EGR Problems

Discussion in 'Chevy C/K Truck Forum' started by revscott, Mar 20, 2012.

  1. revscott

    revscott New Member

    I have a 88 C1500 5.7 TBI

    I was experiencing rough idle and bad hesitation at take off. I replaced plugs (bosch +4 platinum), wires, rotor, dist cap all to no avail. I replaced the egr and the egr solenoid also no change. While checking for vacuum leak, i broke one of the plastic hoses to the egr solenoid. I drove the truck to autozone with the hose off, the truck ran GREAT. When I replaced the hose the problem came back. I currently have the hose unplugged with a little fuel filter stuck in it to help filter the air intake. the truck runs good, but I get a light at hwy speeds. Switch off and back on, no light. I would like to give it a proper and permanent fix however. Any suggestions would be greatly appreciated.
  2. mfleetwood

    mfleetwood Epic Member 5+ Years ROTM Winner 5000 Posts

    Last edited: Mar 21, 2012
  3. moogvo

    moogvo Epic Member 5+ Years 1000 Posts

    There's yer problem! Bosch plugs are made for Euro cars! What wires/cap and button did you use? If not AC/Delco, rip 'em off and try again.

    About your problem, I am having a similar one. I don't think that it is all about the Bosch plugs since I have DELCO in mine. I get the same CEL at highway speed. My next test is going to be fuel pressure.
  4. revscott

    revscott New Member

    I had all of that tested, checked out good. Its definitely an egr problem but I can't figure it out. The egr is not even engaged at idle but if the hose is plugged to it, it has rough idle and hesitation. Its puzzling me!

    ---------- Post added at 01:46 PM ---------- Previous post was at 01:14 PM ----------

    It is firing well, this thing pulls like a russian race horse! Its just when the egr vacuum hose is plugged in that it has the rough idle (like a misfire) and bad hesitation. I have changed the egr, gone back and cleaned the tubes out a second time. Changed the egr vacuum solenoid and replaced the vacuum hoses from the intake to the solenoid and from the solenoid to the egr. ??????? Its driving me nuts. New parts should equal change in performance! But it hasnt.
  5. Scott_Anderson

    Scott_Anderson Rockstar 100 Posts

    Almost sounds to me like the control source "telling" the egr to open is acting up and activating it when it shouldn't be.
  6. dogred

    dogred Member

    I have a 93 w/ the 5.7l and am experiencing the same problem. Mine is a tad bit different with the hesitation still happening with the egr silenoid vacuum hose disconnected, but it is not as bad as having it hooked up. I took out my egr to check if it was working properly, no problems there. I think that we need to check the IAC or other sensors. The chiltons states the egr silenoid gets a input from the the computer based on the out put of three other sensors. I don't have the book with me right now to pull up the correct verbage.
  7. revscott

    revscott New Member

    Thanks Scott, any suggested fix or replacement?
  8. Revredneck

    Revredneck Rockstar 100 Posts

    I know it's not ideal, but I drove my '91 for five years and several thousand miles with the EGR hose disconnected and plugged with no problems at all. If yours affects the idle, then you need to test the EGR control system, most likely you have a faulty EGR control solenoid. But if you're a poor country preacher like me, and can live with the light on, just drive it.
    Good Luck and God Bless
  9. dogred

    dogred Member

    Found this on another site, it is a pretty thorough write up.
  10. revscott

    revscott New Member

    LOL Preacher! The poorest lol, I pastor a church in an area of alabama called Pigeon Creek! Made famous by the movie 'Sweet Home Alabama'. It doesnt effect the idle, just the light at highway speeds when the egr would kick in. Just worried that it may be running too lean which could cause problems. In the city it runs great.

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