Making EFI harness. Any hints?

[GetMore]

I'm getting everything together to make the harness for my EFI system, and was wondering if anyone has any hints, tips, or tricks.

[Pro X]

If you have any questions contact Mike Noonan at EFI Connection. He is very knowledgable and helpful. Their Email and phone are http://www.eficonnection.com and 814-566-0946

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Ironically, I just got off the phone with him yesterday. I just bought my connectors from him.
As you said, he was very helpful and ordering the connectors was very easy.

[EFI69Cam]

That guy is doing some really innovative stuff with the LT1.

[GetMore]

He's also got a setup for folks running the RamJet intake setup. If I build a 350 I think I'll use it. Coil-near-plug ignition, and the ability to use Drive-by-wire, cruise control, electronic transmission, and an inexpensive, OEM PCM that has lots of tunability.

[Samckitt]

I know I should ask him, but thought I would throw it out here anyway. is the LS1 better than the one for the LT1? Other than having no cables & nothing extra to use cruise, what is the advantage of using the electronic controlled throttle body. Looks like a lot of extra work to use the LS1 PCM because of the needed extra sensors.

[WS6]

the throttle body is merely for looks. Cable or motor driven affects nothing in terms of performance.

The LSx PCM can read boost. The LT1 can not. The LT1/Optispark are RPM limited as well. The LSx PCM will work as high as the motor can possibly turn. LSx ignition is the best from a factory car ever. The LSx PCM is a better processor too which plays a huge roll in how big a cam you can put in an LSx and still be drivable. I'll be switching to an LSx PCM once I build the turbo system. For me, it's simply the ability to read boost. The LTx PCM works perfectly fine otherwise

[EFI69Cam]

There is a 24x sensor wheel available from GM that works with the Gen 6 big blocks. HD trucks 1999 and 2000 used LS1 coils and PCM on their 454s. The Vortec distributor was used as a cam sensor only.

[Pro X]

There is a 24x sensor wheel available from GM that works with the Gen 6 big blocks. HD trucks 1999 and 2000 used LS1 coils and PCM on their 454s. The Vortec distributor was used as a cam sensor only.

Do you know if this is the Cam sensor/Oil pump drive Monza Racer is referring to in post 3 of Vortec Dist Cap thread in this fuel injection Section? If it is can you provide a Delco pt#?

[EFI69Cam]

Do you know if this is the Cam sensor/Oil pump drive Monza Racer is referring to in post 3 of Vortec Dist Cap thread in this fuel injection Section? If it is can you provide a Delco pt#?

The only difference between the vortec dist and cam sensor oil pump drive Monza is talking about is the cap. There was a now discontinued cover for the dist.

Here is an aftermarket version.

http://cgi.ebay.com/ebaymotors/Seale...30178006r27944

[Samckitt]

Hmmm, use that & get rid of the LT1 optispark in favor of the LS1 style coil per cylinder.

[Jim Nilsen]

whatever you do make sure you run the harness so that it can be removed easily and the next best new system can be installed.

making it easy to remove also make it easy to work on if needed.

The main thing is that updating can be a pain or painless if it just removes easily.

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How do you go about making sure it removes easily? Just make sure it's not all intertwined with other parts, or something else?

Right now I'm planning on having it come up as one piece near the distributor, then split to the right and left sides of the intake. Obviously it's going to pick up the injectors on each respective side, and then it'll run to whatever is nearby.
For instance, the CLT is on the driver's side, while the TPS and IAC are on the passenger's side. Seems simplest to have each tied in with the injector wires on each side.

Of course, I could do it the other way, where the harness only splits off to reach individual connectors, so it would be run in a "U" shape around the intake.

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One of the biggest questions I have right now is where to start.
What I have is an "unterminated" harness assembly. It has the controller side of the harness completed, all ("all") I have to do is install the connectors for the inputs and outputs.
I guess the biggest questions is where to make the first cut? I don't have the car together yet, so I don't know where things are going to go. I'm guessing that maybe I should figure out what the longest wire will be and work from there.

The next question is how much stick out/slack/loop to have at each connector? From the harness to the injector connectors, or the throttle body connectors, how loose should the wire be?

[Ollie8974]

I started at the engine and ran the wires to the back by the distributor and left about 6 inches of slack. Using a combination of Weather pack and Mecric pack 280 plugs so that none of the circuits can be cross conected.
After you decide where to mount the ECM, run the wires through the fire wall and connect to the ECM.

[Hammered]

I sorted everything out and once I had teh engine running and everythng in its permanent location, I cut the harness at the ecm connector. I worked backward from each sensor/injector and tied them together where ever they naturally came together. I finally got down to the ECM and clipped everything at length there. You can get 16 pin WeatherPak connectors to create a break at the intake for the injectors. You can also buy bulkhead style Cannon plugs that you can mount on the firewall.

If I were upgrading my ecm to another brand, I would just repin the harness at that point to the new ecm. That would be way easier than running a new harness. Thus, mine is a permanent part of the car.