Won't shut off! Stumped!
Thread Starter
Cruising
Joined: Mar 2008
Posts: 13
Likes: 0
From: Casa Grande AZ
Won't shut off! Stumped!
I've got a 84 CFI, 4+3. After I had the clutch replaced it won't shut off with the key, it's not dieseling, it just flat does not turn off when you cycle the key. The trans shop said they could not get the car to come out of reverse, so they disabled the reverse interlock, now the car won't shut off, when you turn off the key everything stays on just like the key is still in the on position, if you turn off the key hold the brake and stall it with the clutch, everything shuts off like the key got turned off. The lock cylinder is new, and before the trans shop screwed with it, it started and shut off just fine, is there something in the reverse interlock that would keep it running? Or is the main ground bundle connected to the bellhousing? I'm sure this is something really stupid, but I haven't had time to dig into it yet, so I just don't drive it.
Pat
Pat
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
I suspect that the link rod that goes from the lock cylinder down to the actual ignition switch located right behind the dash has come undone and turning the ign sw doesn't activate the ign sw to, "off". Take a look.
Thread Starter
Cruising
Joined: Mar 2008
Posts: 13
Likes: 0
From: Casa Grande AZ
Ignition switch
I kinda thought that too, but when you turn the key on, and back off without starting the car, it turns off just fine. I checked after starting, and after turning the key off (with the car still running), I even grabbed the rod and tried to pull it and push it, thinking maybe it was severely out of adjustment, but it changed nothing.
Pat
Pat
Thread Starter
Cruising
Joined: Mar 2008
Posts: 13
Likes: 0
From: Casa Grande AZ
New info
I found out yesterday, that when I turn off the ignition (engine still running), all the accessories turn off, and the antenna goes down, i'm kinda thinking maybe the alternator field is staying energized and backfeeding the ECM, keeping the car running (IIRC, these use a resistance wire for the field, since they don't have a batt light), but I'll also ring out the ignition switch, as well. I probably won't get too far on it this week, as the A/C in the house just quit, so the "project" is way down on the list of concerns right now.
Pat
Pat
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
The alternator output is connected directly to the battery so your theory isn't correct. You have a contact in the ignition switch (ign sw is three switches) that is stuck closed and it powers the ECM keeping the engine running. I wonder if the clutch repair crew shorted 12v futsing around with the reverse switch and welded one switch contact in the ign sw.
Thread Starter
Cruising
Joined: Mar 2008
Posts: 13
Likes: 0
From: Casa Grande AZ
Ruled out
I've replaced the ignition switch, no change, I think I'll check the oil pressure switch circuit next, as it uses batt hot at the switch and also controls the fuel pump. Does anyone have a FSM for an 84 with schem.?
Pat
Pat
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Something is supplying to your ign circut, key off. As you state , it will turn on/ off without starting and shut down everything else when running ;the only factor different is the alt supplying power when it is running.
Basic schematics here (84-85 chassis)
http://www.autozone.com/az/cds/en_us...rInfoPages.htm
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Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
I'm beginning to think that the transmission shop did some creative wiring trying to get the reverse switch to work and supply power all the time to the ignition circuit. You have proven it isn't the ignition switch. I'd ask them to show you what they did so you can undo their UN-handywork!
Instructor
Joined: Jan 2006
Posts: 113
Likes: 0
From: Angelo Texas
I'm beginning to think that the transmission shop did some creative wiring trying to get the reverse switch to work and supply power all the time to the ignition circuit. You have proven it isn't the ignition switch. I'd ask them to show you what they did so you can undo their UN-handywork!
Thread Starter
Cruising
Joined: Mar 2008
Posts: 13
Likes: 0
From: Casa Grande AZ
Got it!
I found it, it was the P.O. fault! He added a jumper from ignition hot to the fuel pump wire, because the ECM signal wasn't making it to the fuel pump relay. The oil pressure sending unit uses batt hot at the sender, which back fed the fuel pump and the ignition hot that it was jumpered to. Whew! That was a tough one. I'm going to replace the oil pressure sending unit as well, since it gives some goofy readings when the key is first turned on, and it gets hard to start after it's hot. Thanks again to all who replied! You can never get too much help!
Pat
Pat