contribution test inside need thoughts

I have a code P0263 cylinder 1 injector circuit contribution failure/balance failure. i took all 8 injectors out while studding got everything back together and seem to have something bad. ICP and duty is good. truck smooths out on rev just rough idle and stumble from the start.

but these tests is throwing me off.

any insight or advice.








i turned engine off and back on for each of these tests and they are all at standard operation temps

Did you do a buzz test? If so what was the results from it. How long has it ran after you put it back together?

78f100 said:

Did you do a buzz test? If so what was the results from it. How long has it ran after you put it back together?

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Buzz test was done hot and cold each start up. All passed. I have ran it for about 30 min in the drive way idling and I took it out on the highway a couple miles. Everything up top seems ok. It's just down low an idle it stumbles off of. Thanks for the reply

Started it up with Balance test running runs perfectly smooth til it starts to get warm and back to Dame results. I did have a number 6 contribution failure now and a lot of white smoke coming out of the exshuast. I unplugged both 1 and 6 and no change in engine running so I would think they are bad.

Alright seems that the truck is good now ran it for a little longer maybe air in oil. But I am getting massive amounts of white smoke from exshuast for about 10 min. Gonna see if coolant level is dropping but it smells like raw diesle . This is all happening with powerbalabce showing steady. Wierd. Makes me thing head gaskets...

If your coolant smells like raw diesel, I would be thinking that you have a cracked injector sleeve or head.

lenzhotrod said:

If your coolant smells like raw diesel, I would be thinking that you have a cracked injector sleeve or head.

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Sorry on my phone and some of my paragraph erased before I submitted. The white smoke coming out of exshuast smells.like pure diesle fuel. I'm thinking a bad injector it smokes like a train for a while then warms up and.goes away slowly.

Powerbalance is tricky sometimes on a injector that's over fueling. You may see a up spike in the graph if it's over fueling on a cylinder.

78f100 said:

Powerbalance is tricky sometimes on a injector that's over fueling. You may see a up spike in the graph if it's over fueling on a cylinder.

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Sorry here's the scoop. I turned each injector off one by one. Diagnosed engine rpm and actions. As I'm wrighting this I should have commanded injector pressure steady:fustrate:

1. Small diffrence. Diagnosed weak
2. Good
3. Engine almost dies. Possible over fuel or compensation
4 good
5 good
6. Dead no change
7 Engine almost dies. Possible over fuel or compensation
8 dead no change

Def tricky to diagnose when there most likely more then 1 bad as they counter act.

Double checked ficm no chafing and voltage never drops below 48 even cranking according to raw data from a/e

Coolant level did not change from over night and no pressure out of degas I'm ruling out gaskets at this point.

I'll be jumping in agian taking a look see at cups, injector seals, copper washers, and disembling injectors to look for stiction and contamination

78f100 said:

Powerbalance is tricky sometimes on a injector that's over fueling. You may see a up spike in the graph if it's over fueling on a cylinder.

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BTW 7.40 @ 82 is hauling ass. Nice numbers what was your 60 ft

As of right now took all injectors out took them apart noticed a little water in 2 injectors on fuel side. I noticed separation on top of metering of the oil and water. I ultrasonic cleaned everything and resembled each one in clean diesle fuel. Now installing each injector I have a remote for stater and I bump it over to make sure no hydrolocking is present on each inHector install. Everything went well and spins nice and free. But when I cranked the engine over full time after all installed I hear a slight stumble in the crank rotation which leads me to think a compression problem on a cyl. Can anyone confirm what a good cranking 6.0 engune sounds like. May have weak batterys that could ciase a sort of lope while cranking. Almost like it gets to a certain point goes slow then back to normal. I also checked all copper washers when takeing all out they looked good no leaks. I am waiting on blue spring upgrade and 6.4 banjo bolts to come in then I'll check fuel pressure and fire it up. I did take a look at all valve movement while cranking but all vales and push rods seem to move equally to the eye and no interference with pushrod guides.

ghostriderblk said:

BTW 7.40 @ 82 is hauling ass. Nice numbers what was your 60 ft

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I can't remember 60ft I have the slip somewhere. I broke the trans on that pass. That was the first time I ever sprayed the full nx kit. It was my best et but slowest trap speed that I can remember. If the trans would have held it would have been a low 7 or maybe even a really high 6.

As far as your truck sounding odd starting, if it has any left over fuel, or oil in a cylinder from a bad injector it can cause that. It's trying to compress it and fire. Might not be a bad idea to compression test it while it's apart though.

78f100 said:

I can't remember 60ft I have the slip somewhere. I broke the trans on that pass. That was the first time I ever sprayed the full nx kit. It was my best et but slowest trap speed that I can remember. If the trans would have held it would have been a low 7 or maybe even a really high 6.

As far as your truck sounding odd starting, if it has any left over fuel, or oil in a cylinder from a bad injector it can cause that. It's trying to compress it and fire. Might not be a bad idea to compression test it while it's apart though.

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Damn that is pretty fast. Impressive. To bad for trans seems to always be an issue with big power.all years

I am gonna fire it up 1 more time it all back together minus fuel regulator and banjos. I cleaned the lines and bowl out in case moisture or anything was caught in there. I'm just hoping it's just maybe weakend battery's when turning over. Seems to crank better after leaving it on charge for a while. I wonder what would ca use lower compression just doing studs and egr ******.. truck ran decent besides stiction. anyways contrabution on each cylinder will help me pin point bad cylinder as well hopefully

Fired it up valve covers off had it running for about 6 minute. Ran smooth and cranked smooth with charged batteries. I think that eliminates compression issue. Fuel pressure is at 70psi just clouds of white smoke on startup which could just be oil gonna button it up for the road and do some data logging. Hopefully everything is in order now. Initially I think my injectors got contamination some how.

Well back to crap agian. It ra good for about 10 min I put it in drive and as soon I did sure enough truck barley moved pedal to the floor. Did contrabution test and 8 and 6 are dead agian and 4 comes and goes sometimes it fails sometimes it doesnt. 1 you can hear the change but I'm wondering if it's messed up from number 8 being dead. I'm gonna buy some 190/stock injectors from warren diesle. Hopefully this will fix the problem. May still do a compressi9n test to make sure.