Need some help

[Jonathan734]

Ok guys I just put two new injectors in my truck (3,8) and now it is starting to do the same thing. It starts fine and idles fine, but once you take off it acts like it is running on 7 cylinders. I have actually felt it kick to all 8 and the truck runs fine. It runs fine once warmed up completely, it just does this when it is cold. I used a superchip to pull PO237 PO743 PO603. I just put a nvk4 pcm in and it changed nothing. I installed my DI regulated return about 1 month ago and have been stock every since then, so I am rulling out a chip bringing up the PO603. Need some help this is pissing me off.

[Jonathan734]

Cmon somebody has to have an idea of why I am getting the PO603. Last night my truck ran real rough, like its on 7 cylinders, so I floored it and it cleared right up and ran perfect the rest of the way home. Would an ICP sensor have anything to do with it?

[Deputydog]

Originally Posted by Jonathan734

Cmon somebody has to have an idea of why I am getting the PO603. Last night my truck ran real rough, like its on 7 cylinders, so I floored it and it cleared right up and ran perfect the rest of the way home. Would an ICP sensor have anything to do with it?

Code P0603 is a KAM error and is caused by a loss of power to your PCM generally from disconnecting the batteries or removing the PCM.. It is nothing to be concerned about and is a common code for trucks with a chip..

As far as running on 7 cylinders, have you done a injector buzz test and a cylinder contribution test? This will check your injectors and indentify any faulty ones. I had a similar issue and it turned out to be a chunck of the old o-ring from an injector fell into the cylinder bore and was over looked and was keeping the new injector from seating properly.

[Jonathan734]

I haven't had the buzz test run since I put the two new injectors in. But it doesn't always do this. I would think if it had something stuck in the bore that it would always act weird. After it warms it up runs fine.

[bigcountrysg]

Maybe injector o-rings on the other injectors. When the engine warms up. The O-rings swell up and then all your injectors fire correctly.

Or you have more injectors that are bad. Or you have a bad connection with the UVC. Or the UVC has a short in it.

[Deputydog]

Yep, might take a look at the UVC harness.. Can you pull the stored codes?

[powerjunky]

Just to ask a dumb question and state what you have probably all ready done. But what about your glow plugs?

[Jonathan734]

Well when I changed injectors 2 and 8 I also put in new UVC harness's and glowplugs. I guess the other injectors could be acting up, but I hope not. I mean it is almost like a light switch, it can be running rough and then all the sudden fine. I guess that could be the point that the o rings finally seal. Wish I had the money to do it up with stage 2's but I currently don't .

[Deputydog]

Originally Posted by Jonathan734

Well when I changed injectors 2 and 8 I also put in new UVC harness's and glowplugs. I guess the other injectors could be acting up, but I hope not. I mean it is almost like a light switch, it can be running rough and then all the sudden fine. I guess that could be the point that the o rings finally seal. Wish I had the money to do it up with stage 2's but I currently don't .

I rebuilt my injectors and changed them to stage 2 single shots.. Its under $1000

[Diesel Monkey]

Take a look at the engine harness where it connects to the valve cover connectors. The metal in the connector gets vibrated and thins out. It is actually a metal loop. Take a fish hook or needle and spread the metal, making it larger so it will connect with the valve cover connectors with more pressure. I had three injectors that came online when I did this.