extreme bogging, stumbling and stalling quadrajet E4MC
July 15th, 2012, 08:25 AM
#1
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Location: South Jersey
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extreme bogging, stumbling and stalling quadrajet E4MC
So the olds started its carb problems again this time something new.
So as I'm driving when i attempt to speed up the carb starts popping and stumbling, the rpms are jumping between 1500-2500 and i lose all power and sometimes stall out. The cars been running great for weeks since my last problem i had and i replaced the carb to fix it. sometimes even from a dead stop it will stall when i touch the gas.
And if i'm accelerating from a dead stop with maybe 1/4-1/2 throttle it will run great for a couple seconds and then lose power start popping and stall.
I replaced the ignition control module again with a new unit just last night and also a new fuel filter cause mine was done. And i tried swapping ignition coils with a known good one and still nothing. I'm thinking its something with the carb.
The m/c solenoid and tps are adjusted properly and functioning as they should. And no check engine light
Please help i'm stumped on this 1
So as I'm driving when i attempt to speed up the carb starts popping and stumbling, the rpms are jumping between 1500-2500 and i lose all power and sometimes stall out. The cars been running great for weeks since my last problem i had and i replaced the carb to fix it. sometimes even from a dead stop it will stall when i touch the gas.
And if i'm accelerating from a dead stop with maybe 1/4-1/2 throttle it will run great for a couple seconds and then lose power start popping and stall.
I replaced the ignition control module again with a new unit just last night and also a new fuel filter cause mine was done. And i tried swapping ignition coils with a known good one and still nothing. I'm thinking its something with the carb.
The m/c solenoid and tps are adjusted properly and functioning as they should. And no check engine light
Please help i'm stumped on this 1
July 15th, 2012, 09:05 AM
#2
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Join Date: Sep 2010
Location: Shorewood, Il.
Posts: 3,057
Pull your distributor cap to the side and turn the balancer back and forth to check your timing chain.
If you've more than 2" of play, figure chain, gears, and a water pump, and maybe 6 - 8 hrs. labor.
Good luck!
If you've more than 2" of play, figure chain, gears, and a water pump, and maybe 6 - 8 hrs. labor.
Good luck!
July 15th, 2012, 09:18 AM
#4
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Posts: 7,286
So, you replaced the carb and then it ran ok for a couple weeks?
Replaced ign coil and voodoo module in, I assume, an HEI dist'r?
Symptoms sound almost like dirt in the carb, occasionally blocking the fuel flow passages. Have seen odd stuff like that happen.
But, I believe it was the hallowed halls of ClassicOldsmobile where I read something to the effect of "90% of all carb problems are ignition related"
which I recently found to be true myself.
What you describe sounds exactly like something that happened to me yrs ago- the vacuum advance in the HEI moves the pickup a little. That motion eventually fatigues and breaks the wire[s]. Usually it will make contact ok, but once in a while it comes apart. Then the engine dies, vacuum is lost, pickup coil is repositioned, and then it runs ok again.... for a while. I found this by tugging on the pickup coil wires, and it came right apart. After swapping modules and coils to no avail.
To test, you can swap in an entire distributor. Olds HEI's are not hard to find, at least around here. It need not be tailored perfectly to your engine, just has to fit in and more or less work.
Or, tug at your pickup coil wires and see if you find and obvious flaw there.
Replaced ign coil and voodoo module in, I assume, an HEI dist'r?
Symptoms sound almost like dirt in the carb, occasionally blocking the fuel flow passages. Have seen odd stuff like that happen.
But, I believe it was the hallowed halls of ClassicOldsmobile where I read something to the effect of "90% of all carb problems are ignition related"
which I recently found to be true myself.
What you describe sounds exactly like something that happened to me yrs ago- the vacuum advance in the HEI moves the pickup a little. That motion eventually fatigues and breaks the wire[s]. Usually it will make contact ok, but once in a while it comes apart. Then the engine dies, vacuum is lost, pickup coil is repositioned, and then it runs ok again.... for a while. I found this by tugging on the pickup coil wires, and it came right apart. After swapping modules and coils to no avail.
To test, you can swap in an entire distributor. Olds HEI's are not hard to find, at least around here. It need not be tailored perfectly to your engine, just has to fit in and more or less work.
Or, tug at your pickup coil wires and see if you find and obvious flaw there.
July 15th, 2012, 02:02 PM
#5
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Thread Starter
Join Date: Nov 2008
Location: South Jersey
Posts: 262
So, you replaced the carb and then it ran ok for a couple weeks?
Replaced ign coil and voodoo module in, I assume, an HEI dist'r?
Symptoms sound almost like dirt in the carb, occasionally blocking the fuel flow passages. Have seen odd stuff like that happen.
But, I believe it was the hallowed halls of ClassicOldsmobile where I read something to the effect of "90% of all carb problems are ignition related"
which I recently found to be true myself.
What you describe sounds exactly like something that happened to me yrs ago- the vacuum advance in the HEI moves the pickup a little. That motion eventually fatigues and breaks the wire[s]. Usually it will make contact ok, but once in a while it comes apart. Then the engine dies, vacuum is lost, pickup coil is repositioned, and then it runs ok again.... for a while. I found this by tugging on the pickup coil wires, and it came right apart. After swapping modules and coils to no avail.
