v6 not running well.checking maf rotor arm & anything else?

[hogggman]

hi all,
my 2.5 v6 is running a bit rough of late,especially when cold,and never really runs perfectly smoothly.when you listen to it running there`s a definite miss or blip every 5-6 seconds or so,and the revs will dip briefly.i have fitted new plugs recently but still have this minor issue.i removed the lambda sensor and cleaned it,which may have helped slightly.one thing to note is that the heat sensor on the cat is knacked,broken in half,and doing bugger all.the`heat`light comes on and then goes off when you start the engine.
what can i try?where do i find the maf?how difficult is it to remove the distributor cap and clean inside?are there any other sensors i can check/clean?
thanks in advance
jamie

[apole]

Hi there,

Disty cap is fairly easy to remove, there are 3 8mm bolts holding the cap on, just be careful when removing/refitting that you don't drop anything as it's a difficult angle to work on.

You will have to remove a few leads to see into the cap properly, label them first as you don't want to get them mixed up.

You may well find the points inside the cap are blackened with carbon, clean them up as best you can. The rotor arm will look like the surface of the moon, not saying it's not worn but I can't see there is much you can do to clean it up. New ones can be purchased from Japanese auto solutions, Mazda can also supply and were cheaper but had a long delivery time when I checked.

Changing these made a good difference to how mine ran, but try cleaning first.

MAF sensor, that is in the air intake under the drivers seat. You need first to remove the electrical multiplug then the section of pipe. Use Forte MAF cleaning fluid (£5 on ebay) and whatever you do don't poke anything down there. BTW the MAF sensor is a tiny hair like wire in the middle of the pipe, from memory there is a small pipe within the main pipe, inside that pipe is the MAF wire. This made mine tick over alot better.



Other than that, check all the HT leads are in good condition, including the king lead from the coil pack to the disty. Also take a look at the spark plug holes in the engine both sides, you don't have any stray oil down any?

Not sure on your heat sensor as mine doesn't have this, check with Cheffy as he had problems with his.

Good luck.

Andy

[cheffy34]

Had the same prob on mine jamie after changing dizzy and rotor arm had me baffled, turned out to be a loose coil lead just needed to splay the end out at the coil connection slightly to make it tighter fit, check all your leads are tight on and fully home sounds like you been in that area of late with plugs listen for the def click when pushing the plu on and pay special attention to dizzy cap end and coil push in plugs, sounds more of a lead prob to me tho, although i beleive that a small itermitent blip on idle can be indicative to the coil giving in, I did my maf with carb cleaner and as for the heat sensor as far as i can find out don't waste your money on it leave it , it is a jap optional extra tells you when your cat pipe has overheated usualy due to excess fuel gathering in the cat pipe would be a sign of lambda over time, or another reason for rich mixture or a missfire in my case it was excess water in cap caused a 3 cylinder missfire it dumped the fuel down the exhaust and cooked the sensor the chances are it prob cooked my cat pipe aswell but i will wait for the mot , i took the sensor off a long time ago, just cable tie it out the way if it broke, if you disconnect it at the plug you get no dash light at all the mx5 crew all disconnect them



Dar


Dar

[dandywarhol]

Have you considered that the fact your cams/followers are so worn that the engine management system is having a hard time understanding what the hell is going on in the engine and is causing the intermittant blip?

[cheffy34]

Phewwwwwwweeeeeeeee glad mine was an easy fix although it did put a hole in the side of the connector