i dont know what to do anymore
#1
i dont know what to do anymore
listen guys, i have asked a number of people including my father and nobody can tell me what i have done wrong.
i consider myself to be very mechanically inclined, but i just dont know who to turn to for help anymore...
this is what is going on here with my 350 olds.
even with the choke on, it have to furiously pump the gas pedal to get the car to start in the morning, and untill it reaches operating temp it runs like straight crapola. and even when it reaches operating temp it runs like crap.
once the car is moving and in 3rd gear it runs great, but from a stop, accelerating, the motor is stumbly when i am light on the throttle. this car is my daily driver, and it has all ready passed emissions, everything is brand new or rebuilt including the q-jet 4bbl.
now i all ready started a topic asking about my cam shaft, but nobody seemed to care or pay attention to it. so perhaps this is not my problem.
i can only think that it has something to do with my carb. i have tried adjusting all sorts of ways, and the more i turn out the adjustment screws the more it smells like rotten eggs... now when this carb was rebuilt it was jetted to match the camshaft, and the guy who rebuilt it is now out of business so i can not go back there to ask for help. i have tried my best to adjust the timing properly, but my timing tab does not go up to 20 degrees and i have no idea how to keep the car at 1100 rpm while i am trying to do the timing. i can not tell you how frustrating this is to me, and then to come to an oldsmobile website only to be ignored in previous topics that i have made is even more so...
can nobody just stop for a minute to help me out? there is something that i am obviously doing wrong, and i am afraid that i am damaging my motor by driving it like this.
i consider myself to be very mechanically inclined, but i just dont know who to turn to for help anymore...
this is what is going on here with my 350 olds.
even with the choke on, it have to furiously pump the gas pedal to get the car to start in the morning, and untill it reaches operating temp it runs like straight crapola. and even when it reaches operating temp it runs like crap.
once the car is moving and in 3rd gear it runs great, but from a stop, accelerating, the motor is stumbly when i am light on the throttle. this car is my daily driver, and it has all ready passed emissions, everything is brand new or rebuilt including the q-jet 4bbl.
now i all ready started a topic asking about my cam shaft, but nobody seemed to care or pay attention to it. so perhaps this is not my problem.
i can only think that it has something to do with my carb. i have tried adjusting all sorts of ways, and the more i turn out the adjustment screws the more it smells like rotten eggs... now when this carb was rebuilt it was jetted to match the camshaft, and the guy who rebuilt it is now out of business so i can not go back there to ask for help. i have tried my best to adjust the timing properly, but my timing tab does not go up to 20 degrees and i have no idea how to keep the car at 1100 rpm while i am trying to do the timing. i can not tell you how frustrating this is to me, and then to come to an oldsmobile website only to be ignored in previous topics that i have made is even more so...
can nobody just stop for a minute to help me out? there is something that i am obviously doing wrong, and i am afraid that i am damaging my motor by driving it like this.
#2
lets start with the basics: Are you getting gas? are you getting spark?
Check to make sure you are getting adequate fuel pressure to the carb via the fuel pump.
Check that you are getting a strong spark.
If you start to rule out things methodically then hopefully this will lead you in the right direction.
If you are getting proper fuel to the carb. then start looking at the carb.
If you are getting proper spark then lets look at timing, vacuum, camshaft.
Lets get a complete history of what has been done to the 350 and maybe that will tell us something also.
I will give what little knowledge I have.
Check to make sure you are getting adequate fuel pressure to the carb via the fuel pump.
Check that you are getting a strong spark.
If you start to rule out things methodically then hopefully this will lead you in the right direction.
If you are getting proper fuel to the carb. then start looking at the carb.
If you are getting proper spark then lets look at timing, vacuum, camshaft.
Lets get a complete history of what has been done to the 350 and maybe that will tell us something also.
I will give what little knowledge I have.
#3
It is very difficult to diagnose problems like this over the internet, thus the lack of responses. But, I will try.
