No DTC's - What could be going on?

I could use some input from you guys. I guess I have 2 questions here: 1. what are the chances of my SCT Livewire TS+ not picking up DTC's, and 2. what might be happening with my car? I had a little trouble with it dying in a parking lot ('03 turbo) a while back, and finally had a little time on my hands this weekend. No DTC's popped up. Car is fairly new to me - PO said he had no problems with it and has been honest on all else as far as I can tell.

I chatted with SCT and was told that it's possible a Ford scanner or my tuner might be able to pick something up that my TS+ wouldn't. What would they pick up that the SCT wouldn't? SCT said there's not a history of that happening but it could be my device.

My TS+ is brand new and was reading the car fine on all points from what I was able to see, and when I went to codes there was nothing there. I don't have a CEL, and nothing on my dash seems off, but I had an issue with the car about 2 months ago where it cut out and died multiple times in the parking lot after a 10-12 minute drive on a very hot day (drove it, parked and it sat for 15-20 min. in the sun in the parking lot while I ate lunch). I started inspecting it and nothing stood out but some parts were still a little to hot, so I let it sit until night, checked everything I could then tried to start it - no problems - drove the car home and let it idle - all seemed normal. It's been sitting in my garage with only a couple of starts and idle times over the past couple of months without any issues. But I haven't had time to really go through things, and I haven't had an opportunity to take it out where I would be okay with it possibly stranding me while I got a ride back.

I got the TS+ the other week, and yesterday was the first time I plugged it in. I'm happy that no DTC's showed, but I'm also a little confused as to what my initial problem could have been? Maybe something like an overheated sensor/sensor going bad, a relay, fuse, or module on its way out, loose wire/bad ground, fuel pump, CCRM? But wouldn't some of those pop up as codes?

I did go over as many connections as I could, but didn't find anything that was obvious. I was trying to figure it out before taking it to my mechanic, as I'm limited at home, but I was almost certain I would have had at least one code that might point me in a direction to maybe solve things myself. I ran the diagnostic multiple times and it didn't pick up anything.

Thanks in advance.

Not everything will throw a code. What type of fuel system do you have? Does the car shut off while driving or only at idle? Honestly it almost sounds like the fuel pump is getting really hot and shorting itself out and cutting fuel to the car.

Thanks for your reply - Twin Walbro 450lph's. Car is e85.

BlckBox04 said:

Not everything will throw a code. What type of fuel system do you have? Does the car shut off while driving or only at idle? Honestly it almost sounds like the fuel pump is getting really hot and shorting itself out and cutting fuel to the car.

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Will it shut off while you're driving?

Every once in a while while slowing down if I just let off it completely and coast then it will die - but then starts right back up. Thought that might be the IAC valve? It's very inconsistent and it's just a weekend car so I haven't taken it out enough to really draw any constantly-recurring connections. This main issue does seem heat related. But most times it doesn't have a problem idling or anything whether hot or cold. Fuel pump related could definitely be it. I thought something affected by heat - just not sure where to look. My mechanic said it sounded air or fuel related, but I didn't find any vacuum problems/loose connections.

brigs said:

Every once in a while while slowing down if I just let off it completely and coast then it will die - but then starts right back up.

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this right here leads me to believe it's fuel related also

if the FPDM is still being used I've seen other threads with a weak/failing FPDM cause it to stall or not restart in hotter weather

Thanks - I've read this, too, and will have to look into it. I thought this would trigger a code.

DSG2003Mach1 said:

if the FPDM is still being used I've seen other threads with a weak/failing FPDM cause it to stall or not restart in hotter weather

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brigs said:

Thanks - I've read this, too, and will have to look into it. I thought this would trigger a code.

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As mentioned not everything triggers a code. Even events that will trigger a code, there's a threshold for them. If you have a misfire it has to occur X number of times within Y number of revolutions. Some things have to occur either a certain number of times in what Ford considers 1 drive cycle or it has to occur with Y number of drive cycles before it throws a code. There are so many occasional hiccups that can/do happen if it threw a code the first time for everything the CEL would probably never go out

Sounds tune related to me

Your hand held should read pcm if a
Code was given.

You can test it.

Start car.

Unplug something. iac,maf
Or a vacuum line to a sensor.

It should catch everything you do
This is I learned code chasing.

Pcm is extremely smart

I have had times my light was on and tuner said no codes found.

I was going to parts stores to get read.

Now I own a better tool to scan other than hand tuner.

Coils getting weak.

This was my stall issue. Never a code.

Being they are expensive

Instead of just throwing parts

I found a member near by with a good set of 8 to test first.


I have also seen pcv cause this on my ride.

what kind of fuel system and what is the fuel pressure when it dies? I had a similar issue with my original return fuel setup but it would take 30-40 min on a hot day to start giving me issues starting with a loud fuel pump.

Thanks for the replies. It's return style (twin Walbro 450lph e85 fuel pumps in-tank -8 feed -6 returns), 80 lb. Siemens Deka injectors, Fore rails. Stock coils, Ngk tr7's.

Tuned by PBD in person on their dyno.

One time it died after idling at a light after a few minutes after a long drive (40+ min.). One time while coasting towards a light after being on the road only a few minutes. And then the time above. First two times it started up right away no problems...this last time in the lot was when it really bugged me.

Not sure of fuel pressure activity leading up to it dying....

keith89 said:

what kind of fuel system and what is the fuel pressure when it dies? I had a similar issue with my original return fuel setup but it would take 30-40 min on a hot day to start giving me issues starting with a loud fuel pump.

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Given that you can restart it right away I would rule out fuel system. I would lean towards either the IAC going out or a tune issue.

Id also check IAC. My car died when coming to a stop until i re-learned the idle.

Haven't had much time lately, but had a small window to drive it yesterday in 70 degree weather here. Went through the car for a few minutes checking connections before the drive. Drove for an easy 5 min., let it idle, no problems. Parked and drove it about 15 min. later for 5 min., made some decent pulls - no problems. Let it idle for a few minutes then drove it again, parked and idled for a couple minutes then a nice easy drive for 5 more min. and idle cool down (about 20 min. being on that round with some spirited driving). No problems, no dying. Temp stayed between low 170's and a high of 192. Battery at start was 14, then at it's hottest it was around 13.5 idling (dipping to the 12's sometimes at 192°). A/F mid 14's at idle. Leads me to further believe it's heat related, as the problems I had before were on very hot, humid south FL days, but going to do some more testing.