3500 Swap Finally Underway, a few questions

[Jonpro03]

You forgot to take pictures!

[jmgtp]

Finished up all the wiring except for the alternator. I've decided to reuse the stock LX9 spark plug wires since they are in good shape. This does mean cutting off the terminals at the coil end and crimping on new ones since the LX9 coil uses different terminals than our more familiar 60v6 DIS, there should be enough slack in the wires that the inch or so I'm losing off each one shouldnt matter. Despite the wiring being 99% done I'm not happy with the wire loom that crosses from the ecm to the engine. There is just too many different looms coming over and it looks bad and creates bulk. I am going to remove all the separate looms and use a single large size to carry the bulk of the wires over. It's definetly going to take some time to do it but the end result will be worth it.

I have the throttlebody mounted and the plenum bolted on.
Hopefully I'll get to the spark plug wires tonight and then it is ready for a test fire!

[CNCguy]

Whenever this thread is updated, I always read it.


Colin,
I have connector kits for the new style MAP sensors in stock. If your wires are long enough, it's easy to cut the old connector off and install the new one.

[HOYS]

I did find the wiring for the MAP connector for my '03. Looks to be the same, just need a harness adapter.

[jmgtp]

The new small size MAP sensors are labeled on the back! GM made this easy for us. The pins are labeled Gnd, Out (which is signal) and 5v. So now I know the correct pins on tne new map and can match the wires up easily. I don't know what the wires on my harness are but I can easily reference my factory service manual for that information. So, yes I did figure it out but I haven't wired it up yet. I'll take a pic of it showing the labels in case yours doesn't show it.

I am a set of ignition wires and a throttlebody gasket away from first start - maybe Saturday.

[HOYS]

Did you figure out anything with the MAP pinouts? I'm looking at using the smaller MAP sensor instead of my 03 style MAP.

[jmgtp]

Turns out you can mod a 96/97 3.4 DOHC throttlebody to bolt up without an adapter plate. I had to do some cutting, grinding and drilling but it lines up and bolts on. In the pic you can see the bores are a millimeter or so off, but since the pic was taken I took a die grinding/cutting bit to the manifold and opened up the TB hole enough so that there is no longer any overlap.

The only thing that isn't perfect is that the 3.4 TB is exposed on the backside where there are ports that see full vacuum - meaning without something to seal them off I will have a giant vacuum leak. My plan is to cut a gasket from a rubber gasket sheet and just leave that part intact to seal the area. I'll have to use some silicon to ensure it seals and the top bolt hole on the dohc TB can also be used to secure the gasket since it is not used to bolt onto the manifold.

I washed the manifold in the kitchen sink afterward to clean the aluminum shavings but after I dried it (in the oven, I can get away with that when my girlfriend is not home) I could see that shavings were still in the ports. Back to the garage to use compressed air to clear it, but still the shavings were not all gone! Finally, I went to shower...and I took the manifold with me! I used the high pressure setting on the removable shower head (the thing with the hose, I don't know what its called) and that seemed to do the trick but its getting compressed air again before going on the car.

And that is all I did tonight!

[jmgtp]

Glad I have some fans of the swap!

I'll hopefully work for a few hours tonight. I've been plagued by low back problems that have really slowed me down, what I really need is a solid 2 week break from car work to heal up right but I need this car done and my garage restored to some kind of order. Thankfully the grunt work is done but even standing up and leaning into the engine bay for a few hours takes its toll. The wiring/hoses etc is taking longer than I expected mostly because the LQ1 wire harness has some significant differences from a pushrod motor. I had to rework, lengthen or reloom MAP, CTS, ICM, CPS, KS, injectors, Charcoal Canister, alternator and then some. I used strong soldered connections and shrink tubing. Then used a digital volt/ohm meter to measure the resistance of the wiring from the connector pins all the way back to the connector on the ECM just to be sure that I didn't have any shorts to ground or open circuits.

If I get really ambitious I think I can fire it up for the first time tonight, if only for a second or two. Off the top of my head, to run, all it needs is a throttlebody, map sensor and ignition wires. I may just bolt up that 3.1 throttlebody I have lying around as a temporary solution to finally get the satisfaction of hearing it run - but don't count on it, there is always 'something' to hold you up.

[pocket-rocket]

I do as well, obviously...

[Jonpro03]

Also read it.

[bszopi]

I'm reading it! Of course, I read every single post on the site, but if I didn't, i'd still keep track of this one.

