Mx-5 gone, pug 107 and 300C now here.

[paulplom]

On 6/12/2020 at 1:42 PM, SiC said:

I have vague recollections that bottom end can go a bit flat if the O2 sensor is knackered. Once you get above around 3k, it runs open loop hot or cold. Disconnecting the sensor will make it run open-loop all the time and may appear to fix the issue. This is possibly old enough to not need worry about a working Catalyst for MOT. Mine on K-reg was right at the edge for needing one. Will burn more fuel without it connected though. 

I've done quite a bit of googling and it looks like you're right. I'm going to unplug it when I get in from work and take it for a blast. It only hesitates when warm, never when cold or warming up.

Do you have a spare one @gm?

I'v ordered one of these too. Should be handy to keep in the glove box.

https://www.ebay.co.uk/itm/Diagnostic-connector-fault-code-reader-LED-Mazda-MX-5-mk1-mk2-Eunos-MX5/400429915759?fits=Model%3AMX-5|Plat_Gen%3ANA&hash=item5d3b7b9e6f:g:bb0AAMXQTghROKWS

[gm]

1 hour ago, paulplom said:

Do you have a spare one @gm?

Not really, there is one in the manifold on the donor engine but they tend to get destroyed when removed, better to buy a new one. There are two types, yours will likely be a single wire type, connector is behind the coil pack. 

[paulplom]

New tool day.

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[paulplom]

Wasn't bad value. £80 from JTF.

I still rage about my all my gear being stolen everytime I think about it.

30 years worth of car tools. All top gear as well. Bastards.

This stuff is just hilka bit seems pretty sturdy. It'll do for diy occasional use, I suppose.

 

 

 

 

[Tickman]

That looks a decent six sided socket set with all the sizes, non of this 16mm missing nonsense like some.

What is jtf?

[paulplom]

That looks a decent six sided socket set with all the sizes, non of this 16mm missing nonsense like some.

What is jtf?

JTF is a national cash and carry. They sell everything including a fair bit motoring stuff, oil etc.

Anyone can join.

 

 

 

 

 

[paulplom]

The kids are at my mothers, the sun is out and I have a full day to myself. Mazda fettling is a go.

This looks to be the wire from the o2 sensor. I'll disconnect it and take it for a run to see if the flat spot vanishes. Other jobs are, remove passenger doorcard and fix this bunched up window rubber. I'm going to replace the rotten drivers door with one I bought from[mention=4462]gm[/mention]

 

 

 

 

 

[paulplom]

Unplugging the o2 sensor has transformed it! Completely different to drive.
Great news and a relatively cheap fix. I've ordered one from ebay.
Will leaving it unplugged till it gets here, cause any problems?

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[paulplom]

Nice suprise on removing the door card. I thought the stereo sounded good.

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[paulplom]

That was quick delivery from ebay. I only ordered my 'code reader' yesterday.


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[paulplom]

Back together. New cubby hole, cup holders and door rubber fixed.


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[paulplom]

I've just got in from a 110 mile hoon around Northumberland in 20° plus heat. It's proved it's reliability anyway. Two things I did discover though were the light's don't pop up anymore and the electric windows have stopped working. I'm a tit and in my haste to put it all back together earlier to go for a blast, I forgot the multi plug for the hazards/poppy up light switch and the connector for the windows.
I've just had to strip it again to connect them. Doh!

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[Shirley Knott]

On 6/16/2020 at 1:45 PM, paulplom said:

I've managed very carefully. I've used a magnaclean magnet to extract them. The tips are very oily and two of them dripped oil as if it's running rich. Other than a blocked air filter, what could cause that? Maf or o2 sensor maybe?

I don't think these have been changed for years.

 

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Oily plugs on these is almost always indicative of a leaking can cover gasket IME- Very common and can result in pronounced missfiring. Footnote: Only use genuine Mazda gaskets here unless you fancy doing it again in short order.

[gm]

2 hours ago, paulplom said:

in my haste to put it all back together earlier to go for a blast, I forgot the multi plug for the hazards/poppy up light switch and the connector for the windows.
I've just had to strip it again to connect them. Doh!

I think we've all done that at one time or another  glad to hear it's running better now 

[paulplom]

Oily plugs on these is almost always indicative of a leaking can cover gasket IME- Very common and can result in pronounced missfiring. Footnote: Only use genuine Mazda gaskets here unless you fancy doing it again in short order.

I did notice when I removed the connector for the o2 sensor the rear of the engine was very oily. It must be what the mot tester was on about. Another one for the to do list.
I'm sunburned to feck after todays drive. Sun screen next time.

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[gm]

You'll be needing one of these little fellows then

https://www.mx5parts.co.uk/sensor-ring-mk1-p-243.html

 

 

[Shirley Knott]

2 hours ago, paulplom said:

I did notice when I removed the connector for the o2 sensor the rear of the engine was very oily. It must be what the mot tester was on about. Another one for the to do list.
I'm sunburned to feck after todays drive. Sun screen next time.

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^If it's down the back of things then that's almost certainly the CAS o-ring (The part the learned chap above has linked) Feel the wiring that comes from the back of the cam angle sensor, if it's wet with oil then that's definitely what that's all about. 

[paulplom]

More stuff bought. This car is turning into a massive money pit.

 

 

 

 

 

 

[Robson3022]

33 minutes ago, paulplom said:

More stuff bought. This car is turning into a massive money pit.

 

 

 

 

 

 

Doing well @paulplom I can’t wait to buy it to be honest!!! 

[paulplom]

You'll have to wait a bit longer. I need to get the rear arches sorted first.

[Robson3022]

12 minutes ago, paulplom said:

You'll have to wait a bit longer. I need to get the rear arches sorted first.

Yeah I’m a mere apprentice when it comes to paint work. You’re the expert. Make sure you service it first too please

[motorpunk]

Wow! You’re really lavishing the old thing!

[xtriple]

If it is the CAS seal, get it changed sharpish as it leaks onto a coolant pipe for the heater and rots it causing leaks. BIG leaks...

[paulplom]

I'll fit it as soon as it arrives.


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[paulplom]

Yeah I’m a mere apprentice when it comes to paint work. You’re the expert. Make sure you service it first too please

I'm gonna get it done properly along with the drivers door.

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[jon.k]

34 minutes ago, xtriple said:

If it is the CAS seal, get it changed sharpish as it leaks onto a coolant pipe for the heater and rots it causing leaks. BIG leaks...

I reckon it took me about 45 minutes to get the sensor back in place with the new seal, but what a feeling when it finally clicked in! I can remember it vividly about ten years later.

[gm]

Before you remove the cam angle sensor, mark a line or notch across the join so when you refit it, your timing will be correct.

try not to move the spindle as it only goes back in one way - that bar is slightly off centre so it won’t fit 180o out

[paulplom]

Oof. This looks technical. What are you doing next weekend@gm ?

[gm]

Easy enough but if you want to bring it through we can check / adjust the timing at the same time. If your heater pipes are in a bad way, you can have the ones off the donor mx5, they are no use to me anymore  

[SiC]

On 6/20/2020 at 10:11 AM, paulplom said:

Will leaving it unplugged till it gets here, cause any problems?

Increased fuel consumption because it's running open loop and if it's got a cat, can bugger it up running rich. However I think this age doesn't have one and certainly I don't think needs one for an MOT. Also would struggle to pass an MOT without it connected.