Whatever!!!!!!!!! Gearhead-EFI Edition

[EagleMark]

Good read!

[RobertISaar]

i imagine because "for the money, acoustic detection works well enough".

GM spent it's R&D money oddly at times...

from that article, it sounds as if it were coming from one of the northstar calibration engineers. apparently they did really simple methods though, just manually watching an ammeter, i guess as a backup to the knock sensor itself?

[EagleMark]

How would GM explain they used a Ion, built by Saturn to help with development?

I thought the used a pressure sensor in development? I looked into them once, a company build them into a spark plug and can data log off 5 volt refernce. But at IIRC $1000 per plug it's not going to happen.

I think the only affordable option to pursue this is still EGT gauges. Good info in there on how EGT drops during detonation, probably how guys get in trouble and keep advancing becuase temps are still cool? Already passed MBT...

[1project2many]

How would GM explain they used a Ion, built by Saturn to help with development?

A different kind of car.
A different kind of company.
A different kind of test.

Saturn was doing some really kewl stuff in the beginning. It's too bad GM corporate treated Saturn like any other acquisition and stripped everything good out of it.

Guys forget to use common sense. If temps are going up, up, up and they suddenly drop when they should be going up more, the answer is not to believe the Laws of Physics suddenly lost the battle with magic and wrong calibration values now are right. You cannot, cannot, cannot advance timing infinitely. I really have no idea why this myth still persists.

apparently they did really simple methods though, just manually watching an ammeter, i guess as a backup to the knock sensor itself?

Read again. They were learning to use ION detection without the additional complication of reporting results back to pcm. The SAAB system watches amount of ionization current, just like an engineer with an ammeter. So if an engineer can learn it, we can too. :)

I got to drive an Isuzu that had a Honda engine and Ion detection once. I expected a noticeable improvement in idle or performance but really, I felt it ran poorly. I wanted to spend time with using a scope to look at signals but I just didn't get the opportunity. What was interesting imo was the amount of complaints on the 'net by people with similar vehicles trying to cure misfire issues. In this case a basic tune up was all this one needed. But IIRC it was a 3.2 liter V6 and it had mostly GM electronics including a GM pcm and I suppose if you wanted a complete ION system for a V660 that would be a good starting point.

[RobertISaar]

i seem to remember an isuzu rodeo with a 3.2? maybe i'll investigate some more.

from what i'm told, the ion detection system is VERY sensitive to spark plug selection/wear.

waste-spark seems like it could be a potential issue as well, since while you could individually monitor half of the cylinders with no problem, the half that fires backwards would need some kind of trickery (significant negative voltage?) to monitor those... or maybe just replacing the inductive coilpacks with some DIY CDI coils, would still be firing as waste-spark, but at least the polarity wouldn't be a problem.

[RobertISaar]

http://lists.diy-efi.org/pipermail/g...il/008689.html

well..... that explains a bit. i have a 6401 here and have opened it up a few times... i never could figure out where the extra 512 bytes of RAM were coming from...

so, turns out there are at least a few different P4 processors... it's the wrong package to be a P6 and none of the factory code uses XGDX when it would have been beneficial to do so.

[Playtoy_18]

I saw that truck just a few minutes ago in my facebook feed lined up with a gold fox body on the street,both launching it looked like. (And the camper window was up :) )

I've seen that truck before, unbelievable launch. The camper window opening at launch is priceless!

[EagleMark]

That camper window that pops up is not by accident... it has a banner inside for advertising the NOS...

[1project2many]

Robert,

The Honda engine had individual coils. 2000 to 2004 Rodeo with 3.2. IIRC the SAAB Ion system used large diodes on the secondary side which would have precluded waste spark.

Interesting that the reman process might have installed wrong processors. Boy, wouldn't that make for a bad day in the repair bay if the replacement ecm behaves worse than the one you took out.

[jim_in_dorris]

LOL My son is a chrysler/dodge/jeep mechanic, and that happens all the time to him, sometimes it takes 2 or 3 factory new replacements to get one that works correctly. I think that they need to do some serious quality control.

[RobertISaar]

i can't think of any problems that would be caused by using the 1K P4 in place of the 512 P4... well, unless you have some really tweaked hardware and have opened up the 200-3FF range in a 64KB PROM(and are using it), since in that instance, the 6811 is supposed to read only it's internal RAM when the addressing allows... but since the P4 isn't a 100% 6811, it might not have that feature.

[1project2many]

I was referring to the comments to initialize the stack pointer at a higher address. If the code assumes a larger stack area there could be some interesting errors.

[gregs78cam]

Yeah, it's DONE!!!!! Been working on this for a couple of months now, in between two jobs at 70+hrs a week. I had to MAKE the die, and the bender to get a 10" Centerline Radius in my shop press. I coped all the cross tubes on the mill. And that shiny piece between the diamond plate is 3/4" thick, it took a LOT of preheat. I used my new water cooled torch, and my homemade 'Franken-Cooler'. All together it came out pretty well I think.


DSC00080.jpgDSC00081.jpgDSC00083.jpgDSC00087.jpgDSC00086.jpg

[dave w]

I was working in the shop this afternoon making an adapter for a Vacuum TBI EGR to fit a Vortec EGR mounting. It's an emission thing. Here are the pics. Its a two part adapter, one plate bolts to the EGR. The second plate is needed because the valve of the EGR is about 1/2" and I did not have a piece of 1/2 stock to work with. I also made a drill guide plate so the new EGR can be drilled in the same locations as the EGR pictured.

dave w

[EagleMark]

Yea, it's DONE!!!!! Been working on this for a couple of months now, in between two jobs at 70+hrs a week. I had to MAKE the die, and the bender to get a 10" Centerline Radius in my shop press. I coped all the cross tubes on the mill. And that shiny piece between the diamond plate is 3/4" thick, it took a LOT of preheat. I used my new water cooled torch, and my homemade 'Franken-Cooler'. All together it came out pretty well I think.

or you could have borrowed my bender...

That's a nice wake/ski tower.