Mrgref92

I'm replacing the quadrajet carb with a 1406 edelbrock carb, can someone please tell me what exactly I need to make the switch, I don't have a vacuum advance on the distributor, I have an electric choke, I have the 700 r4 with the tv cable that goes to the carb, I'm just not sure if I need anything.

five7kid

iTrader: (14)

You need to rethink what you're doing.

Why are you considering this? This is a downgrade in every respect. There is no way that Edelbrock has to performance or economy potential of the q-jet, to say nothing about it being illegal for street use.

You can't do this without a vacuum advance distributor. You also need a geometry corrector bracket for the TV cable. The Edelbrock won't bolt to a stock intake manifold (you didn't indicate if you have an aftermarket manifold already or not). You'll need to do something to get the TCC lock-up to work.

What are you trying to fix? There's about a 99% chance that fixing what's wrong will be cheaper and more effective than putting on the Edelbrock.

If you're looking for more power, the Edelbrock is absolutely without doubt the wrong move.

Mrgref92

There are a few reasons I want to do this, first is because the quadrajet I have is 24 years old and hasn't been touched and it performs very badly, bogs down, never wants to start (hot or cold), another reason is because I'm not even sure if the computer is doing any good because I dissconnected a lot of things under the hood when I did the engine swap, the only way I got it to run a little better is by putting a 1 inch spacer inbetween the carb and manifold, and since I did that I couldn't adjust the throttle bracket and t/v cable adjustment so now my shifting is around 2700 rpm and it shifts hard. I want to get the carb so car will run better perform better than it is, and so I can take the spacer out and make all the cables work like they are suppose to. If there is a better solution to my problem I would be very happy to hear it, but i've been told you can't adjust the mixture on a quadrajet, so mine is running really really rich, the spark plugs are black, when I took the carb off there was a good amount of carbon in the manifold. and i'm getting 8 mpg or less, 8 on a good day. please help

five7kid

iTrader: (14)

For the computer to be able to control the carb (and distributor), it needs:
Throttle position (contained in the carb itself)
Cam signal (contained in the distributor itself)
Exhaust oxygen (the "O2 sensor" in the driver side exhaust manifold)
Manifold vacuum (sensor located in the rear driver side corner of the engine compartment with a vacuum line that runs over to the intake manifold)
Barometric pressure (a sensor that looks like the manifold vacuum sensor but on the cowl above the heater/AC box - but with no vacuum line on it)
Coolant temperature (a sensor located in the thermostat housing)

The computer also controls the EGR valve, A.I.R. diverter, TCC lock-up, but not having those doesn't affect the way the engine runs (although not having the EGR solenoid hooked up electrically will turn on the SES light and set a trouble code). Your car also originally had a knock sensor (sensor located in the passenger side water jacket drain, control module next to the manifold vacuum sensor).

The reason you can't adjust the mixture on a computer q-jet is the computer does it automatically - if it has the right inputs. Giving it the right inputs is a piece of cake. That's really good news - a carb that adjusts itself. What more could you ask for?

Although you can get an Edelbrock to run decent, it will never adjust itself to changing conditions. I already listed the other disadvantages.

I've been running a computer q-jet for 10+ years. 2 of those years were with a souped up 305 (headers, cam, ported heads). The last 5+ have been with a healthy 350. It's a daily driver, including today (after 6" of snow, started it when the temp was 9 degrees F).

(Are you sure about the "L69" part? There were only a very few made in the '86 model year, so if you actually have one, it's a very rare car.)

Mrgref92

Thanks for the input, the L69 is right, it's not the original engine though. I should have said when the Engine was replaced all the pollution stuff was taken out. I'm not positive on some of those connections you were talking about, the manifold vacuum, barometric pressure, and the knock sensor. If I got all this hooked up(if it isn't already) I would be very happy on keeping the carb and try it out or go buy a new quadrajet. Since I don't know what those 3 things are i'm going to take some pictures and if you could try and point them out to me after I post them that would be great. thanks again

marc12321

that wasnt smart disconecting the wires to the carb i did that on my firebird it just pours fuel in your engine its not good at all. i took a old q-jet off my dads car and it passed inspection with no problem and the gas milage isnt that bad u can probly buy one for like 25 on ebay

Mrgref92

I didn't disconnect all the wires, I just got rid of the pollution, well here are some pictures I just took, if you could tell me if those things are hooked up that would be great

marc12321

you still have them connected. those 2 plugs the one on top and the on the side are connected to your computer and the computer tunes pumps in your carb. if you unplug then they open all the way and it dumps gas in but you still got them connected so your fine. do you use your camaro as a daily car or do you race a little bit with it?

Mrgref92

some more

Mrgref92

last 3

Mrgref92

oh it's a daily car, every once in a while I'll give it some gas on the road but nothing to terrible

marc12321

since its a daily car i would say buy a older q-jet like from the 70s like i put on my car the gas milage isnt bad at all and it has a bit of power for a 305

five7kid

iTrader: (14)

NOOOOOOOOOO!!!!!!

It appears all of the critical stuff is there. Some has been disconnected (like the bowl vent to the vapor canister), but you aren't looking at a bunch of junkyard trips to get it running properly.

Is your SES light coming on? Is the SES light working?

