5.7 vortec long crank

[slow_c1500]

The NutZ Set...
Went through 3 of them on my 4.3L...
Back then they were $350 a set...

(TBI is better/more simple... for this reason alone...)

The detergents and seasonal fuel additives cause crumbs of metal nano particles to form behind the screens in that octopus and inside the filters and injector circuits.

These small brown micro specs will cause a lot of problems, as they magically grow inside this poorly designed nightmare unit.
If the NutZ set is old, the plastic screens are cracked and the tubing will be brittle, so you cannot fix or dis-assemble it without making things worse.
Nothing can clean the system if those plastic injectors are corroded and full of the brown crumbs.

Plan on replacing the NutZ Set every 2-3 years, if your local fuel stations are all using fuel from the same contaminated source...
Most people have no idea the gas stations all use the same tanks at the source of truck deliveries.
The only difference is the small batch of proprietary cleaners which the depot dumps into the truck, before it leaves the Tank Yard for delivery to the fuel stations, based upon which station brand name is on the sign.

It is all basically the same gas no matter who you buy it from.

Where I live, the fuel travels over 100 miles over the mountains where the trucks change altitude of over 5000 ft.
When the trucks are 1/2 full, the altitude and air density causes condensation and water to form inside the tanker trucks, so we get water in our fuel systems all the time. Dry gas helps, but it does not fix all the sediments and corrosive problems which any water causes once it is inside the entire fuel delivery network. The Nutz Set is the final destination for all that contamination.

Buy a new NutZ set and fix every o-ring in the entire system or keep having pressure issues...
Do NOT buy a used NutZ SET. Please...

I would recommend you buy 2 and keep a working backup in case auto parts deliveries become screwed up again, if you intend to keep this engine in the configuration you have now.

If the injectors are semi-blocked, or leaking, the intermittent back pressure on the entire system is blowing out your worn or defective o-rings, wherever you have not already replaced them (in my experience...)

Then the leaks or blockages, are confusing your computer and possbly ruining your engine and burning your pistons, if the computer or lack of pressure causes a lean condition.

The age of your truck denotes the entire system MUST be inspected and brought up the spec.
This is good practice for you before you build your new engine, so try to stay positive.

GM Engineers designed a system... you cannot expect to peck away at one thing and fix everything, if you have no clue what else you might find by thorough investigation.
Your local repair shop is hoping you get frustrated and fix one stoopid thing at a time... 1) $$$$ 2)$$ 3)$$$ 4)$$$$

You should plan on pulling the valve covers and adjust your rocker arms.
All the rough idle, pinging and lean condition, could easily have mal-adjusted your valve train.

Take 2 hours and re-adjust your valves to factory specs, so you do not confuse rough idle or timing issues with this current fuel system dilemma.
You may experience what seems like timing issues, due to sloppy rockers and valves.
Check for loose lock nuts on the rocker arms and replace them if they were found on a loose rocker, before you bend a valve.

When one thing screws up, the vibrations can cause additional issues.

Don't worry. Take your time and document everything you touch, on paper, by the numbers.
Take photos of everything before you disassemble the plenum to expose the NutZ Set and rockers.

When you open the plenum to get to the injector/FPR set, you may as well adjust the valves, while your entire top end and vacuum system is all opened up!

Lots of pictures, label every wire, do not drop the bolts, use a magnet. Don't get distracted and do not work in the heat of the summer sun.

If you break one or two or three of the injector clips and it goes into your engine through the holes in the valley, you have to plan on dropping the oil to get the plastic out before in breaks up and clogs your oil pump and oil starves your main bearings.

Cover the holes into the engine with clean rags before you unplug any injector remove a single NutZ Set screw.
If you are missing a torx screw, you cannot install the new set or run the engine until you find it.


You got this!

This is probably a newbie question, but I have never heard of the NutZ set. What part is it?

 

[RanchWelder]

The picture the gentleman showed you with the injector octopus is called the Nutz Set by GM.
The damn thing will drive you Nutz because you have to rip the entire plenum top cover off to expose it.

It is not a joke, that's what GM calls it.

It's OK, we were all new at one time.


Your mission is to remove it and replace it without losing anything and adjusting your valves.

