THE OBD1.5 to OBD1 Conversion Thread

[ForcedFirebird]

Yeah. There are 2 ECM options when picking from a list at RockAuto, car-part etc. One is the regular "federal" and the other is for flexfuel.

EDIT: I asked about the foreign cars because I am doing a GM OBD1 swap in my 1986 BMW 325es if you do find it, though, you can email/pm it to me to keep the thread on topic.

You the man! Thanks again...

[robertisaar]

hmmm... converting foreign cars to run on GM ECMs...

well, i'll look around when i have time

[robertisaar]

ok, here's something for 95sleeperacheiva

this is for running a 3100 with NO tranny control from the PCM. last i knew he is working around tranny control by using microswitches, essentially making a brainless automatic aka, manual shifted automatic.

now the graph i posted is for using a 1227730 in place of the OBD1.5 PCM. using the cruzers.com pin interchange i came up with this, but it seems like it is only utilising 1 injector driver... meaning its firing all injectors at the same time. now this happens anyway at high-rpm, but its also happening at low-rpm as well. now the only thing that concerns me is that i don't know if the 1 driver is strong enough for all 6 at full throttle...

[bszopi]

All batch fire systems fire all 6 injectors at the same time, although they typically utilize 2 injector drives. If you look at the wiring pinouts, you will see that there are 2 outputs, but they merge together outside of the ECM.


And of course, I can't find a diagram that shows that right now... I'm pretty sure I have one at home though, so I'll update this thread later tonight.

[robertisaar]

All batch fire systems fire all 6 injectors at the same time, although they typically utilize 2 injector drives. If you look at the wiring pinouts, you will see that there are 2 outputs, but they merge together outside of the ECM.


And of course, I can't find a diagram that shows that right now... I'm pretty sure I have one at home though, so I'll update this thread later tonight.

aren't 7727/7730 and similar capable of bank-firing? if not, then whats the point of the Async Fuel setting? correct me if i'm wrong but, that value determines when the injectors go from bank-fire to batch-fire, right? i've seen a lot of BINs have it set somewhere around 10mS, which requires a lot of throttle to require that much fuel, at least on a stock LH0 it does. i think somewhere around 4000RPM, wife's GP was at around 11mS, and thats WOT passing grandpa's caravan doing 30MPH on a wide-open 55MPH road.

[ForcedFirebird]

AFAIK the '7730 is not capable of batch fire since you would need a cam sensor so that the ECM would know what TDC a particular piston was on (TDC intake, or TDC exhaust). It would be my understanding that any ECM without cam sensor input would have to be batch fire.

[robertisaar]

AFAIK the '7730 is not capable of batch fire since you would need a cam sensor so that the ECM would know what TDC a particular piston was on (TDC intake, or TDC exhaust). It would be my understanding that any ECM without cam sensor input would have to be batch fire.

in that case, i would really like to know what the hell async fuel is used for...

[robertisaar]

new version of the guide, removed some of the things that bothered me, and fixed 1 error. i had one of the pins for the N-Bodies set for A11, while the other two platforms had A1, which was correct.

john, i can get you the pinouts, found a disk, but it will take a while to get here. covers BMW from 1982-2008 IIRC.

EDIT: newest version is one page 1, post 1.

[robertisaar]

here you go john...

did i miss anything important?

[ForcedFirebird]

I started a new thread to help deal with issues I am having so far...

http://60degreev6.com/forum/f121/93-camaro-obd1-swap-t43890#post393747

[robertisaar]

FRET NOT MY PEOPLE!!!

due to being cut off from the internet for a while, i got some things accomplished

i mounted the 9396 PCM in place of the 1.5 PCM using the existing tray(after cutting a LOT out of it) and unfortunately i didn't have any type of fastener to hold it down, so i layed a thick coat of bondo(classy, i know) around the parts of the tray that the PCM touches. if i break/remove the bondo, i can still mount the 1.5 PCM in there if needed, but right now

1 reigns supreme where 1.5 once lived...

so mechanically, its ready to hit the road(even though the belt tensioner liked to rub up against the front cover under heavy load... i'll replace it when its actually running).

legally, its still uninsured and the registration will be invalid next month.

what a dilema...

now time for the glourius pics!


everything tucked away from the motor.

same idea, different angle

from the top. i should have painted the bondo black, but it will do for now

top again: lots of clearance between the harness and the motor

next to the relay/fuse box: PLENTY of room to swap chips

and finally... a shot showing most of the externally noticeable mods

most noticeably the white upper strut bar(i ran out of black paint and it was starting to rust)

then the red Taylor Spiro-Pro plugs i made(complete with electircal tape insulation due to a tool slipping and taking off some of the "ugly" red silicone

then the black intake... its VHT Ceramic-Silica, expensive but good stuff

smaller details include the oil dipstick, which is the flat style as opposed to the stock ring-style(another tool slipping accident)

and the fuse block that runs under the strut bar and goes to a dual battery system i made(fuses removed since the second battery is removed as well)

not shown: donkey dong bypass(look at underside of your intake, you'll know what i'm talking about) and gutted/smoothed airbox(for the lovely 3100 noises to be even louder, which combined with my glasspack makes me want to violate the chrome turndown in ways only true enthusiasts could understand...

[asylummotorsports]

Ghetto mechanics FTMFW!! But I trust it works.

Another great use for bondo.

I just have to finish my PVC roll bar, and make a tinfoil helmet.

[robertisaar]

stays perfectly still(in relation to the frame) when the motors running, so i'm more than happy with it. the better solution would have been to get a 94-95 3.4DOHC PCM mount, but being as broke as i am, that was not an option. plus its nice to know you don't need more stuff...

i almost want to make a PVC rollcage just to mess with the ricers around here...

i'll keep my chameleon painted motocross helmet though, it looks a little fancier than tinfoil...

EDIT: guide has been moved to post #1

[ForcedFirebird]

The '9396 and '7727 bolted right on place of the f-body PCM. It just used a hole in the side of the bracket and it sits right in the stock location. Did you try using the stock OBD1.5 bracket to hold it in? I think I have pics, if I do I'll upload them here in a few.

You should have used that Bondo to clean up the 90* turns on the stut brace

[robertisaar]

i did do a little work to cover up my funny looking welds... 20 year old 110volt arc welder FTL!!! but it was a busy day, so i didn't have much time and it needed done....

it sounds like the tray is different between the FWD and RWD stuff... mine had three tabs that held down the stocker and didn't have anywhere to use the removeable nut/stud combo...