Holley HP EFI + Cruz Harness Install

[TurboTnZ06]

Follow along as I take out the remaining stock junk and step up to the current century...

Removed: Stock ECM/powerlogger, add-on gauges, add-on senders, coil pack, rail, injectors, engine harness.

Modified: Single -8 feed/-6 return now going to dual feed dual return to relocated Aeromotive FP regulator. Throttle body modified to have 2 1/8 npt vacuum ports, shorten the MSD plug wires.

New: Holley HP EFI, Cruz engine harness, Holley 100 psi oil press sender, Holley 100 psi fuel sender, Holley 3.5 bar map sensor, Holley 120# injectors, Holley smart coils, Cruz fuel rail -8/-6, Cruz 1 inch spacer for air temp, and vacuum ports, vacuum block off plate on top of throttle body.

Here she was before the mods started:

 

[TurboTnZ06]

Lots of things to undo, but pretty straight forward. If there is a wire, unplug it. I chose to remove the wiper motor to access the harness on the driver side, don't have to, but life is much easier to clean around it with it out of the way, although those 3 bolts holding the wiper motor on are a bit of work. The driver side harness has a bolt in the middle, so don't just try unplugging that one first, just unbolt it and it'll come out easily. I also have hydroboost, and not a powermaster.

Then remove the passenger inner fender. You don't really have to remove it, you just can pull it away from the firewall side, but I wanted to because I need to clearance the firewall flange for my downpipe - totally unrelated to the harness install. If you want to pull it all the way out, remove the coolant/alky tank, and battery. There are a few bolts holding the plastic inner fender on, and 2 are a pain to get to that you can't see. There is one that you will want to have a fine tooth 1/4 socket wrench to get to as you have no room to wiggle by the HVAC from the top. I had to reach up to get the last one from the bottom. The stock harness looks like Mr. Snuffleupagus as well. Once the fender is out, you can easily access the grommet and two little screws holding the stock harness to the firewall. A few metal retaining clips hold the stock harness in too, leave them in case you want to use them to hold the new harness.

 

[TurboTnZ06]

Once that is out, you won't need any connectors off of it, the Cruz harness is plug n play and can be custom since you'll really want to convert everything to Holley sensors. I already had a Racetronix fuel injector harness so I reused that one piece. I opted for Fuel, oil, wideband and air to be all Holley sensors and the harness came with that spec'd out to play nice with the upgrades and no adapters needed.

In the last pic of this post is the two coil harnesses. I'm planning on mounting a fuse block right off the battery to run all my hotwire leads but run the Holley ECU directly to the battery. Hotwires will be Fan, the two coil harnesses and the Weldon fuel pump, with relays for the fan and Weldon to be switched on manually.

Ignore the random other AN fittings, fuel pumps on the bench, that was from my old boat project, but it did have some good AN fittings to remember that I have in inventory.

 

[TurboTnZ06]

Funny that my AN fittings box has a 'No Crybabies' warning label right on it from the factory...

 

[Royal-T-Ltd]

Cool! Thanks for taking the time to document it. I love seeing photos and build threads. -aaron

 

[TurboTnZ06]

Oh yes, Cruz coil mounting brackets too, for GN1 heads/valve covers w/ breathers. The 1" spacer meant I could locate the air temp sensor right under the throttle body. I also used a 90 deg 1/4 for the PCV and a straight 1/8 for vacuum signal, probably to the regulator or HVAC.

First, I always double check all metal parts for burrs or shrapnel shavings. Buy a case of brakleen, and make sure everything is nice and smooth and debris free. Even shipping styrofoam or dust or whatever, I don't want any junk getting in my fuel injectors if I can help it during assembly.

The other key to the injector and rail install is to not tighten anything, leave it loose. I also dabbed some dialectric grease on the orings to get them to seat. Since you can do one side at a time, it is 100x easier than the stock rail to install.

Next is the coils. Now, this is for test fitting, plan on them coming out later to make plugging in the harness much easier on the passenger side at least. I run a stock turbo bracket, note that you might not have room to install the forward most coil bolt if the turbo is installed, so the nut faces the turbo, otherwise you might not ever be able to get it off if you install a turbo on with the bolt going the other way...

