2004 5.9 surge at light throttle and stalling

[W Bench Farms]

My 2004 (8/2003 build, so has the 555 engine) started having some issues with cold starts, rough idle, surge under light throttle, and will stall when downshifting. Has the 6 speed manual. Little background on this truck. I purchased new in 2004. It is 100% stock except for the straight pipe and exhaust brake. Currently has 242k miles. Replaced the engine at around 237k miles. Had an injector go bad and melted down the rings in #5 and 6. Truck has good power and runs good. Started a couple months ago running rough on cold starts and rough idle. When shifting it has a dead spot when you get back in it. At steady throttle it has a slight surge. When you downshift to stop or turn it will sometimes stall. Seems to have some injector rattle when cold, and less at idle. Smooth sailing going down the road.
List of what has been done: New motor has about 3k miles, along with new injectors. Stock lift pump has about the same amount of miles. I did lose the ground in the harness to the pump, so ran direct to ground. Have replaced the FCA.
Just wondering the next step on what to look for. Seems to have started suddenly. Hoping it's a sensor, but not sure the next thing to look at.

 

[Darkbloodmon]

My 2004 (8/2003 build, so has the 555 engine) started having some issues with cold starts, rough idle, surge under light throttle, and will stall when downshifting. Has the 6 speed manual. Little background on this truck. I purchased new in 2004. It is 100% stock except for the straight pipe and exhaust brake. Currently has 242k miles. Replaced the engine at around 237k miles. Had an injector go bad and melted down the rings in #5 and 6. Truck has good power and runs good. Started a couple months ago running rough on cold starts and rough idle. When shifting it has a dead spot when you get back in it. At steady throttle it has a slight surge. When you downshift to stop or turn it will sometimes stall. Seems to have some injector rattle when cold, and less at idle. Smooth sailing going down the road.
List of what has been done: New motor has about 3k miles, along with new injectors. Stock lift pump has about the same amount of miles. I did lose the ground in the harness to the pump, so ran direct to ground. Have replaced the FCA.
Just wondering the next step on what to look for. Seems to have started suddenly. Hoping it's a sensor, but not sure the next thing to look at.

Welcome to the Forums.

Is the engine new with the corresponding pistons and injector nozzles?
What injectors?
OEM FCA?
Do you have any gauges or the ability to measure fuel delivery pressure and rail pressure while cold and at op temp?
Is the CP3 original from the previous engine?
Is the APP sensor original from the previous engine?

Sounds like a fuel issue, but more information is needed given the engine was replaced. If you have any relative time stamps for when something changed and then noticed a difference in running condition that would help.

 

[Ozymandias]

How old are the batterys?

 

[W Bench Farms]

Welcome to the Forums.

Is the engine new with the corresponding pistons and injector nozzles?
What injectors?
OEM FCA?
Do you have any gauges or the ability to measure fuel delivery pressure and rail pressure while cold and at op temp?
Is the CP3 original from the previous engine?
Is the APP sensor original from the previous engine?

Sounds like a fuel issue, but more information is needed given the engine was replaced. If you have any relative time stamps for when something changed and then noticed a difference in running condition that would help.

Engine was a reman long block. Injectors were reman stock and installed with the engine swap. FCA was a stock Bosch. Only gauges installed are boost and pyro, however I think they didn't hook up the thermocouple when they put the engine in. Batteries are new. Engine was changed June 2020, these symptoms started August 2021. Original CP3. Let me know if you need any other information.

 

[Killer223]

your injectors are the issue. get new BBi, or you're about to melt down another engine.

 

[Ozymandias]

Reman BBi are as good as new.
By the way they have now a BF sale, 100$ of for each injector.

 

[Darkbloodmon]

Engine was a reman long block. Injectors were reman stock and installed with the engine swap. FCA was a stock Bosch. Only gauges installed are boost and pyro, however I think they didn't hook up the thermocouple when they put the engine in. Batteries are new. Engine was changed June 2020, these symptoms started August 2021. Original CP3. Let me know if you need any other information.

I'm leaning towards injectors with @Killer223 if they are reman stocks. Who rebuilt them? I would also recommend a new rail pressure relief valve. If you want verification on the problem you're going to need a scan tool(dealer level/price point) to read values, flow rates, etc. Fortunately the injection system only has so many components that can fail so the parts cannons are relatively small in comparison to front end suspension/steering. The ugly side of it is the cost for those parts.

Before you put injectors in I would recommend getting your ECU flashed to the very latest DRB III updates, speaking from experience only on my 03 truck (mfg. 8/6/2002). I installed New BBI stage .1s with new tubes and a new OEM Bosch FCA and my ECU did not recognize the injectors or FCA until a reflash. I had all the idle hang symptoms of my old injectors on the new ones till the reflash with updates.

 

[MGreer]

Ordered new bbi's and tubes today. Their bf sale is good until the 5th of Dec.

 

[W Bench Farms]

Any recommendations on a shop near Youngstown, OH, or will I be OK with a local dealer?