Needing a stock 3500 tune put in my '98 Lumina ECM

[JBA11]

Hello everybody
I have a 3500 and a 3400 that needs a rebuild and I have done a 3400/3500 hybrid on OBD1. I would like put the 3500 in the car but I have not decided which way to go. The thing that is holding me back is tuning OBD11. I would rather put the 3500 in it but I was wondering if any one here could flash the stock 3500 fuel, timing, ve table, etc. into my ecm. I will probably put it in stock for now but if anyone knows of headers that will bolt on to 95-98 Luminas or Monte Carlos, I would install them when I put the engine in. I can get the 3400 stuff flashed into my ecm with no problem but I do prefer the 3500. Thanks in advance for any help that you may offer.

[3400-95-Modified]

All you would need are those tables to put in a 3400 file... and the only ones that would do you good is Spark and VE... You can't use the MAF table unless you are using the sensor the 3500 uses... and the injector constant would be whatever injectors you end up going with which may not be the same as the 3500.

[JBA11]

Thanks Modified. A few other questions:

1. Would I benefit from running the 3500 MAF?
2. Do I really need to run a MAF or can I program it out?
3. Have you done this before and how did it perform?
4. Do you have these tables?

I have tuned OBD1 before but OBD 11 is new to me. I also have access to a GM TECH 2 and was wondering if I could use it to make these changes to my ecm?

[3400-95-Modified]

I don't know if the Tech 2 can make the changes, I dont think you have free editing rights to the inside of the file, it may only flash a certain file you pick.

as far as the tables yes I have the VE and spark tables, I put them on my car as a starting point and moved from there since I'm ported, but it worked fine to start with and had me much closer than starting with a 3400 file.

As far as programing out the maf I don't know why you would want to do that. Speed density is an old technology and as long as you are not exceeding the flow of the maf sensor you'll get much better resolution and fueling using it... At least I fell that way, others may disagree. I'd rather have my ECU know the flow of air coming in rather than having to calculate it from other tables.

The 3500 maf itself you would only benefit using that if you can't fit the regular 3400 one in the bay somewhere. IIRC the 3500 maf is much smaller

3400 Maf


3500 Maf notice you would have to make a housing to mount it to be in the intake track.

[Fireball]

I don't know if the Tech 2 can make the changes, I dont think you have free editing rights to the inside of the file, it may only flash a certain file you pick.

as far as the tables yes I have the VE and spark tables, I put them on my car as a starting point and moved from there since I'm ported, but it worked fine to start with and had me much closer than starting with a 3400 file.

As far as programing out the maf I don't know why you would want to do that. Speed density is an old technology and as long as you are not exceeding the flow of the maf sensor you'll get much better resolution and fueling using it... At least I fell that way, others may disagree. I'd rather have my ECU know the flow of air coming in rather than having to calculate it from other tables.

The 3500 maf itself you would only benefit using that if you can't fit the regular 3400 one in the bay somewhere. IIRC the 3500 maf is much smaller

3400 Maf


3500 Maf notice you would have to make a housing to mount it to be in the intake track.

Dear lord how do you clean that one if it gets oily/dirty?! lol

[robertisaar]

looks like one of those nasty Hitachi(IIRC) units that the 3800s used forever.

[JBA11]

Thanks for the info. Modified, could you send me those tables by any chance? I would greatly appreciate it. As far as the cam position sensor I believe that I would have to use the one for a 3400, is that correct?

[3400-95-Modified]

You can use whatever for the cam position sensor, I have a 3500 one on my engine since I used the plug and wiring from that style engine, the plug is directly on the sensor rather than having the long pigtail. Its the same plug/sensor as used on the 03+ 3400's IIRC

PM me your e-mail and I can send over those tables for you to look at.

[JBA11]

Modified, Thank you for the files.
Do you know if the 3400 has all of the files that you sent, if so I could just copy and paste them in? Should I just use the VE and spark tables or should I use them all? I am just going to run the 3400 MAF as I believe that would be the easiest route to go. By the way what tuner are you useing?

[3400-95-Modified]

I'm using a DHP and yes those tables should be seen in a 3400 file, obviously depending on which one your starting with, some vary with names and I know my 97 file is a bit more scarce than say a 03 GA file or something.

I would suggest starting with what you changed... mostly the VE and spark yes, but I would also double check that your injector flow rate is right for the injectors your running and I would possibly use the Acceleration Enrichment tables from a 3500, but then again they changed how those were used from year to year so you may want to leave them alone and just tweak whats there to give you better throttle response off idle IF you see an issue.

I included the VE, MAF, AE, IFR, Good fuel spark, bad fuel spark and mean best torque spark. I don't know when the ECU switches to the MBTS table though.

[Z26-T]

I have tuned OBD1 before but OBD 11 is new to me. I also have access to a GM TECH 2 and was wondering if I could use it to make these changes to my ecm?

You can't "tune" with a tech2. Tech2 is primarily for diagnostic purposes. You can upload the factory program into your ecm using the tech2 via pass-through or remote. But when it comes to changing stock parameters, it doesn't do that. Unfortunately. And again, to even upload the factory programs you need access to their websites.

[robertisaar]

if you have access to the GM SPI files, you actually can upload custom BINs if you download the BINs from the site, grab them from where they are cached on your computer, modify them however you see fit, then upload them to the PCM.

it's how somebody got into the 96-up northstar PCMs.