 

[TurboTnZ06]

Next I fabbed a plate to mount my Aeromotive regulator where the stock coil pack bolted down. The plan is to run 180 returns from the front of the rails back to the regulator and feed from the back. The Y block I'm planning on mounting on the frame near where the brake valve is. I also used a big rubber bushing from my boat fuel pump to hopefully let me not pass vibration to the fuel pressure sender that has a 90 fitting right on the regulator. 1/8 npt as always. Earl's fitting too I think. I couldn't find short enough bolts, so for now I'm mocking it up with nuts. 6-32 was what my regulator had for thread size on those. The regulator is all -6, with oring fittings on the regulator side and regular AN -6 on the outside.

I still have to mount the relays for the coils, and tidy up the routing. Waiting on running the fuel lines so I left it all just laying about for now. I'll zip tie the looms together and make it neat at the end and loom the red coil power wires too.

All grounds I ran to the back of the heads. Each coil harness has a ground and there is a ground from the driver side harness.

The starter wires are plenty long and make the install a breeze compared to the relatively short stock starter wires. A mini-starter makes the install even easier.

 

[TurboTnZ06]

I really didn't like the look of my crusty stock heater line. So I put a SS one on it. And it didn't fit. Looks like it was welded crooked. That meant it didn't clear the coil bracket. So out came the blue wrench. I made the S just exist in 2 dimensions, not 3. Basically bent the top one back towards the dog house.

 

[TurboTnZ06]

Ok now maybe I can start wiring.

This I think is the external harness for adding more stuff, not sure if I'm gonna use this as I'm keeping it simple for now. The kit comes with the other side, unterminated, just a bunch of wires.

I also decided to try running the main trunk of the harness over the top of the HVAC box. Notice I have that rear passenger coil out to make the fuel line and other wiring easier to get to for now.

 

[TurboTnZ06]

Ever get finished with something only to think, I wonder if that'll fit? I have a 45 deg angle IAC mount. And I modified the Accufab 70MM throttle body by drilling a good sized hole through the water port behind the butterfly to get vacuum/boost. Now's a good time to see if it'll fit. And it does! Except the 3.5 bar will be mounted straight out not with a 90 as the first pic shows, just has more room there. I might end up remote mounting it, and then I'll stick a vac line there easy enough. The temp sensor might only be connectable with the throttle body off, but I could remove the IAC adapter to solve that problem, but its already on the car so I'll see if I ever have to touch it again. I also changed the PCV port that is 1/4 npt in the spacer to a 1/4 90 to 3/8 nipple. I have a E2 Elite catch can in my Suburban, I'll get another one for the Buick, and it used 3/8 line and 3/8 fits the PCV better too. The other pics show a 1/4-1/4 fitting.

 

[TurboTnZ06]

Then I went to set the cam sensor to 240 BTDC, and discovered the interrupter ring was wobbly and moved side to side and all around. I didn't want to install more stuff only to get in the way later, so this is as far as I've got for now. Sent it to Scot at GNS for a sensor rebuild and balance. Currently I set the motor to 0 right on #1 since I had the cap off and made the job much easier. Now I won't wonder which stroke I was really on when I go to install the sensor.

Another cool trick, I put a socket on the alternator, and a socket on the water pump, with both, I can turn the motor over very slowly with the belt installed. I have a SLIC, so I can't turn the crank with a socket.

 

[TurboTnZ06]

Deep thoughts - after messing with all the brass pipe adapters and fittings and trying to get it to work running all new rubber vacuum lines and setting it up, now I understand I should have just got the push lock vacuum block remote manifold solution, it would have been way easier. Knowing is half the battle. Maybe for Christmas...

 

[Royal-T-Ltd]

Deep thoughts - after messing with all the brass pipe adapters and fittings and trying to get it to work running all new rubber vacuum lines and setting it up, now I understand I should have just got the push lock vacuum block remote manifold solution, it would have been way easier. Knowing is half the battle. Maybe for Christmas...

I was wondering why you didn't use Pushloc fittings ... keep up the good work!

 

[TurboTnZ06]

Looks like now I'm going to see about using the Holley HP unit to drive my Alky, says it can, but with a Holley solenoid (2) and nozzles, using Razor's pump, tank and lines.

 

[TurboTnZ06]

Made some PTFE return lines in -6, I think I'll change them to 90's instead of 45's someday to the regulator. 180's off the front of the rails. Plenty of room between/over the rails and coils.

