Previous Thread
Next Thread
Print Thread
Page 4 of 10 1 2 3 4 5 6 9 10
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: Strawdawg] #1077454
09/26/11 07:17 PM
09/26/11 07:17 PM
Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar Offline
master
451Mopar  Offline
master

Joined: May 2008
Posts: 5,399
Aurora, Colorado
The voltage drop when cranking is likely resistance in the battery cables and/or connections (cable to block, cable to battery posts, ect.)
Replacement battery cables are pretty inexpensive too.
You already proved you get good voltage to the coil under normal (non-cranking) draw (Switch, bulkhead connections, fuseable link are OK.)
A 14 awg wire from the block to the ECU case will help the ECU detect the signal from the magnetic pickup in the distrubitor.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: 451Mopar] #1077455
09/27/11 04:15 PM
09/27/11 04:15 PM
Joined: Jan 2003
Posts: 1,263
Southwestern Ontario Canada
racealittle Offline
pro stock
racealittle  Offline
pro stock

Joined: Jan 2003
Posts: 1,263
Southwestern Ontario Canada
My 1974 Challenger had all these issues when I bought it. It was set up to start with a button.

I spent hours testing all the wires, voltages, values. I made my own harness and switched to an aftermarket ignition.

I still had the same results. I tore the ignition switch and related switches out of the coloum for individual tests.

Still not resolved, but that is because the car is in the paint shop at this time.

If the problem doesn't want to be fixed, a button will go back in


Too many cars, too many parts, too little coin, too little space to work in, too little time left to make it all happen! Update: down to one ride, still too many parts, a little more jingle in the pocket, gaining space, and it's going to happen this year!
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: racealittle] #1077456
09/27/11 10:58 PM
09/27/11 10:58 PM
Joined: Mar 2005
Posts: 862
Iowa State fan
kilroy Offline
super stock
kilroy  Offline
super stock

Joined: Mar 2005
Posts: 862
Iowa State fan
Didnt feel like reading all the post so sorry if its a repeat....

When my car did this it was due to (a rewire screw up) the distributor pick up wires being switched. I had put a new end on the wire harness side and didnt pay close enough attention. Would not start unless you released the key and got lucky.


1973 Charger, former SE, former auto

I'm not trying to be difficult, it comes naturally....
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: kilroy] #1077457
09/28/11 11:04 AM
09/28/11 11:04 AM
Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
MONC Offline OP
master
MONC  Offline OP
master

Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
Borrowed some brass feeler gauges from a buddy last night.
Didn't have time to check gap.
Will do so today if time allows.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: RapidRobert] #1077458
09/28/11 11:06 AM
09/28/11 11:06 AM
Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
MONC Offline OP
master
MONC  Offline OP
master

Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
Quote:

the 4 pin ECU (that ran at one time) has been switched out to another 4 pinner right? I'd disconnect the hot lead to the "point" of the ECU pentastar connector and disconnect ALL leads off of the coil primary terminals then jump 12V to the coil positive primary and to the "point" of the ECU pentastar connector and reconnect the 1 wire (that you just took off) from the coil negative primary to the appropriate ECU pin then crank it with or without the key. It must start! Oh dont forget to check the reluctor gap and a quick visual for any damage (teeth etc)while you have the rotor out adjusting the gap. yes he could try another battery or jump from another one with cables just like a regular jump start and if his batt has a bad cell it could be dropping voltage fast when cranking but I am a k.i.s.s. guy but we are running out of ideas & sometimes off the wall stuff does happen (part of Murphy's law) and yes I agree the voltage is going to go way up when the starter is disengaged.




These tests are getting complicated ( for me anyway), let's hope it's the gap.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: MONC] #1077459
09/28/11 11:58 AM
09/28/11 11:58 AM
Joined: Jan 2003
Posts: 4,664
Newfoundland
M
mopar_man Offline
master
mopar_man  Offline
master
M

Joined: Jan 2003
Posts: 4,664
Newfoundland
I still think ECU is not being powered while key is in start mode .

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: MONC] #1077460
09/28/11 01:03 PM
09/28/11 01:03 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Quote:

These tests are getting complicated ( for me anyway), let's hope it's the gap.


