Idle question
Melting Slicks
Joined: Apr 2015
Posts: 3,081
Likes: 1,130
From: NEW YORK
Well I only have the car 7 months or so and because of our really wet winters this was my first longer drive than 10 minutes, and I first noticed the problem after leaving the highway the engine was nice and hot and it would idle real low it even idled for 350 for a second or 10 after that it died and would fire right up and as soon as throttle is applied it drives like you would expect it to do. The next day nothing wrong start up the car idles at 1500 until I drive it for 5 minutes (choke cuts out because engine is warm) and the car idles at 450 again and eventually it can't stay on with the extreme low idle and dies, again fires right up.
Edit: forgot to mention the fuel is 7 months old, filled it up when it arrived with 98.
Edit: forgot to mention the fuel is 7 months old, filled it up when it arrived with 98.
If low idle is the only problem and it is running strong through the gears I am betting you just need to set the curb idle.
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
I hope that's the case the only thing it does besides low idling is humping(as if you try to drive off in a car with to little throttle and to fast clutch release) when you try to drive a constant rpm, like 2000 or so in first or second gear, driving on the highway on a constant rpm is no problem
Last edited by Twan Sloot; Mar 31, 2017 at 07:07 PM.
Melting Slicks
Joined: Apr 2015
Posts: 3,081
Likes: 1,130
From: NEW YORK
I hope that's the case the only thing it does besides low idling is humping(as if you try to drive off in a car with to little throttle and to fast clutch release) when you try to drive a constant rpm, like 2000 or so in first or second gear, driving on the highway on a constant rpm is no problem
Safety Car
Joined: May 2014
Posts: 3,783
Likes: 655
I hope that's the case the only thing it does besides low idling is humping(as if you try to drive off in a car with to little throttle and to fast clutch release) when you try to drive a constant rpm, like 2000 or so in first or second gear, driving on the highway on a constant rpm is no problem
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
No that's not what I mean, hard to describe for me in english, I mean that when I try to drive a constant RPM so 2000 or 1800 it feels like it stumbles, it's very little not enough for the tach to show any bounces, but you can feel it in the car. This only occurs when I drive a constant RPM any form of accelaration and it's fine again. So pulling off with the car is no problem and again all the problems are gone when the choke is still engaged. But I will work on the car today, and see where I can get with all your great advises already.
Last edited by Twan Sloot; Apr 1, 2017 at 06:07 AM.
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
Does this 300hp engine have it's stock camshaft.. You are saying the engine has a surge at the 2000rpm range, Correct? Make sure there are no vacuum leaks and check the vacuum advance control to make sure it holds vacuum. You have got to start with all the simple things and eliminate them before going to the carburetor .
But again all solved when coke is engaged.
Ps have to add that it won't stumble if you drive a constant speed at a highr RPM so highway driving isn't a problem
Last edited by Twan Sloot; Apr 1, 2017 at 06:05 AM.
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
the choke engaged richens the mixture and driving at higher speeds increases the load on the engine thereby richening the mixture.
sounds like a lean surge
why do I think that? because that is the way I adjust my fuel injection; I lean it out until it surges and then richen it till it just goes away
Bill
sounds like a lean surge
why do I think that? because that is the way I adjust my fuel injection; I lean it out until it surges and then richen it till it just goes away
Bill
Last edited by wmf62; Apr 1, 2017 at 06:12 AM.
Safety Car
Joined: May 2014
Posts: 3,783
Likes: 655
Nope not a surge just a slight stumble when I drive a CONSTANT speed at any rpm. You can accelarate the car through all the rpm's and all the gears with no problem at all. But it idles too low and driving a constant speed it stumbles so slightly.
But again all solved when coke is engaged.
Ps have to add that it won't stumble if you drive a constant speed at a highr RPM so highway driving isn't a problem
But again all solved when coke is engaged.
Ps have to add that it won't stumble if you drive a constant speed at a highr RPM so highway driving isn't a problem
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Team Owner
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Army
The accelerator pump is not the cruise problem...there may be two problems...
