i was wondering if anybodys got tips to make the install smooth ive got an 84 z with a 305 not an HO

 

Edelbrock what?

 

600 performer electric choke

 

^ Get a vacuum gauge. Disconnect the O2 sensor, this will force Open Loop, and the ECM will continue to hold timing. Put a few bricks behind the rear wheels, place the tranny in reverse, and begin adjusting for the highest reading possible on the vacuum gauge (which you'll have plugged into the carb). I just did this today w/my '86 Z28, I've honestly forgotten how easy it is to tune a carb (as opposed to burning chips all the time lol)....

 

i still gotta install but thanx for the heads up

 

What? Are you serious?

The ECM is going to be in open loop just by putting the Edelbrock carb on. I hope you picked up a vacuum/mechanical distributor at the same time, because you won't get anywhere close to the proper timing advance without it. If you have an automatic transmission, your torque converter clutch won't lock up and you'll burn out your 3-4 clutch pack. You'll also need a TV cable geometry corrector, or ditto the burnt out transmission.

Oh, the carb won't bolt to your stock intake manifold. You'll need a spreadbore to squarebore adapter, which will raise your carb and air cleaner and promote vacuum leaks.

That Edelbrock is an absolute downgrade from the stock carb in every sense - power, driveability, economy, longevity, expense. The best thing you could do for your car and yourself is to take it back and get your money back.

If you want something that says "Edelbrock" on it, get a Performer intake manifold. That would be an upgrade (although only a slight one on an otherwise stock 305).

For the record, using bricks (or cinder blocks) as chocks is a good way to get hurt.

 

The Devils advocate might tell you that the Edelbrock carb can actually be tuned to make the same power on a relatively stock motor, while retaining fair fuel economy, and greatly simplifying the system. If you've got everything for a CC-Qjet setup and it all works, I wouldn't switch - the power gains are typically a wash, and the CC stuff defintely does make better mileage. If the computer controlled stuff is all hacked up, and you're not hell bent on that last MPG or two, then going with a mechanic setup is certianly a lot easy to do, and a lot easier to tune. It certianly isn't a power down-grade - so what if a Q-jet can flow 800+CFM, a stock-ish small block will never utilize that kind of flow.

Drivability - a well tuned 1406 Edelbrock will cold start, hot start, idle, and drive every bit as good as the Q-jet. My wife has never been behind the wheel of a carb'd car before, and for the last two weeks has been daily driving my Sport Coupe everywhere without any driveability problems. (her Pontiac is sitting in the garage going through its second low intake manifold gasket change)

No TCC will burn out the 3-4 clutch packs? I'm not sure about that. Too much heat will eat a tranny every time, but no TC lockup does not spell automatic clutchpack failures - a good tranny cooler has kept me daily driving just fine without a lockup on my 2500rpm stall.

I know five7kid has a bug up his *** with Edelbrock carbs, but don't let that scare you away, its a good functioning unit. There are certainly better carbs out there - but its not the kiss of death, waste of money he makes it out to be. Its actually nice and easy to work on, and performs, in my application, better than my Q-jet ever did.

 

Disconnecting the connectors at the stock quadrajet will only set a code, it won't force open loop, he'll need to disconnect the O2 sensor entirely. I'm not worried about the advance, as it's doing fine right now, besides, I can always alter it later on. I myself didn't install an Edelbrock, I'm running a Holley 600 w/electric choke. As for the transmission, he can simply keep it out of overdrive until he buys a painless kit, eliminating the need for the ECM....

 

I have to agree with Five Seven. The CCC Q-Jet will blow the edelbrock out of the water. I have done two seperate buildups using CCC Q-Jet carbed engines. Both were engine swaps to larger engines. 307 oldsmobile to 403 olds and 305 to 355 vortec chevy.

https://www.thirdgen.org/forums/carb...t-capable.html

 

Disconnecting the TPS will keep the ECM from going to closed loop - that's another way of saying it will stay in open loop. And, what advantage do you think there is to being in open loop? Nothing will function properly. And, you will not get proper ignition advance without the TPS input.

The point of the TCC lock-up is it's another expense usually not calculated when people assume "installing an aftermarket carb will give me more power", when that is definitely not the case here. Count up all the cost of converting from CCC carb to non-CCC carb, and without exception you will be spending more (assuming new parts) than fixing even a FUBAR'd CCC carb.

And, yes, you will burn out the 3-4 clutch pack of a TH700R-4 if you don't have the TCC locking as it should. Leaving it in 3rd all the time is another loss of fuel economy and increased wear on the engine & tranny.

 

Converting from a properly functioning CCC carb is a waste of money on a stock 305. There is no getting around that.

