3900 6spd With ECM ?

[bnevets27]

I know there as been swaps done with the 3900 and the 3500 but as far as I know , no one has used the stock ecm. I know that the engine is drive by wire, so at the very least the gas pedal would have to be included.

I guess my question is, what all is needed to be taken from a donor car to be able to keep everything running as stock?

Is this plausible?

[Superdave]

drive by wire is terrible.. and i personally can't stand the new ECM's. IMO running it on OBD1 is the way to go.

It is plausible but a HUGE pain in the ass.

[bnevets27]

The well one of the reasons I figured it we be good to retain the stock ecm is for VCT and variable resonance intake manifold (not sure if thats the correct name). I am referring to the different length intake runners. As far as I know, no one has been able the control VCT and has to lock it in position.

This is deffinately not my field of expertiese but could it be possible to send the ecm what its looking for as far pedal position input. Maybe use something like a Throttle position sensor. Then you could get rid of drive by wire.

[robertisaar]

want to control the intake? use a vette LT5 ECM.... if you can find one anyway

that could be done with a solenoid and rocker switch or maybe a PWM solenoid that is controlled by the TPS... there's a few possibilities, but it just depends on how much of a pain in the ass you're willing to deal with. i'll eventually have a 3900 and F40 running on a 16149396, but it will be a LONG time before i have the funds necessary...

as far as controlling the VVT.... i don't know if you could, i don't know what kind of signal it wants.

[TiredGXP]

Unlike Superdave, I like the DBW on my LS4 (had it for 4 years now), and GM did a good job on it in that application. Throttle response is crisp, you can't tell that it's there. (Mind you, I did a bit of tuning to get rid of most ot the torque management that uses the ETC). The only issue that bugs me is how much cruise control varies with slight gradients (+/- 2-3 kmh).

I'm trying to learn OBD 1 tuning so I can use $59 for the Fiero, but it's a tough slog.... Still prefer the GUI interface that HPT has for OBD II - that's the way I'd go to keep VVT and the variable intake.

[bnevets27]

Funny you mention that TiredGXP, thats where this engine would be headed. I've read a good portion of the builds with 3500's and 3900's going into fiero's. Seems like it takes a bit of work to convert everything to run on OBD1, and after you do, you lose the VVT and variable intake. Both things I think work help make the engines output like it was meant to run. I know many things can be done to make it perform fine without VVT and varible intake but this would be mostly a daily summer driver and I'm quite happy with keeping it stock.

I have already installed the 7730 ecm setup to run the stock engine so I COULD use that. But I figure if you take the whole setup out of a G6 it wouldn't require as much if any tuning and trial and error with setting up OBD1. This is just from what I have seen by reading Joseph Upson's build. Someone has started a 3900 build on pennock's using OBD II as suggested by darth.

If there isn't much that has to be taken out of the donor car, then this seems like an option. Does the ecm interface with the dash??

And I'm only looking at using the 6spd that comes mated with it so I don't have to worry about ETC.

[IsaacHayes]

It's possible to control the VVT and VI with a window switch I'm sure. Kick on/off at a certain RPM. Sure it won't be probably as smart as far as engine load/etc.

Drive by wire has torque management and other BS that doesn't let the throttle open when you tell it.

Other issue is that it's probably a CAN bus and will be looking for all these other modules. Body control module, trans control module, etc etc I don't know what options the tuners give you to edit that stuff out though. And yes the dash/gauges will run off the CAN signal and so you won't have that for your car, or at the very least will have to find a way to tap into the sensors to get the signals you need for your dash, possibly using a VSS pulse converter for the right pulse for the dash, and tapping off the ICM for the RPMs.

Either way, if you swap the stock ECM you are going to need to tune it to get rid of the torque management and errors of the missing modules. Or swap over every single wire, sensor, module, etc...

If you aren't in a hurry just watch the OBDII swap the guy is doing there on fiero.nl and see what issues he runs into.

