loss of power and poor fuel economy - NB 2000 reg Icon

[owen.m]

Hi,

I did the timing belt about 10k miles ago and had a service done about 3 weeks ago but my fuel economy is at about 22mpg. The air filter and plugs were changed.

The car revs fine but it doesn't translate to speed, i.e. if I put the pedal down in first the rev counter shoots up but the car moves like it's in third? There are no warning lights and the engine sounds fine, idles at about 850rpm.

Any suggestions?

Tks,
Owen.

[franksm]

Owen, sounds like the clutch is on its way out. Or else the slave cylinder has lost its fluid. The latter is the cheapest to fix

Or perhaps the brakes are binding. Are any of the wheels very hot after driving for 10 mins ? Lift the car safely on a jack and axle-stand, and see if the wheels can spin freely by hand. If not, something is binding.

To check the clutch hydraulic system: check the resevoir under the bonnet, make sure it has fluid in it. Check the rubber boot on the slave cylinder on the side of the gear box. If it's been leaking, it'll show there.

To check the clutch itself - try starting the car from a rest in 2nd gear gently. If the engine revs, and the car stays still, it means it's new clutch time.

It does sound to me like it's the clutch - they generally last 100,000 miles in these cars - and first sign of problem is as you describe: engine revs fine, but no drive to the wheels - aka clutch slip

[owen.m]

Hi Frank,

I don't have a jammed brake, car rolls freely on the slightest incline, I changed a caliper for this reason last year.

Don't think it's the clutch either, I can drive up an incline in 2nd at very low speed. ( I do this to park every day in work). I drove another car a few months ago with a slipping clutch plate and know what this feels like, also I only have 78K miles up.

I was reading about the timing belt having slipped a tooth, would this have other symptoms? Or what about the oxygen sensor? I should expect a flashing engine management light for this?

Tks,
Owen.

[owen.m]

Hi,

Mechanic tells me it's the air flow meter, which looks expensive judging by mx5parts.co.uk s price for a mk 1 version. Any reason why the site doesn't list a meter for a mk2?

Anyone put in a used meter from a scrapyard, is it worth doing?

Tks,
Owen.

[sidewaysreilly]

i have one here if you wanna try it. Unsure of the actual condition but its worth a try.

[owen.m]

Thanks, but I picked one up very cheap in a local scrapyard, the engine is definitley running a bit smoother but i'm not sure the power is back. I'll have to do a few miles to see if the fuel economy is improved.

[owen.m]

I'm back unfortunatley.

fuel economy is now down to 19mpg. I press the accelerator and nearly nothing happens - I press it about 5% and have to wait for the car to slowly pick up speed. It revs fine in neutral.

Things done so far:
plugs
air filter
cat - (needed for NCT - failed on emissons and passed when replaced)
Leads
Air flow meter (2nd hand)

Things checked: (it's not these):
Slipping clutch.
Seized caliper.
Sensor in airbox - disconnected and battery light came on so I reconnected

Mechanic has checked diagnostics and it comes up with no faults - he suggests air flow meter again. I kept the old one and put it back in yesterday and the car is exactly the same but the car was performing better when I changed it so would expect an improvement....

Could the fuel filter cause this? As far as I know it's never been changed.

Kinda desperate here - next step is mazda main dealer and that could be a massive cash extraction exercise.

Tks,
Owen.

[MX5Spares]

Don,t even think about dealers unless you are desperate and have 70e plus vat PER HOUR plus any parts .We have good used air flow meters you can try also we have other related bits .WHERE ARE U BASED?? Still sounds like clutch problem to me but I can have a look at it if thats suits.Possibly throttle body,stuffed exhaust/cat,various other items but always fixable !!! 086 8226506 Robert

[Fergus]

What happens if you put the pedal flat down to the floor ? As in 'Floor It'.
If the engine 'bogs' then it's fuel/air, if the engine revs up to redline without gaining speed then it's clutch.
Filter is easy to change, could be dirty injectors to.

[owen.m]

If I floor it in neutral I can redline it, if i floor it in gear nearly nothing happens. I've driven another car with a slipping clutch plate and this definitley doesn't feel like it.

Could a gummed up fuel filter cause this loss of performance and 19mpg.


Robert, really appreciate the offer, I'm based in Limerick, I will be back to you after I get the fuel filter fitted.

[charged_rs]

coil pack

[owen.m]

coil pack

Christ not again, I put a 2nd hand set in less than two years ago. Is their any definitive test to show it is the coils?

[charged_rs]

coil pack

Christ not again, I put a 2nd hand set in less than two years ago. Is their any definitive test to show it is the coils?

thats the trouble using 2nd hand parts.

unplug your ht leads from the coil pack and peep in the holes...if there is a greenish blueish powdery guff in there , clean it out with a micro screwdriver so the metal is shiney and clean again...loads of wd40 then that should keep you mobile for a while until you save for a new one.

have you tried the cheapest options ? new ht leads and plugs first tho ?

[Fergus]

Contact 086 8226506 Robert and do a simple test swap out - if it works then it WORKS !
I'm sure he'll sort it out cheap as there are lots for sale over in the UK and on FleaBay and Rob's a good guy here on Mx5 Ireland

[owen.m]

After a conversation with Robert I realised I had a spare coil - when I replaced my last coil I replaced both even though only one coil was gone so I had a spare without realising it.

So it's not the coil...

I got tired of running at 16mpg so I took it to another mechanic and --------- the crankshaft pulley was wobbling...........this is a mk2 2000 reg car.

it gets worse:

The crankshaft bolt loosened and then stopped turning, he thinks it's threaded or was overtorqued when the belt was done. also said if he takes it out and it is threaded then the engine might have to come out to maybe thread a new bolt or worse a new crankshaft.

He has welded it for now and it is running a lot better but not good enough.

Opinions please on my options or likely outcome if I try to get this fixed properly?

A) force the pulley bolt, if it is threaded, lift the engine and tap a new thread for a new bolt? Is this possible?
B) as above but tapping a new thread isn't a new option so I need a new crankshaft? Anyone know ballpark cost of the parts involved and hours required?

he's quoted €350 labour for engine lift out and in plus whatever happens afterwards.

Tks