His cruise prob is a lean surge or the timing is over-advanced (e.g. too much vacuum advance). Those are the two issues that cause cruise speed "trailer-hitching"
His cruise prob is a lean surge or the timing is over-advanced (e.g. too much vacuum advance). Those are the two issues that cause cruise speed "trailer-hitching"
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
okay so I think there is more going on now. I am going to start this from the day I bought the car that's best I think.
we bought the car when winter was upcoming and we drove it for 15 to 20 minutes with 41 degrees Fahrenheit outside temp. the car drove great, no sounds not one thing wrong. then we stored it for winter. it was fired up twice during winter to let some friends hear the sound no probs. probably 3 weeks ago I drove it for the first time again, the outside temp was now 63 degrees. the car ran great but after 5 minutes of driving I heard a bang from the engine, but with the side pipes it wasn't really sounding loud and I didn't think to much of it since the car didn't had any issues until then. after that ride I drove it in the garage and have no idea if the car idled low already, at least didn't took notice of it.
a few days ago the first 30 minute drive was up and after coming down the highway it idled at 400, and all the problems that you read earlier in this thread appeared.
today I was planning to work on the carb, so I drove the car and opened the hood to adjust the curb idle screw, while doing that I asked if my brother could give the engine some gas and releasing the throttle again. and now I heard the bang from the enige I heard earlier but now heard it with the hood openend and I am for sure something is wrong. allthough the engine keeps running fine that bang scared me.
what could this bang from the engine be?
PS I have to add that the first time the bang appeared while shifting, now it appeard with clutch fully pressed and gear in neutral.
we bought the car when winter was upcoming and we drove it for 15 to 20 minutes with 41 degrees Fahrenheit outside temp. the car drove great, no sounds not one thing wrong. then we stored it for winter. it was fired up twice during winter to let some friends hear the sound no probs. probably 3 weeks ago I drove it for the first time again, the outside temp was now 63 degrees. the car ran great but after 5 minutes of driving I heard a bang from the engine, but with the side pipes it wasn't really sounding loud and I didn't think to much of it since the car didn't had any issues until then. after that ride I drove it in the garage and have no idea if the car idled low already, at least didn't took notice of it.
a few days ago the first 30 minute drive was up and after coming down the highway it idled at 400, and all the problems that you read earlier in this thread appeared.
today I was planning to work on the carb, so I drove the car and opened the hood to adjust the curb idle screw, while doing that I asked if my brother could give the engine some gas and releasing the throttle again. and now I heard the bang from the enige I heard earlier but now heard it with the hood openend and I am for sure something is wrong. allthough the engine keeps running fine that bang scared me.
what could this bang from the engine be?
PS I have to add that the first time the bang appeared while shifting, now it appeard with clutch fully pressed and gear in neutral.
Last edited by Twan Sloot; Apr 2, 2017 at 08:14 AM.
Team Owner
Joined: Aug 2007
Posts: 58,061
Likes: 7,145
Army
okay so I think there is more going on now. I am going to start this from the day I bought the car that's best I think.
we bought the car when winter was upcoming and we drove it for 15 to 20 minutes with 41 degrees Fahrenheit outside temp. the car drove great, no sounds not one thing wrong. then we stored it for winter. it was fired up twice during winter to let some friends hear the sound no probs. probably 3 weeks ago I drove it for the first time again, the outside temp was now 63 degrees. the car ran great but after 5 minutes of driving I heard a bang from the engine, but with the side pipes it wasn't really sounding loud and I didn't think to much of it since the car didn't had any issues until then. after that ride I drove it in the garage and have no idea if the car idled low already, at least didn't took notice of it.
a few days ago the first 30 minute drive was up and after coming down the highway it idled at 400, and all the problems that you read earlier in this thread appeared.
today I was planning to work on the carb, so I drove the car and opened the hood to adjust the curb idle screw, while doing that I asked if my brother could give the engine some gas and releasing the throttle again. and now I heard the bang from the enige I heard earlier but now heard it with the hood openend and I am for sure something is wrong. allthough the engine keeps running fine that bang scared me.
what could this bang from the engine be?