Yes and I am getting carpal tunnel. Lets get this baby up & running


live every 24 hour block of time like it's your last day on earth
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: RapidRobert] #1077461
09/28/11 03:18 PM
09/28/11 03:18 PM
Joined: Sep 2011
Posts: 369
California, USA!!!
W
WheelsUp73 Offline
enthusiast
WheelsUp73  Offline
enthusiast
W

Joined: Sep 2011
Posts: 369
California, USA!!!
Easy fix ...We had the same problem so I went to an MSD box and coil with the stock distrubitor and have not had any problems since.

http://youtu.be/t0OVIsU01mg

6846474-Lisa5-30-11.JPG (97 downloads)
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: WheelsUp73] #1077462
09/28/11 08:44 PM
09/28/11 08:44 PM
Joined: Jan 2003
Posts: 1,448
right between milan dragway & ...
F
Flite_727 Offline
pro stock
Flite_727  Offline
pro stock
F

Joined: Jan 2003
Posts: 1,448
right between milan dragway & ...
it's been many years, but i'm another victim of having this same problem being caused by a bad pickup coil. mine would only act up when hot. you can check the resistance of the pickup with a digital multimeter(i don't remember offhand what the range/specs. are, but the info is out there) & mine would be in spec. when cold, but out of spec. when hot. a couple of times it started with a huge backfire from all the fuel in the exhaust from cranking for so long!


'06 Magnum R/T Daily driver, 5.7 N.A.- [email]12.63@109[/email]
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: mopar_man] #1077463
09/28/11 08:50 PM
09/28/11 08:50 PM
Joined: Nov 2007
Posts: 21,808
Kirkland, Washington
Pacnorthcuda Offline
Too Many Posts
Pacnorthcuda  Offline
Too Many Posts

Joined: Nov 2007
Posts: 21,808
Kirkland, Washington
Quote:

I still think ECU is not being powered while key is in start mode .




That's what I think too...

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: MONC] #1077464
09/29/11 03:11 AM
09/29/11 03:11 AM
Joined: May 2008
Posts: 5,399
Aurora, Colorado
451Mopar Offline
master
451Mopar  Offline
master

Joined: May 2008
Posts: 5,399
Aurora, Colorado
I was thinking about this today on a way to test the grounding. If I recall, the ECU will ground the coil "-" terminal till it sees a pules from the distrubitor pickup?
I think if you unplug the dist pickup, the ECU should keep the coil "-" grounded while cranking the engine.
So try this test:
#1 - unplug dist pickup wire.
#2 - Connect a good voltmeter (positive/red meter wire) to the ignition coil "-". Connect the meter negative/black wire directly to the battery "-" terminal.
#3 - jumper a wire from the battery "+" terminal to the ignition coil "+" terminal.

Test: The voltmeter should read nearly zero volts. The only voltage drop should be the ECU transistor junction voltage (maybe less than 1 volt?)
Now crank the starter to put a high current load on the wiring. Because the dist is unplugged, the ECU should remain grounding the ignition coil "-" terminal. Ideally, the voltmeter reading should be the same as before. If the reading goes up, it is because of resistance in the ground path(s).

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: 451Mopar] #1077465
09/29/11 08:27 AM
09/29/11 08:27 AM
Joined: Jan 2003
Posts: 4,664
Newfoundland
M
mopar_man Offline
master
mopar_man  Offline
master
M

Joined: Jan 2003
Posts: 4,664
Newfoundland
Just thinking , have you by any chance got an aftermarket tach tied into the system? if you have ....chop chop

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: MONC] #1077466
09/29/11 10:54 AM
09/29/11 10:54 AM
Joined: Dec 2009
Posts: 1,023
pa.
D
dan9 Offline
super stock
dan9  Offline
super stock
D

Joined: Dec 2009
Posts: 1,023
pa.
I would drop the switch out of the dash and check the bigger wire , i think it is brown. I would use a test on it while you are cranking. It may be a bad terminal connection.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: dan9] #1077467
10/02/11 02:27 PM
10/02/11 02:27 PM
Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
MONC Offline OP
master
MONC  Offline OP
master

Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
I checked the reluctor gap and it did see a little more than .008 , so I regapped.
But it didn't make a difference, same issue occurs.

