My GPRXP build

[beerdart]

I have spare A and B harnesses if needed.

[smokeysevin]

When you do the wiring, if they are just single, unshielded wires I recommend swapping the stock wires for the cam and crank position sensors out for shielded cable or at a minimum, doing a twisted pair and adding some of the shielded heat shrink from wirecare. Even though I believe the doo sensors are hall effect and not vr, the last thing you want to screw with is noise on those inputs. I really fought with that on my 15f.

Sean

[John's truck]

A little bit of fun. I'm using the Microsquirt harness chart and the SeaDoo wiring schematics to match up which wires I need to splice. Micro has 35 wires, looks like I need about 19 of them. This is going to be a pretty minimal install. There are wires which will get multiple connections though. Sensor 5v will be spliced to 5v for the TPS and MAP. Sensor ground will be spliced to ground for TPS, map, Mat, clt. But I won't need Can high and low, and a bunch of the extra relay controls or analog sensor inputs. I'm going to redo the spreadsheet with the wires I am using only, and then I'll have room to type in all the SeaDoo wire splices in the blocks

[John's truck]

Started a spreadsheet then decided to go all-out and dummy proof it for myself. I gotta decide if I’m going to use any other relays or sensors but this might be my wiring plan

[John's truck]

Revised my color diagram a little more so it’s harder to screw up when the time comes



And I made a table of the wires I’m not using. I’m going to leave them in the harness connector in case I want to add knock control, more sensors, or IAC stepper control in the future

[John's truck]

So I just realized something. I need to open the Microsquirt back up and switch one of the switches. Here's why: the SeaDoo crankshaft position sensor is magnetic. Metal rotates in front of it and it crates its own square sine wave A/C voltage. The CAMshaft sensor is Hall effect. It has 3 wires, one of which is a constant power supply from the battery and it switches on/off to create alternating current signal. The Microsquirt has 4 internal switches. 1 and 2 are to enable the ALED and WLED outputs as logic spark signal. 3 and 4 are to put resistors on either the crank or cam signal input wires so the ECU can handle the signal from a Hall effect sensor, which it turns out we have.





and here it is straight from the wiring diagram. CPS (crank) is 2 wire no connection to power. CAPS (cam) is 3 wire fed from the fuse panel.

[John's truck]

Talking TDC. I understand for locking the crank and swapping cams, the engine is set to TDC for ignition on cylinder 3 (front).



BUT, I need to set base ignition. SeaDoo firing order is 1-2-3 from the rear. So I need to set cylinder 1 (rear) to TDC ignition stroke and clamp the degree wheel on at zero and make a reference mark. The crank lock marks won’t line up, but I’ll use either a stick or a dial indicator and watch the rockers move.

[smokeysevin]

Interesting that the crank is a vr sensor, I thought they were both hall effect for some reason. Being a vr sensor, make damn sure you use shielded cable. A good local source of sheilded cable is your local music store, I used microphone cable with a copper braid shield on my harness, its a twisted pair with external braid in a durable cable and its cheap.

You can do the tdc with a dial indicator or piston stop, doing it with a stick is less precise than you will probably want (it is also how I did my 15f and that didn't explode)

Sean

[John's truck]

Interesting that the crank is a vr sensor, I thought they were both hall effect for some reason. Being a vr sensor, make damn sure you use shielded cable. A good local source of sheilded cable is your local music store, I used microphone cable with a copper braid shield on my harness, its a twisted pair with external braid in a durable cable and its cheap.

You can do the tdc with a dial indicator or piston stop, doing it with a stick is less precise than you will probably want (it is also how I did my 15f and that didn't explode)

Sean

So the harness that came with the Micro Amp has shielded cable for the crank and cam sensor inputs (2 grey cables). I plan on going from this directly to the factory connector. Shouldn't need any extensions.



Flipped the switch #4 for Cam sensor to handle the hall-effect. I'm really glad I bought the Amp version and don't have to solder resistors in to my harness

[John's truck]

Ordered a little tube of zinc oxide thermal Paste for the ignition and they included a cute little spatula/cupcake frosting spreader. all for $2

[GP1200AZ]

Very cool build

[John's truck]

Very cool build

Thanks! I haven't made much progress lately since it was cold out and I was being a little bitch- more to come soon though

[John's truck]

So I didn’t really want to post this, but I’ll admit I made a mistake. My 48 pound injectors… well I started getting nervous they were too small. I found a reference to an RXPX 260 tune for the 137 wheel, stock injectors with rising rate/boost referenced fuel pressure. I think it maxed out at 8400. So that would have gotten me on the water but wouldn’t have really worked long term. Well I hit the Google and found what I thought was a solution. Injector decapping.

Yes it gets a bad rap. But if you decap an LS injector so it flows twice as much and put it in your Camaro with no ECU tuning, of course it’s going to idle like shit. My plan was to decap my 48’s and hopefully increase their flow to at least 60 lb. Well, the short of it is, it’s a much smaller injector tip and I wasn’t careful and destroyed the first one. So I stopped and gave up. I’m getting rid of the other 2. I have a line on something a little crazier. Stock Evo X injectors. Supposedly they’re high impedance and flow 60 at 43 psi and 70 at 58 psi. So I’ll be picking them up this weekend and then the Frankenstein will have another random vehicle part in it. Oh and since it’s a set of 4…. Maybe I’ll try my hand at decapping one of them… But seriously I’ll be able to use the Microsquirt ECU to test injector dwell and flow rate, so even being random injectors I can generate my own data for them and get them dialed in.

[John's truck]

One last thing, ignition coils. I'm probably going forward with the Audi ignition module with stock coils, but I wanted a backup plan. So I'm still looking at smart logic level coils. If I had a 300 valve cover, it would be a no-brainer. Toyota coils are ALL Denso 4 wire logic level. And their wiring harness is ALL the same. You just need to find the length that matches the stock 300 NGK expensive ass coil and bolt it to the valve cover. Well I wanted to see if there were coils that worked with the 215/255 cover. So after a bunch of research and guessing, I scored a Cadillac/Acadia coil for $11. Hopefully it works. If not, it was just $11 to find out. And I'll stop screwing with this and go to the 300 valve cover

[John's truck]

Another change of plans. The Mitsubishi evo X injector deal fell through so I went back to the drawing board and Facebook marketplace. I just got a LS (L96) intake manifold with 8 injectors for $50. These are the flex injectors that give about 75-80 lb @ 58 psi decapped. I have the harness adapters already, just need to order some spacer hats.