To test, you can swap in an entire distributor. Olds HEI's are not hard to find, at least around here. It need not be tailored perfectly to your engine, just has to fit in and more or less work.
Or, tug at your pickup coil wires and see if you find and obvious flaw there.
Replaced ign coil and voodoo module in, I assume, an HEI dist'r?
Symptoms sound almost like dirt in the carb, occasionally blocking the fuel flow passages. Have seen odd stuff like that happen.
But, I believe it was the hallowed halls of ClassicOldsmobile where I read something to the effect of "90% of all carb problems are ignition related"
which I recently found to be true myself.
What you describe sounds exactly like something that happened to me yrs ago- the vacuum advance in the HEI moves the pickup a little. That motion eventually fatigues and breaks the wire[s]. Usually it will make contact ok, but once in a while it comes apart. Then the engine dies, vacuum is lost, pickup coil is repositioned, and then it runs ok again.... for a while. I found this by tugging on the pickup coil wires, and it came right apart. After swapping modules and coils to no avail.
To test, you can swap in an entire distributor. Olds HEI's are not hard to find, at least around here. It need not be tailored perfectly to your engine, just has to fit in and more or less work.
Or, tug at your pickup coil wires and see if you find and obvious flaw there.
Could a float problem cause this? cause it seems like it drives fine and then drains the carb bowl or something. and will start acting up. but then will fire right back up after a couple pumps of the gas pedal
July 15th, 2012, 03:44 PM
#6
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Location: Poteau, Ok
Posts: 40,559
Qote: But, I believe it was the hallowed halls of ClassicOldsmobile where I read something to the effect of "90% of all carb problems are ignition related".
Did this issue crop up after a fuel fillup?
Let's start at idle, how does the car run at idle? Did you check all your vacuum lines for leaks? Same with spraying carb cleaner around the manifold and carb base?
Have you checked your timing and the function of the your vacuum advance? Made sure mechanical advance plate is moving freely? So with a timing light does your advance work smoothly as you increase RPM to say 3000, both with vacuum advance disconnected and connected?
With the engine off and looking down the throat of the carb, operate the throttle and observe a solid 2 streams of fuel spraying.
Hook up a brass tee in your fuel line and install a fuel pressure gauge and see if its getting good pressure. Should be no more that 5-7 lbs? If you can make the line long enough to observe when driving.
Did this issue crop up after a fuel fillup?
Let's start at idle, how does the car run at idle? Did you check all your vacuum lines for leaks? Same with spraying carb cleaner around the manifold and carb base?
Have you checked your timing and the function of the your vacuum advance? Made sure mechanical advance plate is moving freely? So with a timing light does your advance work smoothly as you increase RPM to say 3000, both with vacuum advance disconnected and connected?
With the engine off and looking down the throat of the carb, operate the throttle and observe a solid 2 streams of fuel spraying.
Hook up a brass tee in your fuel line and install a fuel pressure gauge and see if its getting good pressure. Should be no more that 5-7 lbs? If you can make the line long enough to observe when driving.
July 16th, 2012, 02:41 PM
#7
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Join Date: Nov 2008
Location: South Jersey
Posts: 262
Well the cars fixed. i took apart the carb Sunday night. and noticed that the fuel level in the bowl was really low. I figured the needle and seat were bad since they were original. replaced the needle and seat assembly and no more bogging and stalling.
I fried the starter saturday night at advance auto parts Though. The car wouldnt stay running as soon as i touched the gas it would stall. Then the starter would only crank a little bit and start whining and smoking so I had to get towed home. Ordered a new 1 went to pick it up and it must of been dropped cause it had a giant crack in the solenoid. Have to wait till tomorrow for the new new one to come in. Then hopefully it should be okay.
I wish i would of replaced the needle and seat first before spending 30 bucks on a new ignition control module, but i guess i needed it anyway since the one that was on there was from a junkyard.
I fried the starter saturday night at advance auto parts Though. The car wouldnt stay running as soon as i touched the gas it would stall. Then the starter would only crank a little bit and start whining and smoking so I had to get towed home. Ordered a new 1 went to pick it up and it must of been dropped cause it had a giant crack in the solenoid. Have to wait till tomorrow for the new new one to come in. Then hopefully it should be okay.
I wish i would of replaced the needle and seat first before spending 30 bucks on a new ignition control module, but i guess i needed it anyway since the one that was on there was from a junkyard.
July 16th, 2012, 07:06 PM
#9
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Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
Glad you've fixed it, but I am a bit confused -
A bad needle and seat will leak, which will make your fuel level higher, not lower.
You may have had a piece of crud stuck in or around the needle orifice, which happened to have been fixed when you replaced it, but after seeing a low fuel level, I'd at least readjust the float, and consider replacing it.
- Eric
A bad needle and seat will leak, which will make your fuel level higher, not lower.
You may have had a piece of crud stuck in or around the needle orifice, which happened to have been fixed when you replaced it, but after seeing a low fuel level, I'd at least readjust the float, and consider replacing it.
- Eric
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