Ericc

I've been running the EBL flash forever in my Suburban. I normally run without the EGR enabled and only get a few counts of knock if I run on 89 octane. Right now I have 91 in it.

The engine is a 350 with edelbrocks MPFI + their performer heads (60859). Headers and a mild edelbrock cam. I have the Port mod with the EBL Flash.

I have my bi-yearly smog coming up and I enabled the EGR again and I noticed that I'm getting knock at 1800 rpm 70/75/80/85 map ranges.

It's retarding 3/2/2/1 degrees there. Normally I'd expect the EGR to reduce knock. Is the EBL advancing timing when the EGR is open? Or is it something else.

I thought I'd check in here before I start mucking around in the bin again.

Thanks
-Eric

RBob

iTrader: (1)

There is spark advance added and the fuel is reduced. If the EGR isn't working this causes knock.

RBob.

Ericc

I'll pull the EGR and and verify it and the solenoid are working. I also wonder if the sensor is picking up something else as counts. I can't hear any knocking even as I watch the counter tick up.

-Eric

RBob

iTrader: (1)

A quick check of the EGR is done at idle. Reach under the valve and push up on the diaphragm. The engine should die. If not then the EGR passages are clogged with carbon.

RBob.

Ericc

It looks like the EGR is working.. I did the diaphragm lift and it does want to stall. The solenoid is working.

Over the years I tweaked the SA table and ran without the EGR. If it's advancing the timing when the EGR is on I can see why I'd get some knock even if I cant hear it.

I pulled some timing out of those cells and the number of counts has come way down.

I'm using the eddelbrock 60859 performer aluminum heads with their MPFI (+port mod). If I need to go back to a reference .BIN to check the timing table against what would be a good one to look at.

-Eric

RBob

iTrader: (1)

This parameter controls how much SA is added:

EGR - SA Added

It is likely better to change it then the main SA table. Although, making changes in the SA table for EGR isn't unknown...

RBob.

Ericc

How is the EGR - SA On/Off Multiplier table applied.

Is it (SA Table * Multiplier) + SA Added

-Eric

RBob

iTrader: (1)

It is used to fade the EGR SA in and back out as the EGR is opened and closed. This way the driver doesn't feel it as a sudden change.

RBob.