Sequential Central Port to Multi Port Fuel Injection

[killian96ss]

GM upgrade kit part # pk12568332 for converting from CPI to MPI @ GMpartsdirect.com



The current price is $196.90

Steve

Edited title-HJ

[HenryJ]

That changes from the old SFI poppets to the MFI injectors.
Kind of old news- New design 96-up SFI injectors!

Upgrade kit for the Sequential Central Port Fuel Infection to the MFI system,

Typo, or Freudian slip"?

[killian96ss]

That changes from the old SFI poppets to the MFI injectors.
Kind of old news- New design 96-up SFI injectors!

Upgrade kit for the Sequential Central Port Fuel Infection to the MFI system,

Typo, or Freudian slip"?

It must be a typo unless this kit is somehow infectious.

I added the info to ZR2USA and copied it here, but I forgot we already had this info.

Steve

[Rockrz]

I've never had any injector problems, so should I wait until I do to upgrade my stock '96 truck with this upgrade?

Is there any performance gains, or if this done just because the quality is much better than stock?

[HenryJ]

This just eliminates the problematic poppets. If you don't have problems, don't fix it. There are no gains.
I have the same system as yours and do not plan to upgrade until I have problems, or desire new injectors. Maybe at 150-200k miles?

[Rockrz]

Maybe at 150-200k miles?

I just turned over 192,000 miles and haven't had any issues with the entire truck other than replacing normal wearing items.

Actually, I'm wanting to get a nice low mileage 2003 Ext Cab and maybe put a new engine in my '96 and give to someone as a gift since I'm not going to get much trying to sell it.

At that point (if I decide to do the engine) I'll make sure this upgrade is done. This is good info. I'll put this in my S10 knowledge base file

[HenryJ]

Like I said, maybe. Properly maintained the injectors will go a very long time and still provide good pattern.

[Rockrz]

I've been using Techron fuel system cleaner about every couple of months and I keep a good fuel filter on it and it's never given me any problems at all.

Plus, out where I'm at they don't have 10% ethanol in the gas. I've heard this stuff can be hard on seals within your fuel system if you have an older vehicle.

[jrichmonds10]

Bringing this from the dead. I am thinking about doing this to my 04 CC with 126,XXX miles. Reason being is I am having "hard starts" in the AM and after the truck sits while i'm at work. I've read on s10forum.com that this has been a fix for the same problem i'm having. I would just hate to change it and it not fix the hard starts. Other than this, the engine is sound. Would this be a valid reason to consider the upgrade? I plan to keep this truck for some time and want to keep it in good running order since it is my DD. Thanks in advance!

[ApproachMedium]

Do it, eventually the stock POS system leaks and causes problems. Mine was so bad it wiped out my cat. Even if it doesnt fix the problem, it will save you in the long run. Plus if you never changed your intake manifold gasket that will get done too when you change this. The intake manifold gasket is a common source of issues on these trucks. While you are at it do a good coolant flush loose the dex and get some prestone extended life. All in all its just peace of mind for future problems that could occur.

[jrichmonds10]

Do you recommend doing the lower intake gasket as well since ill be in there?

[ApproachMedium]

Might as well, the stuff is stupid cheap, and if you take it apart again for them lower gaskets you have to replace the upper gasket again anyways. With the mileage you have the lower is probably not a bad idea to change them as well.

Disclaimer: I have not done any of this work myself lol. My recommendations only come from what I have been told to do with my old motor and now with my v8 swap motor.

[jrichmonds10]

No worries. I appreciate the heads up. I don't want to tear it apart twice when I can do it at the same time.

[AVTekk]

Def do the lower intake while youre in there, if its real bad youll see coolant seeping around the back drivers corner. Once you pull the intake off youll almost always see gasket separation around the intake and coolant ports, its just a matter of time before it fails entirely.

[jrichmonds10]

Well I finally did the swap. I did notice the later models already had the MPFI installed, however, I went ahead and swapped it out. While I was in there, I did the lower gaskets, fuel filter, water pump, radiator, and hoses. I did notice the truck starts smoother and easier now. Hopefully this was the fix for the hard starts.

[crew cab sonoma]

Just FYI, all 2003-up 4.3's come factory equipped with the "upgrade"
poppetless injectors.
For 2003, the LU3 engine replaced the L35. The key change for the LU3
was the new style injectors.