5.9l Misfiring

[dapepper9]

I have limited it down to the heads being cracked and the valves being caked in carbon. I did a running compression test about a week(ish) ago and can see that a couple cylinders have a bunch of overlap during the compression cycle, which I am thinking is why my cylinders have been having issues. So my plan is to swap heads, lifters, rockers, push rods, cam, and modify my TB.
I have run through all the wiring, swapped injectors 3 times, swapped Ignition coil, cap, rotor, pickup coil, ECU, plugs, and wires with no avail. So I've narrowed it down to just old age and needing to be refreshed/upgraded.

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I would not touch the cam if i were you. Unless you're looking for more power but cam changes are gonna cost an extra few hundred dollars in tuning and wideband 02 to properly tune it.

If you haven't taken it all apart yet, get some amsoil power foam or Mopar combustion chamber cleaner and use that. You may be surprised how much that does for you.

You can do mods if you're wanting to, I'm not saying don't do that lol. That would just make me a hypocrite lol. But, don't think that he's being cracked means they need changed. Maybe 10% of the factory heads in these trucks AREN'T cracked. It's just something they do and 99% of em don't see any kind of running difference from it.

You can go either way. If you want to mod it, go for it. If you just want it to run like it used to, try a chamber cleaning and go from there

 

[Nysm1]

I would not touch the cam if i were you. Unless you're looking for more power but cam changes are gonna cost an extra few hundred dollars in tuning and wideband 02 to properly tune it.

If you haven't taken it all apart yet, get some amsoil power foam or Mopar combustion chamber cleaner and use that. You may be surprised how much that does for you.

You can do mods if you're wanting to, I'm not saying don't do that lol. That would just make me a hypocrite lol. But, don't think that he's being cracked means they need changed. Maybe 10% of the factory heads in these trucks AREN'T cracked. It's just something they do and 99% of em don't see any kind of running difference from it.

You can go either way. If you want to mod it, go for it. If you just want it to run like it used to, try a chamber cleaning and go from there

Ive tried many different cleaners, but I wasnt looking to gain massive power. I'm looking for more useful power thats all. The heads are original, I now have a coolant problem where I'm losing a gallon a week with no drops, and I am tired of the issues. The truck is rust free and one of my favorite trucks of all time. So I am looking to just making it run better lol. The cam I was looking at is a better than stock replacement and I was planning on getting a SCT tuner also. I dont want a drag racer just a reliable driver lol.

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[Nysm1]

The axles have also been regeared, so thats helped a bunch.

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[dapepper9]

Yeah after i posted that i was like "wait, i think he said he tried that before" and sure enough on the first page i found it lol.

Yeah using coolant like that plus the misfire there's a good chance it's the heads.

 

[Nysm1]

I refuse to sell the truck lol, so I'm selling my YJ and using that money to rebuild the truck.

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[kyle watson]

You also can't be sending a pulse to every cylinder, physically impossible with the way the distributor works. What you can have is frequency transfer between wires that creates its own pulse and the fix for that is wire looms or tsb style routing. Thicker more insulated wires also does the trick

A COMPLETE AND TOTAL NEGATIVE NANCY!

 

[kyle watson]

I know what I have found and fixed.
g I hope people don't take his word for bibble babble
good luck you will need it here

 

[pacofortacos]

It could be carbon on the valves, but I think you will find it is the valve seats that are the issue and not the carbon when you pull it apart. Are you going to re-ring it also?

Nicest thing about the aluminum heads is how light they are but you can get a set of nicely done steel heads that will flow really nicely from Brian at IMM engines for about the same cost, if you do the supporting mods.

I put a set of EQ heads on my mostly stock (tune and 1.7 rollers) 5.9 dakota and it was a power loss, I should have stayed with the stock smaller port size head. But I tow a good bit and was only really interested in lower rpm torque.

 

[dapepper9]

The aluminum heads flow more than the EQs. You didn't lose power you reshaped the power band and aluminum will do the same.

Also, Brian at IMM is pretty against using bronze valve guides which are extremely important in valve reliability. You're better off buying them bare and having a local machine shop assemble and clearance them

 

[dapepper9]

Before it gets mentioned that the aluminum heads supposedly bump compression to 10.2:1 with a 58cc chamber, they almost never actually cc to 58. They're actually more commonly 63ish. Stock is 62.

