Hello Everyone,
I have started to replace my 4.3L Vortec engine for my 1998 ZR2 (Vin “W”). I purchased a remanufactured (I’ll call it new since it is new to me (plus it takes less letters)) engine and have pulled my old engine. Tonight I began pulling off parts to put on the new engine. I’d really appreciate your input as I go along, and as time allows me to work on it. As you can see from the markings on the old engine in the pics below, the PO appears to have put in a non-original engine. As I have been working on this truck there has been several things that were done pretty shoddy and I have concerns and questions about a few things. So as not to draw this first posting out, I’ll start with just my first concern. By the way, I want to get the truck “back to basics” as they say (stock configuration) for a couple of reasons. First because this is for my wife as a daily driver and second because if I do want to do any type of mods or improvements in the future I’d rather start with a clean slate.



In the pic where I have the exhaust manifolds you will notice that these are the manifolds for an A.I.R. pump. I’m not sure if the manifolds are original to the truck or not. As you can see they have been capped off. Does anyone know if the ’98 Zr2’s came with the pump? I either want to mount a pump on the new engine or replace the manifolds with ones not designed for the A.I.R. pump. I am looking to put everything back to original so the PCM and the engine are in harmony (for lack of a better word). I will have more postings in this thread of things that do not look correct to me, either obvious or not so obvious and also things I am stuck on. Thanks for all your help!

 

Dont screw up like I did adjust and tighten down the rocker arms while the engine on the stand.As for pump That year of engine didnt have one,theres a metal tube that screws from the exaust to the intake.

 

Thanks. I didn't think so either, but when I go on part manufactures websites and search for the pump...there it is. Has me second guessing myself.

Just curious, why is tightening the rocker arms on the engine stand a problem? I won't be re-torquing until after the initial start-up process when the engine is back in...but curious what happened in your case?

Thanks again.

 

The front acessory brackets are in the way and you will have to remove those to either remove your valve covers or install them.I was thinking the old school way of how we could adjust our rockers when the engine was running even though it made a mess.Nothiing about these engines are old school.

 

there should be a secondary air injection pump located under the radiator on the passenger side... you are missing the tubes and check valves on the manifolds. if you don't have emission check where you live you can just keep them blocked off and run without it. it will set the check engine light without it (unless you get a tune and have it removed)

 

The fitting on the left manifold is for the connection up to the intake and since your right hand side manifold has a fitting with hose it does probaly go to a pump.Your is slightly different than mine sorry for the incorrect info.

 

Thanks. I don't remember noticing anything under the radiator that looks like something is missing. I'm going to try and get out there tonight to do some work (thank god for kerosene torpedo heaters). I'll take a look. I also didn't notice anything that looked blocked off on the intake. I think the engine came out of an S-10 and was pieced together at a scrap yard. That's why I don't even know if the manifolds are original to the Blazer, or to the engine.

 

the air injection pump should look like this

 

Thanks much cool. That should be helpful.

 

New question...I'm having a difficult time removing the reluctor ring from the old engine crankshaft (reman does not come with one). With as touchy as I have learned on here the CKP sensor and related parts are...can I use a gear puller to remove the ring? Or is that a big no-no?

On another engine I have torn apart..I am sure I probably used a gear puller...but now I am not sure if that is ok to do?

EDIT: Disregard...I used the gear puller and it popped off easy.