"now when this carb was rebuilt it was jetted to match the camshaft"
You stated this, what are the camshaft and engine specs?
First thing in the morning, before you try and start it, remove the air cleaner and check the choke. Open the throttle once and see if the choke flap closes and has light pressure. Now, hold the choke open and use a light to look into the carb. Open the throttle, do you see fuel squirting in? Q-jets are notorious for leaking down.
OK, get it running and up to temp. No engine will run correctly if the timing is way off. No timing tabs go to 20 degrees, get a timing tape for your balancer or a dial back light. Once the timing is set/verified, with the engine idling, slowly place a towel over the carb. If the engine picks up rpm and smooths out, you have a vacuum leak or are running lean. Do these things and get back to us.
"now when this carb was rebuilt it was jetted to match the camshaft"
You stated this, what are the camshaft and engine specs?
First thing in the morning, before you try and start it, remove the air cleaner and check the choke. Open the throttle once and see if the choke flap closes and has light pressure. Now, hold the choke open and use a light to look into the carb. Open the throttle, do you see fuel squirting in? Q-jets are notorious for leaking down.
OK, get it running and up to temp. No engine will run correctly if the timing is way off. No timing tabs go to 20 degrees, get a timing tape for your balancer or a dial back light. Once the timing is set/verified, with the engine idling, slowly place a towel over the carb. If the engine picks up rpm and smooths out, you have a vacuum leak or are running lean. Do these things and get back to us.
#4
lets start with the basics: Are you getting gas? are you getting spark?
Check to make sure you are getting adequate fuel pressure to the carb via the fuel pump.
Check that you are getting a strong spark.
If you start to rule out things methodically then hopefully this will lead you in the right direction.
If you are getting proper fuel to the carb. then start looking at the carb.
If you are getting proper spark then lets look at timing, vacuum, camshaft.
Lets get a complete history of what has been done to the 350 and maybe that will tell us something also.
I will give what little knowledge I have.
Check to make sure you are getting adequate fuel pressure to the carb via the fuel pump.
Check that you are getting a strong spark.
If you start to rule out things methodically then hopefully this will lead you in the right direction.
If you are getting proper fuel to the carb. then start looking at the carb.
If you are getting proper spark then lets look at timing, vacuum, camshaft.
Lets get a complete history of what has been done to the 350 and maybe that will tell us something also.
I will give what little knowledge I have.
#5
It is very difficult to diagnose problems like this over the internet, thus the lack of responses. But, I will try.
"now when this carb was rebuilt it was jetted to match the camshaft"
You stated this, what are the camshaft and engine specs?
First thing in the morning, before you try and start it, remove the air cleaner and check the choke. Open the throttle once and see if the choke flap closes and has light pressure. Now, hold the choke open and use a light to look into the carb. Open the throttle, do you see fuel squirting in? Q-jets are notorious for leaking down.
OK, get it running and up to temp. No engine will run correctly if the timing is way off. No timing tabs go to 20 degrees, get a timing tape for your balancer or a dial back light. Once the timing is set/verified, with the engine idling, slowly place a towel over the carb. If the engine picks up rpm and smooths out, you have a vacuum leak or are running lean. Do these things and get back to us.
"now when this carb was rebuilt it was jetted to match the camshaft"
You stated this, what are the camshaft and engine specs?
First thing in the morning, before you try and start it, remove the air cleaner and check the choke. Open the throttle once and see if the choke flap closes and has light pressure. Now, hold the choke open and use a light to look into the carb. Open the throttle, do you see fuel squirting in? Q-jets are notorious for leaking down.
OK, get it running and up to temp. No engine will run correctly if the timing is way off. No timing tabs go to 20 degrees, get a timing tape for your balancer or a dial back light. Once the timing is set/verified, with the engine idling, slowly place a towel over the carb. If the engine picks up rpm and smooths out, you have a vacuum leak or are running lean. Do these things and get back to us.
when i pull the choke open, i mean the slightest touch on the throttle will release the choke.
once i get the motor started, with light pressure on the throttle, ither in gear and moving, or in park, the motor hesitates, and smooths out at about 1200 rpm or so...
i had to use a carb spacer, and i checked for vacuum leaks the old fashioned way, except for the towel method that you have described. i have not started the car yet today, would you like me to take a video of what i am seeing for you guys?
