{ENGINE} Interesting EGR Info.....

[88grandmarq]

I found this posted on corral.net. So, if you got a EGR code (31,32,33,34 or 35) and have crappy MPG, this might explain why.
This also applies to all you guys who think blocking off the EGR "improves" performance.

Quote:
"you shouldn't run the block-off unless you're either not running EGR or there's an alternate supply for it, because...

...the fuel management strategy assumes the presence of a functioning EGR system and you'll get an overly lean part-throttle cruise if you block it off and don't have a chip tune to tell the computer not to...and when you have a lean part-throttle cruise, the EEC picks that information up from the O2 sensors and adds fuel. But it doesn't just add fuel to part-throttle cruise operation, it adds compensating fuel even during open-loop (non-O2-feedback) conditions such as startup, idle, and WOT.

Short story is since the EEC assumes a functioning EGR, and if you haven't instructed it otherwise, you're setting yourself up for rich running and resulting performance/driveability issues by blocking off its flow."

[Blaze86Vic]

So true. It's good to have a littel extra fuel, but too much just makes thing worse. And if its adding more fuel to the open-loop mode, that is deffinantly too much.

[grandpaslincoln]

I solved that problem by pulling the computer.

Too much fuel can also fuck up your cats.

[Blaze86Vic]

A 3 foot pole is what *ucked up my cats. LOL Gut them suckers!

Still a rich fuel mixture can cause a good se of cats to get red hot. Can even melt down the inside of the cat which is how it ruins them.

[atlantic3000]

I deleted EGR on my 83 and it runs better with out it. It does not run rich and gets 20 to 23 in suburban driving and high 20s on the highway. I also deleted cats, EGR cooler, air pump and air injection. It runs great and no more surging at light throttle occasional miss at idle. I don't think the computer cars if it's missing or not

[gadget73]

Wow, a 20 year old dead thread. New record so far.

[DerekTheGreat]

This troll is on a roll, specifically about EGR too! Just lead him into a room with shiny objects & colorful blocks to try and fit through square & round holes, he'll be entertained long enough to forget he's there.

"I dwilled 2 whole in my hed. In da one hole I put a skwoo der to pwevent da govment from contwolling me in de udder I put V8 juce in directly for vit-a-min infusin! I now studi dat much herder now. Teecher says I now best stewdnt."