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Topic: Car almost starts on its own without turning ignition (Read 2138 times) previous topic - next topic

Car almost starts on its own without turning ignition

85 Cougar
3.8
C5

The reason I say almost is because the starter doesn't turn.

Anyway, I replaced the ignition switch and the fuel pump relay and the problem is still there.

With the ignition off and the key out, I will be near the car, cleaning a panel or something and completely on its own, the whole start sequence begins to the point where the fuel pump pressurizes.  I can hear the series of clicks and stuff that we are all used to hearing when we get ready to start our cars.  The starter doesn't turn on its own though thank goodness and the dash lights don't come on their own either.  The car starts and runs fine when I use the key.
But all the sounds are there as if I turned my key to the "on" position without cranking it.
Needless to say, I have been keeping my battery disconnected when I don't need it.  As soon as I hook my battery up, when I am at the front, the sequence happens.  I can feel that little relay on the passenger strut tower click, I can hear the CFI injectors working, I hear the fuel pump pressurize for a second or so, all this ON ITS OWN.  Then, it will do it again like 5 seconds later, then again, a few seconds later.  Then it won't do it for a while, then maybe 5 minutes later, it will do it.
If I go to start the car after it has done this, the pump won't pressurize I guess because there is enough pressure already.
WTF?
I have been searching this forum and no one seems to have posted about a problem similar to this.

WTF?
_________________
"lol.. because not too many people care for that style of car"
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Car almost starts on its own without turning ignition

Reply #1 –
Its obviously haunted
1980 birds X 3, 1982 bird, 1984 XR7, 1988 TC

Car almost starts on its own without turning ignition

Reply #2 –
I know that weird thing like this can happen when you have bad grounds.  I would first check the ground below the computer.  Then maybe the ones under the hood. I don't recall where the grounds under the dash are but I would hunt for them.
 
 I dunno I may be going in the wrong direction.
One 88

Car almost starts on its own without turning ignition

Reply #3 –
Quote from: CougarSE
I know that weird thing like this can happen when you have bad grounds.  I would first check the ground below the computer.  Then maybe the ones under the hood. I don't recall where the grounds under the dash are but I would hunt for them.
 
 I dunno I may be going in the wrong direction.



I've been trying to understand the electrical flow with various diagrams and such to see how power is getting to some parts but not others.

The things that sound like they are getting power are the fuel pump relay, fuel pump, the CFI injectors, the starter relay or whatever that relay is on the passenger strut tower, and I can hear that diaphragm thingy under the air cleaner move.
"lol.. because not too many people care for that style of car"
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Car almost starts on its own without turning ignition

Reply #4 –
ok you replaced the switch maybe its still getting power to the on position. I replaced mine with a brand new switch a while back and I have no accessory position now. The key turns all the way back to where it needs to be but theres no juice to anything. Im guessing maybe I didnt get it positioned right when I put it in. If by ignition switch you mean the piece with the wires in it that is. Some people call the lock assembly that you put the key in the ignition switch. The one Im meaning is the one on the underneath side of the steering column with the wires plugging in. I would try fiddling with that switch some and make sure its where it needs to be. If its not the switch I would say CougarSE is somewhat on the right track but I would check power wires personally instead of grounds.The only time Ive really had a problem with grounds nothing worked at all it didnt make the whole haunted ghost car scene. It sounds to me more like a switch bad somewhere or a bad wire.
Honestly if nothing else name the car Christene and dont stand in front or behind it. When it fixes itself back to new on its own I want the secret though.
87 T-bird two tone diarrhea color. 5.0 converted with AOD.  GONE BUT NOT FORGOTTEN
 
94 Lincoln Towncar, Dark Metallic Green, 4.6L AOD
SOLD!!!!
 
99 Mercury Cougar. V6 MTX75 Trans. CURRENT PROJECT DAILY DRIVER.

Car almost starts on its own without turning ignition

Reply #5 –
My daughter had an '84 3.8L Mustang about 12 years ago with the same problem you are describing. She called me to look at for her. I couldn't start it because the gas tank was bone dry. I remember wondering how in hell did she drive it home and park in the yard and now the tank is empty? When I got some gas in it and started it, it had no oil pressure. All the gas was in the oil pan and had diluted the oil.
The WOT AC cut out relay by the passenger side strut tower was also picking and the wires to it look like they had been over heating.

