Misfire, rough idle, shuts off when stopped and engine light is on

ASH THOMPSON

MEMBER
1999 HOLDEN CALAIS
5.7L
V8
2WD
MANUAL
20,800 MILES

VT clubsport LS1. Has rough idle, struggles at low rpm and then a bit of power suddenly kicks in as the rpm gets higher and it shuts off when I stop at a corner and blows black smoke when you open it up, engine light is on too.

I have replaced the coils, leads and fuel pump and I cleaned the throttle body and sensors.

3 Replies

KASEKENNY

MECHANIC
18,907 POSTS

Black smoke, rough idle, and low power are symptoms of over fueling. Unfortunately we don't have a manual on this vehicle to help determine the root cause because this vehicle is not offered in the USA.

Here is a guide that talks about black smoke. We need to run through this and start looking at the fuel system.

https://www.2carpros.com/articles/engine-black-smoke

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Tuesday, July 7th, 2020 AT 2:43 PM

ASH THOMPSON

MEMBER
2 POSTS

Okay, yeh I got a new MAF sensor and spark plugs and it's still the same, I'll try injectors next. It's got an engine light on but the scan tool says there's no fault codes on the vehicle.

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Wednesday, July 8th, 2020 AT 7:56 AM

KASEKENNY

MECHANIC
18,907 POSTS

Okay. I would suggest checking the fuel pressure and then testing the injectors. This will not tell if they are leaking so I understand if you are going to just replace them. Let us know what happens.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

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Wednesday, July 8th, 2020 AT 8:22 PM