#6
i am just really confused why i have to pump the gas pedal about 25 times while i am turning it over to get it started... even with the choke help open...
that is why i think something is wrong with the carb, someone had mentioned that the accelerator pump linkage is in the wrong adjustment slot, could that be the problem?
DSC02452.jpg
DSC02451.jpg
that is why i think something is wrong with the carb, someone had mentioned that the accelerator pump linkage is in the wrong adjustment slot, could that be the problem?
DSC02452.jpg
DSC02451.jpg
#7
Get a Holley 600-650Dp and be done with that ole quadrojunk,They work good when there new but when they wear out I woudnt hesitate to replace it.....This is my .$02 so you factory carb guys dont get your panties all bunched up..........
#9
Here we go again, I sound like a broken record. If the engine was rebuilt using stock cast replacement pistons, the compression ratio could be as low as 7.8 to 1. Add in a cam that is too big and it would account for some driveability issues, though not the hard starting. If the cam was large enough that the carb needed to be re-jetted for it, your cam might be too big. Can you do a compression test?
I'm with Jerr, at this point borrow a carb that you know works and just bolt it on. See what happens. But you have to know that the timing is correct or none of this other stuff is valid.
I'm with Jerr, at this point borrow a carb that you know works and just bolt it on. See what happens. But you have to know that the timing is correct or none of this other stuff is valid.
#10
It could be as simple as a plugged fuel filter or a bad fuel pump. I have had new fuel pumps fail right out of the box. Disconnect the fuel line from the carb and attach a couple of feet on rubber fuel line to it and stick the end in a five gallon bucket have someone crank the engine and check you fuel flow it should pump a gallon real quick. Lets take one thing at a time here.
#11
Here we go again, I sound like a broken record. If the engine was rebuilt using stock cast replacement pistons, the compression ratio could be as low as 7.8 to 1. Add in a cam that is too big and it would account for some driveability issues, though not the hard starting. If the cam was large enough that the carb needed to be re-jetted for it, your cam might be too big. Can you do a compression test?
I'm with Jerr, at this point borrow a carb that you know works and just bolt it on. See what happens. But you have to know that the timing is correct or none of this other stuff is valid.
I'm with Jerr, at this point borrow a carb that you know works and just bolt it on. See what happens. But you have to know that the timing is correct or none of this other stuff is valid.
when i had the heads off i noticed these marks, i am pretty sure this wouldnt cause a driving issue, but its the only pic of the pistons that are in there...
DSC01851.jpg
DSC01852.jpg
DSC01853.jpg
if the pistons dont match the cam, how did it pass emissions? or is that irrelevant?
#13
#14
#15
ok gents, this is what i have done so far. i zeroed out the adjustment screws for the primarys and this is what i got, the passenger screw was 11 half turns out, and the drivers side was 14 turns out, so after zeroing them, i truned them to 7 half turns for a base line. with the air cleaner off i looked into the primarys while pulling the throttle, and i cant see any fuel squirting in there really at all if i remember anything from highschool auto shop, and a few years in the shop in the Marines, there should be a visible stream being fired into the primary right?? does that mean that the accelerator pump is on the wrong setting? i do remember seeing it being squirted in while the car was running ( obviously it has to be doing it at some time or the car wouldnt run at all lol ) sadly, the only carbs i can fix are small engine carbs, and i have seen the diagrams of the q-jet and its pretty complex.
the only reason why i believe it may be a carb ( or undiagnosed vacuum problem) is because i gotta say, when the car is in 3rd gear it runs pretty good, and despite it being a 3 speed, it gets up pretty good on the highway considering what the car is and how much it really weighs...
