I'm looking to buy a used MFI spider assembly for my 96 S10 blazer. It was pulled off a 2003 Silverado with a 4.3 vortec with 150,000 miles. To my knowledge GM switched to MFI after 2002. If that's correct this thing has 150,000 miles on it. My question is how long do these things last?

 

I've seen plenty of trucks with 300,000 miles on the originals that had never had any problems. I really wouldn't even consider it a wear part.

 

Ok, awesome! I really would rather buy a used one than an aftermarket. Should I replace the regulator? Or do those last 300,000 too?

 

The regulator should be fine, too, but it might be cheap insurance.

 

Ok, got you! The one that is on it doesn't have a vent tube. All the replacements do. Is there a reason for that??

 

Beats me, lol. Sorry I don't have more info for you.

 

Does the new MFI spider require the same regulator as the old spider? I can't find a regulator for a 2003 Silverado with a 4.3.?? Not even rockauto.

 

I've never replaced the regulator by itself. Maybe you can't on the newer ones?

 

if you have the spider in your possession a picture would be good help, the rear of the spider should have a brass or steel "bulb" for lack of a better term with a clip holding it in.

 

I don't have a picture, but I know what your talking about. I've taken apart the upper plenum almost a dozen times. I have three of the older spiders and I made one good one. Two had the older AC Delco adjustable regulator on it. I adjusted it until my fuel trims were as close to zero as possible. I'm having problems with it again. I'm just going to break down and by a MFI. All of this trying to save money is wasting my time. Time is money...