Cylinder Balance Test Cylinder Sequence

[FoMoCo17]

Does anyone know for sure the sequence the EEC IV uses when cutting off cylinders for the Cylinder Balance Test initiated with a code scanner (i.e. 1-2-3-4-5-6-7-8, 5-6-7-8-1-2-3-4, 1-3-7-2-6-5-4-8) or any other order utilized?

Thank you for your help .

[decipha]

i do not, never needed to do a cylinder balance test before

[FoMoCo17]

Well thanks ... anyone else ...

I’ve been told it goes through 1-8 successively. However, w wideband and and QH installed its showing me that’s its starting on Bank 2 cylinders 5-8 first ... rather then cylinders 1-4. I know it’s starting on 5-8 bec this is where my wideband is mounted and QH is confirming it showing the lean spikes of each cylinder being cut out on the AFR ... THEN .. you can see it going through 1-4 via the rpm graph.

Thus, if anyone can confirm this anomaly, I’d appreciate it! As I said, I’ve been told that it starts and completetes Bank 1 first (1-4) before proceeding to Bank 2 (5-8). Starting to wonder if my Injector wires are flipped side to side though all I can find if accurate says their correct!

Any help appreciated!

[red5.0fogger]

I'd use the wiring schematic and ring them out with a multimeter from a few injectors to the salt and pepper plugs. Seems simplest way to me. First check the injector order in the tune.

[Paulie]

Disconnect the connector for one of the injectors and rerun cylinder balance test to see if it identifies the correct cylinder

[FoMoCo17]

Great point/idea! Will have to give it a try when I have a chance ... thank you! But guess it’ll be mighty rough disconnecting one cylinder and the computer shorting out an additional cylinder each time ... but guess it was designed for that .... guess the best time to disconnect it is while running after the KOER tests have been completed and idle is raised right before I depress the throttle to initiate the test.

[FoMoCo17]

Thanks again Paulie .... tried cylinder balance test 3 times on both banks and the test proved out and found the disconnected cylinder accurately all three times! Thus, all looks good, though I have to review again the O2 responses for each ... they looked iffy on one test ... but will recheck. Anyway, after doing 3 tests and analyzing the graphs, would you believe, it appears the the EEC IV shorts the cylinders in the the Cylinder Balance Test in the following order 8-7-6-5-4-3-2-1 opposite of what I was told at a different mustang site. Pisses one off after 6 hours of verification of erroneous info that people just throw out there and are wrong. Anyone that can or wants to verify this would be appreciated! I think it’s important because problems can be diagnosed relating to the system by logging this test! Definitely shows up nicely while logging in the QH. And, definite problem areas can readily be seen via QH and different PID’s.

[blocmi]

I was wondering the same thing as I waited for a cylinder balance test to run its course recently. Although I can't confirm the entire sequence, number 8 being tested first is plausible given my experience recently. In my case it was #8 not firing due to the injector mysteriously being assigned to a disabled HEGO mid drive... I must have corrupted something at some point...

After running the test multiple times I would only count 7 rpm drops, and the first rpm drop took a substantial amount of time from test initiation, which lead me to believe #8 was being tested first.

After running the test 3 times I had enough time to ponder the question and deduce, it's a moot point... In the end, the computer is going to tell you what cylinder isn't pulling its weight, the test order is irrelevant... unless the first cylinder being tested is the dead hole and you don't want to wait thru 7 more cylinder tests for results, but there I go thinking again..