Holley HP install and tips

[randy merritt]

I have been working on my Holly HP EFI install for a little while now, and figured I would post some pics and helpful tips. I did this entire operation without cutting any factory wires. I tucked all the factory connectors behind the dis. and could restore it at any time. All of my splices into Holley connectors were done with new/donor connectors. This post will be a work in progress, but I thought I should put up something before I forgot the good stuff.

First, why the HP and not the Dominator setup? Well, I don't have a 4L80e, and don't intend on getting one anytime soon. The Dominator has 30 inputs/outputs, compared to the HP, which only has 4, but I guess 4 will do fine for me at this point. I will be keeping my manual boost control, and my Alkycontrol meth setup. The HP and Dominator have the same wiring harness, so most of this stuff (other than the location of the ECU), should apply to both setups.

Loose wires:

Red with fuse - battery positive
Black - battery negative
Red/White - switched positive. I think I ran mine to the fuse box
Green - fuel pump. Either directly to fuel pump (if amp load is not to high), or trigger the stock or aftermarket fuel pump solenoid. This wire is capable of directly powering a stock or Walbro 255.
White - NOT USED
Yellow - NOT USED

First, where do I locate the ECU? After some hunting around the cab, I decided to locate mine in the glove box, where it fits perfect.




Here is a pic after the ECU has been installed:



Next, I asked where do I run the harness to the motor? I went through the hole that the factory ECU runs through. It is easy to get through in the pass. floor board, and comes out under the A/C box. Removing the metal bracket/heat shield that is on the firewall makes things a lot easier. Removal of the pass. tire and inner fender is necessary at this point.





I found that installing the harness through the firewall where the input/output pigtail is just inside the passenger cabin seems to give a good fit.






Here is a pic of the wiring harness ran up to the glove box. (see pic above)




Now the big boy pants stuff. The Holley TPS and IAC plugs, as well as the knock sensor will not just plug into the brand new Holley wiring harness.

You can repin the stock fittings, but after I studied the factory connections, I realized that I could not replicate the factory pin crimping without a $150 pin crimping tool, which I do not have. I opted to cut, splice and solder my factory connections onto the new Holley harness.

First was the TPS.



Here is a good picture from Alex that shows the correct HOLLEY wire colors for the TPS to the factory connection. Alex had a good crimping tools, apparently, but I just matched the wire colors up the the correct position on the connection.

 

[randy merritt]

Re: Holley HP install and tips

Next is the IAC. Here is the wire color from the Holley harness to the factory SY/TY connector:

The rectangle at the top of the pic represents the push release connector on the factory plug. The lines on the circle representations of the connector lugs represent the slots in the lugs. I show this because I cut a IAC controller plug off a junk vehicle so I would not have to cut my factory plug. This is just for reference. This view is from the pin side.



Next to solder in the factory fit IAC to the Holley harness. This could be done with repining and proper crimping of the lugs, but I I think solder and shrink wrap should work just fine.



More to come.

 

[randy merritt]

Re: Holley HP install and tips

The Holley knock sensor looks like this, which is a standard 3 pin metric 150 connector:



In order to make it work with a one wire knock sensor like ours, I bought a pigtail for our knock sensor (about $10), so I would not have to cut my factory one, and cut a metric 150 male connector off a junk vehicle.



You only need one wire off the connector cut off the junk vehicle for the knock sensor to work. The BLUE/BEIGE wire on the Holley harness needs to be connected to our knock sensor. I soldered these together, then reinstalled it. This is the only wire that need to be run for the knock sensor. Here is a link to the Holley forum discussion on this issue:

http://forums.holley.com/showthread.php?2534-Connecting-amp-Tuning-Knock-Sensors-Holley-EFI

 

[randy merritt]