I don't know if I fixed it, or if it went away by itself, but the last thing I did was replace the TFI ignition module. I can't begin to theorize how the ignition module could cause it, but for what it is worth that is what I did and it never came back.

Car almost starts on its own without turning ignition

Reply #6 –
I have put about 4,000 miles on this car since I got it tagged about four months ago. This problem temporarily went away the morning that I took it to be safety inspected four months ago and has only resurfaced once since then.  It seems to be moisture-related.  It happened when it had been raining all day and everything was soaked and the air was just damp and muggy.
"lol.. because not too many people care for that style of car"
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Car almost starts on its own without turning ignition

Reply #7 –
Is there a remote starter or alarm system connected somewhere under the dash? A relatively easy way to see if it has something like that is to look for the hood pin switch...
2015 Mustang GT Premium - 5.0, 6-speed, Guard Green - too much awesome for one car

1988 5.0 Thunderbird :birdsmily: SOLD SEPT 11 2010: TC front clip/hood ♣ Body & paint completed Oct 2007 ♣ 3.55 TC rear end and front brakes ♣ TC interior ♣ CHE rear control arms (adjustable lowers) ♣ 2001 Bullitt springs ♣ Energy suspension poly busings ♣ Kenne Brown subframe connectors ♣ CWE engine mounts ♣ Thundercat sequential turn signals ♣ Explorer overhead console (temp/compass display) ♣ 2.25" off-road dual exhaust ♣ T-5 transmission swap completed Jan 2009 ♣

Car almost starts on its own without turning ignition

Reply #8 –
Quote from: Thunder Chicken;107102
Is there a remote starter or alarm system connected somewhere under the dash? A relatively easy way to see if it has something like that is to look for the hood pin switch...


No evidence of anything like that...
"lol.. because not too many people care for that style of car"
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Car almost starts on its own without turning ignition

Reply #9 –
by the ignition switch you mean the one in the stearing column or the key and tumbler?  If not those then i'd say wiring.  The starter solinoid wouldn't cause the sequence, if it was bad then the starter would usually kick on and not kick off, or not work at all.  (unless you get out and pop the hood and beat on it a bit ;D)
84 TC 302 -5.0L/t5/7.5 locking rear and a 3.45 gear, Edelbrock Intake, Aluminum Heads, Edlebrock 65mm Throttlebody, Edlebrock Cam, 24lb injectors & MAS Air Sensor calibrated via chip,  BBK headers, Catback H pipe, Magnaflow lers :evilgrin:
:pics-stfu:

 Project Thread with pics

Car almost starts on its own without turning ignition

Reply #10 –
I would look in the Steering column myself to see if the connector that is causing everyone problems on the fords could be shorting out on something , look for burn't places, that would do it but, I know it don't rain in there...
 

Car almost starts on its own without turning ignition

Reply #11 –
This is an interesteing one. Was the cause of this 2 year old problem ever found?

Car almost starts on its own without turning ignition

Reply #12 –
I would take a good look at main wireing harness comming up the steering colum to the ignition switch.  I once came across a customers used car, where a command start HAD at one time been installed.  When the system was removed (presumably before the car was sold) the main harness wires (exposed) were haphazzardly all taped together causing some very interesting starting, problems.  Actually I was surprised the car didn;t burn down.

One other thing.  Are there mice around where you store your car?  Perhaps they chewed up the wireing somewhere.

Car almost starts on its own without turning ignition

Reply #13 –
I would take a good look at main wireing harness comming up the steering colum to the ignition switch.  I once came across a customers used car, where a command start HAD at one time been installed.  When the system was removed (presumably before the car was sold) the main harness wires (exposed) were haphazzardly all taped together causing some very interesting starting, problems.  Actually I was surprised the car didn;t burn down.

One other thing.  Are there mice around where you store your car?  Perhaps they chewed up the wireing somewhere..