High RPM Stumble OBS 7.3L

[Irishcream]

I am at the end of my patience with this issue. My truck died on me a few weeks ago cooking the IDM. I had noticed a "dead spot" at around 2400-2600 rpm. It feels like a rev limiter or a top speed governor cutting out the fuel. The truck died and didn't start up again until I replaced the IDM. I also replace the CPS with a cheapy one but not sure if that even works. I ran an injector buzz test after getting the truck back up and running with the new IDM and all injectors tested fine. The ICP and IPS sensors checked out under cranking and running. I killed the PCM by attempting to install my TS 6 pos chip but I don't wanna talk about it. lol. The only code I had was for the exhaust back pressure sensor. I removed the tube, unplugged it which took about 4 hours. It was jam packed with soot. I replaced the sensor as well. I am running an electric fuel system that is reading 6o psi regulated return. I did an ohm test on all the injector wiring and that checked out too. I am sending my chip back to Tony to have him look it over before I reinstall it the correct way. I have the same issue whether the chip was in or not, no matter the setting I was in so I don't think that is the issue. the chip is out now and I still get the stumble. Before I forget it's a manual transmission.

 

[Andrew]

Sounds like injector armature clearance. Are the injectors reman or new how many miles ?

 

[Irishcream]

original injectors. Injector Armature clearance? that's anew one to me. Can you elaborate?340,000 kms

 

[Lethalthreat7.3]

You replaced the cps but don't know if it is good? I would spend the $25 and go buy another one. Get a BWD. They work great on most sd's, just check for the intermittent wiper issue problem(didn't have any issues on mine).
Had the same issue and could not figure it out. A buddy said to try it.
Worked

 

[Irishcream]

I bought the BWD one but still have the issue. that was the cheapy one. I'm gonna get the motocraft one this week. I have an OBS not the SD though. Intermittent wipers? Do I roll the windows down and blink my eyes 5 times too? not sure I follow you there.

 

[Arisley]

Moved to the OBS section.

 

[m j]

have you had the injectors out? orings ok?

mine has about the same mileage and the 5 of them were chewed from oil blowing in to the fuel side

 

[Irishcream]

it doesn't smoke at all so I would have to assume there is nothing wrong with the O-rings.

 

[Irishcream]

Is there something that senses atmospheric pressure? Today is was a little cooler and raining and the truck ran like a champ. No high RPM stumble or nothing. I kept trying to get it to buck but nothing doing. I've previously unplugged the MAP connector but that didn't get rid of the issue. Just think it odd that rain gets rid of an issue. usually it's the cause.

 

[old man dave]

There is a Barometric pressure sensor that works like the MAP and compensates for altitude. Its up under the dash.