Re: Holley HP install and tips

Next is the fuel pump relay. The Holley has a relay built in, but I will be using this to simply trigger the factory relay. Yes, I will have two relays for the fuel pump. This is much easier than rewiring the entire fuel pump wiring system. This pic shows the factory relay. The green "fuel pump" wire (one of the "loose wires" in the instructions) from the Holley will replace the factory relay trigger wire which is green with a white stripe. I removed the factory green/white wire from the stock plastic relay socket. The factory green/white wire comes from the factory ECU, which will no longer be used. I ran the green Holley wire across the firewall to the driver's side, and then I used a junk wire lead to solder onto the Holley fuel pump harness green wire so I did not have to cut my factory harness. I then reinstalled the green Holley wire into the stock plastic relay socket and plugged it back into the stock fuel pump relay. I left the stock green/white wire dangling after I put some electric tape over the terminal (even though it will never get any power).

Here is the wiring diagram for that relay:

 

[Z SKI]

Re: Holley HP install and tips

Great stuff.... Keep it coming... That's the exact type of data that I need... Thanks Randy!!!!!!!

 

[randy merritt]

Re: Holley HP install and tips

I buttoned up the wiring through the fire wall by cutting the factory rubber plug with an razor knife to allow the Holley harness through, and then pushing the plug back in and reinstalling the factory metal shield. I figure the Holley mesh wire loom should protect the wiring good against the metal of the fire wall:

 

[randy merritt]

Re: Holley HP install and tips

This is a pic of the interior as it stands today. I think that after I reinstall the lower trim panels, the wiring will be barely visible. ( I still have to hook up that red/white wire to a switched power source, but that should be easy).

 

[randy merritt]

Re: Holley HP install and tips

One final note on the MAP sensor. I have a GM 3 bar map, and the connector from the Holley does not plug in. You can make the fittings work with a Dremel tool, and rescale a map sensor in the Holley program, but I decided to just buy a new ($85) Holley 3 bar map sensor. As it turns out, the new Holley map sensor that I just received came with an new connector that you have to repin into the factory Holley harness, and this new connector happens to fit my old GM map sensor. Oh well. One more repin.

 

[midnightbluS10]

Re: Holley HP install and tips

One final note on the MAP sensor. I have a GM 3 bar map, and the connector from the Holley does not plug in. You can make the fittings work with a Dremel tool, and rescale a map sensor in the Holley program, but I decided to just buy a new ($85) Holley 3 bar map sensor. As it turns out, the new Holley map sensor that I just received came with an new connector that you have to repin into the factory Holley harness, and this new connector happens to fit my old GM map sensor. Oh well. One more repin.

So basically you still have to physically do the same thing for either sensor, but no scaling with the holley sensor? In your opinion, is the cost worth the trouble and time it saves?

 

[JSM]

Re: Holley HP install and tips

So basically you still have to physically do the same thing for either sensor, but no scaling with the holley sensor? In your opinion, is the cost worth the trouble and time it saves?

Simple razor blade is all that is needed, and you just need to cut a slot in 2 places I believe for the indexing part of the map sensor.

Rescaling of sensor inside the holley software takes all of 30 seconds. I think on one of the trucks I even selected holley sensor and it worked fine. Been a few months now though since I messed with one.

 

[randy merritt]

Re: Holley HP install and tips

So basically you still have to physically do the same thing for either sensor, but no scaling with the holley sensor? In your opinion, is the cost worth the trouble and time it saves?

Probably not, but I was not sure about the factory map sensor. The part # on my factory sensor and the part # in the pull down menu of available map sensors in the Holley program did not match. Jeff would know more about this than I, since I am new to this. It sounds like my factory map sensor would have worked just fine. These are the kinds of questions that I had no answers to, and why I started this thread.

 

[Don W.]

Re: Holley HP install and tips

Nice writeup. If you're talking about a crimp tool for Weatherpac terminals I picked one up at Fry's. Works good. Probably the one at the top of this page but I'd have to see it to be sure.

http://www.frys.com/search?search_type=regular&sqxts=1&cat=&query_string=crimp+tool

 

[randy merritt]

Re: Holley HP install and tips

Nice writeup. If you're talking about a crimp tool for Weatherpac terminals I picked one up at Fry's. Works good. Probably the one at the top of this page but I'd have to see it to be sure.

http://www.frys.com/search?search_type=regular&sqxts=1&cat=&query_string=crimp+tool

Thanks.