As for ease of working on, all I've ever done to mine in 9 years is a basic rebuild (done once), basic adjustments (done once when first got the engine running after the V6 to V8 swap, again after the carb rebuild), replacement of the choke pull-off (once - it was the factory original and started leaking after 20 years), and changing the secondary rods & hanger (as easy as changing rods on an Edelbrock). It does all of the other adjustments itself, unlike a non-CCC carb. Oh, included in all of that is it's been on 3 different configurations - stock 305, hopped-up 305, and the current 350.

 

Hmm, and yet, when I plug my O2 sensor back in when running my non-CC Holley 600, my timing get's completely thrown out of whack. This of course wouldn't be the case if TPS removal forced open loop on an LG4, while keeping the O2 sensor plugged in....

Timing is controlled through a preset configuration. No advantage, just an easy way to help with the swap. If others desire a vacuum advanced distributor than so be it. However, if one isn't around, and he's on a limited budget, there is nothing wrong with the stock electronic ignition....

My advance is working fine, also, what nothing are you referring to here?

You didn't really read what I wrote. I said that he can keep it in 3rd gear until he buys a painless kit, eliminating the need for ECM control. As for fuel economy and increased engine wear, 90% of the member's here aren't even concerned with that....

 

You are not going to win this one. If the TPS is disconnected, your timing is NOT working the way it should. Yes it will advance, but it will be using the 1 line IDLE timing table rather than the Main spark advance table.

 

Never said ditching a proper functioning setup was the way to go -

 

ON AN LG4 ECM FAST....??????

 

ABSOLUTELY! The LG4 ecms have highway mode spark, coolant temperature compensation, TCC locked/unlocked spark compensation, lookup tables for mixture control duty cycle for TPS vs. Coolant temperature. This is a LV2 .bin, but the same thing is going on in the LG4 ecm.

 

Was very curious, so I reached out to my cousin who's much more familiar with the system than me. From what he just told me, the only electronic function of the CC-Quadrajet is to regulate air/fuel mixture delivered at idle. The ECM receives data from the O2 sensor, Spark Advance Sensor as well as the Throttle Position Sensor to achieve this, in turn pulsing the piston driver solenoid at higher or lower frequencies....

Thanks Fast, I'll bring this to his attention....

 

The system does alot more than that as well. It controls the TCC, the idle compensation, vacuum break when needed. It often controls the A/C clutch. In vehicles equipped with a ceramic grid heater under the primary(ies) it controls it. It also controls the air divert valve and switching valve. The systems code is pretty complex. It even includes a Decel Fuel Cut-off like function that gives maximum duty cycle to the solenoid (leanest setting) when the throttle is shut at higher speeds. The only time the ECM does not have control of the fuel mixture is at WOT. Even on a cold start the system runs at a pre-programmed mixture control duty cycle to regulate the fuel delivered. That is why proper adjustment to the carburetor is VERY important. Do it by the book here and it will save alot of cussing and hatred toward this carb setup.

 

Oh no no, I agree with you there, I'm just questioning the Throttle Position Sensor's relevance w/controlling spark advance (on LG4/L69 ECM applications only). From what I was told, data taken from the TPS is only used to help determine/regulate air & fuel, and that the ECM will hold and advance ignition timing (in the same manner) regardless if the TPS is being read or not....

 

The simple way to think of it is the TPS in a way acts like the vacuum advance on early distributors. Instead of a vacuum to increase or decrase advance past mechanical the TPS signal is used to elctronicaly do this. The only computer controlled dizzy that the tps doesent do much on is the truck setup which is just an odd setup to begin with..

 

No it doesn't. I'm responding to this for my cousin, as he sent me this thread last night in an e-mail. The LG4's ECM isn't as sophisticated as the batch/sequential fire oriented ECM's.

The Throttle Position Sensor on LG4 employed vehicles supplies throttle position information in which the ECM will store an average of operating conditions with the ideal air/fuel ratios for each of these conditions. When the ECM receives a signal indicating throttle position change, it immediately shifts to the last resulted in an ideal air/fuel ratio control. This memory is continually being updated during normal operating conditions....

Now, the O2 Sensor will generate a voltage signal based on the differences of the oxygen content of the exhaust and that of the outside air. The ECM, depending upon the value of the signal received, will issue a command to adjust for a more rich, or a more lean condition....

Electronic Spark Control, however, a reference pulse, will indicate engine RPM which is sent to the ECM. The ECM determines spark advance from this data for the engine operating conditions and then sends an EST pulse back to the distributor. Under normal operating conditions, the ECM will control spark advance through the RPM information being sent by the Electronic Spark Control, however, in certain instances, the distributor will control spark advance on it's own through something called Bypass Mode, but this will occur when the lead is grounded or open circuited (or open loop)....