my dad may be a little old and forgetful these days, but when he built this motor i gotta say, im pretty sure he knew what he was doing, and i trust that the components that are in the motor are correct. everything was magnafluxed and it was carefully put back together by the book. the only mystery is the black spots...
i know one of you old geezers has seen something like this before, and if you guys cant help me fix it im not sure anyone can! because i sure as hell aint gonna pay someone to fix it! i have fixed everything else on this damn car!
i will check the timing again in the morning and report back
thanks
the only reason why i believe it may be a carb ( or undiagnosed vacuum problem) is because i gotta say, when the car is in 3rd gear it runs pretty good, and despite it being a 3 speed, it gets up pretty good on the highway considering what the car is and how much it really weighs...
my dad may be a little old and forgetful these days, but when he built this motor i gotta say, im pretty sure he knew what he was doing, and i trust that the components that are in the motor are correct. everything was magnafluxed and it was carefully put back together by the book. the only mystery is the black spots...
i know one of you old geezers has seen something like this before, and if you guys cant help me fix it im not sure anyone can! because i sure as hell aint gonna pay someone to fix it! i have fixed everything else on this damn car!
i will check the timing again in the morning and report back
thanks
#17
Maybe it's just the picture but is the carb throttle linkage hitting the accelerator pump rod linkage? They should not be contacting each other and the throttle linkage should move freely full open to close (idle screw)
#19
You mentioned it smells like rotten eggs. Do you have a catylitic converter on it? If so I bet you dollars to donuts that it is clogged. The late 70s GM catalytic converters used beads that could be removed and replaced. If the converter became clogged (a common problem) it would constipate the engine and you would smell sulfur dioxide (the rotten eggs smell) because the converter couldn't keep up with all the hydrocarbons getting dumped into it.
Other than that, your idle mixture screw were WAY TO FAR out. Base line is 2.5 turns out.
You should do a complete tune up and then go from there. Make sure your choke, dwell, timing, idle speed, and idle mixture screws are all set correctly. You will need a tach / dwell meter, vacuum gauge, and timing light. All available at your local auto parts store.
Other than that, your idle mixture screw were WAY TO FAR out. Base line is 2.5 turns out.
You should do a complete tune up and then go from there. Make sure your choke, dwell, timing, idle speed, and idle mixture screws are all set correctly. You will need a tach / dwell meter, vacuum gauge, and timing light. All available at your local auto parts store.
#20
You mentioned it smells like rotten eggs. Do you have a catylitic converter on it? If so I bet you dollars to donuts that it is clogged. The late 70s GM catalytic converters used beads that could be removed and replaced. If the converter became clogged (a common problem) it would constipate the engine and you would smell sulfur dioxide (the rotten eggs smell) because the converter couldn't keep up with all the hydrocarbons getting dumped into it.
Other than that, your idle mixture screw were WAY TO FAR out. Base line is 2.5 turns out.
You should do a complete tune up and then go from there. Make sure your choke, dwell, timing, idle speed, and idle mixture screws are all set correctly. You will need a tach / dwell meter, vacuum gauge, and timing light. All available at your local auto parts store.
Other than that, your idle mixture screw were WAY TO FAR out. Base line is 2.5 turns out.
You should do a complete tune up and then go from there. Make sure your choke, dwell, timing, idle speed, and idle mixture screws are all set correctly. You will need a tach / dwell meter, vacuum gauge, and timing light. All available at your local auto parts store.
everything, but everything is brandy new! catylitic converter, everything, you name ti and its brand new, or in the q-jet's case rebuilt...
#21
#22
i dont remember if i mentioned or not, but the other day, i just poured a little bit of gas straight into the primarys and it fired right up, is it possible that the fuel pump works, but is too small of a fuel pump? i rememebr someone i knew awhile ago had big block in his dually, and he needed a new fuel pump for it, and got the one for the smaller big block or something, anyway, the pump was a lower gpm, and it caused the truck to be a lot slower, is it possible this fuel pump is for a 307? i cant imagine a 307/350 needing different fuel pumps if they both are carbbed
#23
Where exactly do you live? There are tons of guys here and on other boards that would lend you a carb and a hand. I am wondering why the carb needed re-jetting if it was a near stock rebuild. I would make sure the timing is right then beg, borrow, or steak a carb.
