mx5cartalk.com

Hey

Just got a MX5 the other week.. got some minor flat spot problems on accelleration, and trying to work out what is wrong with the lovely thing.

I have a MX5 factory CAI, but I do not have a Air Flow Meter before the pod, is this the norm, Did the 1990 aus specs come with air flow meters or was it all just MAP sensored, as I have been seeing photos of some with the AFM, unless they are the 1.8ltr or US versions..

thanks for your help

The flat spot is on initial acceleration, with under or not under load, and changed the sparks and leads already, just trying to work out the problems, I have also got a hunting idle when lights are on.

Regards

whattt? have u got an after market ecu ?

if not then u should have a afm. so u will need to get one

hey

where ud have the afm usualy I got a straight pipe but I have a sensor of some sort in there its not a AFM though, like the usual ones on the I have seen

also the last owner didn't know anything about the car, the guy before him did all the modifications,

Saying about the ecu, I did see the passanger foot well panel loose yesterday i didnt think twice about someone changing the ecu to something differant...

see the attatched photos of my bay

i dunno man that does look dodgey anyway. I would suggest u check the passenger footwell to see if u can notice a different ecu which should be pretty noticeable.

If that fails call the previous owner and ask what the go is. Do u have a mod list or anything?
or a sale add ?

no afm that i can see & the sensor in the side of the white pipe looks like a GM air temp sensor - also looks like there's a vacuum tube following the brake lines near the heater hoses which probably attaches to standalone map sensor or to an aftermarket ecu with built in map sensor. either way you should find an aftermarket ecu somewhere near by, which sounds like it needs a tune.

Hose coming out of the intake manifold just after the throttle body would suggest some form of MAP. I'd follow that hose to see where it ends up and/or check under the panel in the passenger footwell to see what the ECU is.

Last owner doesn't know what is what,

Had a look under the passenger foot well no ecu there, unless it's smaller than one I've seen before

Will hAve a good look around the bay today to see what is going on, drinks alot of fuel as well I did half a tank some freeway some local with a small amount of spirited driving and only 200km.

Saying that after the little flat spot it really does get up and boggy thou!!

Yep, I have worked out I have a wolf 3d, where do I take it that will know how to tune a wolf 3d properly or should I just change back to the stock ecu with a afm

well there has to be a reason that the ecu would be in there..
If there isnt and its just running like an exhaust then go back to stock, it will save u dramas.
But if u are planning on modding the engine, leave it and get it tuned at some place around ur area.

charlie_91 wrote:well there has to be a reason that the ecu would be in there...

it's there because the car's not running an afm - you could revert to standard if you bought also the necessary parts, but then it wouldn't get up & boogie as well as it does!

Zpeed wrote:The flat spot is on initial acceleration, with under or not under load,

This is normal with aftermarket EMS's.
On initial throttle opening, the engine is not yet operating inside the "normal" fuel and ignition maps, but is functioning on some sort of acceleration enrichment that is programmed in based on a formula that gives the engine what it needs to get the car moving. Not overly efficient, hence the flat spot, but effective.

Besides swapping back to original equipment, the only solution is top name, top $$ EMS like MoTec, Autronic, which have the ability to give you load points everywhere.

93_Clubman wrote:

charlie_91 wrote:well there has to be a reason that the ecu would be in there...

it's there because the car's not running an afm - you could revert to standard if you bought also the necessary parts, but then it wouldn't get up & boogie as well as it does!

but he's complaining that its not though. I said there has to be a reason because if u only had exhaust and cai u really wouldnt bother.

I suggest you find out more about ur car.

Can't really find out much more about it other than opening up the motor, never driving another 5 with Cai and full exhaust so can't really say if it has cams or something,

thanks for the explanation re the initial flat spot, might get it retuned for the cold startup though as it's a few seconds before the car stumbles to start when it's cold, and maybe it would fix the idle hunt??

Anyone got any recomendatikns for a wolf tuner in Melbourne, maybe mx5 factory did the work in the first place as it has a mx5 factory roll bar in there as well!!

charlie_91 wrote:

93_Clubman wrote:

charlie_91 wrote:well there has to be a reason that the ecu would be in there...

it's there because the car's not running an afm - you could revert to standard if you bought also the necessary parts, but then it wouldn't get up & boogie as well as it does!

but he's complaining that its not though.

in the 1st post op is complaining about the flat spot & wondering if there should be an afm. if running the wolf3d v4 or v4+ there's no need for an afm as wolf has a built in map sensor.

wolf dealers/ tuners: http://www.wolfems.com/Locate/2.htm