6-8 hour job, first timer, so long as you follow my recommendations and don't get distracted.
Find a youtube video or two and learn the process.
One for the injector set and one for adjusting your rockers.
Get your tools sorted and take your time. Don't break any connector clips, nudge them off gently or they will crack and break. You'll need to buy a few cans of brake cleaner or carb cleaner, whichever has the biggest cans on sale. It's the same stuff. You'll find some crud in the manifold you'll want to wash thoroughly. Buy a small plastic round carb cleaning tray locally and a bunch of shop paper towels, the blue ones on the roll, the box of rags, whatever.

In fact, before you pull the valve covers, buy a set of new Comp rocker arm nuts, when you order the part number on the ACDElco box from the huge picture. (It is on the label on the sticker for you. One of those numbers is your part number).
They are 5/8" socket or 15mm, I'm not certain which you have. You might have to grind a few mils off around your deep socket so the rocker does not get the socket stuck, during the adjustment process.

You rotate the push rod, tighten the nut with your socket until it get pressure, so you can't spin the push rod and then turn 1/2 turn extra. Simple. Do them in order then rotate the entire assembly a few times to pump up the lifters and do it all over again, to be certain. Anything loose, after the first go around, needs to be double checked the cam is not compressing anything and done again.

You have to make certain the cam lobe is not at a height which the valve is under compression.
Use a 1/2"socket driver and a long socket to turn the crank shaft bolt to turn the engine to rotate the valve train until it is not compressing the next valve and move on. But using a socket on the crank can wear you out fast, up and down...
brutal.

I use a starter thumb switch connected to the starter and bump the engine with the covers opened up and watch the rotation. It won't hut anything, so long as you do not get the wiring stuck in the fan or cause a short with poor connections to your starter solenoid nuts. You put one clip on the big red starter bolt and another on the tiny nut which actuates the solenoid. Watch a youtube video on this gadget too.

This unit works well. The quality of the thumb switch is critical on these. Buy a good one, or they get broken easily and the clips suck:
https://www.summitracing.com/parts/wmr-w80586

You must be registered for see images attach

$21.99

The OEM version is $62.00 at Sum.
They are not the same quality. Rock might have different ones.
AZ will have the OTC version, if you can afford it. It's the one i use.
Your local parts store will have the cheaper versions, so buy the fat wired one or get it online.

If you use this, there's no fussing with the crank shaft bolt, but be careful.
You should be able to clamp it on, standing on something tall, from the passenger's side fender well, reaching down into the starter switch studs. It sucks getting it just right, but if you are careful and want it bad enough, you'll get it.
Rubber gloves are cool, it gets hot in there. Disconnect the ground wire, before you stick your sweaty hand in there and then test it is correctly attached to the right studs. Carefully re-attach the ground ONLY after you are certain the clamps are on the right studs and ONLY the right studs, or you see sparks fly. The tiny stud is tricky but you will get it to stay if you are crafty. The big stud requires super human grip on the clamp. Same situation.

If the LED lights up, you are good to go. LED tells you you have power and can bump the engine over. Try not to lose connection more than 3 times, or it will get old quickly, reinstalling it safely by disconnecting everything over and over.
Safety first. Watch the fan. It will eat this thing and the wiring or take your hand off with a quickness.

After you have tested the rocker arms for proper function like the video taught you, replace the covers and snug the cover bolts. Do not over tighten them and crush the gasket, or it will leak oil. 5 ft pounds is not much.

You want the ACDelco injector set, if you can find it or afford it. It's from overseas too, but it will be OEM injectors and the plastic clips will be better quality polymer. You want the better quality polymer. Standard Automotive is good too. Delphi...

As a rule of thumb, I fish everything at RockAuto and search for the best deal of the day I'm buying.
It always changes, so search for the best rate and pull the trigger from a good company online or ask the counter guy to order the correct brand. If you want fast service, RockAuto has different shipping speeds.

If you buy local, you may not get the option of the Delco and you cannot return it if it's bent or beat up from the local store. They will not refund this item, once you open it and it gets dirty. If you buy it locally, make sure they will allow you to check for all the seals and gaskets and small parts. If it is opened or dirty, refuse it.

You want those gasket o-rings he showed you as well. It might be a separate part number.
Look up the parts at Chevrolet parts online and search for the diagram with everything you might need then write down all the OEM part numbers and the exact name of the items you need.