The Holley wires are a thinner gauge than the factory wires, and I just thought I could get a more secure and stable connection by keeping the factory style pins and just soldering to a short length (2" or so) of factory style wiring. Once the Holley wire loom is put back on, you would never know that the wires were spliced.

 

[Don W.]

Re: Holley HP install and tips

Thanks.

The Holley wires are a thinner gauge than the factory wires, and I just thought I could get a more secure and stable connection by keeping the factory style pins and just soldering to a short length (2" or so) of factory style wiring. Once the Holley wire loom is put back on, you would never know that the wires were spliced.

Good plan. Hard to beat a good solder joint. You're probably already there but heat shrink tubing tops things off nicely.

 

[randy merritt]

Re: Holley HP install and tips

More work today and yesterday.

I can't say enough about the customer service at Steve Morris Engines. One of their tech guys (Ryan), got on the phone with me yesterday and was helping me solve my no start issue. He linked to my laptop via Team View software (free), and adjusted my tune until the truck would start. We were on the phone about 2 hours or so, and will be back to more adjustments on Monday. Alex told me this was standard customer service, but I was very impressed.

Here is a pic of some of the wires and looms I was able to remove. I still have all of the stock stuff, in case I or someone else ever wants to go back to stock. I just tucked them behind the dis..



Pic of the motor after the install of the wiring harness. By the way, removing the hood is a must for this.



Here is the interior after the install. I only left the Input/Output pigtail exposed because I will most likely use the Holley to control my TC at a later point, but for now, I just left the stock ECU in place to control the TC and did not mess with the stock computer (other than remove the Ostrich).



Little closer pic. You would not know it was there from the casual look.

 

[randy merritt]

Re: Holley HP install and tips

It was keeping me up at night worrying about my new Holley harness getting burnt in half by touching the exhaust manifold. This is a bad pic, but you can kinda see how close they were:



I decided to remove the factory heat shield that covers the stock ECU main harness and add about 2 inches to it to make sure the Holley harness cleared the exhaust manifold. After welding an extension panel on the stock shield, I wrapped the shield with exhaust heat wrap. I know it is not pretty, but the only way to see it is to remove the pass. inner fender, and it does the job of keeping the harness out of harm's way.

 

[randy merritt]

Re: Holley HP install and tips

I got the A/C on the truck working again today. It seems that the factory ECU will not allow the A/C to work without the factory sensors hooked up. I, with some consulting with DaveP, bypassed the factory ECU by jumping a wire from the low pressure switch on the dryer/accumulator straight to the compressor. Next will be hooking the TC lockup into the Holley. The tuning of the truck is going great so far, and again, I can't say enough about the customer service at Steve Morris Engines.

 

[randy merritt]

Re: Holley HP install and tips

I had the guys at Steve Morris look at my fuel graph one more time yesterday, and I think I am done with tuning (except for small changes in the start up fueling) for now. The truck runs great and pulls strong with 22 PSI, a target AFR of 11.5, and 22 degrees of total advance. If you are lazy like me, and if you feel like spending the money, this is the best way to go for tuning IMO.

 

[JSM]

Re: Holley HP install and tips

So when do you plan to hit the track? Are you happy with the return on investment of the system?

Looking at your combo with 22 lbs of boost, you should be laying down some respectable numbers.

 

[randy merritt]

Re: Holley HP install and tips

So when do you plan to hit the track? Are you happy with the return on investment of the system?

Looking at your combo with 22 lbs of boost, you should be laying down some respectable numbers.

Hope to go back to the track soon. I am happy with my return on investment, and I believe if I added all the cost up to convert from stock to Code59, including tuning expenses, I think I would have been money ahead to just go with the Holley to start with. Of course it was not for sale at the time, but you get the point.