obd1 to obd2 conversion

[choppester]

ok I know we've had this tread but what we never talked about whats the process of switching obd1 to obd2. can we cut and splice wires from a 94-95 ob1 to a obd2 96 or do we have to switch out all the wiring harnesses dash, engine, and drive terrain, and what have any of the people who have done it in the past explain to me how did it turn out

[IsaacHayes]

In the L bodies, you can swap the engine bay harness and fix a couple wires on the inside and it's done.

I've heard another L body who just repinned the connectors on the inside.

but this is obd1.5 to obd2.... Full obd1 will need a lot more work than jsut repinning.

[timg]

W-bodies require a new engine harness and PCM. The firewall connector needs to be re-pinned, but most still work. RedZMonte has done the swap.

Tim

[OldSkoolGP]

OldskoolGP has done the swap too. He's even got it working with a 5 speed. I have no idea how, you'd have to ask him.

[robertisaar]

refering to yourself in third person....

i'm thinking it involves a switch that tells the PCM the car is in neutral when the clutch is depressed?

[pocket-rocket]

Pocket-rocket thumbs his nose at OBD 2 and says "KISS" (keep it simple stupid), but I think he's kinda weird...

refering to yourself in third person....

i'm thinking it involves a switch that tells the PCM the car is in neutral when the clutch is depressed?

That would be one approach to launch rpm control...

[robertisaar]

Saar also does not like OBD2, hence the OBD1.5 to OBD1 conversion. it removes the second crank sensor and cam sensor for even more simplicity. Saar likes simplicity...

[OldSkoolGP]

refering to yourself in third person....

Well, everyone always forgets that I was the first or second one to (insert DOHC related modification here), so I I know a lot of the problems and the pitfalls. It's not pretention, just goofiness.

Simpicity is nice..........

Until you want to know how much air you're actually getting into the engine. Then you need OBD-II. Also, SFI never hurt anyone. OBD-II is really not that complicated. The extra sensors you need aren't even a problem if you start with a 96 or newer engine. If, like me though, you start with a 92 engine, you gotta change a lot. But even so, I'm glad I did it because now I can tune my car without having to pulls chips in and out. I reflash it right in the car in 30 seconds. And because HPtuners accepts input from a wideband O2 sensor, I have all my data and calculations in one nice little package. Simple!

Oh, and the trick to getting OBD-II to run a manual transmission is to convince the computer it still has a transmission to control. The solution is unusual, but again, simple!

[robertisaar]

uh-oh is time to start school:

$DF calulates how much air is going into the engine, not directly since its a SD system, but assuming the VE tables are correct it will give you the right number is grams/sec...

SFI....... what a gimmick, when i fired up the monte yesterday for the first time with the DF PCM, i've never had it idle so well, sure emissions might be a little lower, but in michigan, there's no testing. and OBD1 has had SFI, actually back in 1984 i believe, when the first GN came around. i bet i burn chips and swap them out faster than it takes to flash your PCM... ZIF sockets FTW.

for me, there's no advantage to OBD2...

[pocket-rocket]

Well, everyone always forgets that I was the first or second one to (insert DOHC related modification here),

5 speed swap? Oh yeah, that was me... Tapered TB, oh yeah, me again.

[IsaacHayes]

Or u can use the moates emulator so you don't have to swap chips........

[robertisaar]

i'll stick with the 90 it would cost me for the burner + chip, rather than the what 170 for the emulator? still cheaper than obd2, and faster too.

[IsaacHayes]

I haven't looked at the prices lately. Depending on how irritating it is swaping chips, I would probably get the emulator, tune, then once I had a decent tune that was drivable, sell the emulator and swap chips when I get a more precise tune or after a small mod.

I guess it depends how far off the LQ1 tune is from stock, or how radical of an engine swap you have if it's worth the convince.

[robertisaar]

it usually only takes 2 or 3 tries to get the VE right, then the spark is pretty easy as well, just look for knocks, and reduce it there by .5 degrees at a time until it disappears. maybe another 4 or 5 there. obviously bad sensors could cause issues, but in general it isn't worth it to me to spend the initial investment on something i'm only going to use maybe 10 times per setup.

[OldSkoolGP]

I'm not gonna sit here and debate which is better. That's for each of us to decide. You got your reasons and I got mine. But I'm not let anyone get away with saying that PFI is better than SFI because that is ridiculous. With PFI, all the injectors fire at the same time. With SFI, the injectors fire when the intake valve opens. If your fuel isn't puddling on your intake valve and staying atomized from injector to combustion chamber, you get a better burn, pure and simple.