I am in the process of ditching my ECM and all the related wiring etc. I will still be running a Q-jet, which has an electric choke. how should i go about wiring up the choke since the stock choke uses the ECM? TIA.

 

Use the good old elec. heated coil one. Your carb doesn't have that? I'm not real familiar with CC Q-jets so sorry.

If it doesn't have it, then just snag one off an older Q-jet. Then hook it to an power source that is controlled by the ignition switch and you're good to go. Of course you'll have to adjust it accordingly, but that's not too complicated.

AJ

 

Im switching to a NON_CC carburetor and distributor. Im removing the ECM, so I cant use the stock choke wiring, which is controlled by the ECM. I knew the part about running it off something connected to the ignition, just need specifics.

 

The choke is not controlled by the ECM. just leave the wiring alone and hook it up like it's supposed to be, and it will work fine.

Study your car's wiring before yuou take a pair of dykes to anything. you will see that the entire ECM harnes is completely separate from the wiring for the rest of the car. Remember, these cars were built on a production line, so the wiring is all modular, and goes with whatever options were installed; so the wiring for the ECM was put in at a different place on the line. It all goes to the pass side, into the fender well; the wiring for the engine itself, the temp gauge, alt, chole, etc., all comes from the driver's side.

If you carefully disconnect the ECM's sensor and whatnot wires and pull them back, you can remove the ECM harness in one intact unit, unmolested; and re-install it later if you want.

 

I agree, the choke is not "controlled" by the ECM. However, the power wire to the choke thermostat is contained in the harness you are telling him to remove.

 

RB83L69-On my car, the big harness goes into a bulkhead behind the brake booster area. Then it goes along the firewall, and then down into the passenger fender to the ECM. As near as I can tell, its all one harness. Would i be able to see see the 2 separate harnesses if i removed the harness sleave stuff(you know, the black plastic covering)? Does anyone have any pics of the 2 harnesses? I know this is probably real easy to fix, but I dont know my *** from my elbow about electrical stuff. Thanks again.

 

No, they are 2 separate harnesses. Been there, done that.

Here's a good way to split them apart:

First, identify the things that are connected to the ECM, and the things that aren't. Some of the things that are include: the AIR pump (2 connections), mixture control solenoid, throtle position sensor, coolant temp sensor on the water outlet, MAP sensor by the brake booster (where you're getting confused), knock sensor, EGR solenoid, a ground at the alternator bracket, and one ignition connection to the car's main harness near the brake booster. There are a few others, but you'll see as you follow them back. Some of the things that aren't: the electric choke, the alternator, the gauge temp sender, the oil pressure sender, the fan switch if you have one, and the fan relay and fan.

Start at each of the ECM things in the list, and one at a time, disconnect them and feed the wires back out of whatever other engine parts they're mixed up with. The MAP sensor has a vacuum line too. As you pull them back out, you will eventually find that all the ECM wires go toward the pass side, and all the "car" wires go to the driver's side. These will segregate back out into 2 completely separate, distinct, disconnected harnesses; and the choke wiring will be in the "car" harness, not the ECM one, as it is part of the alternator wiring actually.

Now of course if someone has been hacking on the wiring, or pretending to make it "neater", all bets are off. I have never once seen any modification to a factory harness layout that improved it; in every instance, bar none, it made it harder to work on and less reliable.

 

I did what you told me and followed all the wires back to their origin, and I got the 2 harnesses separated. Thanks a bunch.