96 Blazer tune up

[Atl XJ]

Does anyone know anything about the 4.3L Vortec? My girlfriend's Blazer has 98K on it and I'm planning on doing a tune up for her on it. It runs pretty good, no check engine lights or anything, but at 98K I figure its due. My question is this, is there anything other than the usual spark plugs, wires, dist cap and rotot that should be changed out. I've already replaced the radiator hoses and serpentine belt. The cooling system was recently flushed when I installed a new radiator and water pump. The notorious intake manifold leak that plagues these engines has already been fixed too.

Is there anything else that I should change out like O2 sensor, EGR valve, pcv valve, etc. Thanks, I have pretty good general automotive knowledge, but I was hoping maybe someone on here was more familiar with the 4.3L Vortec.

Oh yeah, as far as I know, everything tuneup wise is original, they have the 100K tune up deal.
TIA

 

[RichP]

Gee, if it is ALL original I might consider belt, thermostat, plugs, wires, cap I'm not sure of, that is I think it is an HEI ignition and the coil is in the cap. If the truck is run mostly on the hiway at good speeds then the O2 sensor should last a while or if you have a fat wallet go for it.

 

[Atl XJ]

Thanks for the response. I replaced the radiator, radiator cap, hoses, and water pump recently, so the cooling system should be good. I didn't think about the thermostat, thats a good idea, I also am going to check out the fuel filter, unless its an intank design. PCV valves are usually cheap and I found out that you can clean the EGR valve. I also was thinking that it would be a good idea to clean out the throttle body.

 

[MassbayXJ]

mmmm. . . i love working on Blazers(sarcasm).
If mine had 100 k on it. I would replace the following since you are going to be taking care of it for a loved one.
-oil cooler lines
-idler arm
-air injection pump usually bad but you'll get killed at a dealer.
-4wd switch (if it is 4wd) this fails without warning
-ball joints. I've seen some bad ones I won't mention
-o2 sensors(3 i believe) but they set off "check engine " light when bad. Blazer will apper normal.
Everything you already did was good too. just throwing in my .02.

PS - change DexCool (red) coolant every two years if you love your engine.
- when she complains of heat not being as hot, run away. run as fast as you can.

 

[Atl XJ]

Thanks for the info. Is the air injection pump that weird deal in the intake? I had to take the whole intake off to change the upper radiator hose and there was some weird deal in the intake tube. I havent touched it yet, it runs good still but its in Florida right now, but will be returning soon with over 100K on it. Its pretty amazing to me that those engines can go so long without a tune up.

BTW, whats the deal with the heat not getting hot. It works good for now (knock on wood).

 

[MassbayXJ]

the air pump is under the blazer, inside that plastic front airdam. I did one when i replaced an idler arm. It is not under the manifold. I wouldn't worry until the "check engine" light comes on. Replacing the heater core is technically an 8 hour job that involves removing the dash. However, I recently heard that hooking up a simple garden hose to the heater hoses for a while to flush it works too. That will unclog the heater core, but like anyother, it will leak after time.

PS- the 4.3 is 3/4 of a 350 so its pretty stout. some go 300,000 miles and some only go 100,000.