Droid via Tapatalk

[jmgtp]

I'm not sure if anyone is reading this but I'm still posting for my own benefit!

I worked on it for 2 hours last night and felt as if I accomplished nothing since all I completed was fuel lines and heater core lines. I have the spacer bracket from Wot-Tech for the FPR but I still had to grind away a good bit of the throttle body neck on the LX9 plenum to clear. I did pop the plastic 3500 beauty cover on the plenum just to see how it looks and I gotta say I like it, gives the engine bay a more modern feel. Need to trim it a bit since it interferes with the power steering pump - something that the Malibu this engine came from didn't have.

What's left...
-Wire in the new compact MAP sensor - anyone know what the pinouts are for the small MAP sensors? My service manuals are for the '91 so I only know what the wires on the old sensor are but I want to use the small sensor that came with the LX9
-throttlebody, I have a 3.1 GenII TB that bolts up, I may just use this as a temporary solution
-install updated connector for alternator
-install axles, hubs, brakes
-power steering lines
-serpentine belt - noticed I have to pull the CPS out of the external trigger to install it, that makes side of the road serpentine belt change impossible
-radiator, fans, hoses
-throttle cables
-brake booster line and other vacuum hoses
-water + oil
-and ugh, it needs an alignment since I replace the rack

[pocket-rocket]

I considered using a torch to heat the tube to ease the twisting but I decided against it since the tube contains such a hazardous checmical

I'm glad you didn't. Depending on if it was the high side or the low side, it could have already had around 150-300 lbs of pressure in there, IIRC. Heat would have made it much higher, and I'm glad it didn't kink

[jmgtp]

Just a note for future reference in case someone reads this thread looking for answers...

I ran into a problem with the a/c compressor. I'm using an iron a/c bracket from I believe an early 3100 w body (94-95) but it may actually be from a GenII 3.1 car. Anyway, the stock R12 3.4DOHC compressor bolts into the bracket no problem, BUT it holds the compressor at about a 30-45* angle different than the stock 3.4 DOHC bracket. This means that the 2 aluminum lines exiting the rear of the compressor are now also at a different angle. One of the lines appears to be an expansion chamber before it leads off into the hose. The different angle brings the expansion chamber closer to the blcok and interferes with the starter. I am using a 3x00 mini starter and it interferes - if you are using an older starter (like my original 3.4 starter) it would interfere much more since they are much larger.

I used a large monkey wrench and to grasp the expansion chamber and an adjustable wrench to hold the compressor and I twisted the line so it wouldnt interfere. I worked gently and without jerking motions since the lines are thin aluminum. Luckily all went well, no leaks, no creases and no damage. You cant even tell that the line was touched. It appears that the 'twist' occured over the length of the tube which was the best case scenario. I considered using a torch to heat the tube to ease the twisting but I decided against it since the tube contains such a hazardous checmical, I didnt want to overstress it. I was very worried about creating a bend or crease in the line, or worse, damaging the seal on the compressor end and taking an r12 bath. But all went well.

Wiring is all done. I need to fabricate a throttlebody adapter plate, connect fuel and water lines and fire this thing up. Still need to find the right size belt and radiator hoses. I'm not working on it as much as I like, only once or twice a week. I've got a bad back that keeps getting in the way and not enough spare time to spend in the garage.

[jmgtp]

It's coming along... did some wiring last night for the fuel injection.

The 1 wire coolant sensor wiring reached just fine.
Starter, and grounds to bell housing no probs there.
Alternator wiring is all long enough to reach the alternator on the topside (vs the bottom like the DOHC).
I have the injectors in (used the LQ1 ones) and wired up.
The knock sensor wire needs to be lengthened.
TPS and IAC wires look like they should reach OK.
I had to lengthen the coolant temp sensor to reach the cylinder head since the LX9 doesnt have the sensor in the LIM.

The connector on the alternator is different. The dohc uses a 2 wire connector that is a different shape. The connector from the LX9 harness fits the 3100 alternator I am using so I will wire that in to work, though the LX9 connector only uses 1 wire so I will have to check my service manuals and see what the second wire was for (probably just a ground so I should still be ok).

I have a new CPS wire that reaches the ICM just fine. The power/ground wires for the ICM will need to be lengthened. The only challenge (wiring-wise) will be the other connector on the ICM, there is no way it will reach so it needs to be lengthened, I want to say it is 4 or 5 wires in that connector.

Once all this wiring is done I need to fab up a throttlebody, connect the water and fuel hoses, add oil, water, and crank this thing to life.