TPS Adjustment Procedure:

[kenholland]

Thought I'd post this for posterity. It originally came from RS-Productions and is a damn good How-To:







Cheers,
Ken

[Russellg]

Cheers Ken, Looks good
any chance of this being made a sticky?
Wait.. nope don't bother. We'll end up with too many sticies in the main forum if we start that.
I know I'll never be able to find it again when I need it though

possibly one to be added to the DB Jase?

Russ

[kenholland]

I've added the link in the Handy Info thread - which is already a sticky.

Ken

[Mark 626GT]

A highly useful post

Looses me though on the tool required section; 1/4" metrec socket set ?!?

[Mark 626GT]

BTW is it the same procedure if you have no IAC?

[Chastiser]

do i need to print this off for the swap day or is it known by heart ken?


Mike

[Einstein]

Yes Mark, it is for adjusting the TPS and throttle stop..

I need to point out that the method described in the official workshop manual is different..
There is no mention of adjusting the throttle stop, as this is factory set, and should not be touched.. however, the basic idea is that it is just there to stop the throttle from jamming shut by the spring, if the pedal is released suddenly.. so the screw should just touch the throttle body, and maybe just a smidgen more to allow for any wear..
The throttle position sensor is set with TEN & FEN jumped using feeler guages and a multimeter.... although the above method of doing the TPS can be checked afterwards with feeler guages, and using the fan instead of the meter.. 0.15mm (no fan) 0.50mm (fan on)
The idle speed should only be adjusted with the FEN & TEN jumped, and should be set to 650 +/- 50 rpm

And although the manual doesn't say it... resetting the ECU is a good idea.. as it will re-learn the settings.

John

[kenholland]

No socket set needed Mark, just X-head screwdriver for the TPS and idle air screw, one allen key and a 8mm spanner for the throttle position screw, a 10mm spanner for the battery terminal and .5mm and .15mm feelers. Not forgetting the good old paperclip for jumping the diag terminals of course.

IAC? Don't know.

Mike - off by heart. I had enough practice adjusting it for the MoT day after day.

Ken

[kenholland]

Originally Posted by Einstein

There is no mention of adjusting the throttle stop, as this is factory set, and should not be touched..
John

However, if you've removed the TB or swapped it for a rebored one, your stuffed if you don't adjust it...

Usual Mazda - only giving us half the needed info.

The idle speed should only be adjusted with the FEN & TEN jumped, and should be set to 650 +/- 50 rpm

I disagree here John. If the idle is set to 650+/- with the jumper in place it will be far too high when it's removed. As I found out to my cost.

[Mark 626GT]

I haven't got a fing clue where mine will be then as it has a rebored TB and no IAC and uses the screw more or less for idle (i.e keeping the butterfly open a little).

I thought my TPS might be going a little as it doesn't seem to register very slight accelerator pressure then suddenly does and sometimes revs to 1,500 rpm before dropping to 1k before doing the same again. A quick blip of the throttle usually settles that and returns the revs to approx 1,250 rpm.

What do you think, resetting or new tps needed?

[Einstein]

Then something else isn't right...

The Idle should be 650 with the jumper in, so that the ignition timing can be checked/adjusted... makes sense to me.. and it states to check this first anyway..

As you probably know, when the fan kicks in, the idle speed goes up... and the TPS idle switch is obviously connected somewhere... so this could be one reason why your idle went up.. (just guessing here)

All the settings are base settings anyway... once the jumper is out, the ECU will take control over everything..

I agree about swapping TB's etc, but the manual doesn't take any of that into account

As Mazda made it, they should know how to adjust it..

I remember a thread a while ago on this subject... and don't really want to go down there again..



John

[Messiah]

i thought its not good to start ur car with the jumper in? cuz it would fry your ecu

[Einstein]

Nope... it's the correct method, as specified in the official Mazda workshop manual..

John

[Mr.Curious]

I dont know if it is link. But i did set this TBS and air idle and did the jumper correct. Then started perfect and even idled perfect. When i took it for a drive and back, when i then wanted to start it nothing hapens. The ignition lights come on but no engin turning.If you push start the car it starts.

Do you think my starter went. Or did I do something wrong?

Another thing...I had a automatic box in and replaced it with a 5 speed manual box because the reverse on the auto box did not work anymore.And when the car got in operating temp. she did not wanto rev.The problem is still there with this new gearbox.


When the car is cold she revs perfect.But asoon as its operating temperature she dont wanto rev.You haveto play with the petrol pedal to make it atleast driveable.When you depress the petrol fully the revs drop and sometime she backfires a bit.

I did replace my supressor cords and fuel pump(not original but universal pump) since then.Did check the airflow meter and its fine.After that i took it for a diagnosis check and it said that my TPS and Thermo sensor is faulty.Did then replace the thermo sensor with a second hand one and the guy that did my diagnosis borrowed me a second hand TPS.And after i set it acording to this thread the problem is still there.

Please could you help me as I'm close to setting the car on fire.

Ps.Im from south Africa and parts and knowledged tuners are scares.

[Einstein]

Sounds like you could have an air leak... check for loose or disconnected pipes, and for any cracks in the rubber elbow in the intake between the TB and VAF


John