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

On a stone cold engine, fire it up, just idle it for 30 seconds.. then shut it down. You'll be able to just use your

finger (lick it first) OK>> dip it in some water<< and go down the line and find the dead cylinder pretty cheap too.

your good cylinders should just make it sizzle, and the cold dead one will just slowly evaporate.. 'warm', but not hot.

After a minute, the test gets fuzzy, cause the cold cylinder will gain enough heat from it's buddies

Dang, Yesterday I got a 354 perkins that suddenly started a dead miss!!! Upon shut down, It goes 'whoof, whoof whoof...out the straight pipe. My prognosis; dropped valve seat. Always something in the toilet here @ Ranch.

For Perky info, go to www.4btswaps.com under the Detroit section. Great guys there that know them well.

 

Ed

Well paint and clear coat are on... Hopefully I'll be able to work on it this weekend!

Oh MAN... fresh paint, and leaning over the fender to work on the engine!!! Wish you all the luck in the world!!!

Well paint and clear coat are on... Hopefully I'll be able to work on it this weekend!

20141029_074013.jpg

From the picture it looks like a nice clean spray..and straight 

Paint guy says he has to buff it this weekend.... Looks like it will be another week before I can get anything done!     

Well while I am waiting to get this thing back I decided to start designing my summer project (Hopefully). I plan to add mounts for shackles and possibly a bull bar... What are your thoughts?

I like it!

... what program did you use for the drawing?... oh hell, just send me (or sell) the plans! I'd probably change the name tho... and use my cattle brand.

I used SolidWorks for the design. I looked on the internet for hours and couldn't find something I liked so I combined multiple designs into one. I will never use a winch, and almost all of them come with winches, and they are HUGE. I want something tough but looks sleek and doesn't weigh down the front end. I really like the look with a bull bar on there, but I am constantly doing engine mods so it could become a PITA to work around! Once I have my truck back and can make all of the measurements necessary I will finalize the design. If I do happen to build one and have a good design that people like I may consider selling the design. As for sticking in a brand that is probably the easiest part of the whole design! 

that is a nice bumper! you adding a winch to it?

I used SolidWorks for the design. I looked on the internet for hours and couldn't find something I liked so I combined multiple designs into one. I will never use a winch, and almost all of them come with winches, and they are HUGE. I want something tough but looks sleek and doesn't weigh down the front end. I really like the look with a bull bar on there, but I am constantly doing engine mods so it could become a PITA to work around! Once I have my truck back and can make all of the measurements necessary I will finalize the design. If I do happen to build one and have a good design that people like I may consider selling the design. As for sticking in a brand that is probably the easiest part of the whole design! 

Not real sure how this works: These 'plans' will have inputs for ComputerAidedMachining?? Local shop has a plasma table.. I'd buy your design... and all the little parts would be accurately cut on their table? Or is it something more simple... scan the plans in, and 'scale it up' to proper size? Their computer would do the rest?

Dad used to have a shop with a simple 9 head pattern torch, which had a simple auto-trace feature.. As a kid, I'd sit there for hours watching that thing!

Keep this project visible in the forum!

that is a nice bumper! you adding a winch to it?

Nope... I don't like how the winch bumpers stick way out there. I'm sure I could easily modify it to fit one though

 

Not real sure how this works: These 'plans' will have inputs for ComputerAidedMachining?? Local shop has a plasma table.. I'd buy your design... and all the little parts would be accurately cut on their table? Or is it something more simple... scan the plans in, and 'scale it up' to proper size? Their computer would do the rest?

Dad used to have a shop with a simple 9 head pattern torch, which had a simple auto-trace feature.. As a kid, I'd sit there for hours watching that thing!

Keep this project visible in the forum!

From what I have seen most shops don't have SolidWorks, so I would have to give a drawing of all of the parts then it could be drawn into whatever program they have. It shouldn't take too long as half of the parts are just flipped duplicates.  I have not finished designing the mounts or the bracing yet.. I just have the front look done. It is made of 26 pieces of 3/16 steel. 

Edited November 2, 201410 yr by TFaoro

Only thing about the receiver... that's gonna be a real knee capper! Nice addition, but is there a way you could have it telescope flush when not in use? or you could have the front face flush with the bumper, and would then have to go behind to pull the pin to remove the hitch...

The other 2 ears... those for tow bar?

Edited November 4, 201410 yr by rancherman

I'm not sure I like the receiver.. Honestly I will not put one in my bumper when I build it, it was just a suggestion from some other guys. The two ears are for shackle mounts! Since we don't have factory tow hooks I figured I'd throw some in

Having a front receiver is very useful. It makes moving trailers a breeze, allows mounting a removable winch & allows for flat towing.

Ed

Hmm... maybe I could recess a section of plate into the big plate that way the receiver would be almost flush

The only problem would be getting at it to put a pin in it. You will have to reach up underneath the bumper to do it with the tube recessed. Might be kind of a pain if the truck is muddy or whatever.

Give me till Monday and I will show you what I mean. The pin will still be on the outside 

Latest news on this: I just got back up to college. I went as planned and used an infrared temp gun. I found number 1 was 40-50 deg cooler than the rest. Number 6  was 10-20 degrees cooler than the rest as well. I decided to replace both of those crossover tubes to see if that would fix my issue. It definitely helped some, as the miss only sounds half as harsh as it did before and the exhaust has a less harsh miss feel to it. I didn't not have time to pull the valve cover and loosen the injectors before installing the new tubes.... So I'm hoping that is my issue. I forgot my temp gun at home so I won't be able to use that when diagnosing for the next couple days. Any thoughts guys?