Title says it all.

I am noticeing a kind of lack of power at about RPM range that the VE tables may change from the first table to the second. When I looked at the values at the peak RPM level of the first table, which was 1600, I noticed that the values were not equal to what the second VE table starts with, again 1600 RPM. I went ahead and changed the first table values to match the second, but unfortuately, I didn't get a chance to test drive today. I will work on it first thing tomorrow, but I was just wondering if making them the same was a good idea. It seems to make sense to me that they should be of equal values. Then again, I don't know all of the intricacies of the 7730 ECM. Maybe someone can explain to me. Should those values be the same? If not, how does the ECM "know" which values to use and how would I go about tuning the correct values, if they are to be different? This could just be a simple mistake I made some time ago when I began to work with the VE tables, maybe I changed the values...

Thanks

 

$8D? Uses the RPM term. Up to and including 1575 RPM the lower table is used. Once at 1600 RPM and above the upper table is used.

Yes, both 1600 RPM rows should be the same.

RBob.

 

This same problem plagued me for over a year after I bought a custom chip. My car would crap out and sputter from 1400 to 2000 rpms at wot shifting from 1st to second gear manually. I tried everything to find out why. I spent 1k on parts to upgrade my FI system because of things people told me. Recently I sent my chip to a friend here on tgo and he read it for me. Found out that among other problems my VE tables were the same as yours. Two different sets of numbers in each of the two 1600 tables. They have to be the same. What was happening is that the ecm would bounce back and forth trying to read two different sets of numbers. Thank gawd this is being resolved. Sent the chip back for reburning. Now I am buying my own chip burning stuff to burn my own. Laptop will be here any day now. Cant wait to get started. Bottom line is this...I spent 400 dollars for a starter chip about 18 months ago because of a lack of research on my part. A lesson well learned.

 

the tables *MUST* overlap for the interpolation (look-up routine) to work.

RPM | %VE
made up numbers just for example

RPM = 1575
1500 | 76
1575 | 78.75
1600 | 80

RPM = 1615
1600 | 80
1615 | 81.5
1700 | 90

does that help?

 

Be sure to repeat this regularly to the new guys asking about generic chips.

It seems like there's been an entire industry that in large part has just been good at seperating the unknowing from their money. BTW, BTDT, on having been ripped off.

 

Thank you all for your reponses.

My cars performance has been really bothering me recently. I have fixed so many things that I feel obligated to really make the engine run at its potential. I still have not test driven it with a chip made to correct for the stagering VE table values, but I hope it helps.

Another thing I have been getting is the engine just seems to fall on its face when I go to half or more throttle once its warmed up. When its cold, she runs fine. And I have recently installed a WB O2 and been noticing what others have posted about recently with the AFR values showing 15-17 when the BLM shows 118-132. I am thinking of researching how to keep it in open loop and just use the WB and plug readings to tune it appropriately. All of this to attempt to get better performance out of it. Just brain storming for know though...