SPONSORED LINKS

Car wants to die at a stop

Tiny
GATERTAMER
  • MEMBER
  • 1993 MAZDA MX3
  • 220,000 MILES
Car wants to die at a stop. When accessories are turned at idle like heater, lights, or touching brake pedal rpm's drop so low it dies. Recently tuned up, new vacuum hoses, new maf, no codes, tested iac valve and tps both react how their supposed to when unplugged and resistance is in correct range, injectors are clicking fine, cleaned throttle body and air boot, alternator is putting out 14.5 volts, new fuel pump and filter. Pressure is good, vacuum guage reads about 20 steady. Any ideas?
SPONSORED LINKS
Saturday, January 5th, 2013 AT 11:54 PM

30 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Go here: https://www.2carpros.com/articles/engine-idles-too-low
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 3:05 AM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Neglected to say it was 1993 mx3.1.6L. Sohc. Manual. According to chiltons it says if you unplug IAC when warm rpm's should drop. Instead. They go up about 600. Did resistance check and its within spec and thoroughly cleaned. What do you think?
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 3:45 AM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Should IAC valve move either in or out for this model with key on?
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 5:08 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,650 POSTS
The IAC should move in and out when the key it turned on and off.
Was this
answer
helpful?
Yes
No
+1
Sunday, January 6th, 2013 AT 6:06 AM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Why don't you just open it up and clean it out with a bore brush and carb cleaner and see what happens-appreciate the B/U Joe-hope the holidays when well-TY
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 10:51 AM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Thank you. Done it a couple times. Took off IAC and turned key on it's gettin 12.5 V to it and it starts to spin rapidly and moves a little too. Plus the RES is right on guessin it works ok. On to something else.
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 3:46 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Did you try adjusting the idling speed?
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 8:29 PM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Thing is it idles pretty well. Rpm's drop a little when you turn on heater then a little more when you turn on lights then a little more when you hit brake pedal til it dies or almost dies. Is there another way to adjust idle than messing with TPS. ALT is putting out 14.5V same as what batt reads.
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 9:33 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Try doing this:

Connect Diagnostic Tester (49 B019 9A0) to diagnostic connector and select SELF-TEST mode, or connect jumper wire between diagnostic connector terminals TEN and GND. Connect tachometer to diagnostic connector terminal IG (-).
If idle speed is not within specification, rotate idle air adjusting screw on throttle body.

Adjust to 700rpm
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Sunday, January 6th, 2013 AT 10:14 PM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Code 03 is appearing. Dist no g1 or g2 signal. Is there a simple way for a backyard mechanic to figure it out?
Was this
answer
helpful?
Yes
No
Monday, January 7th, 2013 AT 12:43 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Refer to chart
Images (Click to make bigger)
Thumb
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Monday, January 7th, 2013 AT 12:47 PM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Thank you for diagrams. Not quite sure about step 6 what is voltage supposed to be. With key on or off. Dist connected or not. And step 5 how do you check for ground. Step 8 with dist disconnected but is key on or off. Thank you
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Tuesday, January 8th, 2013 AT 11:13 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
When checking voltage, the ignition must be ON.

When checking for ground it means check for shorts. One end of ohmmeter to wire/terminals and the other to body.

Is your vehicle Federal or California Specifications?
Was this
answer
helpful?
Yes
No
Tuesday, January 8th, 2013 AT 1:39 PM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Its federal. Just dont know when it says is voltage ok what is voltage supposed to be?
Was this
answer
helpful?
Yes
No
Friday, January 11th, 2013 AT 11:28 AM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Is there an easy way to check and see if internal voltage regulator is working correctly?
Was this
answer
helpful?
Yes
No
Friday, January 18th, 2013 AT 8:56 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Sorry for the delay in replying. Was away for the past week.

Here are the pin voltage chart.
Images (Click to make bigger)
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Tuesday, January 22nd, 2013 AT 2:44 PM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
Thanks for diagrams. Did step 6.(Tested ecu terminal voltage from dist.). It was 5 volts with key on but stayed 5 volts at idle it didnt drop to 1.5V like it should. The 2E terminal was at 5V with key on and dropped to 2V at idle. Like it should. There is continuity between dist. Wire and ecu. Step 7 tested at 5V and it says replace dist. However when performing step 8 there is no voltage and it says replace ecu. Does step 7 superceed step 8 because it tested at 5V and it says replace dist. If it were you which one would you replace?
Was this
answer
helpful?
Yes
No
Saturday, January 26th, 2013 AT 10:49 PM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Any fault with the ECU takes precedence over others.
Anyway step 6 showed voltage, why does the voltage disappears when measured at ECU?
Was this
answer
helpful?
Yes
No
Sunday, January 27th, 2013 AT 6:22 AM
Tiny
GATERTAMER
  • MEMBER
  • 33 POSTS
It asks for the dist. Connector to be disconnected. Im assuming thats why there is no voltage. Also distributors are sold with or without modules what does that mean? And could it be just a bad module in dist. And I dont need to replace entire thing?
Was this
answer
helpful?
Yes
No
Sunday, January 27th, 2013 AT 9:12 AM
Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
If the module comes separately, you can just replace that because the problem is only within the module circuit. However you need to check/test the wiring circuit within the distributor as it could be bad wires as they become brittle over time and any movement of them can result in breakages/poor continuuity.
Was this
answer
helpful?
Yes
No
Sunday, January 27th, 2013 AT 7:18 PM

Please login or register to post a reply.

Related Engine Stall At Idle Content

Engine Stalls After Dead or New Battery
GUIDE
Engine Stalls After Dead or New Battery
So you installed a new battery and now the engine stalls? You have done nothing wrong because believe it or not this is normal. The engine computer has a learning cycle...
VIEW MORE

Sponsored links