i just have a quick question about the "upgraded" fuel injectors available at pretty much any parts dealer. Has anyone purchased these? if so what was the reason for replacement and was there any improvement in fuel economy?

I recently replaced my lower intake gasket and i pulled the stock injectors and soaked them in techron to try and clean them since they were beyond dirty. couldn't tell if they were leaky though.

Thanks in advance
-Mike

 

Upgraded injectors refer to running design changes by any given manufacturer-are they better? Perhaps,but if you need new injectors:don't scrimp! Buy Bosch and be done with it! Some GM products used Bosch injectors as OE as did most other engine manufacturers worldwide:gas or diesel! Once you install the new ones, use quality fuel and add Marvel oil to keep them clean! Every Tank! You'll never have another injector issue!

 

Stick with Delphi or AC Delco ONLY for your fuel and tune up components, on these engines. You'll pay less for other aftermarket parts, but chances are you're gonna be tearing things apart to replace them again at some point if you go cheap.

Normally, on any other engine, there is never a reason to change fuel injectors unless they are damaged or get clogged. The only other example (besides the 4.3 series of engines) is the Jeep 4.0. It was a VERY common upgrade to throw Dodge Neon injectors in place of the stock Jeep injectors. The reason being the Neon injectors had fuel spraying from 4 holes and the stock Jeepers had 1. It was an easy upgrade for 1MPG and a kick in acceleration. (Better fuel atomization). This was a PERFORMANCE upgrade, though, not one needed to fix a problem.

Anyway, on the topic of the 4.3. The stock injector system uses poppet nozzles which are guaranteed to go bad at some point on these engines. They will eventually leak fuel into the intake and you'll experience hard starts, acceleration issues, and other issues related to fuel delivery. I would guess that probably at least 90% of the people on here have the upgraded injectors, the other 10% needing them, lol. This is an upgrade to fix an engineering defect, not necessarily one done for performance. My Jimmy has just shy of 200k on the clock and just now needs the new injectors. Just like the lower intake gasket, they are almost guaranteed to go bad/leak at some point.

 

thanks for the reply guys. I would never stray away from AC Delco with this motor i was just curious what the hype was about the supposedly upgraded ones.

now to follow bill with a question. If the stock parts have an engineering defect and are AC delco parts, if i buy new injectors from the dealer or AC delco would they have the same defect? or is this something that has been fixed?

 

Nobody, as far as I know, sells the old style injectors. Here's an image so you can compare:


Edit: V8 version shown, V6 looks the same minus two injectors.

The top set of injectors is the stock "CPI" style injectors. The bottom set is the upgraded/fixed "MPFI" style injectors. They are plug and play and require no special wiring or anything. For the OBD II 4.3, the part number should be FJ10565. Get them off of Amazon to save yourself some money. It comes with the fuel pressure regulator and mounting bracket. If you use the "Does This Fit My Vehicle" thing, it might say it doesn't...but it is the right part.