[cbouchaya]

What's up guys and gals. Recently swapped my 485's to twin 525's in my Visconti stage 2 basket (with original hardwire kit). I did recently switch tuners after the 525 install as well. (on E85 BTW)

The car drives great around town and WOT. Recently however it developed an issue where after spirited driving either sitting at a light or crawling through a parking lot the engine will stall and shut off immediately. I'll try to restart it: start it and it will crank, then fire then sputter and stall immediately almost as if there's a fuel issue. I will have to attempt a few times to restart it before it actually fires and idles. After the last attempt i got back on the free and was cruising and the car drove fine. I even got on boost a bit and the car still drove fine. I got off at the exit and at the light it stalled on me again and took a few attempts to stay on. I've used the ECUTEK app to test the pumps individually with the car off after it stalls incase its a pump but I hear them just fine. (primary is much quieter then the secondary).

According to the ECUTEK app my fuel temps don't get passed 100F so I doubt its vapor locking. When I pull the rear seat cover to listen to the pumps I do feel a lot of heat coming from the pump access. I unplugged the hat harnesses to inspect the plugs and they looked good no burning or any kind of burning smell.

Anyone have any ideas on what it could be?
I am trying to get logs of the stall but its not predictable and hard to time.

I love the car and understand its far from stock, but stalls at lights are no beuno

 

[cbouchaya]

UPDATE

I was driving the car around last night and it stalled on me again. Lucky I happened to be data logging. This time the car wouldn't restart at all. Usually would take a few Attempts but it wouldn't fire and idle, just fire and die.

Upon looking at the log I noticed that the manifold gauge pressure was like 2000+ and pegged on the graph. I call my shop guy who I trust and always hype and told him exactly what was happening and withheld the information about the MAP readings (to see what he says). He thought about it and said "check your MAP sensor, go unplug and plug it back in" I did that and the car started and fired immediately and idled. He then tells me to wiggle the sensor with the car on. I do that and engine stalls again. He said in his experience the sensors crack over time. I do have a 4 bar sensor. I will be ordering a new one and seeing if that fixes my issue long term.

Incase anyone wants to see it I will include a Log of the car driving and the MAP senor pegs at 2000+ around the 305-330 second mark.
Also will include a data log of the failed attempts to restart the car. Notice the Manifold gauge pressure.

Has anyone experienced this in the past or should I chock this up to my amazing luck.

 

[cbouchaya]

So after the car left me stranded the other day my replacement, Omni, four bar map sensor came in and after replacing it car fired right up and idled. So far no hesitation and hasn’t cut out on me yet. So, in case someone else is having a similar issue where their car Cuts out and will not turn back on and they are speed density. Check your map sensor. Not sure what happened why it went bad. Will attempt to open up the bad one and see if there’s any visible damage I’m just assuming after numerous heat cycles, it finally gave out.

 

[Jd223]

Omni sensors are known to just fail out of nowhere. Have a spare one handy in the car or switch to a AEM 5bar…much more robust

 

[Gtrx]

similar symptoms a while ago and it was a map sensor for me as well..

 

[colo_evo]

There was another thread about the omni/ams map sensor failing. Why is this happening so frequently?

 

[L.L.]

Another one bites the dust. After the Omni TMAP failed last year around this time, my car started doing some weird things recently where it would start bucking a little while driving at slow speeds and then either stall or continue running roughly. It threw some mixed codes such as P0605 (Internal ROM error) and C1130 (ABS). This time the MAP sensor at the intake manifold location failed. It stalled immediately after I wiggled it and didn't want to fire up after unplugging it and plugging it back in.

In addition to the TMAP, I guess the MAP and a 10mm socket will be something I'll need to carry around in the car. You'd think they would figure out these issues after so many years in production.

UPDATE 12/28/2022 - replaced the MAP sensor with a newly purchased one and the car is running normally again.