99 ES...lean idle
April-20th-2003, 11:10 AM
#46
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Originally posted by Chastan
Sounds like solid advice to me, I know you can skip the ignition coils, but why not have those mazda guys look at that!
Sounds like solid advice to me, I know you can skip the ignition coils, but why not have those mazda guys look at that!
do you think I came here before doing all these or after doing all these.
April-20th-2003, 11:17 AM
#49
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Originally posted by TheMAN
like I said.. many things COULD cause it... if the AC request signal was processed incorrectly by the ECU, the ECU may not output the necessary adjustments... so let's think.. is that the engine? no... does the IAC (which adjusts the idle speed) know what to do without the ECU telling it what to do? no
there's one reason... there's more
like I said.. many things COULD cause it... if the AC request signal was processed incorrectly by the ECU, the ECU may not output the necessary adjustments... so let's think.. is that the engine? no... does the IAC (which adjusts the idle speed) know what to do without the ECU telling it what to do? no
there's one reason... there's more
But I am sure that nobody here would be an expert enough to change the ECU programming.
Like I said, the problem is repeatable under the following circumstances and this is the exact order of events as they happen:
1. AC has been swithched on
2. Radiator Fan kicks on
3. A/C clutch engages
4. Jerk/ jolt is felt
5. Idle speed increases
Consider this situation whenthe jerk is not felt:
1. AC has been swithched on
2. Radiator Fan DOES NOT kick on
3. A/C clutch engages
4. Jerk/ jolt is NOT felt
5. Idle speed increases
April-20th-2003, 11:33 AM
#50
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Originally posted by TheMAN
there *could* be a problem with the AC clutch which *could* cause harsh engagement but I don't see why
there *could* be a problem with the AC clutch which *could* cause harsh engagement but I don't see why
Originally posted by TheMAN
blown engine mounts is a common cause of this problem
blown engine mounts is a common cause of this problem
Originally posted by TheMAN
the ECU *should* turn on the radiator fans when the AC compressor kicks in no matter what
the ECU *should* turn on the radiator fans when the AC compressor kicks in no matter what
Originally posted by TheMAN
poor engine block grounding can cause stumbling/hessitation issues which affects the ignition system... something which is probably the case in the symptoms you described because you have high electrical load.. engine load is still nominal... the engine has enough power to handle this kind of stuff at idle... not an issue with the engine there
ok, so the IAC *could* possibly be working, but the ECU may not be compensating that with the correct fuel mixture at that brief moment in time
TRY bolting on good quality ground wires to your engine and see what happens... DO NOT get building type wires you buy at home depot... the insulation is NOT meant for a car
poor engine block grounding can cause stumbling/hessitation issues which affects the ignition system... something which is probably the case in the symptoms you described because you have high electrical load.. engine load is still nominal... the engine has enough power to handle this kind of stuff at idle... not an issue with the engine there
ok, so the IAC *could* possibly be working, but the ECU may not be compensating that with the correct fuel mixture at that brief moment in time
TRY bolting on good quality ground wires to your engine and see what happens... DO NOT get building type wires you buy at home depot... the insulation is NOT meant for a car
tnx
April-20th-2003, 11:47 PM
#53
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I have the 1.8L engine in my 2000 protege. I will admit, when I have the AC on and I'm stuck in trafic, there is a little bit of a jerk when the fan engages but i don't find it such a big deal. The car never stalls. The first couple of times I thought that someone maybe nugged my bumper ever so slightly in traffic.
Anyhow, usually when an electic motor is turned on, it draws more current for the first few split seconds to overcome friction and the basic laws of physics holding it still. So a fan blade for example draws more current for the first few split seconds that it takes for it to accelerate to operating speed. Alot of larger electric motors (i'm not sure if cars use them) have built in capacitors that basically help the motor to start rotating from a standstill position. As the Man said, if the grounding wires are not thick enough or not grounded efficiently, it is possible to get somewhat of an electrical bottleneck for the few split seconds that it takes for stuff to engage properly. I don't know if this is the case, I'm not an expert on car electonics.
The reason you probably don't get the jerk at 1000 rpm is 1), becuase you are keeping the engine at 1000 rpm using the gas pedal (i.e. you are over-riding the idle), and 2) usually the engine drops down 50 or 100 rpms or so when the fan turns on with the AC. At idle (750 rpm), this brings you much closer to stalling than if the same thing were to happen from 1000 rpm.
I really don't think that this is something that can be fixed. It's probably a switching device that switches on very fast or not fast enough or a combination of both cases in one or more devices.
Anyhow, usually when an electic motor is turned on, it draws more current for the first few split seconds to overcome friction and the basic laws of physics holding it still. So a fan blade for example draws more current for the first few split seconds that it takes for it to accelerate to operating speed. Alot of larger electric motors (i'm not sure if cars use them) have built in capacitors that basically help the motor to start rotating from a standstill position. As the Man said, if the grounding wires are not thick enough or not grounded efficiently, it is possible to get somewhat of an electrical bottleneck for the few split seconds that it takes for stuff to engage properly. I don't know if this is the case, I'm not an expert on car electonics.
The reason you probably don't get the jerk at 1000 rpm is 1), becuase you are keeping the engine at 1000 rpm using the gas pedal (i.e. you are over-riding the idle), and 2) usually the engine drops down 50 or 100 rpms or so when the fan turns on with the AC. At idle (750 rpm), this brings you much closer to stalling than if the same thing were to happen from 1000 rpm.
I really don't think that this is something that can be fixed. It's probably a switching device that switches on very fast or not fast enough or a combination of both cases in one or more devices.
