I just rebuilt a 4.3L V6 and got it up and running (after a week of fiddling with it)
the problem I've having now is a rich code and really crappy idle.. and less power than it should be making.
bogs off the line and idles from 400-700-400-700 when in drive.. almost stalling.
I have the EGR removed, but after reading this forum a lot i'm going to reinstall it.
heres the things I'm going to check
TPS
IAC
Oxygen Sensor
and Reset the timing (didnt unplug the tan wire last time, whoops)
any other suggestions?
its ODB1

 

Is this from your S-10??

 

if you didnt' unplug the ESC when you timed it, that would be the very first thing i would do.

 

I'm guessing thats a big part of my idle problem. Basically thats cuz the Computer is messing with the timing the same time you are right?

And yes its for the S-10 .. you guys are just a lot more experienced with internal buildups than the s-10 guys.. who are bolt on kings lol.

 

what happens is this.

the computer thinks your base timing is 0*, at idle it adds 20* so your initial timing is 20* if you time it with that connected, when you time it to 0*, the computer has already added that 20*, so you are really running it 20* retarted.

 

damn lol.. would that be causing the rich problem becuase its igninting way to early then?? Thats probably why the holley never worked becuase the timing is probably about 15deg retarted currently

 

yes, being that far retarded, means you are firing it very LATE, and yes it can cause you to read very rich.

 

It will cause the vacuum to read low. The ecm thinks the engine is under load. This causes a rich condition. Just saw a 2.8 blazer that someone did the same thing to. It was actually almost 20* retarded when the wire was unplugged.

 

right late.. I was thinking backwards.. I can probably install my holley Tbi and get it running righ tnow that I remebered that stupid TAN wire for the timing.. becuase the stock tbi isnt enough flow to stall it but the holley just completely flooded the engine.. likely becuase the fuel wasnt being burnt off.

 

BTW sims im on s-series also. My screenname is 96s-10ss. good luck with your problem.

 

thanks I think this should fix it. If you've been following my build at all its been "interesting" and like I said above. not a lot of guys on there have internally built 4.3's.

 

I was going to build a 300ci stroker from my 4.3 but i decided to go smallblock! Im doing a 373 stroker with an offset ground crank to 3 9/16" stroke and 6" rods. Im also going with the dart iron eagle S/R heads. It should be good for around 500-550hp and i will be adding some spray to it as well.

 

nice, I'm looking for around 280 from my build when its all done.. we shall see though. Once its running right and I get the headers, exhaust and other minor stuff.. Might throw vortech heads on down the road for better flow too.

 

Please tell me that youre not using the Stockers.... Get the vortecs for the $100. Thatll be about 20-30hp over stockers out of the box.

 

Stock LB4s that I put about 20 hours of porting into as well as bigger valves. so they're not complete crap. Couldnt find self aligning Vortecs from 92-95.. and 96+ need machining to fit the TBI intake properly. Thats what I want to get is the new vortecs machined to fit, then bigger valves and porting on them.