For those willing to look, 92 CPI 4.3 issues

[Colorado]

My blazer has the first year of the vortec intake, central port 4.3. The first issue was lack of power so I replaced the plenum fuel line and put in a newer fuel reguator. Then it became hard starting. It would 

crank w/o firing. Well I have plugs that fire and injects gas fine. But now it will barely start on starting fluid. If it does it will idle fine, but sputter in gear then die before needing more fluid.

It's gotten to the point that it won't even rev without backfiring. I took the plenum off and starting fluid fires back out the intake tunnels.   This said, I think the timing is done. Any idears?

Thank you for responding if you do. Ryan.

[scooterbob]

dont want sound dumb, but have u removed the cat. converter yet?

[Colorado]

Not a dumb question. The cat was gone when I bought it. It's runnin straight piped exhaust with one muffler. It ran like before the exhaust was done. I thought good exhaust would fix this since it was bad beforehand. The Y pipe has a realllly small leak but nothing horrible. I'm told it's timing. But 

[scooterbob]

how much fuel pressure?  could be timing though

[Colorado]

I don't know the fuel pressure  but the backfiring I know has nothing to do with the pressure. Also, I'm told if the timing is fried then the motor needs rebuilding.

[RIP_K52007]

them pletums are known to go bad. but i doubt thats the problem, maybe try changing the EGR valve in there while you got it apart.

[Colorado]

I don't remember it breaking but a tab on the EGR piece snapped so I gotta get another one.

[mudbrat71]

check fuel pressure should be like  45 psi that will cause lean back fire

[J.C.]

check fuel pressure should be like  45 psi that will cause lean back fire

needs 62 to start and 59 i think to run? i could be wrong tho

[Chevy Racer]

check fuel pressure should be like  45 psi that will cause lean back fire

needs 62 to start and 59 i think to run? i could be wrong tho

I'm thinking in the 60 PSI range too.  Also I think I got an EGR that will work for ya.  I'll look around.  They are like $90 new.  Ask me how I know that.  LOL

[ProGrade]

did you check the distributer gear? wear or damage is fairly common and will make it run like   if you didn't already check plugs and wires too.

[rangerwheelinmike]

did you change the coil? rember how i riged that one on i at the mounds when the other one blew up? lol

[BigFrank]

did you check the distributer gear? wear or damage is fairly common and will make it run like   if you didn't already check plugs and wires too.

check for slop or end play between the gear andend of it those 4.3 can be fussy on the timing  being just right   id think a fuel pressure issue is most likely trhe cause

[Colorado]

I'm thinking in the 60 PSI range too.  Also I think I got an EGR that will work for ya.  I'll look around.  They are like $90 new.  Ask me how I know that.  LOL

So how do ya know that? I can even come get it from ya. (maybe cheaper?)

did you check the distributer gear? wear or damage is fairly common and will make it run like  if you didn't already check plugs and wires too.

The distributor seemed to have no play this summer. It's got a tested good ICM, with new cap. Wires didn't look bad but I have to assume they are old.

did you change the coil? rember how i riged that one on i at the mounds when the other one blew up? lol

It's still got the coil on that we rigged. It even tries to fire without being properly grounded.

And BIGFRANK, I think yer right. Next step is checking pressure. The pump is NOT new at all. I'm convinced the timing is shot which I'm told if that's the case the whole engine needs rebuilding = not worth it.

[rangerwheelinmike]

you need to ground that coil better its not even tight

[randycrane79]

needs 60 psi of fuel preasure to start and if its not there it will send you all over the place to find it check ya fuel preasure before ya do anything

[Colorado]

It was grounded tightly and still didn't run mikey and yes I plan to do a compression AND fuel test after Christmas even though I'm also told fuel won't affect it.  

everyone for the help.

[RIP_K52007]

fuel will affect it dude... it runs on gas

[monsterjeep]

It sounds stupid but if its got a w vin code the temp sensor on the drivers side haed is bad it makes it hard to start and back fires because its not reading the right fuel pressure thru the computer i saw a couple of them at the shop do it If that helps

[Colorado]

Funny you say that cuz I've never tried the temp. sensor AND I don't have a fuel (another story) or temp. reading..... TWO gage clusters later.

My opinion, 4.3's go forever pretty much and I can't picture the timing gone at (purchased miles of) 125k.

And I (still) agree Derik. Anything is poss. with engines.