So, due to the poor condition of the ECM wiring harness, and a host of drivability problems, I've decided to go with a vacuum adv ignition and vacuum secondary carb. I've got those, and swaping that stuff isn't a major problem, the engine was kind enough to come to rest almost perfectly at top dead center on number 1, so getting the ignition back in will be cake, and I've got a Edlebrock 1406. (spare me the jabs - it was cheap and in good condition, if I can't make it run the way I like, I can always swap it off)

So, the question is - can I remove the ECM harness w/o affecting other parts of the car? I've done a lot of reading and searching on here, and I've never found a clear answer than you can pull the harness w/o affecting anything else. I have removed the A/C, so thats not a factor, I do plan to retain the heater and vent, I assume the computer is not factored in there, and I know the gauges are all driven off the other harness. What about the electric fan? This car has an aftermarket fan switch already, I believe this is part of the drivers side harness, but I'd like confirmation. I've found where the harness connects to the drivers side of the car, and I know the ecm is on the passangers side and thats the best place to remove it, I just disconnect it from the drivers side, correct? (I assume thats where power enters the harness.)

Also, a question about the AIR system - I removed the pump and and lines from it, they were plumbed into a manifold for each primary on the SLP headers that are on the car. Is there any reason I can't just put a pipe-cap on the air tube manifold? Same this with the line from the cat, rather than cutting it off right now, I can just put a pipe cap on that as well, right? (Yes, I'm aware that the CAT is designed to work w/ the air system, and may fail eventaully w/o it.)

Question about EGR - if I leave it disconnected, from the computer and from vacuum, it will remain closed, correct? I intend to buy a blockoff plate, but I may be up and running before I aquire that. This is on a ZZ3 intake manifold, if that matters.

Question about carb to intake gasket - the Qjet had a 1/4" thick gasket that does not fit the Edelbrock carb, what should I use for a replacement? I assume my local Advance Auto will have one, I didn't know if I should look for something specific, or if there is a part# somebody knows.

Question about vacuum sensor - on the back of the intake there appears to be a sensor that draws vacuum from the manifold, and is connected to the computer harness. I can do away with this and plug/cap the manifold, correct? I don't need the vacuum sensor up on the drivers side cornor of the firewall either, right?

Question about HVAC - where does it draw vacuum from? I haven't figured that one out yet.

Thats all I can think of sitting at work, I may have a few more quickies to ask when I get home and start finishing this up - the Qjet and CC HEI are already out, I just wanna get the harness out and everything ready to put back together and want to get all my details together, and hopefully only make one trip to the parts store.

 

hvac gets vacuum off the intake manifold

the computer harness is standalone and all on the pass side

unplug the 02 and knock and map and temp sensor on the therm housing and ground wire under the alt bracket bolt and smog pump wires and the whole harness will come out of pass side of the car, and ECM and all

its real simple

it has nothing to do with alternator or starter or temp guage or a/c or cruise or oil pressure or anything else

this has been covered a billion times on this site


plug the tube on the cat yes

stick something in it and get a small u bolt from hardware store to clamp it like an exhaust pipe clamp but smaller

edelbrock carb will take some work to make work and will eat more fuel than a good condition q jet does but you got it for cheap so ok


an edelbrock adapter is usually needed in order to use a spreadbore gasket and intake they are like 30 bucks

EGR you can just block off yes

but no real gain by getting rid of it, other than looks



do you have 700r4 trans ?
the vac sensor on the firewall might be for the TCC

if you have TCC then you will ahve to get a kit to wire it up, as the ECM controls the converter clutch

if you remove the ecm and harness you wont have TCC anymore

good luck

 

Removing the harness and ECM isn't required to lose TCC lock-up - just removing the TPS is enough for that.

The vacuum sensor in the back driver's corner of the engine compartment is the manifold vacuum sensor for the ECM. If you remove the ECM function, you can remove the sensor.

The sensor on the passenger side up by the AC housing is the barometric pressure sensor - it should not have a vacuum line hooked up to it (and can be similarly removed if the ECM is disabled).

Basically, if you remove the ECM harness, you can remove anything the harness goes to (unless you need to leave it there to plug a hole, like the O2 sensor and transmission electrical plug).

The ZZ3 originally came with the EGR block-off plate and hot air choke block-off plate. Still have those around?

Won't need an adapter, the ZZ3 intake takes either square- or spread-bore.

 

Thanks guys. The TCC I plan to sqaure away with a manual switch off the ADAL plug. The ZZ3 was on the car way before it was mine, the hot air choke block off is in place, but I don't have the EGR block off. No big deal, its just unsightly, especially if its not gonna be used.

Again, with the Edlebrock - if I don't like it, I'll find a double pump Holley, but it should basically at least fire up and run nice and easy, add it looks pretty easy to tune. Like I said, the price was right, it was part of larger package of stuff, etc. We'll see. The poor Q-Jet was getting all sorts of crazy idea's from the computer, so it'll be better than that mess.

 

five7 has pointed out some info i was unaware of about the zz3

i have no idea about those enginews, never seen one

ppl around here cant afford such a thing

so ive never seen one


good luck