Buzz test AE results.

[Lilpooh]

Helping out another local member, he's got a '05, EGR delete, welded close EGR valve, the rest of motor is stock. 200k on original injectors.

He's having issues with slight miss when warmed up, and occasional motor stumble when at operating temp and cruising down the road. FICM shows 48v output, FICM input at 13.5v. The only codes to pull up is 3-4-5-7 glow plugs. When cold start up, he had to crank it twice to get it started, but only did this one time.

I was thinking possible stiction issue, he did try the Archoil and the motor ran better, but symptoms did come back.

So I went to do a buzz test with motor at operating temp, initiated the buzz test, we got 3 injectors on pass side to buzz, but that was it only 3. In between the injector buzz sequence of the cylinders, there was just clicking instead of buzzing.

So at this point we are thinking heavy stiction, which he is going to try Rev-X and load test batteries, then we will swap in my FICM to test his truck before he starts digging into the injectors.

I did find some useful info from M-chan68 on this link.
Injectors, how to test or diagnose?

Normally when doing a buzz test on my truck, all 8 injectors will buzz in sequence. On his truck, only 3 buzzed with clicking in between.

So my question is, would bad stiction cause the buzz test to fail? Or is their deeper issues with his injectors.

Thanks, Rich

[Evil Eye]

Pretty sure that the buzz test cycles the spool valves on the injectors, so if they aren't buzzing, you either have severe stiction or a problem with the circuit to the injector (wiring or FICM) like you suspect.

[Lilpooh]

Thanks Shawn, I've never experienced stiction, so I'm unsure of the actual symptoms.

[Evil Eye]

With only 3 actually buzzing, I'm thinking he should replace all 8 injectors. With 200k miles on them, the internals aren't as precise and they won't be building 28,000 psi of injection pressure at WOT.

[U235a4]

when doing the buzz test in the 03-07 you will have all injectors buzz followed by a click test on each injector. It doesn't buzz each injector like it did in the 7.3l motors. Even when using IDS it does this. I would say to replace the injector that doesn't click when hot and see if that fixes it. Also most likely at 200k all 8 injectors are going to need replace as once one is replace the other "might" start showing up as a contribution dtc but that is a wait see. Good luck I have two left in mine to replace I never had a DTC but tried revx and it did work but once I started to replace with new ford remains and the upgrades done to then I could really see a difference in power even stock tuned. so it should go like this "(all 8 Buzz) (1Click)(2Click)(3Click)(4Click)(5Click)(6Click)(7 Click)(8Click) (all 8 Buzz) (1Click)(2Click)(3Click)(4Click)(5Click)(6Click)(7 Click)(8Click)" Here is a video of mine doing the buzz test (turn up your speakers) injector buzz test

[Lilpooh]

That's what threw me off, only three injectors buzzed, but all 8 clicked.

I'll keep you all posted, he's gonna try the cheapest route first (Rev-x). After that, injectors may be nesassary.

[U235a4]

Originally Posted by Lilpooh

That's what threw me off, only three injectors buzzed, but all 8 clicked.

I'll keep you all posted, he's gonna try the cheapest route first (Rev-x). After that, injectors may be nesassary.

if you didn't see I updated my post with a video