Mk 1 Fuelling

[minipickup]

Hi, my car is a 1997 mk1 1600. It was prep'd for its MOT and failed on emmisions. I had noticed it was running rich (sooty plugs) and of course there is no magic adjustment available, I'm reliant on the ECU God!!! Fitting another new cat has been successful but I would like to fix the rich running/emmision problem. I can only imagine that it will be a failed sensor somewhere in the system. All help gratefully received :

[drumtochty]

Do a flash code check to see if you get a code 9, in that case, replace the temperature sensor.

Check the air filter is clean.

New spark plugs and after that if needed plug leads and clean the top connectors in the coil packs.

Replace the O2 sensor say £60.

Replace the Mass Air Flow Sensor around £500 new, so worth looking for a secondhand one.

Getting to be playing parts darts.

Others may have other ideas.

[Mazda Mender]

There are a number of sensor that talk to each other to sort the mix and running...is she standard or aftermarket goodies in the bay.
M-m

[minipickup]

Hi thanks for replies. It is a standard mk2 1600 (donor engine) onto which i have a stainless 4 branch manifold and k/n air filter setup. Obviously a few mods were needed to match the engine to the mk1 wiring. It performs really well but I was a bit concerned about fuel consumption.

[Mazda Mender]

So which ECU are you using?
M-m

[minipickup]

The ECU came with the MK 1 car, nothing has been altered there.

[Mazda Mender]

So you are running it with the MK1 CAS ,intake and AFM etc.
And done away with the cam,crank ,inlet and done away with the MK2 FM.
M-m

[minipickup]

OK I'm trying to get my head around that lot. I can recall having to relocate a sensor (probably cam angle) onto the rear of the inlet cam to mate to the available plug The intake box (air flow meter) is standard apart from K/N filter. The throttle is standard, the exhaust is fitted with a 4 wire lamda sensor. Hope that helps ?

[Mazda Mender]

Seems a lot of hard work when you could of bolted all the MK1 stuff to it and job done , but it sounds like the chopping and joining is the place to start .
M-m

[minipickup]

Hi, I havent done any chopping or joining, all the mods were mechanical to bring the donor engine (mk 2) to mk1 spec so the loom would plug straight in.The ECU is B6 HBA if that helps ?

[drumtochty]

If I remember and I may be wrong, the mid 1993 1.6 cars used one type of fuel injection, the post 1994 ish European 1.6 cars used a different type of fuel injection system. The Mk2 1.6 cars went back to a similar spec to the mid 1993 cars.

Therefore the 1997 car you have is controlled by an ecu that is set up to run a lower compression, softer camshaft engine that produced some 20bhp less than the earlier cars.

The engine you are now running will never get the precise amount of fuel it requires as the Mk2 1.6 engine was again updated over the mid 1993 engines.

Also that MK2 engine has more precise misfire control reporting system that has been thrown to the four winds as the crank sensor is I assume no longer plumbed into the old type ECU.

I believe that the present setup may well give a shorter life to the Catalyst as I assume there will be an amount of unburnt fuel sent to the cat.

[Mazda Mender]

What Eddie said...., So what injector's did you use and what's your timing set at.
MK1 1.6...1989-1993 115BHP,
MK1 1.6 Auto to 1993 90BHP,
MK1 1.6 1995-1997 90BHP,
MK2/2.5 1.6 1998-2005 110BHP
Why is the lamba sensor a 4 pin? ,
Because it's now a case of the standard 1.6 MK1 is not standard, it's not a straight diagnosis issue because of how the two engines are set up different,and we need to get our heads around what as been done and what as not.
So what's still all the original bits carried over and what's been swapped out/changed.
M-m

[minipickup]

Thanks again Guys, All the work to get the engine installed and working was done over 2 years ago. I,m trying to remenber exactly what I did to get it working, all the advice\parts came from Autolink and worked fine. Mk1 inlet cam for sensor, modified thermostat housing for sensor, I think I fitted a throttle pos sensor as well. 1 other thing I haven't mentioned, the mk1 car body came with Mazdaspeed badges and body kit, sadly non of the other stuff, were the tuning kits so different?

[drumtochty]

Not making too much sense here.

The MK1 had the cam angle sensor on the back of the cam, that inlet cam had two raised areas, one to open the the fuel injector and to signal a spark to the the plugs, the other to change what pair of cylinders got a spark and to choose which fuel injector is opened next.

The MK 2 only used the cam sensor for the signal to open that specific fuel injectors and that raised surface is on the front of the camshaft. Therefore you must have changed the cam cover for a MK1 1.6 cover and bought a Mk1 1 cam sensor.

You would require a new MK1 1.6 thermostat cover with a sensor hole and matching front sensor but you should have had the sensor from the old engine. You should have had a MK1 1.6 rear temperature sensor from the old engine.

The inlet camshaft will now match your ecu but the exhaust cam may be different.

Unless the MK2 exhaust cam shaft is a different profile you may get a way with what you have so why are you seeing sooty plugs i.e. a rich mixture, if you are using the late MK1 mass flow meter?

That only now points to two issues.

1) what injectors you are using are they from the MK2 or the Mk1.

The other issue will be the Mk2 exhaust cam which I have mentioned above, that could have a very different cam profile, maybe!!!!!!!!!!!!!!!!.

I'm going out to cut the grass now!

You appear to have the correct ECU for that model year with which has a matching ECU and the keys have a transponder in them.

Later, I will check if the two cars have different fuel injectors and different exhaust camshafts.

[minipickup]

Hi, Cut mine yesterday. Yes to all you mentioned, The exhaust cam was not changed (remains mk2) I do remember having a problem initially with high tick over which we solved by fitting the air valve correctly. The injectors have never been touched. I did swop the cam cover for one provided with the mk1 which appeared identical and was powder coated red to suit the car.