EQs are available in 2 different service sizes, 1.92 intake 1.60/1.65/1.625 depending on who assembles em and 2.02 with the same exhaust valve choices.

 

[Nysm1]

Well, I wonder if anyone has a set of used EQ heads for sale. Then I could have the machine shop run through them. If I could save a couple dollars then might as well.

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[Nysm1]

It could be carbon on the valves, but I think you will find it is the valve seats that are the issue and not the carbon when you pull it apart. Are you going to re-ring it also?

Nicest thing about the aluminum heads is how light they are but you can get a set of nicely done steel heads that will flow really nicely from Brian at IMM engines for about the same cost, if you do the supporting mods.

I put a set of EQ heads on my mostly stock (tune and 1.7 rollers) 5.9 dakota and it was a power loss, I should have stayed with the stock smaller port size head. But I tow a good bit and was only really interested in lower rpm torque.

I'm debating on reringing it, but I think I am going to wait until I pull it apart before I decide. If I'm gonna rering it, then I might as well have the crank clearanced and the cylinders bore-matched

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[dapepper9]

Facebook groups are going to be your best source for some. Dakota rt classifieds and any of the magnum performance pages. That's where i got my heads, brand new rotating assembly, new main caps, cam. Everything lol

 

[Nysm1]

Facebook groups are going to be your best source for some. Dakota rt classifieds and any of the magnum performance pages. That's where i got my heads, brand new rotating assembly, new main caps, cam. Everything lol

Thats the downfall about not having a facebook then haha

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[pacofortacos]

Well if I moved the power band, then it moved completely out of the 0-4000 rpm range via the butt dyno. Truck power was down vs. stock heads across the board - steeper gears (only had 3.55's) may have helped but that wasn't my goal. Only changes were heads and timing chain.

I would have gone stock port head if I had to do it over again - sold the truck so I don't have to now and in fact sold the new stock port heads after I sold the truck as I have no use for them.

I could feel it just normal empty driving, but wasn't too bad. Loaded truck towing about 4500-5000# trailer, it was very noticeable. Truck trailer combo was probably 10500-11000 # or so.

There is one other possibility that may have hurt higher rpm power - mopar stainless valves (stock size) with stock replacement springs. I never took the time to install the beehive setup I have.
Which now that I think of it, I have to sell that stuff too as it won't work on a BB.

 

[pacofortacos]

I'm debating on reringing it, but I think I am going to wait until I pull it apart before I decide. If I'm gonna rering it, then I might as well have the crank clearanced and the cylinders bore-matched

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If it is sucking antifreeze into the cylinder the rings generally are not a fan of that

I know what you mean though, if going that far (re-ringing) why not just refresh the entire motor and be done with it.

I didn't either and a couple of years later #8 cyl. rings ended up just not sealing as well. Would be ok after running but cold I could test blow by on them. A lot of hard miles and running a lot of timing, never any pinging but they just wore with time.

 

[Nysm1]

Well if I moved the power band, then it moved completely out of the 0-4000 rpm range via the butt dyno. Truck power was down vs. stock heads across the board - steeper gears (only had 3.55's) may have helped but that wasn't my goal. Only changes were heads and timing chain.

I would have gone stock port head if I had to do it over again - sold the truck so I don't have to now and in fact sold the new stock port heads after I sold the truck as I have no use for them.

I could feel it just normal empty driving, but wasn't too bad. Loaded truck towing about 4500-5000# trailer, it was very noticeable. Truck trailer combo was probably 10500-11000 # or so.

There is one other possibility that may have hurt higher rpm power - mopar stainless valves (stock size) with stock replacement springs. I never took the time to install the beehive setup I have.
Which now that I think of it, I have to sell that stuff too as it won't work on a BB.

Oh you have some beehives? How much homie?

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[pacofortacos]

message me I can describe the setup.

 

[Dave2018]

What's your vaccuum gauge show at idle? Is it jumping around while it's missing?

 

[Nysm1]

What's your vaccuum gauge show at idle? Is it jumping around while it's missing?

I havent checked Vacuum, but today it cylinder 7 has died completely. Doesnt matter how fast I run or anything... it is 100% misfiring at all RPMs... 1 and 7 have been the worst about the misfire, but thats it.

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