RQ Jay

I am interested in removing all emissions Items (converters, EGR, AIR system, etc..) from my 1985.
Would I have to remove the electronic Quadrajet and replace it with a non electronic version to get the vehicle to run correctly?

Sorry for if this is an ignorant question, I am not nearly familiar with engines or carbs.
Thank you in advance for any help/direction given.

jwfirebird

iTrader: (2)

the computer controls the ignition and trans as well as the carb. so kind of depends what your goal is. if you only put a non cc carb on it it will run fine on the oem stuff. but if you want to get rid of the rest of the sensors, air systems, cats, and such, it seems easier to me to bypass the pcm all together. you can get non emissions sbc headers, one wire vacuum advance hei from aftermarket or 70s chevy. need to research one of the many ways to control lockup on a 700r4. you can get non emissions sbc manifold or block all the ports. if the car is already carbed i think thats it. you would have to get a non cc quad or aftermarket carb

mlbinseattle

The CCC Quadrajet needs the O2 and CTS connected to the ECM and functioning for the ECM to provide feedback to the carb. If you intend on removing the ECM, I would go with a different carb.

RQ Jay

Thank you for some answers... I had no idea the trans was controlled by the PCM as well... will have to learn more on that correction.
My intention is simply a weekend cruiser to take out on Saturdays.
It will be registered as a classic here in AZ, and I expect to put some low miles on it.
Just looking for a simple and clean engine area for a little bit of showoff.

jwfirebird

iTrader: (2)

aftermarket non emissions intake, carb, hei, and headers is what i would go with then. and you can get rid of everything on the harness that goes into the pass side. the gauges might be an issue though, i went with aftermarket the fuel and voltage were the only ones that worked on my 87. you may be able to fix it but i wanted the accuracy. obviously have to do the trans too.

drdave88

iTrader: (3)

You can make all factory gauges work if you delete the ECM, just need to know which wires to connect to. Your speedo is cable driven, tach will run off the distributor, fuel from the pump, coolant temp from the CTS, and volts from the alternator.

RQ Jay

You guys rock! Thanks for the info!

naf

iTrader: (7)

There's absolutely no reason to remove the ECM (not PCM-does not control the trans). It will continue to work fine even with the AIR and EGR deleted. Some earlier models will throw a code when the EGR solenoid is removed, but that can be bypassed.

My 87 runs fine with no AIR or EGR, headers and a six speed.

Saves a whole bunch of $$ in new intake, carb, distributor and converter lock up.

jwfirebird

iTrader: (2)

the early ones still had converter control. the speedo being mechanical is one less thing to worry about. there are wiring diagrams on austinthirdgen.

he is doing the stuff for looks, not just what you need to make it run right. to me even if you plug all the holes the original smog intake and the quad looks bad, too busy. aftermarket HEI, intake, headers, holley dp, looks alot better. only be a couple wires with that setup, and a couple tubes.

naf

iTrader: (7)

I think the qjet looks perfectly fine.

All used the ECM to control converter lockup.

Electric or mechanical speedo makes no difference. Either will work perfectly fine without the ECM.

PCM Powertrain Control Module

ECM Engine Control Module

jwfirebird

iTrader: (2)

so he has to figure which way he wants to go because he is going to use the 700 without the ecm.

when you take the whole harness out and start from scratch only adding what is necessary as i did it makes a difference. my 87 was electronic and it didnt work. the OPs is mechanical so dont have to worry about anything but the lockup.

five7kid

iTrader: (14)

None of those affect the computer carb. Leave it, the computer controlled distributor, and ECM alone. It's a better carb than any possible replacement. Bar none.

I would argue that there's not much point in removing the EGR. It doesn't affect performance, and removing it can lead to part-throttle pinging, which you'll have to combat by using higher octane gasoline, or backing off the timing. Doing either of those will cost you more money in gas, and doing the latter will cost performance. Why do it?

jwfirebird

iTrader: (2)

i did it for two reasons, one all that crap looks bad and busy, and two the old stuff never works as engineered almost 30 years ago, and i dont want to be chasing performance issues on old crap with a million things it could be. been there, not fun. if you have a aftermarket manifold and headers and aftermarket ign you dont have all that nonsense to cause you trouble and it runs good because there is nothing to break. and if you tune it properly it doesnt ping and gets just as good mileage as it would with the qjet. if you dont you didnt tune it right.

five7kid

iTrader: (14)

Perhaps I missed it, but I don't see any reference by the OP to an aftermarket intake manifold.

jwfirebird

iTrader: (2)

he said he was looking for a clean engine area for a bit of show off. thats what that means to me, but its obviously just an opinion, depends what you think "clean engine area" looks like

naf

iTrader: (7)

someone's being snarky...

HTG TGO

RQ Jay

As mentioned I am looking to get the engine compartment cleaned up.
I have a 1996 5.7 from a 3500 truck that I will be looking at placing in my 85.
I have not checked officially, but the engine has a mechanism cal pump boss and block off plate.....just need to have a look and see if it has a fuel pump rod hole drilled.
I would like to keep the engine "old school"

naf

iTrader: (7)

the L31 should not have the fuel pump rod bored. but it is quick work for a shop.

assuming (?) L31 it should have the vortec heads but the stock springs are weak and limit lift. the LS6 spring swap is an economical alternative.

the entire ECM harness can be carefully removed through the fenderwell. the only ECM connection that needs to be replaced is the lockup connection to the trans.

RQ Jay

Thanks for the advice!
Regarding the spring concerns, is that something to worry about if I leave the block stock? I had only planned on an intake manifold change.

naf

iTrader: (7)

if you're keeping the stock cam you should be fine. should make for a solid 250+ HP performer with plenty of torque and decent mileage.

jwfirebird

iTrader: (2)

the 96+ requires the vortec specific intake, not sure if you knew that or not

dmccain

iTrader: (2)

As long as you keep the replacement cam at no more than .470 lift there is a lot to be gained by replacing that stock cam. And the stock heads will take that much lift but I wouldn't try anymore.

RQ Jay

Thanks for the followups on this, I appreciate the help.
Having checked the block it does have the mechanical pump provision, as well as the hold already drilled.
I intend to send the block out for a rebuild /refresh prior, and will have to make both a cam selection and an intake selection.....I would like to get this to around 300-320 Horsepower, and would like to make sure that there are no hood clearance issues with the Qjet installed.

Recommendations?

Ozz1967

iTrader: (4)

Edelbrock Performer is probably the best you are going to find and keep your hood clearance. I've heard nothing but issues trying to get an Performer RPM working.

naf

iTrader: (7)

performer intake is one of only a few available for a spreadbore carb like the qjet.

300 HP is going to require a replacement cam. even if the lift is low I would still recommend a spring replacement. keep it roller.

ensure the fuel pump rod bore is drilled through. seen several blocks that had the hole bored only partway.

86LG4Bird

iTrader: (1)

FWIW, the car in my sig is making about 320 hp through exhaust manifolds with a ZZ3 cam, 1.6 I / 1.5 E roller rockers. Vortec heads are close to stock, only cleanup of bowl area and smoothing around valveguides. Uncut Vortec block, .015" headgaskets, giving a CR of about 9.6:1.
Performer intake, original CCC Q-jet with DR rods / G hanger, runs fine on 87 octane.
Just posting this as concurrence that you need only a very mild cam, especially with headers to make your 300-320 hp target.