CaptDistraction

I've searched, so I guess this isn't terribly common:
(also placed this thread here, as I don't believe its a warranty/service type issue unless the new factory ford wiring is at fault)

My car just had an issue where it went into limp mode because it saw 0 on the TPS voltage, voltage had dropped on a wot run and zeroed out. After restarting the car, everything was fine, drove home without issue.

I've cleaned and checked the plug, the operation of the TPS, and am adding a second ground strap (since the TB uses a chassis ground) to see if that helps. Otherwise monday the accufab TB gets shipped to accufab for repair if I can find a stocker to test against and verify the problem exists in the throttlebody (it uses Ford electronics)

Anyone run into anything like this? It is just my luck, lol.

CaptDistraction

Did more poking around. Man I pray this is it:

CaptDistraction

BLEEPING BLEEP.

It *still* does it. I've fixed that ground issue, and installed new o2 sensors, cleaned every bit of the car and checked all connections, reflashed the ECU, reset the computer.

The weird thing is, the only way to duplicate this is:
1) have livelink running
2) start the run at 2000rpm in 3rd.

I need to do more testing, but if I start higher than 2k, I seem to have no problem finding my way above 6k (all the way up to 8).

Anyone have any thoughts? Or a spare coyote throttle body I could test with for a week?

Bucko

About 4 years ago, I had a simular problem with my F150. Limp home mode. When I got home, the scanner showed a Throttle position sensor. Figuring I'd be buying a new one, I removed the cover of the old to check it's "sweep" motion on the varister. The carbon sweep was dirty, so I cleaned it with some tuner cleaner (showing my age). That gave me another 9 months, until the carbon was gone from one spot, indicating a zero voltage from the TPS.

In your case, it's new, but happening at WOT. Makes me think the TPS is at fault, as I can't see it being worn at this early of it's life. Is the cover removable on your TPS?

CaptDistraction

I bought a new stocker. Should be here next week. However i did go back to the spot and do a run in third from 2k-8k. No livelink or anything plugged into the odb2 port. The run went fine, no issue, no cutout. I didn't duplicate it but this is at least something (it's not easy to find somewhere you can do repeated blasts up to 100mph)

Poisoned Pony

Did it kick a code when it saw zero and went into limp home?

Bucko

I assumed so, since he reported the TBS saw 0 volts during a WOT run, and he was in limp home mode.

How did those graphs get produced? Scanner? Please share.

CaptDistraction

It gives a wrench icon, but no DTCs are stored. Logging with SCT livelink

CaptDistraction

Well I still have this issue after all this time. Got a replacement throttle body from accufab and all grounds are good. I'm going to have to start from scratch on troubleshooting this unless anyone has some ideas.

cdynaco

Could this be your 'missing' problem?


Or perhaps is having a livelink running causing the glitch?

CaptDistraction

well, no livelink this time, and it wasn't a blast from 2k, it was a drag strip run. Same symptom at about the same RPM, in third.

I did however have a aeroforce interceptor plugged in the ODB2 port.

conv_stang

Bad ODB2 port? Since the problem only comes up when there is something plugged into the port?

CaptDistraction

I'm going to have to spend a bit more time troubleshooting this to verify that it is indeed a repeatable result. (again not easy since it involves a lot of speed).

I wonder if that's the case and if so what I can do about it.

here's video of the super-fail drag racing pass:

Its a bad launch, then followed by lots of wheel spin, more wheelspin, a shift to second (more wheelspin), and by the time I get into third, shutdown.

tehMoose

I am having a very similar issue, as far as going into limp mode, and seeing the wrench light come on. However I have not been able to capture it during a data log. The times I have had my logging setup, it runs good. Been very frustrating.

Didn't you install a new motor?

SlowRiderr

He has worked on his car more than Ford did when they built it

CaptDistraction

I know. They could deliver a mustang in parts on pallets, and short of welding and painting I'd have no trouble getting it running.

However, I cannot solve this TPS issue.

tehMoose, give me more detail about what's going on, what mods are on your car, etc.

conv_stang

We're you able to determine if it only happens when a device is plugged into the OBD port? Or does it happen all the time

CaptDistraction

So I'm going to try to get down to a dyno today, work permitting.

I'm going to try to trigger it with the car as is, then do the following:

try to reproduce it with nothing in the ODB2 port (since I have an aeroforce and sometimes SCT livelink)
try to reproduce it with stock TB, with aeroforce or sct in
try without anything, stock TB
try a seperate tune and repeat above.

Its such a pain in the ***.

tehMoose

So I had JPC build me a motor (heads/cams, bottom end, etc), headers, cai, boss manifold, stock throttle body, catback.

So after the last instance it seems that the issue only seems to occur when i go from say about 30-50% throttle to WOT. About 6k rpms, the car will seem to die (goes into limp mode), wrench light comes on. I have to kill it, then restart the car, and it comes back up with no issues. However if I just romp on it from lower rpms (traction permitted) i can pull to redline with little to no problems.

Weather is looking nice out today, so I will again attempt to capture the problem in a datalog.

CaptDistraction

do you have an aftermarket throttle body?

Have you checked the three engine grounds (one by motormount/starter, one at the ECU mount, and the other at the back of the cylinder head drivers side to the cowl)?