197: Vacuum leak - Help

[Brunoandrade98]

Hi all,

I recently made a post about my 197 having a rough idle.

Stupidly, I never though about a vacuum leak, but it's looking like the most likely candidate, as I've noticed for a while now that the brake pedal is hard (not assisted) when I press it for the first time in the morning to start the car. When the engine is running, I can't tell if it's any harder than it used to be, but this certainly indicates a vacuum leak somewhere.

So far, I've done:

1. Checked for punctures of cracks on the PCV valve hose and the one that goes from the throttle body to the right hand side of the battery
2. Added jubilee clips to both ends of the PCV valve hose, as they didn't feel very snug
3. Installed a MAF sensor holder - Those that hold it down so it doesn't move about
4. Replaced the O-rings in the PCV valve so that it fits better and doesn't move about as much

Would someone be able to tell me where every vacuum hose is so I can check them, as well as any other potential (perhaps common) causes of a vacuum leak?

Any input appreciated

 

[RSRowe]

Vacuum leaks are not common. You can try spraying brake cleaner around the pipes. If there’s a leak, the revs will change.

I already advised you that it is likely to be your lambda sensor.

 

[Brunoandrade98]

Vacuum leaks are not common. You can try spraying brake cleaner around the pipes. If there’s a leak, the revs will change.

I already advised you that it is likely to be your lambda sensor.

I plugged in an OBD reader and the voltages on both sensors check out, so I’m afraid it’s not that.

 

[Brunoandrade98]

Vacuum leaks are not common. You can try spraying brake cleaner around the pipes. If there’s a leak, the revs will change.

I already advised you that it is likely to be your lambda sensor.

I plugged in an OBD reader and the voltages on both sensors check out, so I’m afraid it’s not that.

The fact is, there is obviously a vacuum leak, as the brake booster doesn’t hold vacuum after a while, and a vacuum leak could cause a rough/lumpy idle.

It’s my main candidate, at the moment.