Erk! Induction kit install gone wrong! (or has it?)

[Dave-UK-MX3-V6-SE]

Hi there,

I'm new around here, this is my first post, so be gentle with me!

I have a 1994 UK spec V6 Limited Edition (1 of 150, 134bhp standard), which until today was standard. Fitted a HKS Super mega flow induction kit and all seems well in terms of connection (was fairly simple to do..) but when running there are a few issues:

Performance: it's still very good, I wouldn't say better, perhaps slightly worse (before 70mph in 5th was exactly 3500rpm, now it's ~3750rpm) - and top end acceleration seems down
Running: it is very unhappy idling, tachometer reads about 100rpm and the HUD lights flash on (as if it's about to stall). very rarely it cuts out when idling.

at first there was quite a bit of white smoke / steam coming out the exhaust, now i don't notice any but there's still the issue of it idling poorly - before it was happy idling at about 500rpm.

i suppose my questions are:

has anybody else experienced this?
and
how long should the ECU take to adjust to the increased airflow?

many thanks & regards,
Dave

[lakersfan1]

The RPM per MPH issue doesn't make sense. Your gearing is the same either way. Only thing that might make a difference is if your clutch was slipping. Either way, not intake related.

As for the idle, sounds like you may have a vacuum leak. Get a can of starter fluid and spray it around all the couplers betweenthe VAF and the throttle body. If the RPM goes up when you spray one of those joints, then you have a vacuum leak.

[Dave-UK-MX3-V6-SE]

Thanks for the response/advice lakersfan1, but I found out what was causing the issue!

While sitting around in the local cruiser car park, me and my buddies were discussing the design of the HKS filter. If you have a look at http://www.6gc.net/images/part_photos/230_2.jpg you can see the arc'd bits of plastic - they converge at a common point underneath the screw-in cap. what was happening was this point was pushing in the air intake valve (which is controlled by the ECU) so that when the throttle was at idle, the intake valve was slightly open, causing it to gasp for fuel.

while "in the field", we melted this down so that it wasn't touching, and hurrah! the problem instantly went away. power has somehow improved quite a bit as well!

Cheers again (and there's a tip for others in my situation!)

David

[IanL]

Originally posted by Dave-UK-MX3-V6-SE:
If you have a look at http://www.6gc.net/images/part_photos/230_2.jpg you can see the arc'd bits of plastic....

Dave,

Can't see your pic - that site won't allow linking.

Just to clarify, the "air intake valve" is actually the Volume Air Flow (VAF)sensor , which signals the amount of air to the ECU, so what was actually happening was the ECU was being lied to about the amount of air being inducted. That would have made it inject too much fuel, so you were running rich when the airflow was low (i.e. idling).

When the airflow was high, the flow would push the cone further in, and away from contact with the plastic thingies, and there would be no effect. I'm not surprised you did not detect a performance increase then; my personal conviction is that these "performance" filters make little or no discernable difference.

<small>[ September 26, 2004, 06:53 AM: Message edited by: IanL ]</small>

[Dave-UK-MX3-V6-SE]

Ian,

try copying and pasting the URL into a new browser window...

thanks for the more technical explanation as to what went wrong. in regards to performance.. it seems to have more response below 4000rpm (previously it had been a touch slow) - also the growl the new filter gives is superb..

[IanL]

Originally posted by Dave-UK-MX3-V6-SE:
Ian,

try copying and pasting the URL into a new browser window...

Thanks, that worked. I've seen that sort of filter on a car imported from Japan. The owner's changed it now for a K&N - he referred to it as "Mr Cloggy", so you may need to clean it frequently [/b][/quote]Now could that be the high-bandwidth connection between the ear and the butt dyno

[Dave-UK-MX3-V6-SE]

Aha, I used to prefer the quiet power, but recently fancied a change to see how it goes - can always drop back to the standard airbox!

Regarding the K&N - I was unable to find one for this particular car?? Did this guy buy a universal filter and make a custom connector for it or what?

[IanL]

Originally posted by Dave-UK-MX3-V6-SE:
Regarding the K&N - I was unable to find one for this particular car?? Did this guy buy a universal filter and make a custom connector for it or what?

Standard airbox - K&N Part # 33-2083

[Dave-UK-MX3-V6-SE]

Thanks.

I've now encountered another more serious problem. Yesterday while driving in town it was idling fine as usual (waiting in traffic), then the revs dipped close to 0.. engine lights came on and it stopped itself from stalling. 10 minutes later I'm parked outside a house and it does the same, except this time it cuts out.

Turn key, turns over, starts, then instantly the revs drop to 0. Turn key, wont start.

5 minutes later, it starts.

During the drive home it cut out a few times, either during normal driving (once) or a few seconds after hard acceleration (most times). The revs dont just slow down either - they hit 0 from 5000 or so instantly (so does this mean it might be ECU related?)

Any help you could provide would be most appreciated.

David

[Mnemonic]

all your problems sound like a vacume leak, i recomend putting the stock box back on, if the car runs fine after that reinstall the CAI again, if after the re-install it runs like crap again, then there is something wrong with to where it isnt getting a tight seal.

Also did you loosen your Throttle body at all when installing the kit? you could have a minor air leak from there as well.

great way to test for a vacum leak get you a can of WD40 or some break cleaner or carb and choke cleaner and spray in small spots in your engine bay while the car is running. if your car rpms increase you've found the general area of where the leak is coming from. just remeber to spray small amounts so that you can find a closer area.

[lakersfan1]

Originally posted by Dave-UK-MX3-V6-SE:
Thanks.

I've now encountered another more serious problem. Yesterday while driving in town it was idling fine as usual (waiting in traffic), then the revs dipped close to 0.. engine lights came on and it stopped itself from stalling. 10 minutes later I'm parked outside a house and it does the same, except this time it cuts out.

Turn key, turns over, starts, then instantly the revs drop to 0. Turn key, wont start.

5 minutes later, it starts.

During the drive home it cut out a few times, either during normal driving (once) or a few seconds after hard acceleration (most times). The revs dont just slow down either - they hit 0 from 5000 or so instantly (so does this mean it might be ECU related?)

Any help you could provide would be most appreciated.

David

Sounds like your distributor is failing. It's common on the V6. Get another distributor.

[IanL]

UK Mazdas from Nov '93 have the new design distributor K834-18-200A, which is much more reliable than the previous types fitted.

However, I assume that date is when the car left the factory, so, if your car is early '94, it may have the old type, KLY1-18-200.

They are interchangeable, except the three wires into the 3-pin connector need to be swapped round.

You're looking at about £400 for a new one, so let's hope it IS a vacuum leak.

[mmac]

It does sound very much like dizzy failure. Gone through it myself, virtually identical characteristics


If you need distributors or parts you could try :
http://www.probedistributors.co.uk/
They can supply new, recon,used & parts at very reasonable prices. They will test your dizzy if you send it to them. Used them myself and was very happy with service and price

<small>[ September 27, 2004, 10:53 AM: Message edited by: mmac ]</small>

[Dave-UK-MX3-V6-SE]

Hi Guys,

thanks a lot for the support here, unfortunately again it seems the problem was rather trivial. the air filter (despite already being cut back) was still touching the air intake valve, not sure why it was fine to start with, but having cut it WAY back, the problem seems to have gone...

thanks again

Dave

[Gro Harlem]

Yah, pushing in the VAF will mess with the fuel curve. Make sure there isn't any obstructions when you make your own intake system.