Weird stalling issue, help!

[Barracuda]

Hi,

I've finished my rebuild recently, and have driven now for approx 200 miles. Now, the car has been stalling every now and then without consistency. The only thing which is consistant is that the car will not stall when it's still cold. but it usually starts to stall when it's warm.. and coming to a stop (idle). When it stalls, I have difficulties to get it idling again - But after about 15 mins, it starts, and stays on with a slight bucking. Coolant temps are ok.

Right.. I found out that ground wire going to the knock sensor was snapped off so i rewired it along with my PLX SM-AFR sensor ground wire that was relocated. (plx feeds from radio wire) I had no stalling in 3 days. Today it totally pissed me off again.
The symptoms started again.. I have to make clear again that the car never stalls when cold... only when hot! Didn't have my laptop connected this time, but i noticed few things... as I was driving at approx 55mph, i hit a sharp bump - not a big but sharp - and then the car stalled for a half second and recovered itself after that... end of that story. A little bit later it stalled in gravel road, and i couldn't revive it before It stopped completely. I tried to hit ignition right after that but this time it wouldn't even let me run the starter engine. waited about 10 mins and got it running again -> left straight to home -> the car stalled once more (stopped.. no start engine.. 10 mins.. and moving again) before i reached home.

I have a slight suspicion that it might be the battery.... any ideas? otherwise i'm clueless..

major mods:

ECU+ tuning device
BEP 50 trim turbo
EVO 3 exhaust manifold
Wiseco pistons
ARP & Cometic
Engine mounts
Fidanza 3.2 clutch
fidanza flywheel
FIC 650cc injectors
PLX AFR with DM-5 gauge
egr eliminated
3.5" GM MAF

Info from log:

I didn't have USB memory stick at hand when i start writing this but I can say there's some weird data on the logs - some values take a huge spike _just_before_ stalling...

Air temperature (that should be fixed to 80 deg.F!!!) - spike to 163 or 363 deg F
Mas in and out - spike to 4260hz and 4006hz
Coolant temp - spikes to over 300 degrees
All other values in engine monitor - level to zero

these spikes last usually 10-15ms

Any help appreciated, thanks!

 

[mindset]

Hi,

I've finished my rebuild recently, and have driven now for approx 200 miles. Now, the car has been stalling every now and then without consistency. The only thing which is consistant is that the car will not stall when it's still cold. but it usually starts to stall when it's warm.. and coming to a stop (idle). When it stalls, I have difficulties to get it idling again - But after about 15 mins, it starts, and stays on with a slight bucking. Coolant temps are ok.

I know the temps look good but how much coolant did you put in?

Right.. I found out that ground wire going to the knock sensor was snapped off so i rewired it along with my PLX SM-AFR sensor ground wire that was relocated. (plx feeds from radio wire) I had no stalling in 3 days. Today it totally pissed me off again.
The symptoms started again.. I have to make clear again that the car never stalls when cold... only when hot! Didn't have my laptop connected this time, but i noticed few things... as I was driving at approx 55mph, i hit a sharp bump - not a big but sharp - and then the car stalled for a half second and recovered itself after that... end of that story. A little bit later it stalled in gravel road, and i couldn't revive it before It stopped completely. I tried to hit ignition right after that but this time it wouldn't even let me run the starter engine. waited about 10 mins and got it running again -> left straight to home -> the car stalled once more (stopped.. no start engine.. 10 mins.. and moving again) before i reached home.

Battery or alternator maybe? But I don't understand how it's able to start up later. So after it stalled on the gravel road, what you're saying is that it didn't turn over at all? Look at all of your connections to the batter, alternator and the starter. Check for vacuum leaks too.

I have a slight suspicion that it might be the battery.... any ideas? otherwise i'm clueless..

major mods:

ECU+ tuning device
BEP 50 trim turbo
EVO 3 exhaust manifold
Wiseco pistons
ARP & Cometic
Engine mounts
Fidanza 3.2 clutch
fidanza flywheel
FIC 650cc injectors
PLX AFR with DM-5 gauge
egr eliminated
3.5" GM MAF

Info from log:

I didn't have USB memory stick at hand when i start writing this but I can say there's some weird data on the logs - some values take a huge spike _just_before_ stalling...

Air temperature (that should be fixed to 80 deg.F!!!) - spike to 163 or 363 deg F
Mas in and out - spike to 4260hz and 4006hz
Coolant temp - spikes to over 300 degrees
All other values in engine monitor - level to zero

these spikes last usually 10-15ms

Any help appreciated, thanks!

And how much boost are you running? And were you beating on the car and then it stalled out right after?

 

[Barracuda]

No beating, just normal cruising.

 

[mindset]

No beating, just normal cruising.

And boost setting?

 

[Barracuda]

Fixed.

Yesturday I was wondering why vibration/shock could trigger this condition, I came to think of electrical wiring and such wiring that is crucial to the engine. I checked the engine bay and then moved to check the stock ECU and ECU+ head unit.

What I discovered was that one harness wasn't completely connected to the ECU+. So i just fastened it securely and the problems are gone.

Same time.. I found out that 3 nuts were loose and 1 was missing from my front wheels...

After all, I think there's a lesson for us all... DON'T DRINK WHILE WORKING ON YOUR CAR!!