trouble starting when engine is hot
#31
10-20-2005, 06:20 PM
RE: trouble starting when engine is hot
I am speaking from the point of view of my 1988 Audi 90, 4 cylinder, non-quattro. Appologies in advance as I am not sure if this applies to your particular model, BUT...
OK, I am betting that for some reason, your cold start injector (only active while cranking, and engine cold/cool) is active when hot as well. The cold start injector is located coming out at an angle on the intake manifold (my engine). To test this theory, when the engine is hot, before starting, disconnect the connector to this injector. If it starts fine - bingo, then you must determine WHY it is operating when it should not (engine hot).
It is controlled by the ECU, inconjunction with an engine temp sensor/thermo switch (my car).
I am currently working on the reverse problem - my cold start injector NEVER fires, but the injector itself works fine. I am just about to start replacing temp sensors, will keep you informed...
OK, I am betting that for some reason, your cold start injector (only active while cranking, and engine cold/cool) is active when hot as well. The cold start injector is located coming out at an angle on the intake manifold (my engine). To test this theory, when the engine is hot, before starting, disconnect the connector to this injector. If it starts fine - bingo, then you must determine WHY it is operating when it should not (engine hot).
It is controlled by the ECU, inconjunction with an engine temp sensor/thermo switch (my car).
I am currently working on the reverse problem - my cold start injector NEVER fires, but the injector itself works fine. I am just about to start replacing temp sensors, will keep you informed...
#32
10-21-2005, 12:15 AM
RE: trouble starting when engine is hot
I have some sort of same problem or even something smaller like syndrom or even smaller behavior. when the engine cold and fully hot it takes a sec to start up. I mean its harder to start when hot or cold that when its warm or child a little. not as you though. it takes about double time that when warm. wark 1 sec and it starts, cold or hot it takes 3 sec of cranking to start. I would recomend using siries of diagnostics to find out the problem. using lamps and testers cheking when the CSI is working and more.
#33
10-21-2005, 04:01 AM
RE: trouble starting when engine is hot
Whim,
How about if anyone says your millivoltage, square waves and the like do not explain all there is to these machines?
F'r instance, "well, you don't have the signal to shoot the CSI."
As of the last post, it has gotten down to about 30 F, and it will not start. That indicates that the CSI is disfunctional.
These cars are some of the best starting cars in the world.
I have written this before, once upon a time, my coworkers and I decided to go out to try to start our vehicles, because it was sub zero, the first vehicle, a Mercury, took over half an hour and several cans of ether to get to run, the second car, a Chevrolet Citation, same, the 3rd, I said I am going to my own car, an Audi 5000S Turbo, they went to the next car, a pontiac Fiero, another half hour or more to start.
My own Audi 5000S, Turbo, fired instantly. Drove over to them, they at least got to warm their hands.
You don't think you might just be going a little too deep, maybe so deep into the woods, you can't see the trees?
Evidently we are a little less smart than you, we don't go by sine waves nor square waves, nor millivolts. Hell, I don't know if Bentley's does.
If you are trying to impress anybody, you have, I just don't know whom it might be. Not me. Get your hands dirty, pal.
Cheers,
George
How about if anyone says your millivoltage, square waves and the like do not explain all there is to these machines?
F'r instance, "well, you don't have the signal to shoot the CSI."
As of the last post, it has gotten down to about 30 F, and it will not start. That indicates that the CSI is disfunctional.
These cars are some of the best starting cars in the world.
I have written this before, once upon a time, my coworkers and I decided to go out to try to start our vehicles, because it was sub zero, the first vehicle, a Mercury, took over half an hour and several cans of ether to get to run, the second car, a Chevrolet Citation, same, the 3rd, I said I am going to my own car, an Audi 5000S Turbo, they went to the next car, a pontiac Fiero, another half hour or more to start.
My own Audi 5000S, Turbo, fired instantly. Drove over to them, they at least got to warm their hands.
You don't think you might just be going a little too deep, maybe so deep into the woods, you can't see the trees?
Evidently we are a little less smart than you, we don't go by sine waves nor square waves, nor millivolts. Hell, I don't know if Bentley's does.
If you are trying to impress anybody, you have, I just don't know whom it might be. Not me. Get your hands dirty, pal.
Cheers,
George
#34
10-21-2005, 03:39 PM
RE: trouble starting when engine is hot
In reply:
"How about if anyone says your millivoltage, square waves and the like do not explain all there is to these machines? F'r instance, "well, you don't have the signal to shoot the CSI." As of the last post, it has gotten down to about 30 F, and it will not start. That indicates that the CSI is disfunctional. "
- I agree, as I indicated. For example, I removed my CSI, tested it by supplying the correct voltage to it, noted its spray pattern etc. Then I measured the signal (when cold and when hot) to the CSI - none.
"These cars are some of the best starting cars in the world. I have written this before, once upon a time, my coworkers and I decided to go out to try to start our vehicles, because it was sub zero, the first vehicle, a Mercury, took over half an hour and several cans of ether to get to run, the second car, a Chevrolet Citation, same, the 3rd, I said I am going to my own car, an Audi 5000S Turbo, they went to the next car, a pontiac Fiero, another half hour or more to start. My own Audi 5000S, Turbo, fired instantly. Drove over to them, they at least got to warm their hands. "
- Nice story George, "heart warming" (forgive the bad pun)
"You don't think you might just be going a little too deep, maybe so deep into the woods, you can't see the trees? "
- No, simply applying effective diagnostic approaches. In doing so, I have reduced the possible causes to likely sensor failure.