The data sent from both the O2 Sensor and Throttle Position Sensor helps the ECM to determine and adjust for a more richer or leaner mixture which is then controlled through the Mixture Control Solenoid found on the CC-Quadrajet. This data only helps to maintain the correct air/fuel ratio, and does absolutely nothing to effect spark advance. When swapping to a non CC carburetor, you'll want to keep the ECM in a constant state of Open Loop, not because of the predetermined tables, but because if you allow it to go into Closed Loop, the ECM is waiting on the corresponding data between the Throttle Position Sensor and the O2 Sensor, and if it's lacking, it will throw the ECM for a loop (or Limp). However, spark advance is still being controlled through the Electronic Spark Advance either way you look at it. You'll just want the ECM in an Open Loop state, again, not because of lack of spark advance, but to avoid what some refer to as Limp mode, which will effect other things....


Gaspar

Edit: Typos

 

You are correct with the way the fuel learn works. It does however reset everytime the ignition is cycled on the masks I have looked at. It does not make sense to not clear out the learned values everytime the engine is started. Here is why. The choke is mechanical and cannot be accurately accounted for on every startup. This is why their is a DC table vs TPS and Coolant temperature.

The TPS and VAC/Baro sensors (CCC Q-Jet version of a MAP sensor)have an integral part of controlling the timing advance the engine recieves. The TPS is ESSENTIAL in the codes that I have looked at for one thing when it comes to timing. At idle, <=2% TPS, the ECM uses the Park/Neutral or IDLE spark table. Above idle, >2% TPS and <~90% TPS the ECM uses the main timing table. >90% TPS the ECM uses the WOT timing table. Without a TPS input, the ECM resorts back to the idle timing table, which has a greatly reduced value compared to some of the values at cruise.

 

well i got the edelbrock cause my quad after rebuiling it still had issues now that i have it on the issues are gone im not looking for hp just mainly drivablility so i think in my case itll do

 

I have a canadian none CC 305 car. I plan on installing a edelborck 1406 and bought the edelbrock to q-jet kit to put it on. Do i have to worrry about this transmisson thing you guys are talking about?

 

What is the intended purpose of the car? What is the converter and rearend. Depending on start speed and gear ratio, there are potential concerns for overheating the trans under prolonged cruising. You can wire a manual, or vacuum operatered converter switch to solve the problem. As mentioned before as well, you'll need a regular vacuum advance distributor, and the discussed TV cable linkage. You need a key-on 12v source for the choke, and you'll need to adjust you fuel line as the 1406 feed is in a different spot. If you've got specifc questions, go ahead and PM me - I did the swap last year and remember most of it.

 

He doesn't need any of that, except for the TV cable bracketry and the fuel line.

 

So now we're saying that the tranny isn't at risk for heat if run below the converter stall for extended periods of time? I wasn't paying attention RE: Non-cc, so I was off-base on the distributor, thats a fair catch.

 

No, we're not saying that at all. His car doesn't have a computer-controlled TCC. Changing the carb won't affect TCC operation in the slightest.

 

Me and my lack of non-CC knowledge, coupled w/ a quick trigger finger. I suppose the Non-CC cars have no computer, and the TCC is already controlled by other means - right?

 

Right, it's controlled by the TCC valve and the governor in the transmission, and a vacuum switch.

 

Ok well I have my 1406 in with only the throttle cable hooked up (not driving the car or anything , just to hear it run) and it runs like a charm. Now I purchased the Q-JET to Performer adapter kit. Which raises the carb 3/4 of an inch. Will this affect my TV cable geomerty? I am waiting on a new bracker and lever to install it. I also found this:

http://www.streetrodparts.tv/700R4_hookup.htm

From what I understand when the throttle is at WOT the TV cable should be fully extended.

 

It will affect you hood clearance, I wanted to run a carb spacer, but there was no way it would fit. Maybe a dropbase aircleaner would change it enough to allow for it.

 

I'm running a holley 10" open element-non drop base and my hood has plenty of clearance.

 

quick question edelbrock related.. My car has three cables going to the carb , the throttle cable with the small tab end with the hold on it , the TV cable and then a long slotted cable what is the one with the 1inch or so slot ended do? I canont find a place to put it on my carb.

 

Cruise control.

 

didn't even realize I had it lol, I didnt see a "coffee" can under the hood.

 

There isn't a governor on the speedometer cable like there used to be. The cruise diaphragm is located in the front driver's side corner of the engine compartment.