Thanks to RBob for walking me thru the proportional terms.

I was finally comfortable with the way the engine ran (no more black clouds filling the garage!) to check base timing. OOPS...it was at -2*. It liked being at 8*.

The engine still wants more timing. I'm curious what value determines when the cold SA bias table is used.

The engine starts and runs fine. It pulls ALOT more vacuum than it did before thanks to all the timing. It idles fine in park until you put it in gear. Then the extra load upsets something. The kPa goes from ~35 to 50. This change in load must be affecting the spark in a way I cannot figure out. The SA table is the same thru all those values. So why would it retard it? The reason I asked about the cold SA bias table is I'm not sure when that is being used, and since the load scale is in vacuum I do not quite understand it.

What is barometric spark correction? @ 0x1AE

...I'm getting real close...

 

im not super sure where your tunning is but id check to see if the engine isnt needing a bit more fuel at idle. when in gear. fought with this for a while on a couple of cars. also sometime timing in to much quantiy can make the engien idle smooth but make it prone to stalling. try pulling some advance and see what happens.

 

I paid alot more attention to the inj pw and the SA while I was out tuning.

The engine definatly liked the extra timing. The timing created more manifold vacuum. My inj pw is shown thru WinALDL but it is not converted. It ran REAL nice when the inj pw was at 18000. When I put it in gear it jumps to 22000-24000...I'm guessing because of the load surge. That makes the engine unhappy.

I took more fuel out across the load range it surges into, but I haven't tried it yet...

 

Cold SA (bias) table is used all of the time. The bias is actually the value sub'd from the cold SA table (really the coolant SA table). I've mentioned these name changes because it can help to understand what they really are.

So the coolant SA table is always in effect. The VAC term is the difference between BARO and the current MAP value. Just like hooking up a vacuum gauge to the manifold and using that.

The coolant/vac SA table could very well be causing your change in SA.

The baro SA table @ 0x1AE isn't a SA table. This table is used as the TPS correction to the pseudo baro read.

Baro pressure is read at key on. Then under certain circumstances is read while the engine is running. This is to compensate for hill climbs. Pikes Peak anyone? .

While tuning I like to disable the pseudo baro read by setting the max RPM value real low. Just don't be hill climbing until the cal is settled, then cal it and enable it.

RBob.

 

RBob...thanks again for deciphering the code for me

I did a cold start-up today (~1*C) and the engine ran pretty good for a while. Once the coolant temp got into the 26*C range the timing started to back off and it changed the manifold vacuum. Like I said before, it was at 35 kPa and the timing dropped out and the manifold vacuum went to 45-50 kPa. So it dumped alot of fuel in and it started to run like crap.

I'm almost sure that it's the coolant/vac SA table. I'm about to go out right and try another PROM where I put alot more timing in the table all the way up to engine operating temp.

You said the vacuum is BARO - MAP = VAC ...correct?

If that's right I want to use an example...Let's say BARO was read at 100.0 kPa. So if the engine is running at 35 kPa then the VAC = 65. Correct? Less manifold pressure equals more vacuum...

I want to fully understand how read the coolant/vac SA table works before I assume anything wrong.

thanks

 

Your welcome.

Your understanding of the vacuum value is correct. Then at WOT the vac will be very close to 0.

RBob.

 

Cool. I got it driveable yesterday I'm still working out a nasty bog at slight throttle tip-in. I think it's too much AE...I'm about to go find out...

Also...can I still count on the BLM and INT to be accurate with these tables like so...



On a side note. I've been tuning more by watching the inj pw than the BLM's. It's real easy to see that at the same time engine bogs the inj pw jumps up really high. I'm gonna work on that tomorrow. The fuel table is still all screwy because I was just trying to get it to idle...so there are some sharp increases on the table still.

 

Not pulling enough timing out fast enough, as you acclerate, can also feel like an AE problem, when in fact it's a timing problem. If you dink with the AE and it doesn't make any change, then try messin with the way you ramp the timing out.

 

Ok. I'll remember that. I'm still playin with it but so far I didn't think I had enuf timing.

Would it backfire thru the intake if there was too much timing?

Maybe you could glance at this and give a comment or two...generally speaking...

EDIT: Grumpy you were right on. I did have too much timing and it didn't drop off fast enuf. Thanks for the tip!

thanks

 

Too much advance is the most common error that people make.

Backfiring thru the intake or exhaust can be caused by a multitude of things, so it's rather hard to say what is causing it.