#24
To set the idle mixture screws turn them all the way in, then turn them out 2 complete rotations and an additional 1/2 rotation. This is baseline. Once you start the car set your dwell first. Then set your timing. Next set your idle speed with the stop screw. Then set your idle mixture screws to maximum vacuum using a vacuum gauge (turn them in 1/2 turn increments). Finally reset your idle speed using the stop screw.
If your idle screws were out 11 and 14 turns that is why you smelled rotten eggs. The fuel mixture was way to rich.
If your idle screws were out 11 and 14 turns that is why you smelled rotten eggs. The fuel mixture was way to rich.
#26
i live in the greater hartford area of connecticut, off of the berlin turnpike
#27
To set the idle mixture screws turn them all the way in, then turn them out 2 complete rotations and an additional 1/2 rotation. This is baseline. Once you start the car set your dwell first. Then set your timing. Next set your idle speed with the stop screw. Then set your idle mixture screws to maximum vacuum using a vacuum gauge (turn them in 1/2 turn increments). Finally reset your idle speed using the stop screw.
If your idle screws were out 11 and 14 turns that is why you smelled rotten eggs. The fuel mixture was way to rich.
If your idle screws were out 11 and 14 turns that is why you smelled rotten eggs. The fuel mixture was way to rich.
#28
i noticed that it ran smooth between a certain degree and a certain degree, but what degrees i am not exactly sure... my friend has a backtiming light, what should i set the dial too, to get correct timing? since the tab by the harmonic balancer only goes up to 12 or 15 i think...
#29
oh i also noticed that sometimes when i am driving and i come to a stop, my tach will be reading higher than normal idle, and i can barely tap the gas and it will return to normal idle...
#30
ok guys!
here is the timing tab
DSC02487.jpg
for some reason, choke on or off, the butterflies are always open like this
DSC02488.jpg
after re zeroing my carb to olds 64's specs the idle was really low and the car would stall with out my foot on the throttle, so i turned out this screw a bit, and it idles great!
DSC02489.jpg
DSC02490.jpg
this is water temp and oil pressure at idle
DSC02491.jpg
and this is where the tach sits at idle ( it sounds pretty mean )
DSC02492.jpg
so after all of this i took it for a test drive, it drives way better than it did before but there is only just a little bit of hesitation ( and it makes a popping noise from the tailpipe ) but not nearly as bad as it was before!
if i had gas in my tank i would have taken it out on the highway to see what it was really made of, but sadly, i have other people to help out, so ill let betsy sit for now, and ill gas her up later and see whats up...
do you guys think it was running like **** because of how i had the mixture screws cranked all the way out like that???
here is the timing tab
DSC02487.jpg
for some reason, choke on or off, the butterflies are always open like this
DSC02488.jpg
after re zeroing my carb to olds 64's specs the idle was really low and the car would stall with out my foot on the throttle, so i turned out this screw a bit, and it idles great!
DSC02489.jpg
DSC02490.jpg
this is water temp and oil pressure at idle
DSC02491.jpg
and this is where the tach sits at idle ( it sounds pretty mean )
DSC02492.jpg
so after all of this i took it for a test drive, it drives way better than it did before but there is only just a little bit of hesitation ( and it makes a popping noise from the tailpipe ) but not nearly as bad as it was before!
if i had gas in my tank i would have taken it out on the highway to see what it was really made of, but sadly, i have other people to help out, so ill let betsy sit for now, and ill gas her up later and see whats up...
do you guys think it was running like **** because of how i had the mixture screws cranked all the way out like that???
#31
If all you did was change the mixture screws then yes.
