuel than the other injectors), that will show as a PERDEL as well. The "delta" is change up or down. It makes me wonder how the system reacts to the "normal" cylinder after a hot one - and 6 fires immediately after 5, then 8 is next. 5 really raises my eyebrow.
Here is a [LINK] that goes deeper into PERDELs.
Torque, even when I was hot on the injector torque trail, I didn't call for everybody to grab a torque wrench. Recent revelations have shown me that injector torque is a little light right out of the factory, and many people that replace injectors are having issues with injector torque. It's no longer just me.
Here is a [LINK] that goes deeper into PERDELs.
Torque, even when I was hot on the injector torque trail, I didn't call for everybody to grab a torque wrench. Recent revelations have shown me that injector torque is a little light right out of the factory, and many people that replace injectors are having issues with injector torque. It's no longer just me.
#9
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