It appears the O2 sensor connector got a little toasty. If the connector was shorting out to the engine, that could cause problems.

Mrgref92

Yes the SES light is working and is on, would the O2 sensor make the engine run badly?, and do you think I need a new carburetor or get something from a junkyard or something else?

five7kid

iTrader: (14)

Yes, O2 sensor will cause problems, primarily running rich.

Retrieve the trouble codes that the computer is setting. Can be done with a paper clip, code reader, or scan tool. https://www.thirdgen.org/service-eng...ht-error-codes

That looks like a very good candidate for rebuilding. The two most common problems with q-jets are a FUBAR'd air horn (either from trying to pry it off when there are still screws in, or overtorquing the air horn screws or front mount bolts), and worn out throttle shafts (personally, I've never had a q-jet with worn out throttle shafts). I ran mine for 5 years before I finally rebuilt it, made a big difference (I've been through many a q-jet, this wasn't any worse than a non-computer q-jet). Had worn out seals, and air bleed tubes that had fallen out of the air horn.

A professionally rebuilt CC q-jet will run you about $300-$350. There's a slightly used one on eBay right now for $25 plus shipping. A 100% feedback seller has a fresh rebuilt for $345 plus shipping. http://cgi.ebay.com/ebaymotors/1986-...item2a02c780ad , calls it "Monte Carlo" but the same thing, free shipping. If I was in the market, I'd be willing to buy from this guy http://cgi.ebay.com/ebaymotors/ROCHE...item5637c477d2 . Jet Performance will go through yours for around $300 (opinions vary on Jet, I haven't dealt with them personally but have heard many that have had great results with them).

I'd say either rebuild yours, or buy a professionally rebuilt unit. I wouldn't bother with the junkyard (most likely would be in worse shape than yours is).

five7kid

iTrader: (14)

I just noticed the center bolt valve covers. L69's never got center bolt heads. What engine is this exactly?

Mrgref92

I was told it is a 305 H.O. that came out of a 1985 monte carlo ss, ok so I did the diagnosis thing with a paper clip, and If I did it right I got the codes 21, 23, and 42. Would any of these have anything to do with it getting 8 miles a gallon and running badly? thanks

five7kid

iTrader: (14)

21 & 23 are throttle position sensor problems, located in the carb. Could be a bad sensor, or could be a bad circuit. Bad/stuck sensor likely, since it set the high voltage code.

42 ("Fault at electronic spark timing circuit") is the distributor signal not getting to the computer. There is a flat 4-wire connector (sometimes referred to as the "EST" connector) that comes out of the distributor base and goes to the firewall harness bundle. If that connector is disconnected (which it should be to set the timing), that code will be set. Make sure it's connected, as not having it would produce poor power and terrible gas mileage. It's not particularly easy to find, so take your time looking for it.

five7kid

iTrader: (14)

Your first picture, https://www.thirdgen.org/forums/atta...1&d=1260233755 , that black wire on the distributor cap with electrical tape on it, looks suspicious. Any idea what is going on there? That wire should be coming out of the distributor base.

five7kid

iTrader: (14)

Yeah, that wouldn't be center bolt valve covers. About the only way to know for sure would be to pull the valve cover and get the casting # from the head.

https://www.thirdgen.org/forums/atta...estion-002.jpg , looks like an '87-up Performer EGR intake manifold with the center two intake mount bolts at 72 degrees. Could be an '87 or '88 Monte HO, though.

Mrgref92

Ok well I'll check that in a minute and get back to you.

Mrgref92

I can't tell in the picture but I believe I cut it once accidentally and rejoined it, I just did a bad job taping, I'll check that also to make sure it's getting a connection.

Mrgref92

Yes, when I bought the manifold I had to return it 3-4 times because they kept giving me the wrong one. I told the guy that sold me the engine(he also talks a lot of bs), and he was so 100% positive in his mind it was a 305 H.O. from a 1985 Monte Carlo. so I just took his word for it. I am really interested in what engine it is now, if you could tell me where to look under the valve covers that would be great. also thanks so much for your help.

Mrgref92

Ok well I looked for that flat 4 prong sensor and it was hooked up, I also looked at the wire, it's just spliced. when I found the 4 prong sensor I unplugged it to see if the car would run differently. It ran better than normal for about 10 seconds then immediately shut off and gas started pouring out of that front vent of the carburetor like a sink. Nothing lit thank god but I plugged it back in and the car runs the way it did. So I should probably get a new carburetor? stock rebuilt one?

five7kid

iTrader: (14)

The casting number is between the 2nd and 3rd rocker arm (from the front on the driver side, from the rear on the passenger side). If the number ends in "081", those are the "good" heads - but, it could still be from an LG4 and not L69. The differences between LG4 and L69 were cam, exhaust, and computer tuning. If, however, the last three are "191", not so good.

I don't believe the car would run if that spliced wire wasn't making a good connection, so that's probably not the problem. You need to check that 4-wire harness, though.

These carbs aren't available new, that's why I listed all the choices above that I did.

Mrgref92

Now i'm getting a code 41 with it, I replaced the distributor and it runs better than it did, but it's still reading the code, should I check anything else?

Mrgref92

Also would this code have to do with the coil built in the distributor?