gontijexx
Probationary Member
- 26
- 5
- Sep 30, 2022
-
Brasília,
South America
Hi everyone,
I’m hitting a wall with my DSM and could use some fresh eyes. Here is the timeline of what’s happening:
Background:
The ECU was recently repaired by @Lintu (new capacitors and trace repairs). Initially, it worked 100% with only a few expected CELs (MAF, Barometric, and O2).
The Issue:
I pulled the trans to replace the clutch. While on the lift, the car started and ran perfectly.
As soon as I put it on the ground, it died. It would start for a few seconds, die, and then eventually show no signs of life at all.
After sitting for a few hours, it started normally again.
I repaired the MAF wiring and the car started better, though idle was surging. I then noticed the MAP/MDP harness was broken.
While driving home, the car died completely. Same symptoms: starts for 2 seconds, dies, then total silence (crank but no start). This time, it didn't "recover" by sitting.
Current Diagnostics:
Spark: Confirmed. I have spark at the plugs.
Fuel: New 110lph pump installed (I'm in Brazil, parts are scarce). I have fuel pressure as OEM standards.
Sensors: Tested CAS and CPS. Both have 12V and pulse between 2.5V - 5V during cranking.
Injectors: They have 12V constant, but no pulse while cranking (can't hear them and the cart starts with fluid).
ECU/OBD: The car stopped communicating with the OBD2 scanner, so I'm currently "blind."
ECT: Was working and it's new
Tomorrow's Plan:
Testing continuity from the injectors to the ECU pins.
Questions:
Since the ECU was recently repaired, could a short in the harness (like the broken MDP or MAF wires) have fried something? Does the loss of OBD2 communication point directly back to a failing ECU or a specific ground I might have missed near the transmission/block?
Any suggestions on what to check next would be greatly appreciated.
EDIT: I NOTICED THAT MY BOOST GAUGE DOESN'T APPEARS TO BE WORKING ANYMORE, WITH SOME WIGGLE ON THE MAF CONNECTOR, IT SHOWS SOME SIGNAL ON THE DASH (IGN SWITCH ONLY) BUT JUST REMAINING DEAD
I’m hitting a wall with my DSM and could use some fresh eyes. Here is the timeline of what’s happening:
Background:
The ECU was recently repaired by @Lintu (new capacitors and trace repairs). Initially, it worked 100% with only a few expected CELs (MAF, Barometric, and O2).
The Issue:
I pulled the trans to replace the clutch. While on the lift, the car started and ran perfectly.
As soon as I put it on the ground, it died. It would start for a few seconds, die, and then eventually show no signs of life at all.
After sitting for a few hours, it started normally again.
I repaired the MAF wiring and the car started better, though idle was surging. I then noticed the MAP/MDP harness was broken.
While driving home, the car died completely. Same symptoms: starts for 2 seconds, dies, then total silence (crank but no start). This time, it didn't "recover" by sitting.
Current Diagnostics:
Spark: Confirmed. I have spark at the plugs.
Fuel: New 110lph pump installed (I'm in Brazil, parts are scarce). I have fuel pressure as OEM standards.
Sensors: Tested CAS and CPS. Both have 12V and pulse between 2.5V - 5V during cranking.
Injectors: They have 12V constant, but no pulse while cranking (can't hear them and the cart starts with fluid).
ECU/OBD: The car stopped communicating with the OBD2 scanner, so I'm currently "blind."
ECT: Was working and it's new
Tomorrow's Plan:
Testing continuity from the injectors to the ECU pins.
Questions:
Since the ECU was recently repaired, could a short in the harness (like the broken MDP or MAF wires) have fried something? Does the loss of OBD2 communication point directly back to a failing ECU or a specific ground I might have missed near the transmission/block?
Any suggestions on what to check next would be greatly appreciated.
EDIT: I NOTICED THAT MY BOOST GAUGE DOESN'T APPEARS TO BE WORKING ANYMORE, WITH SOME WIGGLE ON THE MAF CONNECTOR, IT SHOWS SOME SIGNAL ON THE DASH (IGN SWITCH ONLY) BUT JUST REMAINING DEAD
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