PS I have to add that the first time the bang appeared while shifting, now it appeard with clutch fully pressed and gear in neutral.
we bought the car when winter was upcoming and we drove it for 15 to 20 minutes with 41 degrees Fahrenheit outside temp. the car drove great, no sounds not one thing wrong. then we stored it for winter. it was fired up twice during winter to let some friends hear the sound no probs. probably 3 weeks ago I drove it for the first time again, the outside temp was now 63 degrees. the car ran great but after 5 minutes of driving I heard a bang from the engine, but with the side pipes it wasn't really sounding loud and I didn't think to much of it since the car didn't had any issues until then. after that ride I drove it in the garage and have no idea if the car idled low already, at least didn't took notice of it.
a few days ago the first 30 minute drive was up and after coming down the highway it idled at 400, and all the problems that you read earlier in this thread appeared.
today I was planning to work on the carb, so I drove the car and opened the hood to adjust the curb idle screw, while doing that I asked if my brother could give the engine some gas and releasing the throttle again. and now I heard the bang from the enige I heard earlier but now heard it with the hood openend and I am for sure something is wrong. allthough the engine keeps running fine that bang scared me.
what could this bang from the engine be?
PS I have to add that the first time the bang appeared while shifting, now it appeard with clutch fully pressed and gear in neutral.
Last edited by Frankie the Fink; Apr 2, 2017 at 08:41 AM.
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
But aren't you now suggesting it's a backfire, because this wasn't a backfire at least it didn't sound like one it really came from te engine.
Last edited by Twan Sloot; Apr 2, 2017 at 10:47 AM.
Team Owner
Joined: Aug 2007
Posts: 58,061
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Army
I don't know of anything else that would cause a 'bang' in the engine compartment that wouldn't be a serious issue...
An exhaust backfire (out the tailpipe) is a bit different from one occurring in the exhaust manifold. The former can blow a muffler out, the latter can cause more serious problems; e.g backfiring through the intake manifold and out the carb. I lost eyebrows, a mustache and all my nasal hair, got a nice sunburn and ruined some underwear once from a carb backfire...
I rarely, rarely run a car without the air cleaner on; I'm combustible. Maybe post a video ?
Last edited by Frankie the Fink; Apr 2, 2017 at 11:01 AM.
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
Its subjective.
I don't know of anything else that would cause a 'bang' in the engine compartment that wouldn't be a serious issue...
An exhaust backfire (out the tailpipe) is a bit different from one occurring in the exhaust manifold. The former can blow a muffler out, the latter can cause more serious problems; e.g backfiring through the intake manifold and out the carb. I lost eyebrows, a mustache and all my nasal hair, got a nice sunburn and ruined some underwear once from a carb backfire...
I rarely, rarely run a car without the air cleaner on; I'm combustible. Maybe post a video ?
I don't know of anything else that would cause a 'bang' in the engine compartment that wouldn't be a serious issue...
An exhaust backfire (out the tailpipe) is a bit different from one occurring in the exhaust manifold. The former can blow a muffler out, the latter can cause more serious problems; e.g backfiring through the intake manifold and out the carb. I lost eyebrows, a mustache and all my nasal hair, got a nice sunburn and ruined some underwear once from a carb backfire...
I rarely, rarely run a car without the air cleaner on; I'm combustible. Maybe post a video ?
Race Director
Joined: Jun 2006
Posts: 17,901
Likes: 751
From: Inverness FL
St. Jude Donor '07
terms are getting confused here...
from this link: http://www.6crew.com/forum/showthrea...-Misconception)
BACKFIRE:
A backfire is an explosion that's created by an engine that occurs in the air intake system rather than inside the combustion chamber where it is normally supposed to happen. Fuel and some unburned hydrocarbons are ignited somewhere in the intake prior to making it into the combustion chamber or somehow gets blown back past the intake valves. This condition causes a looud abrubt popping noise and will cause loss of power and forward motion and can and will damage the intake tract or possible other parts IE- turbo, sensors, and etc. A backfire is a separate phenomenon from an Afterfire.
