So I was dismantling the top half of the engine in preparation for a base/runner/plenum swap and noticed that I have a faulty egr valve. I beleive I have been driving with it like this since I purchased the vehicle. I also loosened the crimp ring that holds the egr tube on to the exhuast manifold a month ago when I was changing valve cover gaskets. I also do not have the vacuum solinoid that is supposed to control it. I am in the middle of taking both exhaust manifolds of and cutting and welding shut the air tubes from the air pump asm. I am curious as to whether to cap and weld the egr tube at the same time and just get rid of the egr system all together....since I have been driving the car anyways with a dysfuntional egr system. Can I delete the egr temp sensor(test sensor??) without it throwing a code or do I have to reprogram the memcal? It will probably cost a couple hundred less getting all the parts I need and clean up some space in the engine compartment. Any feedback on this would be greatly appreciated! I am very knowledgable when it comes to mechanics, but not knowledgable enough to work with these chips yet. Thanks guys!

 

The problem with deleting the EGR is combustion chamber temps go way up. If you enrich the mixture, no problem, but with stock calibration the mixture gets very lean. Lean mix and high temp spells trouble. If you are remaping the fuel curve I would think it would be fine. That being said, why delete the system? It does a great job of reducing NOX emissions and does not reduce performance during spirited driving. And it makes it easier to sell the car in a emission testing area.

 

With the right cam you don't need it. No EGR on my LT4.

 

try to keep it. It s good to cool down pistons.

 

Yes this is about the cheapest rout I could go...but they do nothing for fuel and spark advance tables-they leave that stock. And it's not the replacement prom, it's an adapter that they program that plugs into your factory prom which plugs into your computer. I forgot to mention I am also getting an adjustable fuel pressure regulator too. I am not very experienced at it at all, but from what I have read here on the forum, you could make the injectors rich by cranking up the pressure??? I have a set of new bosch III 22lb purchased from FIC that I will be going with. I just don't know that if I raise the pressure, the ecm wont try and compensate with the pulsing of the injectors. That is a question I'll leave to someone more informative than I.

 

Like I said, I am going with an AFR, could you tell me if I can make the engine run a little richer by cranking the pressure up??
I live in Florida, and we haven't had an inspection in over 20 years.
Kinda makes me wonder how the great American muscle cars survived without melting there pistons!! I know my boat has twin 350's and run fine and didnt even come with egr valves; and they are 1984 models. Maybe it has to do with fuel injection, I dont know, but I dont even think that the new marine 350's with fuel injection com with an egr. I think it's some liberal tree huggers conspiricy

 

ttt....

 

bump for a new week...

 

Do you have a way to datalog ? If you have a laptop computer, get Datamaster or Tunerpro RT. Datalogging will tell you if its rich or lean . Tunerpro RT will also let you do the programming if you get the hardware.

 

I eliminated all the EGR parts, 5 years ago. I have yet to throw a code and I sure don't miss the tube from exhaust manifold to intake.

 

Same as above, no trouble without all that stuff.

 

As I said, the LT4 comes from the factory without EGR.

 

I'm not going to try to get technical because I haven't learned how to program a chip (yet). But, I'll try to be intelligent....

The EGR's purpose is to recirculate burnt fuel (crap) back into the intake. The result is a slowing of the "burn" in conditions where damage might occur. This function is really to suppress the formation of NOx gases which occur in high-temp conditions. Your catalytic converter is also designed to filter these gases. (I believe the front's specialize in this operation. Modern 3-way replacement cats to it too).

Basically, if your motor gets too hot, detonation starts to happen. The mixture expodes before it's supposed to. Timing adjustments can deal with that (which reduces power), but I'd think diluting the mixture would too.

If it were my car -- and you were concerned about the life of the motor, doing a scan (to check for knock counts) after disabling it would seem the course to take. Being cognisant of knocking is something you should do at a minimum.

