Buzz test issues
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Buzz test issues
Hello
I’ve got a 97 7.3
I was having issues with low power/ lots of smoke/ rough idle. I got setup with FORScan and ran a buzz test and it came up with p1294 and p1271. Also the buzz test sounded weak on most injectors and didn’t seem to go in order.The UVCH was upgraded to the super duty style previously so I dove into looking for a possible crossed wire or short. Ive gone through diagrams and checked wiring from the idm connector to each harness. I followed the GB Injector Resistance And Wiring Test and everything looks okay. My resistances are 2.9 across the board. I found cracked insulation on some wires on both UVCH’s so I replaced them both. I got an IDM from a known running truck. When I put the newer IDM in the codes went away and each buzz test passes. I accidentally left the passengers bank uvch unplugged and it still didn’t throw a code. It’s hard to pinpoint which injectors are buzzing during the test but I’ll try to describe what I hear.
All 8 buzz, then drivers side buzzes quietly twice, passengers side buzzes loudly once, then 4 quiet and 1 loud final buzz on the drivers side. Still no codes from the new IDM and FORScan says no errors found. Is there maybe a problem with the way FORScan runs the test on an OBS? I haven’t started the truck yet to see how it runs. I’m afraid to damage the newly installed IDM.
I’ve been struggling with this one for a while! Any info is greatly appreciated!
Thanks
-Nick
I’ve got a 97 7.3
I was having issues with low power/ lots of smoke/ rough idle. I got setup with FORScan and ran a buzz test and it came up with p1294 and p1271. Also the buzz test sounded weak on most injectors and didn’t seem to go in order.The UVCH was upgraded to the super duty style previously so I dove into looking for a possible crossed wire or short. Ive gone through diagrams and checked wiring from the idm connector to each harness. I followed the GB Injector Resistance And Wiring Test and everything looks okay. My resistances are 2.9 across the board. I found cracked insulation on some wires on both UVCH’s so I replaced them both. I got an IDM from a known running truck. When I put the newer IDM in the codes went away and each buzz test passes. I accidentally left the passengers bank uvch unplugged and it still didn’t throw a code. It’s hard to pinpoint which injectors are buzzing during the test but I’ll try to describe what I hear.
All 8 buzz, then drivers side buzzes quietly twice, passengers side buzzes loudly once, then 4 quiet and 1 loud final buzz on the drivers side. Still no codes from the new IDM and FORScan says no errors found. Is there maybe a problem with the way FORScan runs the test on an OBS? I haven’t started the truck yet to see how it runs. I’m afraid to damage the newly installed IDM.
I’ve been struggling with this one for a while! Any info is greatly appreciated!
Thanks
-Nick
Lead Driver
Joined: Apr 2016
Posts: 7,172
Likes: 1,332
From: Bahstun
P1294- high side open, chances are the UVC connector has come loose.
P1271-P1278 High to low side open cyl. # 1-8
Open circuit, open injector, failed IDM
this could help test it
https://www.ford-trucks.com/forums/1...load-test.html
P1271-P1278 High to low side open cyl. # 1-8
Open circuit, open injector, failed IDM
this could help test it
https://www.ford-trucks.com/forums/1...load-test.html
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