MMS 3500 swap

[ricklovin93]

i think im gonna swap to a newer pcm, that should allow me to do some tuning, im guessing i would need a pcm that is for a car that uses the 4t60e and either a 3100 or 3400 engine ( deciding if i want to swap my 3100 out for a 3400) then i should be ablt to use the hp tuners (if im correct) but please someone correct me if im wrong

[jman093]

i think im gonna swap to a newer pcm, that should allow me to do some tuning, im guessing i would need a pcm that is for a car that uses the 4t60e and either a 3100 or 3400 engine ( deciding if i want to swap my 3100 out for a 3400) then i should be ablt to use the hp tuners (if im correct) but please someone correct me if im wrong

 

I think a 4T65 PCM would be fine since you'll be putting your old software in the newer module.

[ricklovin93]

but my tranny is a 4t60e wont their be some complication due to the different trannys

[jman093]

but my tranny is a 4t60e wont their be some complication due to the different trannys

 

If you use the software in that PCM. The only 4T60 after 96 anyways is some 97 Luminas and Monte Carlos.

[RobertISaar]

4T60E was used with all 3100 W-bodies up until 2000, when they switched to the 4T65.

 

anyways, more often than not, the PCMs used were identical between all 3800/3100/4T60E/4T65 whatever for a given year. it's all in the calibration.

[ricklovin93]

ill look for a 97ish mc/lumina with a 3100, im pretty sure i could run a 3400 off of it if i had to, do you know if a different pcm would cause any complications with my annual inspection

[RobertISaar]

a 96 and 97 PCM look the same externally, IIRC, and as long as no codes get thrown, shouldn't cause an issue, i would think.

[ricklovin93]

if codes to get displayed couldnt i tune them "out" ya know get rid of them?

[RobertISaar]

IIRC, you need to have them set to an "always pass/done" mode, otherwise the emissions station won't pass you.

 

not that i know the specifics of any of this.

[ricklovin93]

I'll have to contact a garage and see what the rules are haha, i mean its a pcm for a newer car so it cant be a bad thing,

[Jonpro03]

I've used a 97 lumina pcm in my 96 GP before. 2nd gear start wont work. Later it ran my LG8.

 

Swapping a 3500 requires some custom work. Things that come to mind:

 

* Throttle body: Downgrade to a 3400 56mm is easiest

* External 7x trigger

* EGR adapter/block plate

* Install 3x00 timing cover for 24x

* Install 3100 lower mount on oil pan

* Install 3100 driver side dogbone mount

* Forgo or customize passenger side mount

* Use 3100 exhaust for correct downpipe or custom

* Use 3100 alternator/bracket

* Install 3100 power steering pump

* Use 3100 harness and cut/wire the injectors and coolant temp sensor

* Remove oil filter neck and screw oil filter to block

* I don't recall if a 3x00 fuel rail fits under a 3500 UIM, if not use 2000+ 3x00 fuel rail with 3400 upper intake, or modify fuel system to be returnless

* Install 3100 knock sensors (there's a spot for them)

* Don't think the AC is interchangeable so ensure window motors are good

Edited March 2, 2012 by Jonpro03

[ricklovin93]

screw the 3500 swap idea haha, you used a 97 pcm to run a 96 3100?

[ricklovin93]

I figured it out ill keep the 3100 do a 3400 top swap, use the newer pcm for tuning and keep the original pcm for inspetion just in case the newer pcm causees it to fail inspection, so then i can simply take the newer tuned pcm out and replace it with the 96 pcm for inspection, but then when i put the tuned pcm back in will all of my changes still be in the pcm?