My understanding is that your motor can knock w/o really hearing it. And, over time, that might cause damage. Again (w/o being an expert), I'd worry more if you live in an area where it gets very hot for extended intervals -- and you do a lot of city driving. I believe that's where most knocking issues can occur. (Some might say during WOT too, but I'm thinking I read that the EGR is disabled during WOT for maximum power. Carbon doesn't help that much you know).

Also, there is a cheaper "fix" besides getting the ECU EGR control disabled. It involves putting something like a diode in the EGR electronic path. Korvette4U had it on his website I believe.

BTW: I'm skeptical that "the right cam" can offset the need for an EGR. I'm thinking better, newer, faster ECUs can successfully monitor for and adjusting timing when detonation occurs. That's why you don't see it on newer motors. In reality, L98s also have a knock sensor to compensate for this. As such, I wonder about any real risk to the motor. I suspect the factory engineers were really just doing everything they could think of to make a clean motor. I think they succeeded.

My '89 vette has a cleaner looking exhaust pipe -- with a V8 -- than most newer vehicles I observe. How clean you want to keep it is up to you. I'm of the opinion that the EGR is not a critical part of that.

But, then again, I'm no expert....

 

Unplug the solenoid. Unplug the EGT sensor. Remove it all and block it off. There will be no codes. O2 sensor will correct air fuel ratio. Ran this way for years. EGR is not critical. No problems at all.

John

 

Temperature is not a concern, otherwise why would the EGR be disabled under high throttle opening conditions (when cylinder temps are the highest)?

EGR is for diluting the incoming fuel/air charge to reduce combustion temp, which in turn reduces NOx. It is not related at all to protecting pistons or preventing knock. For more info, read the FSM.

 

I have removed the EGR from every car I have ever owned. 3 TPIs and one TBI. All you have to do is put a peice of stainless between the Intake and the EGR port on the cylinder head, remove the pump, disconnect all lines, replace the EGR valve with a plate, and get a new prom.
The entire point of EGR is as said earlier, to reduce combustion temperatures and lower NOx emissions. EGR was a compromise to keep GM from having to dump TONS of money into sequential fuel injection research. Removal of EGR all but completely stops intake coking, lowers intake manifold temps, and increases fuel mileage, longevity and performance of the engine.

 

I just cant believe people think that blocking off the egr gives you some noticeable performance gain.I'd like to see some hard data on how it improves fuel mileage,longevity and performance.I'm not an econut by any means,but I don't see the point in disabling equipment that won't show any performance gains,mabey if you were looking for that last .01 of a second at the strip or something Once Comrade Barack gets into office the econazis will pretty much have free reign,I wouldn't be making permanent mods to the emissions system.

 

I've wondered what the advantages and disadvantages of disconnecting the EGR would be. Is there anyone that has performed this without making another change at the sme time and have some dyno reports. I have read the section on the EGR system in the service manual and don't really see how there could be any adverse effects. As well, I think the computer will compensate to keep the air/fuel ratio at the optimal mixture.

 

I didn't see anyone HOPING for a performance gain. People choosing to do this seem to delete it as more of a cost, maintenance, asthetics issue.

The EGR recirculates SOOT back into the intake. Would you remove your air filter -- if it made the car run cleaner? No. You don't want SOOT run back thru the motor.

Care to guess how well the mixture burns with soot running back into the intake? Do you think it's possible that better mileage results from a reduction in engine soot?

Maybe removing the EGR (and AIR) really make the car less "clean", maybe not. Nothing I've read here over the past year has convinced me of it's "necessity".

I replaced my OEM 2-stage CAT system with new, 3-way modern cats. (3-way fronts and 3-way main cat). IMO, I've now got double-cleaning on the exhaust in my alternative setup.

Even if you retain at least one -- new -- CAT in your system, I'd bet on similar or better emissions than someone who leaves the exhaust totally alone. WAYYYY more people go down that road.

"****" that!

 

Like I said..never mind..not worth arguing over.