Runnining rich
03-04-2018, 05:58 PM
#1
Runnining rich
My 68' 327 is running rich. Haven't been able to figure this one out. Had a holly on the stock manifold and was having erratic idle speed and intermittent stalling problems car was not too bad with running rich. Replaced it with my rebuilt stock Q jet. Still have fluctuating idle speeds but no stalling problems. Car runs strong with no hesitation but strong smell of exhaust at idle. Start up after sitting for a day I have to pump gas pedal 2x crank and repeat process 4 x more before it starts. Manual checked carb squirts fuel each time pedal is pressed so fuel delivery is there. suspected and replaced fuel pump, have adjusted mixture screws per Q Jet procedures, Choke flap operates properly, timing is correct, plugs are sooty no oil, upon starting car spits out black sooty specks on to floor from drivers side pipe (heat riser on right). Suspected a vacuum leak and have searched for it well over a year trying all types of methods to locate it. Unable to locate vacuum leak but have read the car would be running lean not rich with vacuum leak. plug wires and coil new. Have replaced spark plugs (correct stock heat range) Any thoughts on this problem?
03-04-2018, 06:40 PM
#2
Race Director
FOR WHAT THIS IS WORTH:
***hard start/run issue when cold***
I have customers who have QuardaJets on their cars and I take the time and check out something that I am going to tell you to check.
When the car comes in the shop I will let it sit a day...maybe two. THEN I remove the air cleaner. I will make sure the choke plate is open so I can see the fuel squirt ( if any). Then I will move the accelerator linkage and WATCH and see what is going on in regards to the amount of fuel and intensity of teh fuel stream. Due to how the Quardajet is made...the fuel in the bowl can leak back into the fuel pump and thus...be almost out of fuel and the accelerator pump in the carb can not provide a very good stream of fuel.
So..If I see that this is happening. I will tell the customer that they have been spoiled by fuel injected engines of today and they will need to let the engine spin over a few times to prime the carb again. I also check this so I know what to tell them to do.
Then...pump the pedal twice to set the choke and prime the engine with fuel and crank it. The engine will crank and go into fast idle and I let it run on fast idle for a bit and then tap the gas pedal and see if the idle drops and it does not need to be cranked again due to the engine is still cold.
As for your other issue...all I can say is that I am really picky about who rebuilds a QuadraJet and IF they run it on an engine to make sure it is perfect before they send it back to me.
And if you are confident that the timing and all that is correct due to you know for a fact that the notch in your balancer that you use with a timing light to set the timing is in the correct position. Becasue the outer ring of your harmonic balancer can SPIN and thus...move that notch...and if you are using timing light...it can make you think your timing is correct when actually it is not.
DUB
***hard start/run issue when cold***
I have customers who have QuardaJets on their cars and I take the time and check out something that I am going to tell you to check.
When the car comes in the shop I will let it sit a day...maybe two. THEN I remove the air cleaner. I will make sure the choke plate is open so I can see the fuel squirt ( if any). Then I will move the accelerator linkage and WATCH and see what is going on in regards to the amount of fuel and intensity of teh fuel stream. Due to how the Quardajet is made...the fuel in the bowl can leak back into the fuel pump and thus...be almost out of fuel and the accelerator pump in the carb can not provide a very good stream of fuel.
So..If I see that this is happening. I will tell the customer that they have been spoiled by fuel injected engines of today and they will need to let the engine spin over a few times to prime the carb again. I also check this so I know what to tell them to do.
Then...pump the pedal twice to set the choke and prime the engine with fuel and crank it. The engine will crank and go into fast idle and I let it run on fast idle for a bit and then tap the gas pedal and see if the idle drops and it does not need to be cranked again due to the engine is still cold.
As for your other issue...all I can say is that I am really picky about who rebuilds a QuadraJet and IF they run it on an engine to make sure it is perfect before they send it back to me.
And if you are confident that the timing and all that is correct due to you know for a fact that the notch in your balancer that you use with a timing light to set the timing is in the correct position. Becasue the outer ring of your harmonic balancer can SPIN and thus...move that notch...and if you are using timing light...it can make you think your timing is correct when actually it is not.
DUB
Last edited by DUB; 03-06-2018 at 05:36 PM.
03-06-2018, 05:01 PM
#4
have you done a compression test?
you say you adjusted the idle mixture screws, do you get a drop in idle RPM before the screws are fully seated?
exactly what manufacturer and what part number plug are you using?
have you checked the harmonic balancer to insure the outer ring hasnt slipped and the timing would not be what you think it is?
you say you adjusted the idle mixture screws, do you get a drop in idle RPM before the screws are fully seated?
exactly what manufacturer and what part number plug are you using?
have you checked the harmonic balancer to insure the outer ring hasnt slipped and the timing would not be what you think it is?
