- Sun Oct 06, 2024 2:36 pm
#69770
Hi Speeduino Community,
I’m working on my G4JS turbo project. This engine is essentially a Korean clone of the 4G64 bottom end and 4G63T top end. The engine has been rebuilt with forged pistons, 535cc Bosch 0 280 158 117 injectors, a Walbro fuel pump, a TD04-13THL turbo from a Volvo, and a custom-fabricated manifold, running boost at around 0.7 bar.
I’ve set up the engine using a Speeduino v0.4 board. Once the engine starts, it runs perfectly—there are absolutely no issues with acceleration, idling, or cruising. The trigger pattern for this engine is the same as for the 4G63.
The problem, however, is with cranking. Typically, it starts on the second or third attempt. The prime pulse is essential—without it, the engine has a hard time starting. I’ve been struggling with cranking for a few months now, and I’ve tried countless combinations of adjustments to spark, fuel, IAC, trigger skip revolutions, trigger filter, trigger re-sync every cycle, fixed cranking timing with trigger, dwell, and who knows what else...
I'm attaching the setup and logs for three consecutive cranking attempts. The engine didn’t start because the prime pulse was missing. The strange thing is that the ECU seems to lose trigger sync just as the engine tries to start (RPM above 300). As a result, it sounds like it’s about to start but dies right after.
Here are my observations:
Timing is synced with a timing light.
Setting skip revolutions to 3 and maxing out timing to -10 during cranking is necessary—otherwise, the engine kicks back hard (I’ve already gone through two starters).
When "fixed cranking timing with trigger" is ON, the engine kicks back really hard.
Setting the timing to -10 seems to help the engine start more easily.
The IAC setup appears to be a good fit.
I’ve tried more and less fuel, but the results are nearly the same.
The prime pulse has had the most noticeable positive effect as far as I can tell.
I’m really frustrated with this cranking issue and have run out of ideas. I’m starting to think there may be a hardware issue or possibly a bug in the Speeduino code related to the 4G63 trigger setup.
Please take a look at my logs and setup. I’d appreciate any ideas or recommendations on how to improve the cranking/starting process. Thank you very much!
I’m working on my G4JS turbo project. This engine is essentially a Korean clone of the 4G64 bottom end and 4G63T top end. The engine has been rebuilt with forged pistons, 535cc Bosch 0 280 158 117 injectors, a Walbro fuel pump, a TD04-13THL turbo from a Volvo, and a custom-fabricated manifold, running boost at around 0.7 bar.
I’ve set up the engine using a Speeduino v0.4 board. Once the engine starts, it runs perfectly—there are absolutely no issues with acceleration, idling, or cruising. The trigger pattern for this engine is the same as for the 4G63.
The problem, however, is with cranking. Typically, it starts on the second or third attempt. The prime pulse is essential—without it, the engine has a hard time starting. I’ve been struggling with cranking for a few months now, and I’ve tried countless combinations of adjustments to spark, fuel, IAC, trigger skip revolutions, trigger filter, trigger re-sync every cycle, fixed cranking timing with trigger, dwell, and who knows what else...
I'm attaching the setup and logs for three consecutive cranking attempts. The engine didn’t start because the prime pulse was missing. The strange thing is that the ECU seems to lose trigger sync just as the engine tries to start (RPM above 300). As a result, it sounds like it’s about to start but dies right after.
Here are my observations:
Timing is synced with a timing light.
Setting skip revolutions to 3 and maxing out timing to -10 during cranking is necessary—otherwise, the engine kicks back hard (I’ve already gone through two starters).
When "fixed cranking timing with trigger" is ON, the engine kicks back really hard.
Setting the timing to -10 seems to help the engine start more easily.
The IAC setup appears to be a good fit.
I’ve tried more and less fuel, but the results are nearly the same.
The prime pulse has had the most noticeable positive effect as far as I can tell.
I’m really frustrated with this cranking issue and have run out of ideas. I’m starting to think there may be a hardware issue or possibly a bug in the Speeduino code related to the 4G63 trigger setup.
Please take a look at my logs and setup. I’d appreciate any ideas or recommendations on how to improve the cranking/starting process. Thank you very much!
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