GVR-4 GVR4 drivability issues

[TreWebbDSM]

#77 is losing all power randomly, it bucks then no matter the throttle position it backfires and just slowly dies. I can sometimes roll start it but sometimes but it seems to be getting worse. The car has fic 1000cc injectors, aem 340lph pump, 74mm s90, fp red, tuned on sd with a gm style Omni 4 bar, fp2 cams. I’m lost on where to start, it only has these problems when it’s fully warmed up. I do have a couple logs of instances where it will shut off but here’s a clip of what it’s doing. Any help is appreciated

 

[TreWebbDSM]

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[JeffGS-T97]

My guess is a massive boost leak. Check piping visually and run a boost leak test.

 

[TreWebbDSM]

My guess is a massive boost leak. Check piping visually and run a boost leak test.

Thanks for the reply. Nothing really sticks out, I went over the couplers and tightened them so I’m gonna try to test it tomorrow. I’ll update on here

 

[AWD-Tony]

Post the log

 

[TreWebbDSM]

Post the log

it happens around 340 seconds and 392

 

[DSMPT]

I would double check the plugs for PTU, coil packs, CAS, injectors if it's loose/damaged or not. To me, it sounds like a bad PTU or coil pack. But a boost leak test is always a must.

 

[TreWebbDSM]

I would double check the plugs for PTU, coil packs, CAS, injectors if it's loose/damaged or not. To me, it sounds like a bad PTU or coil pack. But a boost leak test is always a must.

If the PTU is bad, would cylinder 1 and 4 be wet? When I changed the plugs a couple weeks ago the plugs were wet on just those two cylinders

 

[DSMPT]

Yes, could be. Should inspect the coilpack and PTU itself and its wirings. Or if you have a spare, replace it and see how the car would be running.

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[TreWebbDSM]

Yes, could be. Should inspect the coilpack and PTU itself and its wirings. Or if you have a spare, replace it and see how the car would be running.

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Will do tomorrow, thank you!

 

[Vegas Smith]

You're not logging your wideband, MAP or IAT so that would be my first suggestion because many problems involve those sensors. PTU is a good start as they will stop function when overheated after a long drive.

 

[TreWebbDSM]

You're not logging your wideband, MAP or IAT so that would be my first suggestion because many problems involve those sensors. PTU is a good start as they will stop function when overheated after a long drive.

Yeah that log is a few days old, I have it setup to log the map now, I need to figure out the iat today

 

[TreWebbDSM]

Yes, could be. Should inspect the coilpack and PTU itself and its wirings. Or if you have a spare, replace it and see how the car would be running.

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So a new omni 4 bar fixed the random shutting off. Now I’m just dealing with it breaking up in boost and feeling low on power.