Idles rough, even rougher in gear

Tiny
JOE JOE PATTERSON
  • MEMBER
  • 1994 CHEVROLET ASTRO
  • 3.4L
  • V6
  • 2WD
  • AUTOMATIC
  • 314,000 MILES
Changed the plugs and wires the fuel filter distributor cap rotor button control module and (bled the brakes) I have checked for vacuum leaks did not find booster line to engine has hose going to power steering it idles funny. I will check timing it does even worse in gear I push the brake pedal down to the floor and it pops and put it in a little more and the idle changes what is going on?
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Friday, July 15th, 2016 AT 12:35 AM

11 Replies

Tiny
JOE JOE PATTERSON
  • MEMBER
Help! This is my work vehicle.
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Friday, July 15th, 2016 AT 12:37 AM
Tiny
HMAC300
  • EXPERT
What pops? It sounds like a vacuum leak or something else check compression see what you have. Make sure firing order is correct.
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Friday, July 15th, 2016 AT 7:30 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Pop is in pedal/ at pedal hard to describe, I can feel it in the pedal, when we got done with it I drove it about ten minutes then all this started.
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Friday, July 15th, 2016 AT 7:53 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Double checked firing order, note, then van was running fine before, just sluggish needed tuneup, the brakes were stiff and would be on the floor, but hold so I bled them now this.
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Friday, July 15th, 2016 AT 7:55 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Double checked firing order, note, then van was running fine before, just sluggish needed tuneup, the brakes were stiff and would b on the floor but hold so I bled them now this
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Friday, July 15th, 2016 AT 7:56 AM
Tiny
HMAC300
  • EXPERT
The only thing I can think of is a camshaft/valve problem that is the only thing that would make it pop like a valve not opening. Or a backfire but you say it ran fine prior to working on it. Check under TBI unit as they like to blow gaskets there either front or rear use choke cleaner and spray it. It will change rpm or stop running rough if it is. Firing order in picture.
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Friday, July 15th, 2016 AT 9:30 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Thank you will be checking TBI gasket soon as I get back.
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Friday, July 15th, 2016 AT 10:26 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Also, I cannot find a vacuum off the booster could the booster cause this? I think you may be right about the gaskets at TBI just wondering about booster, the van has been sitting for a couple years the first thing I did was replace the vacuum lines on top, then the next day the vacuum lines from gas tank to canister just fell out from under it and I replaced them and then yesterday doing the tuneup and bleeding brakes was the most work I have done to it and now I am where I am at with it. So, I am leaning toward the gaskets. Also when the van is running, push the pedal I can hear an electric whining sound comes from around the TBI cannot identify it cannot find EGR valve either there is a cylinder with a plug on the back side of it this sits where I have always known the EGR valve to be. I am trying to put everything out there on this as I am stumped.
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Friday, July 15th, 2016 AT 11:16 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Also once the van is running when I push the brake pedal down the engine stalls.
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Friday, July 15th, 2016 AT 11:19 AM
Tiny
JOE JOE PATTERSON
  • MEMBER
Also, once the van is running when I push the brake pedal down the engine stalls that is kind of why I keep bringing up the booster, I have got good pedal and it stops fine, but since bleeding the brakes the pedal is funny and van stalls when brake pedal is pushed.
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Friday, July 15th, 2016 AT 11:21 AM
Tiny
HMAC300
  • EXPERT
Replace the valve on the brake booster, but you may have a bad brake booster. Also check to see if vacuum is going through canister at idle. If it is then the solenoid is bad as it should not do that until 30 mph. Check hose going to booster as well.
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Friday, July 15th, 2016 AT 11:59 AM

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