1997 f350 passenger bank misfire

[Philip1]

My dad has a 1997 f350 powerstroke and the passenger bank does not seem to be contributing much if anything. I ohmed out the uvch and injectors along with the harness to the idm. From the idm plug through each injector back to the idm plug all read between 3.3-3.5ohms so the harness side appears to be good. While I had the valve covers off I checked the oil flow out of each injector and found the driver bank has strong oil flow out of all 4 injectors while the front 1 and 3 on the passenger side has weak oil flow and 5 and 7 have no oil flow. When I pull the plugs on the uvch (I have the 2 plug per harness version) the 2-4 and 6-8 plugs almost make the engine die while the 1-3 and 5-7 plugs have no noticeable difference when unplugged. The idm is also new on the truck. Any ideas of where next to look?

 

[lotzagoodstuff]

Any idea if the UVCH are original or aftermarket? There's a lot of questionable two plug aftermarket UVCHs out there. If they have been replaced already with some aftermarket UVHCs, I'd look hard at all the connections and move them around when you are measuring the impedance.

I'm sure you've looked at the connections already, and I think you are chasing the right thing looking at the harness from the IDM all the way to the injectors, but the old style twin connector UVHCs are pretty crummy when you look at them next to the newer style. There's a reason they did away with the old twin plug version, and the newer PSD guys see far less issues with the connectors and /UVHCs.

Lastly: did you buzz test the injectors yet?

 

[Philip1]

The passenger side is an aftermarket uvch which is what lead me to believe that was the issue but I would think if it was an issue it would have ohmed out bad. I haven't done a buzz test yet but I'll do that later today.

 

[greenskeeper]

unplug injectors one at at right at the injector. no change in idle indicates the injector isn't working. change in idle means you've disconnected an injector that is firing.

Any codes?

as mentioned, try buzz testing the injectors to check the electrical side. if not the uvch it could be worn armature clearance which can be corrected with a shim kit.

 

[Philip1]

I did the buzz test and a

P1293 Injector High Side Open Circuit - Bank 1

code showed up
Edit: I checked again with a known good uvch (driver side) and I still get the same code so I do not believe the issue is with that.

 

[Philip1]

While working on the truck, I found it has AB injectors in it instead of AA injectors. It is a 1997 non california model so am I wrong in thinking it should be AA instead of AB?

 

[Philip1]

Update: decided to replace all 8 injectors with reman AB injectors. It now runs better than it ever had.