Go to RockAuto and look it all up using the cool parts fish and your vehicle's correct engine.
If they don't have it Summit will.
Rock sells on Amazon and so does Summit and Jegs, so shop for best price.

Gaskets, o-rings, comp rocker nuts, then source rags and a tray to clean, locally.

Double check you have all the proper tools to remove the fuel lines without stripping or breaking anything before you expose the intake to dust and wind or dirt. Cover it with a towel if you have to run for more tools or parts.
Do not allow rain or dirt to get into your engine. With that said, there will be lots of carbon under the plenum, so take your time and clean it all nice. Do not let the crumbs fall into your engine crankcase. Use your blue towels to plug the holes before you start to clean anything. Stainless assortment of the black handle wire brushes will come in handy to scrub the grime. Green dish pads work well too. Polish the thing like you own it.

Now take a few and re read every word I wrote to you in my last post, while looking at the nice picture of the injection system in Caman98's picture.

This thing is spread out like the Movie Alien Baby Monster Creature, inside your Vortec Manifold.
(Provided you have the Vortec intake manifold).

You got this, Be careful.

 

[slow_c1500]

So I’d have to replace the injectors and FPR every 2-3 years to keep it running reliably? At that point an LS swap would be more economical.

 

[slow_c1500]

The picture the gentleman showed you with the injector octopus is called the Nutz Set by GM.
The damn thing will drive you Nutz because you have to rip the entire plenum top cover off to expose it.

It is not a joke, that's what GM calls it.

It's OK, we were all new at one time.


Your mission is to remove it and replace it without losing anything and adjusting your valves.

6-8 hour job, first timer, so long as you follow my recommendations and don't get distracted.
Find a youtube video or two and learn the process.
One for the injector set and one for adjusting your rockers.
Get your tools sorted and take your time. Don't break any connector clips, nudge them off gently or they will crack and break. You'll need to buy a few cans of brake cleaner or carb cleaner, whichever has the biggest cans on sale. It's the same stuff. You'll find some crud in the manifold you'll want to wash thoroughly. Buy a small plastic round carb cleaning tray locally and a bunch of shop paper towels, the blue ones on the roll, the box of rags, whatever.

In fact, before you pull the valve covers, buy a set of new Comp rocker arm nuts, when you order the part number on the ACDElco box from the huge picture. (It is on the label on the sticker for you. One of those numbers is your part number).
They are 5/8" socket or 15mm, I'm not certain which you have. You might have to grind a few mils off around your deep socket so the rocker does not get the socket stuck, during the adjustment process.

You rotate the push rod, tighten the nut with your socket until it get pressure, so you can't spin the push rod and then turn 1/2 turn extra. Simple. Do them in order then rotate the entire assembly a few times to pump up the lifters and do it all over again, to be certain. Anything loose, after the first go around, needs to be double checked the cam is not compressing anything and done again.

You have to make certain the cam lobe is not at a height which the valve is under compression.
Use a 1/2"socket driver and a long socket to turn the crank shaft bolt to turn the engine to rotate the valve train until it is not compressing the next valve and move on. But using a socket on the crank can wear you out fast, up and down...
brutal.

I use a starter thumb switch connected to the starter and bump the engine with the covers opened up and watch the rotation. It won't hut anything, so long as you do not get the wiring stuck in the fan or cause a short with poor connections to your starter solenoid nuts. You put one clip on the big red starter bolt and another on the tiny nut which actuates the solenoid. Watch a youtube video on this gadget too.

This unit works well. The quality of the thumb switch is critical on these. Buy a good one, or they get broken easily and the clips suck:
https://www.summitracing.com/parts/wmr-w80586

You must be registered for see images attach

$21.99

The OEM version is $62.00 at Sum.
They are not the same quality. Rock might have different ones.
AZ will have the OTC version, if you can afford it. It's the one i use.
Your local parts store will have the cheaper versions, so buy the fat wired one or get it online.

If you use this, there's no fussing with the crank shaft bolt, but be careful.
You should be able to clamp it on, standing on something tall, from the passenger's side fender well, reaching down into the starter switch studs. It sucks getting it just right, but if you are careful and want it bad enough, you'll get it.
Rubber gloves are cool, it gets hot in there. Disconnect the ground wire, before you stick your sweaty hand in there and then test it is correctly attached to the right studs. Carefully re-attach the ground ONLY after you are certain the clamps are on the right studs and ONLY the right studs, or you see sparks fly. The tiny stud is tricky but you will get it to stay if you are crafty. The big stud requires super human grip on the clamp. Same situation.

