Strange EGR Delete method???
Thread Starter
Instructor
Joined: Apr 2013
Posts: 104
Likes: 2
From: Greenville SC
Strange EGR Delete method???
Have been battling a P0400 EGR Malfunction on my 1996 LT1, and came across something that looks to me like a crude way of deleting the EGR.
Anyhoo.... I was trying to sort this P0400 out, and was checking for vacuum back to the EGR valve since a new valve didn't fix the code problem. Had vacuum at the intake port and none of the hoses were cracked, and the Solenoid appeared to be functioning.
When I put the new EGR Valve on, I hooked a hand vacuum pump to the valve and made sure it was working BEFORE I installed it.
So today I was using the hand pump to try and move the EGR valve with the OEM tubing hooked up and it would draw and hold a vacuum, but the EGR valve wouldn't budge.
Got to looking at the Rubber 90 Degree elbow that adapts the tubing to the EGR, and there is a tiny Ball Bearing jammed up into the darn thing.
I am assuming that this was some crude way to try and take the EGR out without actually removing all of the components.
What do y'all think?
Anyhoo.... I was trying to sort this P0400 out, and was checking for vacuum back to the EGR valve since a new valve didn't fix the code problem. Had vacuum at the intake port and none of the hoses were cracked, and the Solenoid appeared to be functioning.
When I put the new EGR Valve on, I hooked a hand vacuum pump to the valve and made sure it was working BEFORE I installed it.
So today I was using the hand pump to try and move the EGR valve with the OEM tubing hooked up and it would draw and hold a vacuum, but the EGR valve wouldn't budge.
Got to looking at the Rubber 90 Degree elbow that adapts the tubing to the EGR, and there is a tiny Ball Bearing jammed up into the darn thing.
I am assuming that this was some crude way to try and take the EGR out without actually removing all of the components.
What do y'all think?
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
I used it on my '73 Goat when it was new - the first year EGR came on a car. Damn thing broke and there were no replacement solenoids. I also cranked open the idle screws and advanced the timing. Idled a hell of lot better. Haven't had a need to do anything like it since.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
IF YOU did not put that BB in there? why would you ASSUME that it just appeared?
The EGR valve does have check valves. You also need to verify that you got the correct EGR...there is pos and neg pressure return valves...I am not sure about the LT engine but the L98 uses a neg return pressure valve. If the wrong valve in installed it can leak and cause idle and performance issues.
Besides, you DO N OT delete EGR mechanically...that's done in the "tune". If you just plug off the EGR port or something else, the ECM still looks for EGR and sets timing and fuel based on the assumption that the EGR is doing what the ECM told it to. In other words, if you just block it off you'll create other tuning and running problems. Why do all that? The EGR does not hurt a thing in a street engine and may actually save it from self destruction when its extremely hot and run under high loads.
The EGR valve does have check valves. You also need to verify that you got the correct EGR...there is pos and neg pressure return valves...I am not sure about the LT engine but the L98 uses a neg return pressure valve. If the wrong valve in installed it can leak and cause idle and performance issues.
Besides, you DO N OT delete EGR mechanically...that's done in the "tune". If you just plug off the EGR port or something else, the ECM still looks for EGR and sets timing and fuel based on the assumption that the EGR is doing what the ECM told it to. In other words, if you just block it off you'll create other tuning and running problems. Why do all that? The EGR does not hurt a thing in a street engine and may actually save it from self destruction when its extremely hot and run under high loads.
Thread Starter
Instructor
Joined: Apr 2013
Posts: 104
Likes: 2
From: Greenville SC
IF YOU did not put that BB in there? why would you ASSUME that it just appeared?
The EGR valve does have check valves. You also need to verify that you got the correct EGR...there is pos and neg pressure return valves...I am not sure about the LT engine but the L98 uses a neg return pressure valve. If the wrong valve in installed it can leak and cause idle and performance issues.
Besides, you DO N OT delete EGR mechanically...that's done in the "tune". If you just plug off the EGR port or something else, the ECM still looks for EGR and sets timing and fuel based on the assumption that the EGR is doing what the ECM told it to. In other words, if you just block it off you'll create other tuning and running problems. Why do all that? The EGR does not hurt a thing in a street engine and may actually save it from self destruction when its extremely hot and run under high loads.
The EGR valve does have check valves. You also need to verify that you got the correct EGR...there is pos and neg pressure return valves...I am not sure about the LT engine but the L98 uses a neg return pressure valve. If the wrong valve in installed it can leak and cause idle and performance issues.
Besides, you DO N OT delete EGR mechanically...that's done in the "tune". If you just plug off the EGR port or something else, the ECM still looks for EGR and sets timing and fuel based on the assumption that the EGR is doing what the ECM told it to. In other words, if you just block it off you'll create other tuning and running problems. Why do all that? The EGR does not hurt a thing in a street engine and may actually save it from self destruction when its extremely hot and run under high loads.
First of all, please get your knickers untwisted and take a deep breath.
The "BB" was restricting flow in BOTH directions, and it was obviously put there by a previous owner to keep the EGR Valve from opening.
I DON'T want my EGR deleted. I WANT it working properly for the reasons you stated. I was troubleshooting it to figure out why it wasn't working right when I found the "BB". It was not a "Check Valve" that was there from OEM.
Since removing said "BB", my CEL has yet to come back on with the P0400 code.
