Serious stalling and revving problems with 1998 GT. Videos included.
03-19-2013, 07:32 PM
#1
Thread Starter
Join Date: Mar 2013
Location: New Jersey
Posts: 8
Serious stalling and revving problems with 1998 GT. Videos included.
Hey guys, I've been posting this on multiple forums seeing if anyone could point me in a direction for the strange problem my car is having. It seems the shop I'm at is even having trouble.
Basically what's going on with my car is it starts up fine, drives around fine until the engine starts warming up. Once the engine warms up, the car basically tells me to enjoy being stranded somewhere. If the car is in neutral(It's a 5 speed) and i'm just sitting somewhere idling, the car will at random start revving itself like someone is playing with the throttle or as if someone was trying to record an exhaust video to show off. I took a video of it. My legs are nowhere near the pedal, this is just what is does.
It will also do this in gear sometimes, which can be kind of scary. Normally when it revs like that, it only does it for a short while, and it stalls itself like someone turned off the key. Also it never revs any higher than it does in that video. I've never seen it go to 2500 rpms by itself. You know when it's going to stall because the check engine light starts to flash, and then it just dies. It didn't die in that video, i ended up turning it off because it was late at night and didn't feel like getting noise complaints from my neighbors.
Once it stalls the theft light comes on and flashes repeatedly. The car cranks but wont start. If you scan it, it comes up with codes U1147, B1681, and P1260 which all have to do with the PATS system. There is no aftermarket alarm on this car. The code the theft light flahes out is 1-6 "Faulty link between PATS and EECV. I tried it with both keys and the same thing happens. If I let it sit for a little while the theft system will turn off and let me restart the car. This video is of the car after it stalls. There's a clicking sound coming from the CCRM. The fan also turns itself on after it stalls.
Brought it to a shop, and they had an electrical guy come in and check the wiring. They couldn't find a problem there, but reinforced the grounds anyway. They also replaced the crank sensor, but that didn't fix the problem. They also had that guy from Auto Tech On Wheels come check it out today, but just like with the electrical guy, the car would not act up when they were there. It's a totally random thing. He seems to think it's a PCM issue. What do you guys think? I'm at a total loss at the moment.
Also as extra information, I've cleaned the MAF and the IAC, replaced the plugs in July, and put all new ford racing wires on about 2 months ago. Car ran great up until last month when all of this randomly happened. I tried testing the MAF and IAC by unplugging one at a time while the car is running, and the car runs worse(as i think it should) with the MAF unplugged and stalls within a few seconds with the IAC unplugged.
TL;DR
Car warms up and revs itself, stalls, theft light flashes, cranks and doesn't start, eventually starts back up, and everything happens again.
Basically what's going on with my car is it starts up fine, drives around fine until the engine starts warming up. Once the engine warms up, the car basically tells me to enjoy being stranded somewhere. If the car is in neutral(It's a 5 speed) and i'm just sitting somewhere idling, the car will at random start revving itself like someone is playing with the throttle or as if someone was trying to record an exhaust video to show off. I took a video of it. My legs are nowhere near the pedal, this is just what is does.
It will also do this in gear sometimes, which can be kind of scary. Normally when it revs like that, it only does it for a short while, and it stalls itself like someone turned off the key. Also it never revs any higher than it does in that video. I've never seen it go to 2500 rpms by itself. You know when it's going to stall because the check engine light starts to flash, and then it just dies. It didn't die in that video, i ended up turning it off because it was late at night and didn't feel like getting noise complaints from my neighbors.
Once it stalls the theft light comes on and flashes repeatedly. The car cranks but wont start. If you scan it, it comes up with codes U1147, B1681, and P1260 which all have to do with the PATS system. There is no aftermarket alarm on this car. The code the theft light flahes out is 1-6 "Faulty link between PATS and EECV. I tried it with both keys and the same thing happens. If I let it sit for a little while the theft system will turn off and let me restart the car. This video is of the car after it stalls. There's a clicking sound coming from the CCRM. The fan also turns itself on after it stalls.
Brought it to a shop, and they had an electrical guy come in and check the wiring. They couldn't find a problem there, but reinforced the grounds anyway. They also replaced the crank sensor, but that didn't fix the problem. They also had that guy from Auto Tech On Wheels come check it out today, but just like with the electrical guy, the car would not act up when they were there. It's a totally random thing. He seems to think it's a PCM issue. What do you guys think? I'm at a total loss at the moment.
Also as extra information, I've cleaned the MAF and the IAC, replaced the plugs in July, and put all new ford racing wires on about 2 months ago. Car ran great up until last month when all of this randomly happened. I tried testing the MAF and IAC by unplugging one at a time while the car is running, and the car runs worse(as i think it should) with the MAF unplugged and stalls within a few seconds with the IAC unplugged.
