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blocked fuel filter maybe. or fuel pump. or coilpack.

far too many unknowns. You have not mentioned your stamping ground. It sounds like a job for super MX5 specialist- and there are mechanics around who know the cars. A guy I know was telling me recently how many fuel tanks he has had to drain etc remove due to fuel contamination- not saying that is what is the fault. The KM;s of the car and its history etc may well give a pointer and a check of the diagnostics may indicate specific fault codes.

Do simple checks first, ie. any vacuum hoses loose, all sensors connected properly.
Unplug the Mass Air Flow meter connector, spray a little bit of contact cleaner (WD40 or similar works too), scrub it lightly with an old toothbrush and dry it off completely before reconnecting.

If the above fails, I would borrow a set of leads from another car. Even though they are new, it doesn't necessarily guarantee them to work 100%. The leads doesn't have to be from another MX-5 as long as they are long enough just to fit for a test drive.

SandraD wrote:Thank you all for your posts....
1... My stamping ground is northern beaches (2103) NSW, if anyone can suggest a mx5 specialist in my area?... As I googled and only found a Mazda specialist in Hornsby.... Which is a good 40 or 50 minutes away.

You might want to try TT Auto.

Ive only heard good things about them.

SandraD wrote:Ps... I have forgotten to mention an unusual problem I have with my mx5 (1998 mk II)

1. When fuel tank is 1/4 full
2. Making a left hand turn
3. The car faulters and looses power.
4. I have owned my mx5 for about 4 years and it has had this complaint since I purchased it
5. Has anyone come across this problem before?
6. Would anyone have a diagnosis?

Any advise is welcome
Kind regards

The fuel pump draws fuel from the approximate centre of the tank, if you have a low enough fuel level, and you go round a corner fast enough, it cam momentarily starve the pump and hence your engine, of fuel.

You mentioned a new fuel filter being fitted. Which filter was changed? (There are two, a coarse 'sock' style filter attached to the fuel pump, inside the tank, and a fine canister style filter underneath the car just in front of the driver's side rear wheel arch)

If the one in the tank hasn't been changed it may be partially clogged.

Here's a pic of a new vs. old (brown) pump and sock filter:

http://jimsgarage.files.wordpress.com/2 ... =450&h=523

I've seen pics of some that were chocolate brown in colour and covered in sludge. Unlikely that would happen unless the car has been filled with some truly atrocious fuel.

Additionally, has the car even been run on E10 fuel? I don't think the NB8A (your model) can handle E10 and it may have caused portions of your fuelling system to degrade.

Armed with the info you have I would think a good MX5 technician who can work thru it will find the fault. Not being a Sydneysider I do not have the contacts but someone will The fault your car has would be a blight and the car should be a pleasure to use and drive. Armed with the info you have- well observed and useful - write it down on a summary sheet- and provide this to a repairer. You may certainly not have the car for a few days. You could ring a Mazda distributor or one of the sponsors in Sydney who can point you in the right direction. Caffeine obviously suspects a few prob as well- if a tank is contaminated??
Let us know how you get on

suspect "dirty fuel" issues and fuel stavation issues. is this not a dead givaway for intank fuel pickup/filter being dirty? as per earlier posts?

if it ain't the leads that are the problem, then it is fuel pressure issue. get in that tank before you do anything else.

Caffeine wrote:

SandraD wrote:Ps... I have forgotten to mention an unusual problem I have with my mx5 (1998 mk II)

1. When fuel tank is 1/4 full
2. Making a left hand turn
3. The car faulters and looses power.
4. I have owned my mx5 for about 4 years and it has had this complaint since I purchased it
5. Has anyone come across this problem before?
6. Would anyone have a diagnosis?

Any advise is welcome
Kind regards

The fuel pump draws fuel from the approximate centre of the tank, if you have a low enough fuel level, and you go round a corner fast enough, it cam momentarily starve the pump and hence your engine, of fuel.
.

but on 1/4 tank? that' still over 10L.
This suggests to me of a problem with the pump assembly, hopefull it's just the in-tank filter. Can you hear any clanking noises? Perhaps the pump may have either come loose or if it was replaced (unlikely for a car with that many km), it was installed incorrectly.

1red5 wrote:but on 1/4 tank? that' still over 10L.
This suggests to me of a problem with the pump assembly, hopefull it's just the in-tank filter. Can you hear any clanking noises? Perhaps the pump may have either come loose or if it was replaced (unlikely for a car with that many km), it was installed incorrectly.

I agree that it's unlikely to be just fuel sloshing around with that much still in there. If the sock filter is dirty or partially clogged it may have some effect.

1Red5 - mine does the same thing ... 1989 Na6, less than 1/4 tank, hard left ( i think) and it stumbles ....

seems an early design issue

I have a new fuel pump, clean sock, replaced the in-line filter, flushed the lines and cleaned the injectors - the only component i havnt touched is the regulator !

I've had a peep into the tank and yes, it appears as though the baffling could do with some mods....

I"m guessing that later NAs had these aforementioned mods, and this issue only occurs on early machines ....

Cheers
J

I'm not doubting that it may be surge issues, but I'm just surprised as no one I know personally has had such issues, even on the track.
Having said that though, I was reading an old Motor mag, and the early 2000, bug-eyed, Imprezas (WRX included) has surging issues on spririted cornering in one direction even with half a tank.

Common on NA's even my Sunday only shopping trolley I've found at 7500rpm on the main straight at Lakeside
Coming up to the Start/Finish line, BIG surge if under 1/4 tank of fuel. Cal has the same problem!!!!

SandraD: try Penisula Sports Cars,Revolution Race Gear and speak to Brett, they actually raced one for a while.
Ph 9907 2069 Brookvale

Terry

tbro wrote:Common on NA's even my Sunday only shopping trolley I've found at 7500rpm on the main straight at Lakeside
Coming up to the Start/Finish line, BIG surge if under 1/4 tank of fuel. Cal has the same problem!!!!

Oh... ok then. There you go.
That confirms that I'm rubbish at the track.

SandraD wrote:Ps... I have forgotten to mention an unusual problem I have with my mx5 (1998 mk II)

1. When fuel tank is 1/4 full
2. Making a left hand turn
3. The car faulters and looses power.
4. I have owned my mx5 for about 4 years and it has had this complaint since I purchased it
5. Has anyone come across this problem before?
6. Would anyone have a diagnosis?
Any advise is welcome
Kind regards

A common problem when the fuel pump is replaced
The new intake filter is different to the STD mazda one
1st pic shows the std mazda filter
imagine the table edge is the bottom of the tank



this one shows the filter supplyed with the walbro pump




Now the pump sits in a little sump in the tank
and this causes this to happen if you can get it in
And most of the time is wont.

also the filter faces the wrong way from the one that was pulled out
so the pump goes in the other way


also the filter faces the wrong way from the one that was pulled out
so the pump goes in the other way



when this happens the inlet to the pump via the filter can now suck air
when you go around a left hand corner (even at road speed)and causes
the fuel pressure to drop and the car starves for fuel.