Justering av tomgangen

[Ulti_Man]

Bilen har en tomgang på ca 1700 rpm. Hvordan justere jeg denne ned? Eller er det noe et verksted burde gjøre?

[Roberto]

Har 0 peiling på MX5, men det pleier å være en skrue ved gasspjeldet som kan skrues på. Du kan ikke ungå å se den hvis du har litt praktisk tankegang, det er den som jobber imot gasswaiertingen:)

[larsmx5]

fant dette på miata.net:

 

Idle Speed Adjustment

Robert Meushaw rvmeush@home.com are the tips of several others who helped him.

 

As a matter of intellectual curiosity, I decided to investigate the correlatio shares some of his experiences when working on accurately setting his idle speed. Included n between the Miata tach reading and the IG- signal on the diagnostic connector. Fortunately I have a digital storage oscilloscope and a digital frequency measuring multimeter. The signal coming from the IG- test point is a pulse approximately 2 milliseconds in width and approx. 12 volts in amplitude. I measured the pulse frequency when the tach indicated that the car was idling between 700 and 1000 rpm. The scope reading and frequency meter reading indicated approximately 29 pulses/sec. Multiplying by 60 gave 1740 pulses/min., which is not correct. But, dividing by 2 gives 870 pulses/min which is about right. Therefore, the conversion from the IG- signal to rpm is

 

RPM = ( PPS x 60)/2 or PPS x 30

 

This is perhaps more effort than is needed to get a correct rpm reading, but inquiring minds want to know. Please note that these measurements were taken without shorting the TEN pin to ground, but the rpm signal correlation would still be the same.

 

The tacho connects to the IG terminal on the diagnostic connector.

 

The diagnostic connector is on the driver's side and is cunningly

disguised as a DIAGNOSTIC CONNECTOR :-) (close-up view)

It's nice when things identify themselves :-)

 

If you pop the lid of the diagnostic connector, you'll see a bunch of

terminals and, inside the lid, a little diagram saying what the

terminals are.

 

To set the idle, put a jumper wire between terminal TEN and ground, and

connect the tacho to the IG terminal (that's towards the bottom right

hand corner of the connector block. The TEN <- > ground shorting wire is

necessary to properly set both idle and timing.

 

You may find, as I did, that when you connect the external tacho, the

car's tacho reads zero - don't worry, you haven't broken it, it's just

that most budget analogue meters have fairly low impedance and affect

the tacho filter, so the internal tach doesn't see any pulses.

 

The idle speed adjuster (close-up view) is at the front of the intake manifold on the

passenger side, and should be covered by rubber plug. When I did my

timing, I hunted around for this plug for a bit before realising that

the plug wasn't there and the speed adjuster screw was exposed. So look

for either a likely looking recessed screw, or a rubber plug that looks

like it's hiding one.

 

To increase the idle rate, turn the screw anti-clockwise. It looks like

it's about half a turn for about 500 rpm. The manual I had said that the

idle speed should be between 800 and 900 rpm, but I set mine a little

higher to get rid of the idle-droop I was getting from time to time.

 

When you're all done, bung up the timing adjuster plug, remove the

jumpers, clip the diagnostic connector top, drop the hood and have a

blast :-)

[larsmx5]

fant dette på miata.net:

 

Idle Speed Adjustment

Robert Meushaw rvmeush@home.com are the tips of several others who helped him.

 

As a matter of intellectual curiosity, I decided to investigate the correlatio shares some of his experiences when working on accurately setting his idle speed. Included n between the Miata tach reading and the IG- signal on the diagnostic connector. Fortunately I have a digital storage oscilloscope and a digital frequency measuring multimeter. The signal coming from the IG- test point is a pulse approximately 2 milliseconds in width and approx. 12 volts in amplitude. I measured the pulse frequency when the tach indicated that the car was idling between 700 and 1000 rpm. The scope reading and frequency meter reading indicated approximately 29 pulses/sec. Multiplying by 60 gave 1740 pulses/min., which is not correct. But, dividing by 2 gives 870 pulses/min which is about right. Therefore, the conversion from the IG- signal to rpm is

 

RPM = ( PPS x 60)/2 or PPS x 30

 

This is perhaps more effort than is needed to get a correct rpm reading, but inquiring minds want to know. Please note that these measurements were taken without shorting the TEN pin to ground, but the rpm signal correlation would still be the same.

 

The tacho connects to the IG terminal on the diagnostic connector.

 

The diagnostic connector is on the driver's side and is cunningly

disguised as a DIAGNOSTIC CONNECTOR :-) (close-up view)

It's nice when things identify themselves :-)

 

If you pop the lid of the diagnostic connector, you'll see a bunch of

terminals and, inside the lid, a little diagram saying what the

terminals are.

 

To set the idle, put a jumper wire between terminal TEN and ground, and

connect the tacho to the IG terminal (that's towards the bottom right

hand corner of the connector block. The TEN <- > ground shorting wire is

necessary to properly set both idle and timing.

 

You may find, as I did, that when you connect the external tacho, the

car's tacho reads zero - don't worry, you haven't broken it, it's just

that most budget analogue meters have fairly low impedance and affect

the tacho filter, so the internal tach doesn't see any pulses.

 

The idle speed adjuster (close-up view) is at the front of the intake manifold on the

passenger side, and should be covered by rubber plug. When I did my

timing, I hunted around for this plug for a bit before realising that

the plug wasn't there and the speed adjuster screw was exposed. So look

for either a likely looking recessed screw, or a rubber plug that looks

like it's hiding one.

 

To increase the idle rate, turn the screw anti-clockwise. It looks like

it's about half a turn for about 500 rpm. The manual I had said that the

idle speed should be between 800 and 900 rpm, but I set mine a little

higher to get rid of the idle-droop I was getting from time to time.

 

When you're all done, bung up the timing adjuster plug, remove the

jumpers, clip the diagnostic connector top, drop the hood and have a

blast :-)

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