However, now that the old girl is all of 13 years old (in a '91 S10 Blazer), she has a real problem. After being on the highway for awhile, then coming to a stop, she can hardly idle without bogging down and dying (auto tranny).
She's got new plugs, wires, vacuum hoses, rotor, cap and adjusted timing. Any ideas?
Jaombi
EGR valve
-Bret
Fuel filter.
Bret - all,
Thanks for your suggesti>
It is a valve just behind the Throttle body. (part that looks like the old carburetors of the past)
It has a vacuum line going to it. It's about 2 inches in diameter and comes to a point with a diaphragm inside.
I did the EGR mod on mine with a metal plate. I'll see if I can find the instructions for that.
Lannie
the Exhaust Gas Recirculation system is more or less a way to adjust effective fuel octane on the fly. it is used during cruise to slow the rate of fuel burn (the definition of octane) so more timing can be run, reducing emmissions and increasing mileage. if the EGR valve sticks, when you come off the highway exhaust gas will still be routed through the intake. this will dilute the air/fuel mixture and make the charge barely burnable, hence the stumbling and rough idle.
the egr valve itself is about $40 for a Wells P.O.S. from autozone or around $75 for a quality one from NAPA or Carquest. on a small block V8, it's a piece of cake to change them, I've heard on the V6 it can be a bitch to get them out.
HTH, Bret
LS: Does this still pass Texas emissions test? Thanks, Jaombi
no, it won't and you stand a very good chance of ruining your pistons when the EGR is commanded by the ECM and the timing is advanced by the ESC. pinging is a very bad thing. I've never understood what people hope to gain by bypassing the EGR system which isn't even used at WOT anyways.
-Bret
On the 4.3 it is buried inside the fuel lines and such, difficult to get to, but possible. I believe I had to remove the line from the TBI to get enough room to get at the bolts.
I didn't bypass the EGR, I just made the opening smaller so the ECM would not complain.
LS
The 2.8L (I think that's what the econo-box 4banger in 88 was) is easy a frikken pie. It's hanging right there, screaming "please fix me, I'm not supposed to be hanging off in two pieces". But ole LGM replaced just about everything BUT the obviously-broken-EGR valve, not knowing what this "floppy thing" was.
$100 at the shop.... and a lesson learnt the hard way. Search the other threads as well, there is a link for a site that makes a gasket with a filter that stops the carbon from getting in them (what kills an EGR valve)
-The Lonely Grease Monkey
1985' K5 305CUI TH700R4 NP208 KJ's successor"Ignorance is preferable to error; and he is less remote from the truth who believes nothing, then he who believes what is a wrong." - Thomas Jefferson
what's so bad about Wells?
I work at an auto store that sells them....although we dont sell their EGR valves
Jason
compare any wells part to the equivalent NAPA Echlin part. the differences will become obvious. after the 4th Wells brake switch failed in my truck and after the 2nd Park neutral switch.... I quit trying to save a short term penny by buying crap parts.
-Bret
well, I do completely understand, but I have never seen one of our Ignition modules that they make come back...yet
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