90 Mitsubishi Eclipse - Idle Air Valve Motor

When I turn the ignition 'on' there is clearly a solenoid chattering in = the middle of the engine, between the engine and firewall. Best I can = tell it's coming from about 6-12 inches down from the top of the engine. = Normally I can use a tube to find these things but this time can't = locate the sucker.

A problem I have this time is I'm just learning this car and can't find = any diagrams showing solenoids. Haynes and Chiltons aren't much help = this time.

I know it's not coming from near the starter solenoid. Anyone know what = other solenoids would be in that area?

1990 Mitsubishi Eclipse.

Thanks in advance.

Bob

=3D=3D=3D

Found it - the idle speed stepper motor was chattering. Had to drill = out 3 screws to get it apart. Cleaned it off and seems to work but not = sure. The shop manual says to apply 6vdc to some of the connector pins = and see if it if moves or vibrates. I can barely feel it move every = time I hit a pin with 6v, but no vibration or continuous movement. Same = when terminals swithed. Does this right? I'm guessing that one 6v = pulse from the control unit causes one step in the motor - can't find = that out anywhere and the Mitsubishi place here won't say anything = except "bring it in and we'll test everything for $150".

It would also be nice to know how many steps there are in the motor. No = info from anywhere I could find about this.

Reply to
Guv Bob
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sucker.

time.

I checked one on truck by operating off engine still connected. Just see if it has resistance on all leads, assuming the same ohms. Lubricate.

Greg

Reply to
gregz

save my life. =20

in

can

engine.=20

locate the sucker.

find

help this time.

what

drill

not

pins

time

when

from

"bring

No

see if

Thanks Greg. Coil resistance is 30 ohms, which is within spec. I need = a refresher on stepper motors..... Does it turn once step with each 6v = pulse?

Reply to
Guv Bob

life.

the sucker.

time.

That's what happens, but voltage or ground occurs on all leads, not open.

Greg

Reply to
gregz

save my life. =20

chattering in

can

engine.=20

locate the sucker.

find

help this time.

know what

Had to drill

but not

connector pins

every time

Same when

pulse from

out

"bring

motor. No

Just see if

need a

6v pulse?

open.

OK, after spending Sat & Sun under the hood, I'm officially a shade tree = semi-expert of some of this stuff.

I cleaned and lubricated and shoved as many parts around as I could. = Got the stepper motor back running again. Fixed some vacuum leaks, loose = electrical connectors. Checked every sensor in the book and all were = OK.

Engine starts up fine and runs a lot better, but still has a miss. Will = start again next weekend.

Reply to
Guv Bob

save my life. =20

chattering in

can

engine.=20

locate the sucker.

find

help this time.

know what

Had to drill

but not

connector pins

every time

Same when

pulse from

out

"bring

motor. No

Just see if

need a

6v pulse?

open.

OK, after spending Sat & Sun under the hood, I'm officially a shade tree = semi-expert of some of this stuff.

I cleaned and lubricated and shoved as many parts around as I could. = Got the stepper motor back running again. Fixed some vacuum leaks, loose = electrical connectors. Checked every sensor in the book and all were = OK.

Engine starts up fine and runs a lot better, but still has a miss. Will = start again next weekend.

=3D=3D=3D

Next weekend update....

Took the ECU apart and saw corrosion around 2 capacitors. Scrubbed the = board and other board connections looked OK. Replaced the caps with = same only 105 deg instead of 85 deg. All symptoms gone at engine cold = start. Fine when hot, except when in neutral idle speed cycles between =

1300 & 1500 rpm with about 1/2-second cycle time. This is only when up = to temp.

TS guides say that's likely in the intake air flow -- mass air flow = temp, press or flow sensors, idle speed air sensor, motor, etc.

I'm so jazzed that the main problems are solved that I'm going to call = it a day and go have a BURGER!! LOL!!!

Bob

Reply to
Guv Bob

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