Supercharger question

I have a 96, it has a 2nd Gen supercharger, it's acting funny, I think it needs a rebuild but I want to make sure I have everything right so it boosts proper, I have a 7th injector kit and a ecu from a later year, is there anything else I should be doing?

 

I don't know. You're not giving much detail into the situation.

 

Well when I lay into the gas I hear rattling and I don't have the boost that I should have, hence the thinking about a rebuild, but I want to make sure I have that mods needed to get the boost considering the supercharger is for 97 and newer

 

How much boost are you seeing? Not sure what you mean about having the mods needed. Does the rattling sound like it's coming from the rear of the s/c?

 

I can't really tell if the noise is in the front or back but, deff sounds like it's coming fromantic the sc, and I know you need a ecu from a later years and I was reading somthing about needing a different fuel pump also I'm just curios if there's anything I'm missing, and the noise iso pretty bad sounding

 

Oh well can't help you there on using a later year ecu. Regarding the noise, worn mechanicals wouldn't have much to do with electrical components. However, if you're stating something to do w/ the fuel pump that leads me to believe that you're running lean. Also known as knock, predetonation, whatever you want to call it typically sounds like marbles in a can.

Do you have any way to monitor afr or fuel trims? Any gauges?

 

I have one gauge but it doesn't match up to the vacuum pressure when it's hooked up to a diagnostic, I believe it is broken, there is a list of things to fix, I kinda got ripped off since I was new to this world when I bout this truck to build on... but it does sound like marbles in a can kinda

 

I figured you bought the truck since you don't sound all that familiar with it. I would get some kind of gauge that reads if you're running lean. If that is the issue I would get it remedied ASAP before you cause damage to the engine.

 

You're gauge could just be wrong or the diagnostic tool could be wrong. Cheap versions of either will give inaccurate readings. As for mechanical noises, take the belt off and try to spin the pulley. Your nosecone could need a rebuild or the needle bearings in the back of the blower housing could be on their way out. These are old units, bearings only have so much life to them. Are you noticing a drop in boost pressure or does it not feel as fast as you think it should?

 

My gauge is bad, my mechanics computer is reliable and he said vacuumed is good, I don't know about afr yet though, I will check, thank you for the hand spinning advice I never thought of that, and I have owned 2 other 3.4 4 runners and they along with my finances 3.4 felt a little faster, and It just seems to have a lack of boost, when you lay on the gas it starts to boost then kinda stops boosting and gives a rattling noise in place of boost

 

I had rattling in mine when I first bought the truck that had the SC on it. I replaced the nose cone oil which was really black and on the low side. After adding the proper amount, the rattle was pretty much gone. I'd do all the basic maintenance first, then decide.

 

Do you have to remove sc to change oil? I'm about to hit search on sc maintenance now

 

no on the second gen you can just get a syringe with surgical tubing and suck out the old oil (smells really bad, you have been warned!).

 

One option

http://www.ebay.com/itm/Two-GM-Supe...ash=item19ed78faa6:g:29sAAOSwIzNXO1Hs&vxp=mtr

 

If the bearings were rattling you would need to replace them not just change the oil. Typically it's the needle bearings. But it's going to depend on where the noise is coming from, as they are in the back of the housing.

 

@Blackdawg This sounds very similar to what you experienced with the SC on Frank.

 

Sounds like you just need a rebuild. If the problem persists. You have a fuel problem

 

Yeah hopefully it's not a fuel issue.

 

It sounds like your pinging, if the sound isn't there at idle or just revving with no load. If it where the nose cone bearings you would be hearing it all the time.

If your only hearing it while at max boost or boosting at low rpm then its pinging. You need to do some searching because there is a lot of info about this subject. But off the bat you need to figure out what spark plugs are in the truck, if your running 91+ octane, is the fuel pressure regulator hooked up to the boost port (search free fpr mod) and get a sense for the general health of the fuel system (fuel filter/pump), is the 7th injector in fact working, look at its fueling map.

Edit: Further more if there is not a wideband AFR gauge in the truck then it most definitely is not tuned correctly.