Regarding tests with the ECU, it's more difficult because it is mounted underneath the dash behind the glovebox, and a PITA to get to.
I'll try the battery test first and if that makes a difference.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: MONC] #1077468
10/02/11 03:18 PM
10/02/11 03:18 PM
Joined: Jan 2003
Posts: 8,473
Candler,NC / Myrtle Beach, SC
J
JDMopar Offline
master
JDMopar  Offline
master
J

Joined: Jan 2003
Posts: 8,473
Candler,NC / Myrtle Beach, SC
To answer your ? about the star wheel, you can pry it up and off the shaft with 2 flat screwdrivers. Be careful not to drop the roll pin down into the distributor, or you'll have to remove the distributor to shake it out. Also,if it hasn't been suggested already...make sure the ECU has a good ground. They don't work well if they don't have a good ground to the body of the car.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: dan9] #1077469
10/02/11 03:26 PM
10/02/11 03:26 PM
Joined: Jun 2008
Posts: 10,847
Oakdale CT
gdonovan Offline
I Live Here
gdonovan  Offline
I Live Here

Joined: Jun 2008
Posts: 10,847
Oakdale CT
Quote:

I would drop the switch out of the dash and check the bigger wire , i think it is brown. I would use a test on it while you are cranking. It may be a bad terminal connection.




We had this problem with a 78 power wagon, the ignition switch would drop out enough juice so the ignition box would not fire during cranking.

Let go of the key and it would just catch as the switch contacts went to the run position.

Replacing the switch cured the problem.

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: gdonovan] #1077470
10/02/11 05:02 PM
10/02/11 05:02 PM
Joined: Jan 2005
Posts: 716
Indiana
6
65dragnet Offline
super stock
65dragnet  Offline
super stock
6

Joined: Jan 2005
Posts: 716
Indiana
this is an age old problem change the ballast resistor


E. Williams 65 Coronet 500 3400lbs w/d, 446, Indy EZ'S, A&A transbrake,Comp 650 lift cam, 6.50 @ 105 mph 1/8th 10.25 @ 130mph 1/4
Re: Car starts when key is RELEASED, why? * UPDATE* [Re: gdonovan] #1077471
10/02/11 05:05 PM
10/02/11 05:05 PM
Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
MONC Offline OP
master
MONC  Offline OP
master

Joined: Apr 2004
Posts: 3,653
The Historic Hudson Valley
Quote:

Quote:

I would drop the switch out of the dash and check the bigger wire , i think it is brown. I would use a test on it while you are cranking. It may be a bad terminal connection.




We had this problem with a 78 power wagon, the ignition switch would drop out enough juice so the ignition box would not fire during cranking.

Let go of the key and it would just catch as the switch contacts went to the run position.

Replacing the switch cured the problem.




I already replaced the ignition switch.

I also just replaced the battery , as the existing one was at least 5 years old anyway .

Didn't make a difference, and now it's even harder to start...

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: 65dragnet] #1077472
10/02/11 05:07 PM
10/02/11 05:07 PM
Joined: Jan 2003
Posts: 4,664
Newfoundland
M
mopar_man Offline
master
mopar_man  Offline
master
M

Joined: Jan 2003
Posts: 4,664
Newfoundland
Its not an old age problem , older cars never had 4 prong ballast resistors. when the ballast resistors gave out on older cars the car would run on start and die when the key was released to the run position .
he already stated that he has a 2 prong ballast resistor .

Re: Car starts when key is RELEASED, why? * UPDATE* [Re: mopar_man] #1077473
10/02/11 05:16 PM
10/02/11 05:16 PM
Joined: Jan 2003
Posts: 4,664
Newfoundland
M
mopar_man Offline
master
mopar_man  Offline
master
M

Joined: Jan 2003
Posts: 4,664
Newfoundland
monc, several posts ago i asked you to jump the wiring harness (pos on battery to pos on coil )
Did it start then when you turned the key to start position ?
If it didn't , leave the key in the run position and try cranking it at the starting motor (big terminal on starter jumped to small terminal )

if it starts then , I still say the ecm is not powered when the key is in start position .

Page 4 of 10 1 2 3 4 5 6 9 10






Powered by UBB.threads™ PHP Forum Software 7.7.1