You'll have to run the ETC if you are running the original CAN ECM... it won't work right without it, as it uses the ETC for cruise, IAC valve, etc

[Superdave]

Yah, it's mostly the torque management that drives me nuts. I've almost gotten hit a few times in my Trailblazer because i go 3/4 throttle and it just barely moves.

the cruse thing is weird, i noticed that too.. there were times when it would take me 5-7 over what it's set to. I just took it on a 3500 mile road trip last week.

[CNCguy]

I am planning to use the 1227730 shift light signal to toggle the Intake Manifold Tuning actuator. Although I have completely removed the VVT feature on my LZ9, it too could be set up to toggle at a given RPM. I think that you would need to limit the VVT travel for this mode of operation.

For the E67 ECM to operate it must communicate with the TCM and BCM.

[bnevets27]

By using the 6spd manual tranny, that would eliminate any torque management. Also it would eliminate the need for the TCM.

ETC = Electronic Throttle Control? Not sure all the components that need an input from it to function properly. The ones you mentioned aren't really necessary, if you use a cable operated throttle body. For cruise you can use a standalone unit, from '90 gm's. And the IAC would be different since the throttle body would be changed. That’s if nothing critical needs input from ETC.

Or, since the manual tranny is being used, the ETC shouldn’t really have an effect on performance? So then the ETC could be used without worry of torque management.

I'm in no hurry at all really, so I can watch the progress on the fiero form and see how using an ECM from a 97 venture IIRC turns out.

But I am curious about getting the stock E67 ECM working with a swap. Currently it looks like it would be a big task and the most gain you would get would be retaining VVT and VI functionality.

I guess the biggest factor is what can be disabled in the ECM. I've read a bit over in the hptuners form about the E67, they are able to tune and edit it. But not sure what can be edited out/disabled.

What really would need to be edited out would be the BCM. I don’t know what info the ECM gets from the BCM that would effect the functioning of the engine. But from what has been said here it is needed for the engine to function. Why is that?

There is actually some good info about the E67 in this post, with some wiring diagrams:


If anyone knows somewhere else I can read up on the E67 please let me know.

[jmgtp]

I am planning to use the 1227730 shift light signal to toggle the Intake Manifold Tuning actuator.

That output has a lot of potential for things like variable intakes/cam phasing. The 5 speed code has logic for each gear too.

I just modded the shift light logic to turn on an electric vacuum pump. I have it set to kick on at 4k rpm - which was so easy to do, just had to add the shift light constants to TunerPro. Ideally I wanted to incorporate the RPM kick to also be dependant on a minimum throttle position. I can't seem to get the RPM/MPH windows right though, so for now any time I exceed 4k its on. Let me know if you figure that part out!

[robertisaar]

i don't know if it does take into account the TPS when determining when to turn on the light....

besides, in your example, anytime i'm above 4K its WOT anyway...

EDIT: if you are using DF, then there is a constant for "minimum TPS for shift light on"

[jmgtp]

Yes I'm using DF and I did see the minimum TPS % for on. However, that is overidden by the RPM on switch. Anytime the RPM exceeds the set constant the light is triggered, regardless of TPS.

I think my issue is in the upper/lower windows. For example I set the min TPS constant @ 50% and then widend the upper and lower windows to their max - my assumption was that with the windows at the extremes and one I hit TPS 50% the light would come on. There are also some other things that I tweaked - I recall something that looked at the variance of the TPS, in other words if you were increasing TPS % the light wouldnt come on - I maxed that out too so that any variation wouldnt matter. I havent looked at it in a while now. I may play around with it again soon - I'm kinda hung up on the 'windows' though. Sorry... this is getting a bit far removed from the original posters topic!

I occassionally hit 4k in daily driving at less than 50% TPS. It's different when you have a manual trans and 4k is nothing for the dohc.

[robertisaar]

I occassionally hit 4k in daily driving at less than 50% TPS. It's different when you have a manual trans and 4k is nothing for the dohc.

hence, why i prefer OHV to DOHC, you don't need as many revs with a torque-heavy motor to move compared to the high-end powerband of the LQ1....

and i don't think it really getting off topic since its probably going to be a question that comes up later...