"Evidently we are a little less smart than you, we don't go by sine waves nor square waves, nor millivolts. Hell, I don't know if Bentley's does. If you are trying to impress anybody, you have, I just don't know whom it might be. Not me. Get your hands dirty, pal. "
- George, having a bad day? My references to electrical diagnostics were supplied with the sole purpose of providing as much information as possible for anyone and everyone, which is one of the main purposes of forums such as these. True, my 34 years of experience as an electrical engineer causes me to describe and diagnose more from that experience base. At no time, and in no way have I the slightest interest in "impressing" anybody, just sharing knowledge - George, if I was that "smart", why would I be here asking questions, sharing results? Yes, Bentley's manual does touch on millivolts, ohms, basic electrical diagnostic tools, and other members of the forum have found such references useful. As far as "getting my hands dirty", it is one of my favorite things. I have been rebuilding cars and motorcycles for most of my 56 years of life - dirty is good! Anyhow, no sweat, have a good day!
Ian
Cheers,
George
"How about if anyone says your millivoltage, square waves and the like do not explain all there is to these machines? F'r instance, "well, you don't have the signal to shoot the CSI." As of the last post, it has gotten down to about 30 F, and it will not start. That indicates that the CSI is disfunctional. "
- I agree, as I indicated. For example, I removed my CSI, tested it by supplying the correct voltage to it, noted its spray pattern etc. Then I measured the signal (when cold and when hot) to the CSI - none.
"These cars are some of the best starting cars in the world. I have written this before, once upon a time, my coworkers and I decided to go out to try to start our vehicles, because it was sub zero, the first vehicle, a Mercury, took over half an hour and several cans of ether to get to run, the second car, a Chevrolet Citation, same, the 3rd, I said I am going to my own car, an Audi 5000S Turbo, they went to the next car, a pontiac Fiero, another half hour or more to start. My own Audi 5000S, Turbo, fired instantly. Drove over to them, they at least got to warm their hands. "
- Nice story George, "heart warming" (forgive the bad pun)
"You don't think you might just be going a little too deep, maybe so deep into the woods, you can't see the trees? "
- No, simply applying effective diagnostic approaches. In doing so, I have reduced the possible causes to likely sensor failure.
"Evidently we are a little less smart than you, we don't go by sine waves nor square waves, nor millivolts. Hell, I don't know if Bentley's does. If you are trying to impress anybody, you have, I just don't know whom it might be. Not me. Get your hands dirty, pal. "
- George, having a bad day? My references to electrical diagnostics were supplied with the sole purpose of providing as much information as possible for anyone and everyone, which is one of the main purposes of forums such as these. True, my 34 years of experience as an electrical engineer causes me to describe and diagnose more from that experience base. At no time, and in no way have I the slightest interest in "impressing" anybody, just sharing knowledge - George, if I was that "smart", why would I be here asking questions, sharing results? Yes, Bentley's manual does touch on millivolts, ohms, basic electrical diagnostic tools, and other members of the forum have found such references useful. As far as "getting my hands dirty", it is one of my favorite things. I have been rebuilding cars and motorcycles for most of my 56 years of life - dirty is good! Anyhow, no sweat, have a good day!
Ian
Cheers,
George
#35
10-21-2005, 11:00 PM
RE: trouble starting when engine is hot
Cool! Another electrical engineer! Now I can be rest assured and feel confident that what ever doesn't run will now burn to the ground. 
Lighten up everybody! I think that we have beaten this topic to a pulp and are going of tangents.
[sm=closed.gif]
Lighten up everybody! I think that we have beaten this topic to a pulp and are going of tangents.
[sm=closed.gif]
#36
10-22-2005, 12:49 AM
RE: trouble starting when engine is hot
Sorry, Ian,
You're right. It's just that most of us don't have scopes and the like. To get sine waves and the like would require us to go pay the 70 an hour mentioned above, which we're trying not to have to do.
Some things are in mv and R values. Those we can check with a Radio Shack digital multimeter.
As far as this entire thread, I relaized a few up that I may be speaking on a car and engine I have no experience with. A V6, and as to the injectors being dropped out at WOT, sounds as though they are electronic injectors.
My remark, that Offramp must have misread, too, was about the airplate, not the throttle plates, the butterflies. Sounds to me like my remark was totally off, there is no airplate.
I have to leave this one alone, or get a V6 for my next car. I still do read a lot on these cars, if I do find anything pertinent, I'll post, but here I am out of my depth. Hell, I don't even know if the V6 has cold start valve, or valves, one per bank.
Good luck,
George
You're right. It's just that most of us don't have scopes and the like. To get sine waves and the like would require us to go pay the 70 an hour mentioned above, which we're trying not to have to do.
Some things are in mv and R values. Those we can check with a Radio Shack digital multimeter.
As far as this entire thread, I relaized a few up that I may be speaking on a car and engine I have no experience with. A V6, and as to the injectors being dropped out at WOT, sounds as though they are electronic injectors.
My remark, that Offramp must have misread, too, was about the airplate, not the throttle plates, the butterflies. Sounds to me like my remark was totally off, there is no airplate.
I have to leave this one alone, or get a V6 for my next car. I still do read a lot on these cars, if I do find anything pertinent, I'll post, but here I am out of my depth. Hell, I don't even know if the V6 has cold start valve, or valves, one per bank.
Good luck,
George
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