 

[TurboTnZ06]

Got the cam sensor rebuilt back from Scot at GNS, got my alky pump rebuilt by Julio at AlkyControl. Made up some 3 ft long -8 PTFE lines for the feeds with 45* ends to the back of the rail.

Before putting the cam sensor in, I decided to prime the oil. Well, it wouldn't prime. Hmm, physics, what can I do, usually I'd fill an oil cooler line and backfeed it, but I didn't have one on anymore. So, let's loosen the filter a bit...Yup, that works, primed but spewed half a quart easily on the ground. Tightened filter and spun it up to get the oil going. I used a 18 inch 3/8 wood bit ground down flat, works really well.

Everything was plugged in but it wouldn't fire. Here's where I needed to pay more attention. The coil harnesses are labeled 1-3-5, 2-4-6 of course I put them on the wrong sides, because of the wiring, it won't work that way, they are specific to each side. Once I figured that out, swapped the grounds as well since each goes to each head they are for, it was just a matter of setting the cam sensor next, again.

To set the cam sensor, I had to find 240 BTDC on the compression. So I brought it to 0. Then pulled #1 spark plug. Well, lots of tension, so I had to be compressing another cyl not 1, and was 180 out. So I went 360 around (180 on the cam). Now it turned over easy. To verify, put it at say 30-50* BTDC on 1, and put your finger in the spark plug hole for 1, and bring towards 0, you'll feel air whoosh out. That's #1 compression at 0. 240 degrees BTDC you say? My BHJ is marked as 6.375 in dia. So, 3.14 * 6.375 / 3 * 2 = roughly 13 and 5/16 or 3/8's, near there. So I measured that out on blue painters tape. put one end on 0 and one end BTDC, that was 240. Then I marked the balancer in case the tape fell off. Then roll backwards (to be really BTDC, not 120 after since the cam moves at half rotation). I have a cam sensor cap with a lead on the middle wire, so I turn the ignition on, and rotate the sensor counter clockwise until the voltage drops. Then lock the sensor down.

Now that it is running, next I'm going to pull my fuel feed lines back out of the way and tidy up the wiring where it runs so its tucked down out of sight. I had to pull it all out to get the grounds swapped when I installed the coil harnesses on the wrong side, and just wanted to get it running.

 

[TurboTnZ06]

I haven't touched the tune, just plugged it in, and it fired right up. It's self learning, so I just need to drive it around. My IAC was at 11-12%, so I have to tweak my throttle blade setting some next to get it down to I think 5-7%. But throttle response is awesome, no tip in stumble, just takes off. I got it up to temp in the neighborhood and I have the fan output wire to my low speed input on the stock fan off a relay, and it worked well. Coolant was showing 164.

So far I'm really glad to have upgraded. I was able to ditch every add-on piggyback system, and got rid of all my gauges and tons of wiring under the dash. Once I get rid of my tach, it'll be back to stock under the dash by the fuse panel.

Next up is a longer lead for my 3.5 bar map sensor, 4 inch intake, and dual Holley 1000cc alky injection solenoid/nozzles.

 

[TurboTnZ06]

Been driving the car all summer. So, the key is to let it learn, then adjust the base tune. I had a lean-rich super surge at light throttle taking off from say a stop sign <10% TPS. It'd go lean like 18 on the AFR (higher rpm), then adjust back to 13 (drop in rpm) then 18 then 13 etc at that load. So then look at the base fueling. The really cool thing is it shows a glowing dot on the cells it is referencing in real time. So I then manually bumped that area up (remember it was going lean). So, say, light throttle, high vaccum, relatively high rpm (3600 stall PTC NLU). The cells were say, 6-8-14-9-8-20... So I bumped a few all up so it was more linear, 9-11-13-15-17-20... and it fixed the surging and lean condition at that throttle/load setting. Just type some numbers, sent it to the ecu, bam, fixed.

 

[TurboTnZ06]

 

[TurboTnZ06]

Currently the learn is off in all the low throttle/rpm cells. I manually tweaked everything around town/highway to be what I wanted down low and off idle. Once you get the hang of it, seeing the AFR and adjusting fueling to suit at part throttle, its really an easy system to tweak. Like anything, only make one change at a time and see how it likes it or not.