Got my Autoenginuity, need some tips on buzz test, cyl. cont. test - Diesel Forum

PPrash · 08-17-2006, 09:50 PM

OK, I can go in and see codes, clear them etc. If I go to Powertrain section and "test Onboard Systems" tab I have choices of tests to run. Buzz test, cyl. cont. test, etc. I can click on them to run them and it says "performing test" but nothing seems to happen. Any tips for a newby on using this feature? (I assume the cyl cont. test is ran with engine running?)

klhansen · 08-17-2006, 09:56 PM

Correct, CCT is run at idle.

Injector Buzz Test is a KOEO (Key On, Engine Off) test. That should show up in the test description.

I've had a couple instances where the Buzz Test didn't initiate till I cycled the key off and back on quickly. Scared the crap out of the guys standing at the engine compartment when they started buzzing. [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

2180 · 08-17-2006, 09:59 PM

on the cyl contribution test if they all tested good then it just says test done or completed or something along them lines, on the buzz test you will hear a loud buzz at first that is all the injectors at once then it does each of them indivually

2180 · 08-17-2006, 10:01 PM

http://www.itpdiesel.com/store.php?diags=1

here is a great link

PPrash · 08-17-2006, 10:07 PM

How long does it run the test while displaying "performing test"? Does it stop automatic at some point? I see no button or choice to manually stop it. I waited 6-7 mins and finally whut down the program.

2180 · 08-17-2006, 10:09 PM

mine takes about a minute two at the most

2180 · 08-17-2006, 10:11 PM

AutoEnginuity can be used to execute Cylinder Contribution Tests (CCT) on 94-03 7.3L Powerstroke Diesel equipped vehicles (the 6.0L PCM doesn't have this functionalilty built-in). A common cause of failed CCTs is "EOT out of Range"...which means Engine Oil Temperature is out of range. The following approximate EOT values are required to execute a CCT:
94-97 Powerstroke Diesel: 170°F+
99-03 Powerstroke Diesel: 135°F+
Also, make sure that ALL accessories are turned off (A/C, etc.)

Note: on 94-97 Powerstroke Trucks, you may be able to audibly hear the test turning cylinders on and off (trucks with newer calibrations should complete 3 test cycles). The test will be terminated early if a cylinder is found to be very bad. Once that cylinder is repaired, the CCT will need to be run again to check the rest of the cylinders. You will not hear this on the 99-03 Powerstroke Trucks as the test is performed differently. There is also a potential problem with the CCT if it detects an issue with either the #6 or #8 cylinder. Due to the fact that cylinders #6 and #8 fire in sequence and are physically adjacent to each other in the engine, it is not uncommon for a CCT to mis-report a problem with one cylinder that actually exists in the other.

For 99-03 7.3L, another way to use AutoEnginuity to see if there are problems with a particular cylinder is to monitor the "Cylinder x Change Rotational Vel" or "Percentage of Crank Deceleration" PID (also commonly called PERDEL). This PID exists for all 8 cylinders and is a representation of crankshaft velocity change (decrease) at the time the cylinder is firing. Ideally, these should all read 0%. Any cylinder consistently reading more than 3-5% change in rotational velocity is suspect and should be further examined. Note: Engine should be fully warmed up before checking PERDEL data.

PPrash · 08-17-2006, 10:54 PM

OK, I got it going. My problem is a miss when cold. The cyl. cont. test says cyl. 8 cold or ward engine. Also, the buzz test when cold 1 tried 2 times and injector 5 did not buzz but the faint noise of the rest was heard. After warm up I ran the buzz test twice and all sounded good. I assume I should run the "Cylinder x Change Rotational Vel" or "Percentage of Crank Deceleration" tests next to confirm cyl. 8 is a problem?

2180 · 08-17-2006, 10:58 PM

yeah you could but remember cyl 6 and 8 fire real close together and i have seen some false readings from that test with inj 8 and i have spoke with others with same results.

Grinder · 08-19-2006, 02:09 PM

Where do you find the "Cylinder x Change Rotational Vel" or "Percentage of Crank Deceleration" PID (also commonly called PERDEL).

I'm going nuts trying to figure out how to see this. Where in AE is it and how do I view it. Feeling dumb.

Thanks,

Dave

2180 · 08-19-2006, 02:17 PM

Its in the list with all the sensors you can monitor.

Grinder · 08-19-2006, 02:20 PM

Is it not available on an early 99? I don't see anything on the live sensor list labeled like that.

Thanks,

Dave

Grinder · 08-19-2006, 04:11 PM

Update: I just checked it on my mom's 02 excursion and they do show up under the live sensors.

They do not show up on my 02/98.

Thanks,

Dave

Suns_PSD · 08-19-2006, 04:12 PM

I was just looking at the change in rotational velocity on my early '99 about 1 hour ago but I do have a different ECM.

But I don't understand what this tells you? (they were all at 0% by the way) Is it telling you that this particular piston is not accelerating away quick enough so that this injector must not be firing right? That's my WAG.

Grinder · 08-19-2006, 04:14 PM

I believe it is saying they are all applying the same force to the crank. I guess you can read that, firing correctly.

Dave