LX9 Swap to 99 Cavalier Thoughts and Q's

[Dreamka]

I'm working on putting an LX9 into my 99 Cavalier with a 2001 Getrag F23. I'm still gathering parts and getting everything ready.

Everyone seems to go with the external crank trigger etc... Here's what I'm trying let me know if I may be missing something.

I'm putting the LX9 straight into the car using everything it originally came with in the Malibu I got it from.

I picked up a 3400 return fuel rail and will be using the said 28# injectors from a trailblazer dropping down to a 1999 43.5# Regulator making the 28's roughly 24.8# and from what I've read the stock Malibu injectors are 24# as well.

I am using the gas pedal out of the Malibu so i'll have drive by wire and not have to change anything.

Anyone find any issues with this or can you think of anything I may be missing... Why don't people do this? It's really easy.

[caffeine]

You may need to wire in the BCM and install the ignition cylinder from the Malibu to make it work because the LX9 PCM cannot be tuned.

[Dreamka]

Well now this makes a lot more sense! That is why no one swaps it this way because there is ZERO support. I just checked HP Tuners and that statement is correct.

Back to the drawing board... I guess i'll be swapping the same way as everyone else at this point in time. My plans are to turbocharge the car after it's swapped and if I can't tune it I can't build it this way.

Thank You!

[caffeine]

If you really wanna use the stock crank sensor you can probably alternatively use just about any standalone that can decode a 58x LS1 trigger wheel.

[stargaazer7467]

im already 3400 hybrid turbo swapped in my 95 sunfire, but about to put a full 3500 in it. im using an external trigger with my existing custom pcm. i deleted the whole BCM system.

[Dreamka]

I went to the junkyard today and pulled a wiring harness out of a 2003 Impala 3400 with pcm injectors etc...

I noticed that this car had a reluctor wheel on the inside of the crank pulley and a sensor on the outside of the timing cover. Do I need this pulley and sensor for the swap? It sure looks like it but I can't seem to find any info on it.

[caffeine]

Yes you will need that for an OBDII PCM

[Dreamka]

Maybe someone can explain this to me. So the OBD2 3400 pcm's have 2 crank sensors? One on the crank pulley with a sensor mounted to the timing cover? One in the block reading a wheel on the crank? Why does it need two? What do they both do? Just trying to understand this more.

[3400-95-Modified]

Fine resolution on the spark advance as well as I believe it's used for miss fire detection. Either way that sensor and the Cam sensor are two sensors that are not on OBDI style setups and were seen on the OBD1.5 SFI and up engines. You also do not have to use an external crank trigger, you can buy the internal one but that requires removing the crank, taking off the old and installing the new trigger wheel and the putting the sensor in the block. That's what I'm doing with my 3500 in my Beretta. I don't like having that trigger and sensor on the outside of the block just hanging out there.

[Guest]

Nothing wrong with external crank triggers. I've had them on 3 of my vehicles now, well technically 2 vehicles, but 3 engines. My Jimmy that I drove year round, then used the same trigger wheel (but new sensor mount) on my Nissan L28 turbo, and now on my LX9 in place of the L28. I drive this car 3 out of 4 seasons, and actually as of January 2nd this year you could say all 4 seasons. I've never had an issue with debris or road dirt. The only issues I've had were my lack of planning on clearance to the Nissan crank pulley and how it moves...

OBD2 swaps have been done, but I'm not sure they used the 3500 PCM, or at least used it in an application where the car didn't already support the 3500 PCM. If you want SFI, you could use a 3400 PCM (some of which I believe are tunable) but would still require an external crank trigger. There's also teh possibility that an LS1 PCM could be tricked into running teh V6, but I have not been following the progress on that.

The easiest swap is definitely going with an OBD1 ECM, or going aftermarket, such as Megasquirt.

[Ghosteh]

The easiest swap is definitely going with an OBD1 ECM, or going aftermarket, such as Megasquirt.

"Easy" is a subjective term! lol!

Of the two options above, which is simpler and better for a car that will not be using a stock wiring harness? I looked at Megasquirt's page & am completely confused at all the options and models they offer.

[3400-95-Modified]

Simpler and better would probably be stand alone... The task of trimming down a wiring harness, OR building one to work with a stock type ECU and not get pissy with other OEM components missing may be WAY too much effort vs getting an ECU that can be setup to run ONLY the engine and ONLY monitor what you want it to.

[caffeine]

I dunno IMO OBDI is easy to trim down. There's not much extra to begin with either.

[3400-95-Modified]

IMO I feel OBDI is just such a step backwards and sometimes limiting with it's age and support... Stand alone allows you to be current and open to tune every aspect of the setup with very little limitation.

BUT we all have opinions and everyone's is going to differ