Most of you guys know that your 4.3 is designed to operate at it's most efficient with the EGR that works. I have been noticing a little exhaust smut on the body @ the tailpipe and I immediately thought the van is running rich. My first thought was the Fuel Pressure Reg. was leaking. I started to get the SES light and it was a code 32 - faulty EGR. I replaced my EGR motor this past weekend with great results. I'm getting an average of 18.6 miles per gallon - up by almost 2.8 MPG. The EGR motor is nothing more than a computer controlled valve that allows a little inert Exhaust gas enter the combustion chamber to help fill the space. By doing this the small mist of fuel is contained in a smaller available area within the combustion chamber. THe engine thinks it is smaller than it is and uses less fuel to rotate the engine. There are different types of EGR motors - some are computer controlled and some are vacuum controlled. Either way, these can become lazy in their operation and completely fail due to spring or diaphram fatigue - depending on the type. My EGR part cost $ 96. It should pay for itself in a few months.
The point of all this is your engine will only run at it's peak effieiency if all of the emissions parts work correctly.
I hope this helps some of you in your quest for better MPG.
I got 21.5 mpg doing 80-90 mph on a trip with EGR blocked.I really cant see it doing better than that. my overall average about the same as yours if I not racing all the time.
I pulled that whole stinkin stock TBI manifold off, and installed an Edelbrock 2111 4bbl manifold with a TBI adapter plate.
The Edelbrock manifold doesn't even have a spot to put an EGR, hooray! Mileage & performance improved some.
I pulled that whole stinkin stock TBI manifold off, and installed an Edelbrock 2111 4bbl manifold with a TBI adapter plate.
The Edelbrock manifold doesn't even have a spot to put an EGR, hooray! Mileage & performance improved some.
I'm interested in the MPG gains of blocking this off. Not sure how to make a plate. When you block the EGR off what happens to the wire plug for the EGR motor. Wont it throw a SES code? I can see doing it with a vacuum operated EGR, but my '95 W L35 has the electric operated EGR - the wires have to plug in to make the circuit.. :shrug:
I'm interested in the MPG gains of blocking this off. Not sure how to make a plate. When you block the EGR off what happens to the wire plug for the EGR motor. Wont it throw a SES code? I can see doing it with a vacuum operated EGR, but my '95 W L35 has the electric operated EGR - the wires have to plug in to make the circuit.. :shrug:
This a block plate for a 90 just make one for yours bolt it between EGR and intake just plug it back in.You will get no light but it will show EGR code if you read it.and it will run alot better.More throttle response.wont have to give it near as much gas to climb hills.It is the best thing since a pocket on a shirt.If you got emissions testing take it off clear the codes test put it back on simplest way around that.Mine is electronic also.
EGR can be tuned out of the computer, and I've had cars that had no EGR valves in them from the factory. The function of the EGR isn't to "fill" the combustion chamber to fool the computer into using less fuel. The computer is designed to keep the fuel air ratio at 14.7 to 1, so you aren't fooling anyone.
EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created.
Removing the EGR will give you back a marginal amount of HP and a small MPG gain. Their only purpose is to reduce exhaust gas emissions..that's it.
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