Idle air control motor

Tiny
052361
  • MEMBER
  • 1988 DODGE LANCER
  • 2.5L
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 200,000 MILES
I have been working on this old car for a while. I replaced the distributor, cap rotor, plug and wires. After setting the number one cylinder to TDV on the compression stroke, and tried to set the timing. The timeline mark fluctuated back and forth around the twelve degree ATDC mark on the bell housing. Does this indicates there is a problem with my idle air control motor?
I am going to replace Wii of the o-rings and gaskets in the throttle body, the fuel pressure regulator, fuel injector and the air charge temperature sensor this weekend. Should I also replace the idle air control motor? Is there a way to test a idle air control motor?
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Saturday, October 22nd, 2016 AT 9:32 PM

17 Replies

Tiny
CJ MEDEVAC
  • EXPERT
Sending you the procedure from "Prodemand"

See if you checked timing like they show it.

See picture/ screenshot below

The Medic
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Saturday, October 22nd, 2016 AT 9:50 PM
Tiny
052361
  • MEMBER
I am using a conventional timing light. The idle speed is not adjustable. I warmed the engine to normal operating temperature, and remoxed the coolant sensor lead and check the timing. The rest is as described in my question when I changed the distributor. I also removed the front cover and inspected the time marks and the belt. All was as it was stated in my Hanes manual. I replaced the timing belt about three or four years ago.
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Saturday, October 22nd, 2016 AT 10:02 PM
Tiny
AL514
  • EXPERT
Were you able to get the base timing set correctly before you plugged the coolant sensor back in and was it idling okay at that point?
Ignition timing with the coolant sensor plugged in and at operating temperature should be twenty to thirty degrees BTDC at 2000 RPM. Not ATDC. You may want to recheck that the distributor is not off one tooth when you put the new one in. I think base timing (coolant sensor unplugged) should be around ten degrees.

Also, check and make sure you got all the air out of the coolant system. The coolant sensor cannot read air pockets that may get trapped in there.
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Monday, October 24th, 2016 AT 7:18 AM
Tiny
052361
  • MEMBER
I am unabe to get a true reading because my lines never really meet up. They fluctuate bach and forth to much to get a good reading.
The timing should be set 12 degrees BTDC, like you said and that's where I have the mark on
the bellhousing. I had to go check to make sure I had. It maked right, and it was
The idle is just a little rough. And the smell of gas is real strong.
I have orderd a rebuild kit, fuel injector fuel pressure regulator and an air Charge temperature sensor. The will arrive tomorrow.
The idle air control motor and throttle positions sensor are available locally, if I need them.
Am going to remove the throttlebody and clean it replace the gasket and o-rings anthe components listed above. Then reinstall the throttlebody, adjust the throttle and give it another try. Will let you know what I get. Ij have been unable to find a way to test the TPS or the idle air control motor. Can you tell me how to test tgese components?
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Tuesday, October 25th, 2016 AT 6:49 PM
Tiny
052361
  • MEMBER
This is the emissions sticker underneath the hood.
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Tuesday, October 25th, 2016 AT 6:59 PM
Tiny
AL514
  • EXPERT
The smell of gas is probably because the engine is misfiring due to the timing being off so much, So you're saying that the timing was jumping around with the coolant sensor unplugged? (At base timing) and 12 degrees BTDC?

Also can you send me a full picture of that tag under the hood, i'd like to see those sensor lines and vacuum lines.
I'm wondering if the distributor is in there, off one tooth on the camshaft. The base timing shouldn't be that far out. And also I think I see that the distributor has a vacuum advance on it? Am I correct about that?
Just trying to get an idea of the whole set up. That year car should be a pretty simple basic set up. Have you also checked to see if the timing belt itself has loosened up at all. The tensioner for that car I don't think is spring loaded, so you may want to tighten up the belt abit, since you did a new one a few years ago, it will have stretched some.
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Wednesday, October 26th, 2016 AT 1:27 AM
Tiny
AL514
  • EXPERT
In my first paragraph I meant 12 degrees ATDC?
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Wednesday, October 26th, 2016 AT 1:28 AM
Tiny
052361
  • MEMBER
Yes, I check the timing belt when I had the front cover off. The deflation was within the limits atstated in the manual.
The paint mark I made on the bellhousing is at the 12 degreeBTDC mark. So I dont think the timing isnt that far off.
It is just that when I shine the timing light at the marks they bounce around so much that it is hard to get a good reading.
There are no vacuum line to the distributor. So I dont think I have a vacuum advance. I wii post a better image of the tag.
With the days getting shorter, it is dark when I leave for work and dark when I get home. So, I have to wait till this Saturday to rebuild the throttlebody.
I did start it up last night. It started right up, the idle was OK not great, I drove it around the block a few times without it trying to stall.I am going to reinspect the vacuum system when I do throttlebody. Will let you all know what I find
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Wednesday, October 26th, 2016 AT 5:59 AM
Tiny
AL514
  • EXPERT
I am not too sure how much the ECM might have to relearn also, you did change a lot of parts. So it might take some driving around to see, it might help some. It is an older vehicle, but it sounds like you have everything right so far. Make sure you clean the throttle plates real well also and replace the PCV valve if it has one. Check for any vacuum leaks as well.
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Wednesday, October 26th, 2016 AT 6:15 AM
Tiny
AL514
  • EXPERT
Yeah it is plus or minus two degrees on the timing so it should be close. As for it bouncing around at base timing, that I am not sure of. I have not come across that problem before, it has always settled down when I set it to basic. I will do some research on that for you.
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Wednesday, October 26th, 2016 AT 6:18 AM
Tiny
052361
  • MEMBER
It does ha a PCV valve, and I have a replacement one already I just have not installed it yet. I do all my work on the car in my driveway, and do not have very good lighting.
I will get this all done this weekend, if I cannot get off work tomorrow.
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Wednesday, October 26th, 2016 AT 6:24 AM
Tiny
052361
  • MEMBER
I might just have a crappy timing light. I will rent a different one when I am ready to reset the timing.
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Wednesday, October 26th, 2016 AT 6:31 AM
Tiny
KEN
  • ADMIN
Please let us know what you find so it will help others.

Best, Ken
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Wednesday, October 26th, 2016 AT 10:08 AM
Tiny
052361
  • MEMBER
Will do should be done with this stage on Saturday.
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Wednesday, October 26th, 2016 AT 10:58 AM
Tiny
052361
  • MEMBER
I got the throttle body remove from the intake, and found a few loose fasteners. The gasket between the two halves were soaked with gas.
I replaced the gasket, fuel pressure regulator, fuel injector and the air charge temperature sensor. Reinstalled the throttle body checked my vacuum line and started it up. Started great. Drove it a couple miles, then set the timing. With a rented timing light at twelve degrees BTDC, and it idles good and runs well.
Next job. Brakes, calipers and the rest of the braking system.
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Saturday, October 29th, 2016 AT 4:21 PM
Tiny
KEN
  • ADMIN
Nice work, we are here to help, please use 2CarPros anytime.

Best, Ken
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Sunday, October 30th, 2016 AT 8:34 PM
Tiny
052361
  • MEMBER
Thanks. And I will always use you guys when I need help. You have not failed me yet.
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Sunday, October 30th, 2016 AT 8:42 PM

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