Alright guys I am experiencing a miss at all RPMs. It is pretty noticeable near the engine with a knock, but is extremely noticeable at the exhaust. It is easy to feel that the exhaust is "puffing" per say. Now I just replaced the injectors with a new set of 125hp sacs, but the miss was prevalent before the injector swap. The swap did not make a difference. Everything sounds the exact same as before the swap. I have fuel squirting out of each connection at the cross over tubes while running.

MoparMan and I spoke on the phone earlier and have decided to take a systematic approach to resolving this issue.

Ruled out: 1. Injection pump: Always supplied good pressure, less that 10K miles and miss seems to only be in one cylinder. 2. Injectors: Swap made no difference.

Possibilities (Almost endless): Burnt/ broken valve, broken piston or piston rings, clogged cross over tube, valves way out of adjustment

 

I should receive the truck Friday from being painted and I can start diagnostics. 

The plan: 1: Pull valve cover and quickly check valve lash - just make sure somewhat close to spec. 2. Use an infrared heat gun on the exhaust manifold right were it come out of the head to try and narrow down which cylinder is missing. If that does work I will pull the cross over tube and replace it (I already have 1 new one that will ship out Monday). If that does not fix the issue I will do a compression test on that cylinder to determine if it is the bottom end or the head.

If the heat gun does not find a "cold" cylinder I will pull all injection lines and cross over tubes, then clean each tube and try to determine if there is debris in one of them. If I can not find debris in any of them I will replace them with the new one, one at a time. If that proves inconclusive I will perform a compression test on all 6 cylinders. 

If any of the cylinders are low on compression I will pull the head and determine what is wrong internally.

 

Any suggestions on the procedure or something else I can do to diagnose what is wrong with this thing??

Edited October 26, 201410 yr by TFaoro

I just did a bit of research & "THINK" that there is no adjustment to the delivery valves. CHECK YOURSELF !!!!! Maybe pulling them & inspect for FOD or a bad part?

Ed

ED and I spoke about this today. I "May" be able to get my pump warranted, but I'm not holding my breath. So I will not take anything apart on it. ED and I also spoke about the "2 stroke gum up" that MFWI decided to start lying about... Not sure if I will have those problems with Industrial Injection or not. ED thinks I should be okay, but I'm getting skeptical of everyone now. I'm at 1/4 of a tank so I might run it really low and fill it up without 2 stroke. This would be her first tank without any since this VP went on.....

Edited December 11, 201410 yr by TFaoro

BioDiesel if you can get it is better than anything for lubrication.

I haven't read the whole thread, but, did you change your fuel filter?

He's changed everything but the IP.

 

Ed

Have you checked the valves? See if you have one cylinder with a lot of play in the rocker arm. There is a possibility that you may have a bent push tube or possibly a lobe on the camshaft that may be going away.

Sorry for the late response.... I just got back from Jamaica. I have not checked the travel of each set of valves per say, but I have adjusted the valve lash a couple of times. I guess I could have a buddy turn the engine over slowly and I could measure how far down each set of valves travels. I could then rule out the cam, tappets, and push rods.

 

My injection pump is currently sitting at Industrial Injection, and hopefully I will know the health of the pump on Friday. 

Sorry for the late response.... I just got back from Jamaica. I have not checked the travel of each set of valves per say, but I have adjusted the valve lash a couple of times. I guess I could have a buddy turn the engine over slowly and I could measure how far down each set of valves travels. I could then rule out the cam, tappets, and push rods.

 

My injection pump is currently sitting at Industrial Injection, and hopefully I will know the health of the pump on Friday. 

 

I highly suggest you don't turn that engine at all till the injection pump is back in place.

I highly suggest you don't turn that engine at all till the injection pump is back in place.

AGREED!!! Although if you do all you would need to do is pull the timing cover and make sure all the timing marks are lined up..........

I highly suggest you don't turn that engine at all till the injection pump is back in place.

Thanks for the suggestion! I planned on waiting till I get the pump back, although I don't think the timing gear can slip a tooth while it is inside the timing cover.... I can't remember where I read that may have been on Blue Chip's instruction page.

Yes it can. There was a guy over on my site that had his jump while the pump was off. He had to pull the timing cover to line up all the timing marks to get it to run right again.

I stand corrected! Good info to know. I am calling Industrial Injection tomorrow to see what the heck is going on. I will report back when I have any news

when i rebuilt my engine i checked that very theory about the pump gear jumping, its very close to being able to but no matter how i couldnt get it to skip. i still stand strong on DONT TURN ANYTHING OVER until pump is back in place. im not saying it cant happen though.

Edited December 26, 201410 yr by CUMMINSDIESELPWR

when i rebuilt my engine i checked that very theory about the pump gear jumping, its very close to being able to but no matter how i couldnt get it to skip. i still stand strong on DONT TURN ANYTHING OVER until pump is back in place. im not saying it cant happen though.

That is the way it is suppoed to be done, I don't know how it was done, but the guy did it. I can say for certain it is able to jump a tooth. It is not a difficult fix, but a PITA if it happens.

yup real pita

Spoke with Industrial Injection this morning and the pump tested out perfect. Not sure where to go now?? 

I still  suspect air in the fuel

Could a cam lobe be worn? Just an idea...

Ed

Rancherman I will put a clear line on it when I get the pump back to see if there is air in the fuel. 

Ed - When I have the pump back I will have someone turn the engine over slowly and I will watch each rocker to see how far the valve is pushed down. 

 

Keep the ideas coming guys I really appreciate it

It really takes a dial indicator. I can send you one to do it right. We just need to hire our own driver between us.... LOL

 

 

Ed

Edited December 31, 201410 yr by Yankneck696

We need to hire some kid to ride a bike between us   I don't think a slight difference between valve movement would cause the engine to miss though. And if it was an intake it would definitely cause some smoking.