If the LED lights up, you are good to go. LED tells you you have power and can bump the engine over. Try not to lose connection more than 3 times, or it will get old quickly, reinstalling it safely by disconnecting everything over and over.
Safety first. Watch the fan. It will eat this thing and the wiring or take your hand off with a quickness.

After you have tested the rocker arms for proper function like the video taught you, replace the covers and snug the cover bolts. Do not over tighten them and crush the gasket, or it will leak oil. 5 ft pounds is not much.

You want the ACDelco injector set, if you can find it or afford it. It's from overseas too, but it will be OEM injectors and the plastic clips will be better quality polymer. You want the better quality polymer. Standard Automotive is good too. Delphi...

As a rule of thumb, I fish everything at RockAuto and search for the best deal of the day I'm buying.
It always changes, so search for the best rate and pull the trigger from a good company online or ask the counter guy to order the correct brand. If you want fast service, RockAuto has different shipping speeds.

If you buy local, you may not get the option of the Delco and you cannot return it if it's bent or beat up from the local store. They will not refund this item, once you open it and it gets dirty. If you buy it locally, make sure they will allow you to check for all the seals and gaskets and small parts. If it is opened or dirty, refuse it.

You want those gasket o-rings he showed you as well. It might be a separate part number.
Look up the parts at Chevrolet parts online and search for the diagram with everything you might need then write down all the OEM part numbers and the exact name of the items you need.

Go to RockAuto and look it all up using the cool parts fish and your vehicle's correct engine.
If they don't have it Summit will.
Rock sells on Amazon and so does Summit and Jegs, so shop for best price.

Gaskets, o-rings, comp rocker nuts, then source rags and a tray to clean, locally.

Double check you have all the proper tools to remove the fuel lines without stripping or breaking anything before you expose the intake to dust and wind or dirt. Cover it with a towel if you have to run for more tools or parts.
Do not allow rain or dirt to get into your engine. With that said, there will be lots of carbon under the plenum, so take your time and clean it all nice. Do not let the crumbs fall into your engine crankcase. Use your blue towels to plug the holes before you start to clean anything. Stainless assortment of the black handle wire brushes will come in handy to scrub the grime. Green dish pads work well too. Polish the thing like you own it.

Now take a few and re read every word I wrote to you in my last post, while looking at the nice picture of the injection system in Caman98's picture.

This thing is spread out like the Movie Alien Baby Monster Creature, inside your Vortec Manifold.
(Provided you have the Vortec intake manifold).

You got this, Be careful.

I have already cleaned the intake and replaced the spider with an MPFI one from GP Sorensen which is equivalent to the Standard brand. The injectors I think are fine, it’s just the regulator that I believe is leaking. I am going to pull the plenum today and inspect.

Not sure if I’d need to adjust the valves, There arent any other drivability problems or lean conditions, only a loss of fuel pressure and a hard start when sitting for more than 15 minutes, but less than overnight.

 

[slow_c1500]

Ok y’all I have opened the plenum up and have some good things to report. It seems the regulator is not leaking, but rather the fuel line o rings that are behind the engine. This makes a little more sense, as the regulator is brand new. And also the o rings are way cheaper to replace .

Another small victory: I was able to get out the remains of one of the snapped upper intake bolts.

Does anyone have a link for a good set of fuel line o rings? Or are the ac Delco ones fine?

 

[Caman96]

Another small victory: I was able to get out the remains of one of the snapped upper intake bolts.

So it recently was running while missing one of the plenum bolts?

 

[slow_c1500]

So it recently was running while missing one of the plenum bolts?

Yea it’s been like that for a while.

 

[Caman96]

Leaking plenum can cause misfires. Definitely good if it can seal correctly.

 

[slow_c1500]

Ok, i didn’t think a missing or snapped bolt could cause a vacuum leak, since it still seems to seal fine. But I’ll get that fixed for sure.

 

[slow_c1500]

Does anyone know how many sets of o rings I need for the whole system, and where each goes?