1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Topic: 1984 Thunderbird 5.0, motor shaking at idle,and slight miss?? (Read 7132 times) previous topic - next topic

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

December 06, 2015, 10:31:52 PM

Hey guys back at it again! Car starts up good but at a idle the motor shakes alot like somethings not right? It also has a slight miss sounds like the exhaust under the car though ... If I rev the car it revs strong no Popping or missing in the Rev? I haven't put new plug or new wires or cap and rotor, due to it not really being my car...Its my dads!! I did however wire brush all plugs and cap and rotor though! I Thinking maybe the timing might be a little off any advice? This is a cfi bird and I know there temperamental.. please help

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #1 – December 07, 2015, 04:56:21 PM

Is the idle too slow?
The 5.0L CFI for cold fast idle, uses a carburetor type fast idle cam. Before cranking you must goose the gas pedal to allow the cam to move to the fast step.
After warmup the idle is controlled by a vacuum operated "throttle kicker". The EEC controls the vacuum with the throttle kicker solenoid.

Always a good idea to pull codes.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #2 – December 07, 2015, 07:01:51 PM

No the idle is not too low, and the choke does stick for some reason gotta press it to get it too idle down? And shouldn't the check engine light be on if there's codes?

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #3 – December 07, 2015, 07:57:08 PM

Quote from: dennis89;452833

No the idle is not too low, and the choke does stick for some reason gotta press it to get it too idle down? And shouldn't the check engine light be on if there's codes?

There is no choke but it uses the same type mechanism to control the cold idle. The cam has 3 steps. A "vacuum pull down" should move it off the highest step.
The electric choke heater should move it off the other 2 steps.
Your car has no check engine light. That came in later years.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #4 – December 07, 2015, 10:01:14 PM

Ok so how do I go about pulling codes out of this car?

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #5 – December 07, 2015, 10:09:36 PM

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #6 – December 08, 2015, 12:21:52 AM

I've only owned 86-87 cars, but I think 84 still uses the same procedure.
http://sbftech.com/index.php/topic,2471.0.html

Basically you only need a paperclip and test light or buttstuffong volt meter.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #7 – December 08, 2015, 01:52:35 AM

Quote from: Haystack;452842

I've only owned 86-87 cars, but I think 84 still uses the same procedure.
http://sbftech.com/index.php/topic,2471.0.html

Basically you only need a paperclip and test light or buttstuffong volt meter.

Correct, its helpful to have someone jot down the number of blinks, while the you don't take your eyes off the lights as they flash. Its primitive blinking lights to give the code numbers.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #8 – December 08, 2015, 04:45:15 AM

I usually just record it as a video on my cell phone. Then ya can take it inside and review it as many times as possible instead of bending over the side of a car in the cold.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #9 – December 08, 2015, 09:02:00 PM

I'm a little confused? Where do I put the paper clip in at top right?

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #10 – December 08, 2015, 09:04:43 PM

Then in to the single clip.. Hooked up to a test light.. ?.. I looked at the link and it seem like they said top right and the bottom left.. And u guys help me understand this a little more clearly.. Thanks

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #11 – December 08, 2015, 11:39:33 PM

Here you go.

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #12 – December 09, 2015, 10:29:04 PM

Alright here it goes I did both test, with the car off and with the car running.. And to be honest I believe I found what the codes ment online. .On troblecodes.net.. But really don't know what they mean if that makes any sense!! I figure I'd ask the pro's on here to help out on how I go about fixing these.. So here's what I got...
Key on car off/
- 8/4 guessing that's 84.. EGR position/pressure feedback control circuit failure??
-1/1 guess that's a 11..?System pass???
-4/1 No H02 S Switching Detected?? I have no cue about this one?
-8/2 Secondary Air Bypass Circuit Failure? Again no clue on this one?
-2/1 ETS out of self test range..And this might be because the wires were really bad on it fixed them up so I'm guessing it's ok now..
Now for Key on engine Running!
-41 system indicates lean..? My dad just noticed some white smoke out of the exhaust?? How do I go about looking in too this??
-34 EGR pos,pressure feed back voltage above closed limit??
-32 EGR pos,pressure feedback voltage below closed voltage!?
-77 Operator Error Dynamic Self Test?? No clue once again lol..
And last note I got a few of these codes a few time's I know some are stored codes.. so just thought I'd put that out there.. Really trying to get this car right so and feed back is very much appreciated.. Thanks again guy's.. Looking forward too hearing back from ya..

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #13 – December 09, 2015, 10:56:29 PM

i had the same codes and my bird was acting the same as yours and i unplugged the egr and it runs like a champ didnt delete the egr only unplugged it

1984 Thunderbird 5.0, motor shaking at idle,and slight miss??

Reply #14 – December 09, 2015, 11:14:31 PM

Operator error, some models make ya do stuff like turn the wheel or blip the throttle. Ignore that code all together.

System lean is an o2 code. Pre 87 o2 sensors are not heated. The o2's don't work until they get up to a certain temp, and most times they don't work at all at idle, unless you drive the car some first.

If the egr is stuck open, the car can run funny. Check vacuum lines to and from and then try unplugging it. If that doesn't change anything, it might be gummed up. If you unbolt it, you should be able to move it by hand.

Secondary air bypass is smog pump. This shouldn't effect the way the car runs. Again, check vacuum lines.

Basically all the sensors are electric for reference, but vacuum activatesthem.

Etc (engine coolant temp? This means coolant was cold, usually around 50f.) Usually means the car wasn't warm enough when you ran codes. These do occasionally fail, they are cheap any easy to replace.

Hope this helps.