Fuel Spider -> Anything else to change while there?
 

'98 Sierra 5.7L
89,500 miles
I have no maintenance records before 80K miles

Technically not running rough.
"OK" throttle response.
Oil pressure sender jumpy.
No visible top-end leaks.

If budget was unlimited and I'm in the top end replacing the spider, what's worth doing at the same time?

So far from digging on posts over several hours, I've read:

• Fuel Spider / AC Delco 3029
• Gaskets / Fel-Pro Intake Manifold Gaskets SFLMS98000T
• Oil Sender / AC Delco 19244500
• Fuel filter / AC Delco 89058397 (or is there better option?)

Anything else worthwhile?

Note: I don't have any coolant leaks or gurgling sounds at the heater core.

Re: Fuel Spider -> Anything else to change while there?
 

I would not replace it until it gives you trouble. I have maintained many 5.7 votecs with well over 200 & original spiders. I personally own 2, one with 290 & one at 305 & both have original spiders.

Now, intake gaskets, that's another story!

Listen and learn my padawan...LOL
 

You have to remove the coil and the ICM from the intake at that time. You could decide to change the coil at that time. The ICM is mounted to the heat sink plate using white heat sink compound. After years, the heat sink compound dries up. It is the best time to remove the ICM, clean both it and the plate with alcohol and reapply fresh heat sink compound.

DO NOT CONFUSE DIELECTRIC GREASE WITH HEAT SINK COMPOUND.

You have everything correct except for the spider it self.

All those spiders regardless of who's name is on them, are made by Standard Motor Parts.
Shown here:
https://www.summitracing.com/parts/smp-fj504/overview/

Even if you found them for less on Amazon, I still wouldn't buy them there. Those are usually third party companies and you don't jack $HI+ about their return policy or warranty or anything else.

Stick with a company like Summit. They will always do you right.

The other important thing you already picked up on was the steel intake gaskets. They are the only cure for what ails these engines. Other then the damn distributor correct o cap. POS.

I was almost with the other guy in saying don't change it till it needs it but with one exception. If your engine has the original plastic intake gaskets, they will go first and at that point you could change the injector assembly.

However, if an injector goes bad and floods the cylinder with too much fuel and washes the cylinder walls and causes scratching. Ooops too late. But guess what, I've had one of these new assemblies go bad and dump fuel so there really is no real insurance.

It comes down to what gives you piece of mind.

I'll leave you with 3 points of thought. First you can do the injector change with out removing the bottom half of the intake from the heads. Thus not touching the intake gaskets at the heads.

Another is if you do remove the bottom half of the intake, when you replace it, torgue it in 3 steps. Kinda like a 1/3 a 1/3 and a 1/3. It doesn't have to be exactly a 1/3 each time but take a few steps to get there. If my old mind is correct, the torgue is something like 11 ft*lbs. You use the inside out progression of tightening as usual.

Last, you want torque to be as close to the center of the range of a torque wrench as possible. The closer you get to the ends of the torque range, the less accurate it is. So if you can switch out torque wrenches for something different, do it. For example 11 foot pounds is 132 in lbs. See where I'm going with this?

Re: Fuel Spider -> Anything else to change while there?
 

On the 4.3 SPFI engines with the similar spider injector system and plastic poppet valves they put the fuel pressure regulator inside the intake plenum. They are known to leak fuel when they go bad and it will cause fuel economy and tuning problems. I had to replace mine on my 95. Originally thought it was the spider injector assembly that was the problem but that turned out to be good. Replaced the regulator alone after seeing it was obviously leaking along with the in the plenum fuel hoses and it was running better than ever.

I don't know if the V-8 version has the same in the plenum fuel pressure regulator setup as the 4.3 SPFI engine but I thought it was worth mentioning as something to look for in case it does.

Re: Fuel Spider -> Anything else to change while there?
 

Mine did. If replacing the Spider FI module, I would do the FP regulator while it's apart.

Re: Fuel Spider -> Anything else to change while there?
 

The new injector(updated or poppet) will come with a new regulator already installed onto it.

Re: Fuel Spider -> Anything else to change while there?
 

I replaced two of these in the last few years. One on a 5.7 and one on a 4.3. I went with the updated model on both. I also changed the fuel filter.

Re: Fuel Spider -> Anything else to change while there?
 

True. Didn't even think about that. I replaced my FPR while sorting through the diagnosis process only to realize it was included w/the new Spider module assembly when I ultimately replaced it.

Re: Fuel Spider -> Anything else to change while there?
 

I did a "Delphi" spider upgrade that has 8 actual little injectors on my '97 5.7 (after my wife ran it hot from not looking at the gauge, and then NOT TELLING me after.. Pouring coolant from intake gasket sagging past the water port into lifter valley due to the overheating.

..Anyhow, It started within 3 rev's and ran VERY smooth right off. Great throttle response to.
Remember to check or replace the o2 sensors. If they go bad with this crappy gas it funnels bad EGR gasses back in the intake. (you'll notice lots of black soot/carbon deposits if you take the intake apart. I had to use a drill and die grinder to clear the EGR port!! but the o2 sensors looked 'clean'..?)
Then get on Youtube and search for the BIG-3 Wire grounding. It will all help with your ignition of the fuel even if you don't do the spider swap.
https://www.partsgeek.com/hz45xn3-ch...+Fuel+Injector
Hope it works.
E

Re: Fuel Spider -> Anything else to change while there?
 

The oxygen sensors don’t have anything to do with the egr valve. The egr valve is used to lower combustion temperatures, which reduces oxides of nitrogen. The egr valve will not affect the air fuel ratio. The oxygen sensors will not affect the egr valve. Every engine that isn’t carbureted or throttle body injected will have tons of carbon crud in the intake. It’s normal for carbon to stick to the inside of egr valves and tubes as well. I see cars all of the time that have the tube sealed shut with carbon. I contribute it more to fuel quality.