Greetings,

Recently I replaced the QJet Carb and Intake manifold on a 1986 Stock 305 AT with a Edelbrock Performer 1400 and Edelbrock Performer Manifold. However, I did not replace the distributor.

Here is the good:

1. Car starts right up when warm

2. Car's acceleration is great all the way through the power band and especially at high speeds/rpms.

Here is the bad:

1. Car idles at about 1100 RPM's and seems a little rough. Much rougher than with old QJet. Idle is real rough when cold. Get's better as warms up, RPM's do not seem to increase when cold started. Chock may need to be adjusted.

2. Car almost always diesel's/runs on when shut off. RPM's usually at 1100 when shut off.

3. Gas mileage seems poor, although I have not driven the car that much.

4. Of course, "Check Engine" light constantly on. Assume this is due to non-CC carb. Any ideas how to fake out the ECM to think it is there?

Any ideas would be greatly appreciated. I have seen other post which strongly suggest a distributor swap out as well. Some that say abandon the Edelbrock non-CC carb and go back to the QJet. I would assume if I did that I could keep the Edelbrock and get a spread bore adapter.

Let me know.

Thanks,

Ed

 

the MAP sensor is not conected!!!! it is a little vacuum line that should be on the pasenger side of the engine next to the distributor....vaccum line is comin out from the cables....and the map sensor is on the driver side( a vacuum and 3 cables conekts to it) next to the breaks pump !!! i am pretty sure thats disconected ,it controls the advance of the engine and it needs full vacuum sorce...after u conekt it u will have to ajust carb again

 

Thats what you need to do.

 

I have Holley on mine it's working just fine whit stock distributor

 

No, it isn't. You may think that it is, but without a TPS, the ECM is going to go to limp-home mode. Even if the MAP sensor is hooked up.

 

That would be the smart thing to do.

Getting a Performer intake with the spread bore mount pattern would be better.

 

Well yes I won't argue...it has the mistake about the TPS ...but when u connect the map sensor works fixes the idle and works bethre and it's drivable...anyway u r right distributor is need it aventualy...

 

Great advice guys,

Here is where I am at now.

Found two vacuum lines not hooked up
Replace Distributor Cap/Rotor/Spark Plug Wires
Found two spark plugs wires that were not even clicked on tight
Reset Air/Fuel mixture/idle on Carb

Car now starts up immediately, idles perfectly/roughness gone, heavy gas rich smell gone, acceleration great, gas mileage improved.

Did not replace distributor itself as some had suggested. Not sure if I still need to do that.

But, I do have three more things I would like to resolve:

1. SES Light constantly on. I would assume that is because the computer can't see the QJet carb. I remember before I replaced it that one time I had the air cleaner off and had unplugged the power to the carb the SES was on. Once I plugged that connection in the light went out. Can I simulate by capping this connection and closing the circuit. Will that turn off the light? Any way of faking it out?
2. I am getting codes 23 and 41. What exactly do they mean on the 305CU 4-bbl carbureted engine. I know these codes are vague and have multiple meaning depending on the engine codes. Mine is code "H". When I look in my Chilton's manual it says for engine code "H" Code 23 is Mixture Control Solenoid Open or Ground. Is this because the M/C Solenoid, which I understand is inside the QJett Carb is missing or is the truly the other reason I say for Code 23, Manifold Air Temperature Low? Does this meaning even apply to carbureted engines. If so, where is this MAT sensor located. For TBI injection and TPI I here references to inside the Air Cleaner, Air Tube and Plenum. Would these locales not apply to carbureted engines.
3. What exactly does Code 41 mean in a engine code "H" carbureted engine. When I was replacing the Distributor Cap I did not have all the electrical well connected. Could I have thrown this code when I test started the car?

Should I clear the codes and try again?


Your thoughts?


Thanks,

Ed

 

http://www.extreme-check-engine-ligh...%20Decoder.htm

23 intake air temp sensor out of range, low

41 cam sensor circuit fault, igntion control circuit fault

23 is probably some plug that went into the intake snorkel... is it still there?

41 is the distributor probably. Get a regular HEI.

 

Clear all of your codes by pulling the ECM power wire (single wire off of positive battery post that runs along the fenderwell towards the blower motor). Let it reset and check for codes again. Many of those may have been set by the problems that were fixed.

 

Recheck per https://www.thirdgen.org/service-eng...ht-error-codes

23 for a carb'd engine is "Throttle position sensor error". With an aftermarket carb, and without an external TPS, you will always get that error. Carb doesn't have manifold or intake air temp sensor.

For EST cars, the cam sensor is the distributor. If you don't have the flat 4-wire connector from the computer distributor to the firewall harness connected, this code will be set. If you don't have a computer distributor, it will be a constant.

Now, I'll say again - It may seem like the car is running well, but there is no way that it can be running properly with a non-computer carb and computer distributor. No way, no how (unless you hook up an external TPS). You are leaving performance on the table and pushing dollar bills out the tailpipe.

You need to set it up properly. The BEST way is to put a computer q-jet back on it.

Since you don't have TPS, your torque converter clutch is also not functioning. Keep that up, and you'll burn out your 3-4 clutch pack. Talk about burning $'s...

Oh, did you put a TV cable geometry corrector bracket on the Performer carb? If not, keep that up, and you'll burn out your transmission...

 

Yeah. I thought you'd put the original carb back on.

If you don't believe everything you read on the internet, hook up a timing light to your motor and observe it's timing curve with the computer controlled distributor and no ccc-qjet. You'll see that it only jumps up 10 or 15 degrees at around 1200-1500 rpm. No more. Not the 32-36 degrees you need for optimum performance and no vacuum advance for best efficient low throttle cruise (mileage).

Next observe your fuel mileage over a few tanks of gas. Calculate (or have someone help you) how many tanks you'll go through before you would have paid for that vacuum advance distributor (about $100) or the rebuilt ccc-qjet (about $80 if you do it yourself), compared to the 18-22 mpg you should be getting.

 

Since eca1987 lives in So Cal, his only choice is CC carb (unless he converts to EFI).

 

five7kid...i see u been fulling around whit these cars...i need distributor for my car...what du u think about the cheap distributor 40$ i think it was proform have u ever seen one or instal one see how it works?!! they have them at amazon...i king of cant give right now 200$ for the nice accel and coil ,i will avantualy....=-)

 

Swap in a vaccuum advance dizzy and ditch the ecu. Easy game.


EDIT: Oh crap, you're in Cali! Move to a less restrictive state!

 

Hey I just got my car back from the shop they did a carb cleaning tune up new wires and a thermostat and now the car makes noise when I shut it off
What can I do and I'm very new at this

 

I would not cheap out on the distributor. You have a few options here. The best one for a low budget is find a good used GM HEI distributor, pre-80's for a non-computer style distributor. That would be a whole lot better and the coil would be included. I asked the VP of marketing for MSD about getting a better coil for a HEI system and he said "I can sell you one of mine but it's not going to be any better than your stock GM HEI coil."

A good GM HEI coil is hard to beat so if you got a good stock coil then there isn't a need to replace it. If don't have a coil and need a new one then I would consider an aftermarket coil.