TL;DR
Car warms up and revs itself, stalls, theft light flashes, cranks and doesn't start, eventually starts back up, and everything happens again.
03-19-2013, 08:30 PM
#3
Thread Starter
Join Date: Mar 2013
Location: New Jersey
Posts: 8
Nope, my car is naturally aspirated. I wouldn't think a vacuum hose would cause the theft system to **** itself after it stall, but I wouldn't put it past this thing at the moment. Any main hoses I should look for?
03-19-2013, 09:41 PM
#4
Join Date: Aug 2005
Posts: 3
Mine was a 1" diameter black hose going to my throttle body area that somehow blew off. Your right though its probably not that, but I overlooked it for a week while trying to fix it, until one day I saw the hose just hanging there. lol.
I'm sure you tried this, but if not. Disconnect the battery for 15 mins or so. You never know, it may reset something.
Hope you get it figured out.
03-19-2013, 11:15 PM
#5
Thread Starter
Join Date: Mar 2013
Location: New Jersey
Posts: 8
That hose actually did have a problem awhile ago, ended up replacing it. When mine broke off the car didn't even run haha. I reset the battery last week after the crank sensor was replaced so I could do a base idle reset but it didn't help anything sadly.
03-20-2013, 11:15 PM
#7
6th Gear Member
Join Date: Feb 2006
Location: Virginia
Posts: 11,786
There are two other ways to check if it's the PATS system but neither of which are really economical. The first is a Directed bypass module that you'd use to have a remote start installed. (Not the autoHo remote start a real quality RS.)
And a handheld tuner like an SCT. The tuner can turn off PATS all together.
If it still did it, then it's not PATS.
The thing that surprises me is the codes and the Theft light. I've seen mustangs act up and stall with theft lights flashing when their IAC was completely trashed or a had a bad tune. They Kept trying to start the stalled mustang and after a few turns the Theft light started going nuts.
The one time my Mustang did this was right after I was working on it and I forgot to tighten the Intake tube. It fell off while driving and every time I slowed down or tried to accelerate, ti bogged out and stalled.
And a handheld tuner like an SCT. The tuner can turn off PATS all together.
If it still did it, then it's not PATS.
The thing that surprises me is the codes and the Theft light. I've seen mustangs act up and stall with theft lights flashing when their IAC was completely trashed or a had a bad tune. They Kept trying to start the stalled mustang and after a few turns the Theft light started going nuts.
The one time my Mustang did this was right after I was working on it and I forgot to tighten the Intake tube. It fell off while driving and every time I slowed down or tried to accelerate, ti bogged out and stalled.
03-20-2013, 11:50 PM
#8
Thread Starter
Join Date: Mar 2013
Location: New Jersey
Posts: 8
Yeah I've seen tons of forums posts about the theft light acting up. I don't have a handheld tuner so I can't just disable PATS. The shop the place is at ordered another computer so I'm going to need to get a tuner anyway at some point since this PCM had been tuned long ago before I bought the car but for now that can't happen.
It doesn't stall just when I hit the accelerator or anything, it just does it at random times. I could be sitting with the brake up infront of my house and eventually it'll just act up and die like I hit the gas pedal and turned off the ignition. I don't even have to try and restart it once for the light to come on either, it just comes on automatically or start s flashing while i'm driving. If I see it come on while i'm driving at all I know the car is ready to give up.
It doesn't stall just when I hit the accelerator or anything, it just does it at random times. I could be sitting with the brake up infront of my house and eventually it'll just act up and die like I hit the gas pedal and turned off the ignition. I don't even have to try and restart it once for the light to come on either, it just comes on automatically or start s flashing while i'm driving. If I see it come on while i'm driving at all I know the car is ready to give up.
03-27-2013, 06:35 PM
#9
Thread Starter
Join Date: Mar 2013
Location: New Jersey
Posts: 8
Just an update. I got the car back today. They told me the chip in there was shorting out the computer and ****ed up the board. They replaced and updated the PCM with the newest info. Car's been running for about 2 hours today and no problem yet. Hopefully this is all over with.
04-09-2013, 10:20 AM
#10
Join Date: Apr 2013
Location: TX - Texas
Posts: 6
I'm just reading your post "AHungryUnicorn". My car has been doing the exact same thing as yours, verbatim! It's actually in the shop right now. I tried most of what you'd tried, but I got nothin! We are now down to replacing the computer - as you had to do. Is your car running ok? How much did this ordeal cost you?