WHAT CAUSES A BACKFIRE?
Backfires can occur when running too far of advanced timing, running cams with a massive overlap and having the car not tuned properly for the application as well as just having mechanical valve failure, IE- somehow the valve timing is thrown off or the valves arent seating properly and fuel is push back up past the intake valve during ignition. While there can be more things that cause a backfire, these are just a few.
AFTERFIRE:
An Afterfire, sometimes called Afterburn, is an audible popping sound, individual or multiple that often occurs when the fuel/air mixture is too rich or has a momentary instance of a rich condition. This pop at times can and do resemble small caliber firearms going off. Afterfire occur in the exhaust system post turbo or post engine typically.
WHAT CAUSES AN AFTERFIRE: Richer fuel mixtures are also slow burning. This results in the exhaust gases to have some amount unburned fuel passed on to it as it exits the engine. As it exits the engine, that unburned fuel and any air leftover from combustion mixes and ignites somewhere in the exhaust. Afterfire's are more common where long exhaust ducting retains greater amounts of unburned fuel due to rich fuel mixtures. Afterfiring can also be caused by cylinders which are not firing because of faulty spark plugs, defective fuel injector nozzles, or incorrect valve clearance
Of the two phenomenon's a true backfire is not something any car modder wants to happen. especially a nitrous backfire. An Afterfire is normal and ever vehicle does it to some extent. more pronounced when dealing with higher flowing and free flowing exhaust. but they are common and typically do not pose any immediate threat to the engine and surrounding parts.
Bill
from this link: http://www.6crew.com/forum/showthrea...-Misconception)
BACKFIRE:
A backfire is an explosion that's created by an engine that occurs in the air intake system rather than inside the combustion chamber where it is normally supposed to happen. Fuel and some unburned hydrocarbons are ignited somewhere in the intake prior to making it into the combustion chamber or somehow gets blown back past the intake valves. This condition causes a looud abrubt popping noise and will cause loss of power and forward motion and can and will damage the intake tract or possible other parts IE- turbo, sensors, and etc. A backfire is a separate phenomenon from an Afterfire.
WHAT CAUSES A BACKFIRE?
Backfires can occur when running too far of advanced timing, running cams with a massive overlap and having the car not tuned properly for the application as well as just having mechanical valve failure, IE- somehow the valve timing is thrown off or the valves arent seating properly and fuel is push back up past the intake valve during ignition. While there can be more things that cause a backfire, these are just a few.
AFTERFIRE:
An Afterfire, sometimes called Afterburn, is an audible popping sound, individual or multiple that often occurs when the fuel/air mixture is too rich or has a momentary instance of a rich condition. This pop at times can and do resemble small caliber firearms going off. Afterfire occur in the exhaust system post turbo or post engine typically.
WHAT CAUSES AN AFTERFIRE: Richer fuel mixtures are also slow burning. This results in the exhaust gases to have some amount unburned fuel passed on to it as it exits the engine. As it exits the engine, that unburned fuel and any air leftover from combustion mixes and ignites somewhere in the exhaust. Afterfire's are more common where long exhaust ducting retains greater amounts of unburned fuel due to rich fuel mixtures. Afterfiring can also be caused by cylinders which are not firing because of faulty spark plugs, defective fuel injector nozzles, or incorrect valve clearance
Of the two phenomenon's a true backfire is not something any car modder wants to happen. especially a nitrous backfire. An Afterfire is normal and ever vehicle does it to some extent. more pronounced when dealing with higher flowing and free flowing exhaust. but they are common and typically do not pose any immediate threat to the engine and surrounding parts.
