91 Mazda Familia Manual w/ 209XXXkm. rev's sit steady when cold, but when car gets up to operating temp. they will fluctuate +/- 200rpm.I know it isn't heaps.but I'm paranoid about fixing the issue now. So far have replaced air + fuel filters, cleaned MAF w/ contact cleaner, flushed radiator and replaced spark plugs. Car is def running better with those done but still rev's fluctuating. Next on list is cleaning out throttle body and IACV.anything else I should look into! Thanks
wild-at-heart,
Jun 8, 11:46am
Vacum leak!
lolzor123,
Jun 8, 11:50am
Yeah that was my first thought too. I've had a good look and done the WD-40 check with engine running and there doesn't seem to be any leakage.
wild-at-heart,
Jun 8, 11:56am
Try another MAF sensor
lolzor123,
Jun 8, 12:18pm
Yeah will do. Exam season at the moment so later next week will try cleaning out TB, EGR and IACV. Hopefully that does something. From googling just dismantling and carefully spraying the parts w/ TB cleaner is all that can be done! Also, when pressing accelerator pedal after car has been sitting for a few hours it is initially hard to press.then fine after that. So this is making me think the TB could need a decent clean. Thanks for the ideas.
andy61,
Jun 8, 2:55pm
Clean the throttle body out,take if off the motor if needs be. Usually fixes hunting revs 90% of the time.Get it spotlessly clean.
bellky,
Jun 8, 2:57pm
And lube it up around the linkage when finished.
lolzor123,
Jun 8, 3:05pm
Sweet thanks andy61 and belky. belky - does it matter what I lube the linkage with! Should it be CRC or a heavier oil!
bellky,
Jun 8, 3:08pm
In the past I have 'cleaned' mine with CRC, and then lubed it with gear oil; seems to work nicely.
lolzor123,
Jun 8, 3:16pm
Yeah I was thinking something like gear oil might last a bit longer. Will give it a go next week :) Cheers
red97,
Jun 8, 4:31pm
do the fluctuations cooincide with the electric fan turning on and off! or are they random!
lolzor123,
Jun 8, 5:08pm
Nah, don't think fan related as it is just a random slow movement of the rpm up to ~950rpm then goes slow to ~800rpm. Then back up again. Only notice when sitting stopped and idling once car is warm. I assume it doesn't happen when cold because of some auto fast idle control which masks the issue! Maybe someone can confirm whether that's correct or not.I'm just guessing.
lolzor123,
Jun 11, 8:07am
Ok so took to the throttle body with some throttle body cleaner and an old toothbrush.it is/was absolutely filthy.the ports to the IACV and EGR (the holes near the butterfly - I assume that's what they're for!) are full of gunk too. I managed to get a bit cleaned.but car isn't running any better. I want to take the throttle body etc off to give it a decent clean and see if that helps -but just wanted to check - is it easy enough to buy replacement gaskets for the throttle body! Will Repco or somewhere have them! Thanks
hopie,
Jun 11, 8:20am
definatly sounds like the TB. Def take it off a clean it. yes gaskits are easy to come by
lolzor123,
Jun 11, 8:24am
Awesome thank you. And to save me sounding like a tool, it is a 'throttle body gasket' that I'm after eh! Another thought - after cleaning all the crap out and reassembling - will the timing need adjusted for it to run perfect!
bellky,
Jun 11, 9:13am
I'm no expert but I'm pretty sure the timing has nothing to do with the TB.
lolzor123,
Jun 11, 9:32am
Yeah that's what I thought, but I've seen mentions of it online. I couldn't figure out the logic.I'll get new a new gasket, dismantle, thorough clean and see how I go.
tonyrockyhorror,
Jun 11, 10:02am
You'd be right.
lolzor123,
Jun 11, 10:33am
Ok, so been to Supercheap, Repco and BNT - none of them have a throttle body gasket for a Mazda Familia.where in Dunedin could I buy gasket paper! I think I'm going to have to cut my own
hopie,
Jun 11, 10:44am
drink a 15 box of steineys, and chop up the box to make your gasket :)
go back to repco, they sell gasket paper
lolzor123,
Jun 11, 10:51am
I sort of hinted about any solutions and the LDBdidn't bite and offer the paper. Would there be much difference between using that gasket maker sealant stuff or cutting up the gasket paper and doing it 'properly'!
bellky,
Jun 11, 11:28am
No one has answered for 50 mins so I'd say you can try^ - worst thing that can happen is your vacuum leak gets worse lol.
lolzor123,
Jun 11, 11:41am
Haha yeah that's true. I ended up getting a sheet of 0.4mm thick paper from Repco. I don't know if it's the right thickness but I guess I'll find out
bellky,
Jun 11, 11:49am
Good call^ - you could use gasket sealer with the paper too.
lolzor123,
Jun 15, 1:50pm
Okay so took throttle body off today, gave everything a good clean with throttle body cleaner (didn't take IACV or EGR off separately though), changed oil and filter (cheap castrol at Repco). Car started fine, but now it warm idles at just over 1000rpm (steadier than how it was tho). I thought reseting the idle might help so did that ("grounded" "TEN" pin in diagnostic terminal) and started car. With idle screw in as far as it can go, car still idles at just over 1000rpm.Grrrr. Drives fine and idles smooth enough but I would like to get the idle down to the 750-850 range.Is there anything else I should be trying! I know these cars have a 'pollen filter' - is that just for air con or can it affect idle! Would a dirty cat converter or anything cause such problems! Thanks in advance.
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