You mentioned your "butterflies" are always open, those aren't your "butterflies" that is the choke. The choke valve needs to be nearly closed when the engine is cold after you step on the throttle ONE time. This will help your starting issue.
Since it runs better at idle now hopefully any remaining problem is either choke or fine tuning related. Set the timing, idle, and choke and go from there.
You mentioned your "butterflies" are always open, those aren't your "butterflies" that is the choke. The choke valve needs to be nearly closed when the engine is cold after you step on the throttle ONE time. This will help your starting issue.
Since it runs better at idle now hopefully any remaining problem is either choke or fine tuning related. Set the timing, idle, and choke and go from there.
#32
If all you did was change the mixture screws then yes.
You mentioned your "butterflies" are always open, those aren't your "butterflies" that is the choke. The choke valve needs to be nearly closed when the engine is cold after you step on the throttle ONE time. This will help your starting issue.
Since it runs better at idle now hopefully any remaining problem is either choke or fine tuning related. Set the timing, idle, and choke and go from there.
You mentioned your "butterflies" are always open, those aren't your "butterflies" that is the choke. The choke valve needs to be nearly closed when the engine is cold after you step on the throttle ONE time. This will help your starting issue.
Since it runs better at idle now hopefully any remaining problem is either choke or fine tuning related. Set the timing, idle, and choke and go from there.
this carb was originally hooked up to a stovepipe, but i replaced it with an electric choke, but i am not sure how to hook it up since it only has one connector on it...
as soon as it stops raining ill get right on that
thanks
Last edited by HARDLUCK88; August 12th, 2009 at 02:28 PM.
#34
Yes, you activate the choke by depressing the gas pedal.
To set it make sure the engine is cold. Depress the gas pedal once and make sure your choke moves to the highest point on your fast idle cam. Then loosen the 3 hold down bolts and adjust the choke so that it is open slightly while on the highest point of the fast idle cam. A carbureted car should start easily with the choke set properly.
If you have an electric choke with one tang it needs to be wired to 12 V ignition.
To set it make sure the engine is cold. Depress the gas pedal once and make sure your choke moves to the highest point on your fast idle cam. Then loosen the 3 hold down bolts and adjust the choke so that it is open slightly while on the highest point of the fast idle cam. A carbureted car should start easily with the choke set properly.
If you have an electric choke with one tang it needs to be wired to 12 V ignition.
#35
Yes, you activate the choke by depressing the gas pedal.
To set it make sure the engine is cold. Depress the gas pedal once and make sure your choke moves to the highest point on your fast idle cam. Then loosen the 3 hold down bolts and adjust the choke so that it is open slightly while on the highest point of the fast idle cam. A carbureted car should start easily with the choke set properly.
If you have an electric choke with one tang it needs to be wired to 12 V ignition.
To set it make sure the engine is cold. Depress the gas pedal once and make sure your choke moves to the highest point on your fast idle cam. Then loosen the 3 hold down bolts and adjust the choke so that it is open slightly while on the highest point of the fast idle cam. A carbureted car should start easily with the choke set properly.
If you have an electric choke with one tang it needs to be wired to 12 V ignition.
if i wire it to 12v ignition does that mean power will be always going to it while the car is running? i tried to run 12 volts to it from the battery to see if it worked or not, i understand it is a bi-metallic switch so i only held it on power for maybe 30 seconds, but i figured it should activate pretty quickly... ill try to adjust it as well tomorrow
thanks again
#39
#40
okay guys here is the cold start video that i took. i pressed the gas once and tried to start it, and got nothing, suprisingly since i have re tuned the carb, it takes less pumping to get it started, but none the less, you can see how rigorously i have to pump it to get it to start...
please watch it and let me know what you guys think.
http://www.youtube.com/watch?v=t5EEZHFQYv0
[youtube]t5EEZHFQYv0[/youtube]
thanks!
please watch it and let me know what you guys think.
http://www.youtube.com/watch?v=t5EEZHFQYv0
[youtube]t5EEZHFQYv0[/youtube]
thanks!