03-06-2018, 06:47 PM
#5
Ive checked the harmonic balancer an its snug, no movement and no engine vibration which is a symptom of a spin ring. Idle drops before mixture screw is fully seated. I'm using champion RJ12YC plugs. Ive been thinking about doing a compression test for awhile but I dont have this type of equipment. Hate to buy equipment that I'll only use once but I guess I'm going to have to to eliminate this possibility.
have you done a compression test?
you say you adjusted the idle mixture screws, do you get a drop in idle RPM before the screws are fully seated?
exactly what manufacturer and what part number plug are you using?
have you checked the harmonic balancer to insure the outer ring hasnt slipped and the timing would not be what you think it is?
you say you adjusted the idle mixture screws, do you get a drop in idle RPM before the screws are fully seated?
exactly what manufacturer and what part number plug are you using?
have you checked the harmonic balancer to insure the outer ring hasnt slipped and the timing would not be what you think it is?
Last edited by greggome; 03-06-2018 at 06:48 PM.
03-06-2018, 07:09 PM
#6
Race Director
Ive checked the harmonic balancer an its snug, no movement and no engine vibration which is a symptom of a spin ring. Idle drops before mixture screw is fully seated. I'm using champion RJ12YC plugs. Ive been thinking about doing a compression test for awhile but I dont have this type of equipment. Hate to buy equipment that I'll only use once but I guess I'm going to have to to eliminate this possibility.
Not that what I think or feel matters...but I am not fan of Champion spark plugs.
I have used my Kv tester to see what the voltage at the spark plug is like and I can pin point problems in bad wires or bogus plugs,etc.
I still feel it may be in the carb or fuel related due to its design....but who knows for sure...because you did not respond if you have tried that as of yet.
DUB
03-06-2018, 08:34 PM
#7
The car has sat for a few days and the fuel stream is very little when pressing the accelerator linkage. Cranking the motor and rechecking, the fuel stream has a stronger flow/intensity but I still need do this process at least 4 more times before the car will start up. I notice that the car never goes into a fast idle speed during warm up though the choke plate is closed. The carb was rebuild at Allstate Carburetor, they rebuild and do restoration work on older carbs as well as racing applications and they do run them to test them. I have not seen a specific method to verify if a balancer has spun other then finding TDC on the # 1 cylinder and checking the timing mark. When I change my plugs I'll have to give that a look though as I say there is no noticeable vibration from the engine.
FOR WHAT THIS IS WORTH:
***hard start/run issue when cold***
I have customers who have QuardaJets on their cars and I take the time and check out something that I am going to tell you to check.
When the car comes in the shop I will let it sit a day...maybe two. THEN I remove the air cleaner. I will make sure the choke plate is open so I can see the fuel squirt ( if any). Then I will move the accelerator linkage and WATCH and see what is going on in regards to the amount of fuel and intensity of teh fuel stream. Due to how the Quardajet is made...the fuel in the bowl can leak back into the fuel pump and thus...be almost out of fuel and the accelerator pump in the carb can not provide a very good stream of fuel.
So..If I see that this is happening. I will tell the customer that they have been spoiled by fuel injected engines of today and they will need to let the engine spin over a few times to prime the carb again. I also check this so I know what to tell them to do.
Then...pump the pedal twice to set the choke and prime the engine with fuel and crank it. The engine will crank and go into fast idle and I let it run on fast idle for a bit and then tap the gas pedal and see if the idle drops and it does not need to be cranked again due to the engine is still cold.
As for your other issue...all I can say is that I am really picky about who rebuilds a QuadraJet and IF they run it on an engine to make sure it is perfect before they send it back to me.
And if you are confident that the timing and all that is correct due to you know for a fact that the notch in your balancer that you use with a timing light to set the timing is in the correct position. Becasue the outer ring of your harmonic balancer can SPIN and thus...move that notch...and if you are using timing light...it can make you think your timing is correct when actually it is not.
DUB
***hard start/run issue when cold***
I have customers who have QuardaJets on their cars and I take the time and check out something that I am going to tell you to check.
When the car comes in the shop I will let it sit a day...maybe two. THEN I remove the air cleaner. I will make sure the choke plate is open so I can see the fuel squirt ( if any). Then I will move the accelerator linkage and WATCH and see what is going on in regards to the amount of fuel and intensity of teh fuel stream. Due to how the Quardajet is made...the fuel in the bowl can leak back into the fuel pump and thus...be almost out of fuel and the accelerator pump in the carb can not provide a very good stream of fuel.
So..If I see that this is happening. I will tell the customer that they have been spoiled by fuel injected engines of today and they will need to let the engine spin over a few times to prime the carb again. I also check this so I know what to tell them to do.
Then...pump the pedal twice to set the choke and prime the engine with fuel and crank it. The engine will crank and go into fast idle and I let it run on fast idle for a bit and then tap the gas pedal and see if the idle drops and it does not need to be cranked again due to the engine is still cold.
As for your other issue...all I can say is that I am really picky about who rebuilds a QuadraJet and IF they run it on an engine to make sure it is perfect before they send it back to me.
And if you are confident that the timing and all that is correct due to you know for a fact that the notch in your balancer that you use with a timing light to set the timing is in the correct position. Becasue the outer ring of your harmonic balancer can SPIN and thus...move that notch...and if you are using timing light...it can make you think your timing is correct when actually it is not.
DUB