April-21st-2003, 09:18 AM
#56
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Originally posted by browntrout
I have the 1.8L engine in my 2000 protege. I will admit, when I have the AC on and I'm stuck in trafic, there is a little bit of a jerk when the fan engages but i don't find it such a big deal. The car never stalls. The first couple of times I thought that someone maybe nugged my bumper ever so slightly in traffic.
Anyhow, usually when an electic motor is turned on, it draws more current for the first few split seconds to overcome friction and the basic laws of physics holding it still. So a fan blade for example draws more current for the first few split seconds that it takes for it to accelerate to operating speed. Alot of larger electric motors (i'm not sure if cars use them) have built in capacitors that basically help the motor to start rotating from a standstill position. As the Man said, if the grounding wires are not thick enough or not grounded efficiently, it is possible to get somewhat of an electrical bottleneck for the few split seconds that it takes for stuff to engage properly. I don't know if this is the case, I'm not an expert on car electonics.
The reason you probably don't get the jerk at 1000 rpm is 1), becuase you are keeping the engine at 1000 rpm using the gas pedal (i.e. you are over-riding the idle), and 2) usually the engine drops down 50 or 100 rpms or so when the fan turns on with the AC. At idle (750 rpm), this brings you much closer to stalling than if the same thing were to happen from 1000 rpm.
I really don't think that this is something that can be fixed. It's probably a switching device that switches on very fast or not fast enough or a combination of both cases in one or more devices.
I have the 1.8L engine in my 2000 protege. I will admit, when I have the AC on and I'm stuck in trafic, there is a little bit of a jerk when the fan engages but i don't find it such a big deal. The car never stalls. The first couple of times I thought that someone maybe nugged my bumper ever so slightly in traffic.
Anyhow, usually when an electic motor is turned on, it draws more current for the first few split seconds to overcome friction and the basic laws of physics holding it still. So a fan blade for example draws more current for the first few split seconds that it takes for it to accelerate to operating speed. Alot of larger electric motors (i'm not sure if cars use them) have built in capacitors that basically help the motor to start rotating from a standstill position. As the Man said, if the grounding wires are not thick enough or not grounded efficiently, it is possible to get somewhat of an electrical bottleneck for the few split seconds that it takes for stuff to engage properly. I don't know if this is the case, I'm not an expert on car electonics.
The reason you probably don't get the jerk at 1000 rpm is 1), becuase you are keeping the engine at 1000 rpm using the gas pedal (i.e. you are over-riding the idle), and 2) usually the engine drops down 50 or 100 rpms or so when the fan turns on with the AC. At idle (750 rpm), this brings you much closer to stalling than if the same thing were to happen from 1000 rpm.
I really don't think that this is something that can be fixed. It's probably a switching device that switches on very fast or not fast enough or a combination of both cases in one or more devices.
Like I said, most people either chose to live with the problem or never turned on the AC in stop and Go traffic.
And your explain is what I also believed. The fans are drawing more power than the engine can handle at the 700rpm(in N, drops to ~600 in D) setting that Mazda recommends.
Just the way this engine was designed, possibly, producing a poor torque/hp at idle speeds.
April-21st-2003, 05:54 PM
#57
formerly chastan
Join Date: Jul 2002
Location: California, USA
Posts: 2,350
Originally posted by chikoo
In Drive, with the foot on the brake pedal.
In Drive, with the foot on the brake pedal.
that is bad for your transmission, that's an aside
I suggest you take a look at all the Technical Service Bulletins in the Protege FAQ in the top right, especially 'unstable idling/stalling' and 'alternator improvement.'
April-21st-2003, 09:27 PM
#58
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Location: Montreal, Canada
Posts: 51
It's also possible that it's a bigger issue with an auto transmission than with the manual. I think my car idles at 750 rpm. Having a torque converter in the mix will probably further mess things up.
I really don't think it's the engine that is not producing enough power. It is quite possible that the alternator is not producing enough power or that it takes a few seconds to adjust to the increased power required. If you are drawing more current for fans,AC, etc. , than the power going to the spark plugs may not strong enough causing the motor to bog somewhat until the computer compensates by bumping up the idle speed. Probably not bad engine design, more inclined to think that it would be an electrical/ECU issue.
I really don't think it's the engine that is not producing enough power. It is quite possible that the alternator is not producing enough power or that it takes a few seconds to adjust to the increased power required. If you are drawing more current for fans,AC, etc. , than the power going to the spark plugs may not strong enough causing the motor to bog somewhat until the computer compensates by bumping up the idle speed. Probably not bad engine design, more inclined to think that it would be an electrical/ECU issue.
April-21st-2003, 09:34 PM
#59
formerly chastan
Join Date: Jul 2002
Location: California, USA
Posts: 2,350
Originally posted by browntrout
It's also possible that it's a bigger issue with an auto transmission than with the manual. I think my car idles at 750 rpm. Having a torque converter in the mix will probably further mess things up.
I really don't think it's the engine that is not producing enough power. It is quite possible that the alternator is not producing enough power or that it takes a few seconds to adjust to the increased power required. If you are drawing more current for fans,AC, etc. , than the power going to the spark plugs may not strong enough causing the motor to bog somewhat until the computer compensates by bumping up the idle speed. Probably not bad engine design, more inclined to think that it would be an electrical/ECU issue.
It's also possible that it's a bigger issue with an auto transmission than with the manual. I think my car idles at 750 rpm. Having a torque converter in the mix will probably further mess things up.
I really don't think it's the engine that is not producing enough power. It is quite possible that the alternator is not producing enough power or that it takes a few seconds to adjust to the increased power required. If you are drawing more current for fans,AC, etc. , than the power going to the spark plugs may not strong enough causing the motor to bog somewhat until the computer compensates by bumping up the idle speed. Probably not bad engine design, more inclined to think that it would be an electrical/ECU issue.