Bill
Thread Starter
Burning Brakes
Joined: Jul 2016
Posts: 769
Likes: 123
From: Heerde Gelderland
terms are getting confused here...
from this link: http://www.6crew.com/forum/showthrea...-Misconception)
BACKFIRE:
A backfire is an explosion that's created by an engine that occurs in the air intake system rather than inside the combustion chamber where it is normally supposed to happen. Fuel and some unburned hydrocarbons are ignited somewhere in the intake prior to making it into the combustion chamber or somehow gets blown back past the intake valves. This condition causes a looud abrubt popping noise and will cause loss of power and forward motion and can and will damage the intake tract or possible other parts IE- turbo, sensors, and etc. A backfire is a separate phenomenon from an Afterfire.
WHAT CAUSES A BACKFIRE?
Backfires can occur when running too far of advanced timing, running cams with a massive overlap and having the car not tuned properly for the application as well as just having mechanical valve failure, IE- somehow the valve timing is thrown off or the valves arent seating properly and fuel is push back up past the intake valve during ignition. While there can be more things that cause a backfire, these are just a few.
AFTERFIRE:
An Afterfire, sometimes called Afterburn, is an audible popping sound, individual or multiple that often occurs when the fuel/air mixture is too rich or has a momentary instance of a rich condition. This pop at times can and do resemble small caliber firearms going off. Afterfire occur in the exhaust system post turbo or post engine typically.
WHAT CAUSES AN AFTERFIRE: Richer fuel mixtures are also slow burning. This results in the exhaust gases to have some amount unburned fuel passed on to it as it exits the engine. As it exits the engine, that unburned fuel and any air leftover from combustion mixes and ignites somewhere in the exhaust. Afterfire's are more common where long exhaust ducting retains greater amounts of unburned fuel due to rich fuel mixtures. Afterfiring can also be caused by cylinders which are not firing because of faulty spark plugs, defective fuel injector nozzles, or incorrect valve clearance
Of the two phenomenon's a true backfire is not something any car modder wants to happen. especially a nitrous backfire. An Afterfire is normal and ever vehicle does it to some extent. more pronounced when dealing with higher flowing and free flowing exhaust. but they are common and typically do not pose any immediate threat to the engine and surrounding parts.
Bill
from this link: http://www.6crew.com/forum/showthrea...-Misconception)
BACKFIRE:
A backfire is an explosion that's created by an engine that occurs in the air intake system rather than inside the combustion chamber where it is normally supposed to happen. Fuel and some unburned hydrocarbons are ignited somewhere in the intake prior to making it into the combustion chamber or somehow gets blown back past the intake valves. This condition causes a looud abrubt popping noise and will cause loss of power and forward motion and can and will damage the intake tract or possible other parts IE- turbo, sensors, and etc. A backfire is a separate phenomenon from an Afterfire.
WHAT CAUSES A BACKFIRE?
Backfires can occur when running too far of advanced timing, running cams with a massive overlap and having the car not tuned properly for the application as well as just having mechanical valve failure, IE- somehow the valve timing is thrown off or the valves arent seating properly and fuel is push back up past the intake valve during ignition. While there can be more things that cause a backfire, these are just a few.
AFTERFIRE:
An Afterfire, sometimes called Afterburn, is an audible popping sound, individual or multiple that often occurs when the fuel/air mixture is too rich or has a momentary instance of a rich condition. This pop at times can and do resemble small caliber firearms going off. Afterfire occur in the exhaust system post turbo or post engine typically.
WHAT CAUSES AN AFTERFIRE: Richer fuel mixtures are also slow burning. This results in the exhaust gases to have some amount unburned fuel passed on to it as it exits the engine. As it exits the engine, that unburned fuel and any air leftover from combustion mixes and ignites somewhere in the exhaust. Afterfire's are more common where long exhaust ducting retains greater amounts of unburned fuel due to rich fuel mixtures. Afterfiring can also be caused by cylinders which are not firing because of faulty spark plugs, defective fuel injector nozzles, or incorrect valve clearance
Of the two phenomenon's a true backfire is not something any car modder wants to happen. especially a nitrous backfire. An Afterfire is normal and ever vehicle does it to some extent. more pronounced when dealing with higher flowing and free flowing exhaust. but they are common and typically do not pose any immediate threat to the engine and surrounding parts.
Bill
