[87next2last1]

I'm getting ready to do a tune up on my 87 4.3L ! It has 171,000 & most of the stock sensors, Should I change the sensors out or wait till the service engine light comes on ?? If I need to change them, Which ones should I change ??
I will be changing cap,rotor,plugs & wires ! I think I will get a new 02 sensor & cat !
What other sensors do you suggest I change or leave them alone ??
I don't know all the sensors that's on the 87 4.3L ??
I'm old school guy carb & motor & that's it !! Still learning all this computer control stuff !!
Will also be changing tranny filter & fluid,rear end oil,coolant flush,checking vacuum hoses,spray the throttle body,
Any suggestions on changing some other parts while I'm doing this ?? or things to look for ??
Thanks !! :beer:

 

[steelybill]

Sounds like the ignition parts you are gonna replace will take care of most of it. Don't believe you need to start swapping out sensors that are working, and the after market stuff may not be as reliable as the original stuff that still works.
Check or replace all the fuel filters for sure.

 

[rnhart3]

Changing the o2 not a bad idea, I've changed those before they had a chance to seize themselves in and became un-removable.
Never changed the cat on spec. before though, bit it can't hurt.
Don't forget the fuel filter. Everything else? If it ain't broke............

 

[jlcustomz]

I,d go with the items you mentioned, not any other sensors.If cat is original, I,d definitely get rid of it.
Another little thing I'd do is dump a couple of bottles of chevron techron cleaner in a low tank of gas just before driving it a while.This will give your injectors close to the same cleaning a shop would do for approx $90.

 

[87next2last1]

I,d go with the items you mentioned, not any other sensors.If cat is original, I,d definitely get rid of it.
Another little thing I'd do is dump a couple of bottles of chevron techron cleaner in a low tank of gas just before driving it a while.This will give your injectors close to the same cleaning a shop would do for approx $90.

Joe
My GM buddy told me the same thing about the techron but he said 2 big bottles for a tank of gas ! How much gas do you have when you do this ??
Oh Ya Advance auto has them for buy 1 get 1 free right now !!

 

[jlcustomz]

I was told this by a former caddy tech before. Less gas equals more cleaner concentrate. Also , cleaner evaporates quick, so best to use when you can drive.
Yea, I get the advance 2 fer ones sometimes.

 

[spencersr]

Coolant temp sensor OS bad about going out on tbi will make it run rich.4.3 tbi is the best motor in my option I would kill to have one for a daily driver

 

[steelybill]

My 92 pickup has a 4.3. Changed the ECU temp sensor once, and O2 sensor once. Not too much has gone wrong in 270k miles, but lifters are rattling ! Good on gas too, for a work truck. Oh yeah, the tensioner for that dam serpentine belt has failed twice, (50 bucks), tearing up the belt (30 bucks). I like V belts :smileyb:

 

[87next2last1]

I have another question !! Do I have to replace the cat or can I take it off ?? No emission testing. Is it connected to the ECM stuff ??
Thanks for the info !! :beer:

 

[ccc]

you can pull it if you have no testing .you may have to richen it up a little as you are going to make it breath easier. the ecm doesnt watch the cat on our cars,it wont know its gone

 

[87next2last1]

you can pull it if you have no testing .you may have to richen it up a little as you are going to make it breath easier. the ecm doesnt watch the cat on our cars,it wont know its gone

How do you richen up a throttle body ? Is it controlled by the ecm ?

 

[jlcustomz]

Steve,you can just get rid of cat if wanted.No need for trying to richen up , Computer Will adjust that little bit no problem by readings it gets from oxygen sensor & map sensor. May have a little more exhaust gas smell over a properly working cat, that's all.
Your stock 4.3 ecm shouln't need tuning unless you get into large cam/ported heads type of stuff, which you're not.Your ecm has a removable chip which is swapped or a new program to be burned in by a properly equipped shop,FYI. (laptops instead of screwdrivers)