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Title: vacume reading on idle
Post by: Madden on July 24, 2005, 07:15:45 AM

Hello

Just about to buy an fd and it has a boost gauge in it. On idle the vacume reading is all over the place. Is this common or is there a fault?

Cheers jamie Madden

Title: vacume reading on idle
Post by: Brett on July 24, 2005, 09:29:03 AM

sounds like a theres a problem with the hose or the guage. I\'m assuming it idles ok? Its not hunting or anything?

Title: vacume reading on idle
Post by: 20B_boy on July 24, 2005, 10:19:36 AM

What do u mean by all over the place?

If the car is hunting too, then it probably has an air leak some where. If it is a very small fluctuation that \'could\' be some thing a little more sinister.

Title: vacume reading on idle
Post by: Fish on July 24, 2005, 04:32:19 PM

Also having a strong vac. reading would indicate stock(ish) porting, a lesser reading could mean either its a proted engine or getting closer to rebuild time. At which point you ask for a compression test.

Fish

Title: vacume reading on idle
Post by: iaint on July 24, 2005, 07:15:55 PM

Quote from: FishAlso having a strong vac. reading would indicate stock(ish) porting, a lesser reading could mean either its a proted engine or getting closer to rebuild time. At which point you ask for a compression test.

Fish

Except I\'ve got both porting and strong vacuum :)

Title: vacume reading on idle
Post by: the lemster on July 24, 2005, 10:29:23 PM

i ahve just installed a \'durite\' boost gauge on my standard FD and on idle it sits on -o.5 bar vacuumther is a sligt fluctuation on idle but this seems to disappear when the engine has warmed up a bit...

I under stand that if it is \'all over the palce\' on idle then it could mean the tips or seals are on the way out... am I correct in that?...

under boost it shows +0.7 bar boost +0.5 in transition and the +0.7 on second turbo.

Title: vacume reading on idle
Post by: davegttph1 on July 24, 2005, 10:31:06 PM

Whats "all over the place"? I see a steady reading on the boost gauge but on the PFC I get a reading between -450 and -600 IIRC....

Title: vacume reading on idle
Post by: the lemster on July 24, 2005, 10:36:24 PM

again if the engine is hunting it could mean that the ECU needs resetting....

Title: vacume reading on idle
Post by: Madden on July 25, 2005, 09:32:53 AM

The car is not hunting and it idles fine drives well starts from warm and cold ,boosts fine and it has a proven 40000 miles with only an cat back exhust system as a mod. It just flucuatesa bit on idle?

Title: vacume reading on idle
Post by: the lemster on July 25, 2005, 09:47:44 AM

is it more of a vibration or is it going from -10 psi to -5 psi then to -11 psi then back to -10 or just -10 -11 -10 -11

if the latter then I dont hink it is anything serious.. the first one an I would assume you ahve some sort of boos leak/blockage...

anyone got any other ideas?...

Title: vacume reading on idle
Post by: Madden on July 25, 2005, 09:49:41 AM

Just goes up and down slightly on vacume

Title: vacume reading on idle
Post by: duff on July 25, 2005, 01:11:45 PM

Mine is the same when idling, but on vacuum it seems to flicker not alot but I thought the gauge might be on its way out but it boosts fine to 0.9 but if your driving at about 0.5 boost the gauge flicks a little bit.

What do you reckon?

cheers Ant

Title: vacume reading on idle
Post by: Madden on July 25, 2005, 01:14:22 PM

Same as this my one mate just wanted to check to make sure the ehgine was fu"Â£ed.

Mazda Rotary Club

General => General Technical => Topic started by: Madden on July 24, 2005, 07:15:45 AM