Stepper motor

[CHEF_GOLF]

Damn stepper motor again. What are your thoughts on the copy parts. Any good or just cheap crap. And what the price on a real deal one.

[zacherynuk]

I've seen compatibles on ebay for £10 - clevor trevor sells 'em at ~£80... I've heard mixed reviews on both to be honest.


Austec have just said they need to replace mine and a lambada sensor to try and get my MOT passed on emissions, so I'll have a full answer soon enough.

Need to go electronic really... one day soon.

[Harrytsg]

I bought one from eBay, but the cone lengths were different, and that was after searching trying to find the right one.
I ended up buying the correct one at the £80ish.

Both original and copy are fully retracted.

[zed4]

I bought mine from a local Land Rover independent specialist in Southampton. £90 I think it was.

[TVR Beaver]

Harrytsg said:

I bought one from eBay, but the cone lengths were different, and that was after searching trying to find the right one.
I ended up buying the correct one at the £80ish.

Both original and copy are fully retracted.

Did that matter?.. all it does is open a hole up to let air pass into the Plenum?.. if it opens out of the way 20mm or 10mm, does it make much odd's??? once it's moved more than the dia of the hole you wont get any more flow anyway

[MADMAX2]

DONT BUY THE COPIES...END OF..

I got mine from Racetech he has currently got them 50% off.. THEY ARE THE ORIGINAL OEM SPEC

here:
http://www.racetechdirect.co.uk/tvr-car-part-e0121...

[Harrytsg]

MADMAX2 said:

DONT BUY THE COPIES...END OF..

I got mine from Racetech he has currently got them 50% off.. THEY ARE THE ORIGINAL OEM SPEC

here:
http://www.racetechdirect.co.uk/tvr-car-part-e0121...

Not exactly a 'current' offer, just checked my invoice from them, I paid £69.99 + vat + £8 delivery in July this year for mine.

But it was the cheapest original spec I could find at the time.

[swisstoni]

You'd think there would be a way to rebuild the little barstards things by now.

[blitzracing]

You can strip the shaft out to clean it, but apart from carbon build up, the motor bearing in the back of the housing is steel and it corrodes so the movement becomes jerky, and you cant get at this without trashing the unit. The issue of the shaft length is more critical than you would think, as the ECU is programmed to expect a certain number of steps between fully open and fully closed to get a stable idle, and a longer shaft will alter this outside its correct range. Also the cheap unit I bought off Ebay also leaked air past the motor, so would never have worked.

[CHEF_GOLF]

Thanks gents. Origional part I think. It's not going to make a great deal of difference to my bill as I'm having the out riggers done now too

[TVRJAS]

Question please...

How and when do you know that a new one is needed?

Mine on start up when engine hot or cold revs high going to 3,100rpm for a bout 1-2 secs then drops to about 2,000 for a second or two then drops to a normal 1,000-1,100rpm.

I also noticed for the 1st time on Friday that when driving and doing a slow gear change the revs dropped to about the 1,000rpm (perfect) but when coming to a halt in traffic it would be revving higher at about 1,400-1,500 for 1-2 secs before dropping to about 1,000.

I have cleaned the stepper two times,the 1st time I defiantly noticed a difference. But switching off and starting again it was revving high again,the second time seemed to make no difference.

Are these symptoms of trying a new one?

Very grateful of some feedback please... kind regards Jas

[CHEF_GOLF]

Mine revved high when stopping but it never dropped to 1000. It's about 2000 rpm. Good for noise not so good for fuel but what tvr is

[TVRJAS]

CHEF_GOLF said:

Mine revved high when stopping but it never dropped to 1000. It's about 2000 rpm. Good for noise not so good for fuel but what tvr is

Whoa.... Just looked at your blog and i'm presuming there is an error at an Av of 8mpg

I have covered 3k miles in 4 months and mine and has always rested at about 1,100-1,000 but always done this high rev up thing on start up.

I find it a little embarrassing if anything especially when filling up at under cover petrol stations. Many times now i even take it out of gear and stand out of the car before starting to kind of say "look i ain't trying to get your attention"

I guess also it must me using more fuel,will only know when it's time to fill up again but I have an average of 22.3 so no complaints.

[pac1uk]

When I changed my Stepper motor I needed to reset the base idle. Now ticks over around 900 rpm.

The Stepper motors must vary slightly depending on supplier. Some better than others.

[blitzracing]

The idle control system is quite complex. It needs the following to work:

Correct base idle.
Correct Throttle pot reading. (ie closed)
Correct speed reading (ie 0 mph)
A good Stepper
No air leaks or misfires
Correct mixture. (This should be automatic if you are running the Lambda tune)

The Steve Heath ECUmate manual covers it in some depth from somewhere around page 40 if you want to get technical, so dont just blame the stepper.

http://ecumate.com/docs/Ecumate%20inst.pdf

[blitzracing]

Harrytsg said:

I bought one from eBay, but the cone lengths were different, and that was after searching trying to find the right one.
I ended up buying the correct one at the £80ish.

Both original and copy are fully retracted.

If anyone has a cheap one laying around that wont work that you can send me, Ill give cutting the shaft down a go, as I built a test setup for them so I can strip them apart easily.

[Harrytsg]

blitzracing said:

Harrytsg said:

I bought one from eBay, but the cone lengths were different, and that was after searching trying to find the right one.
I ended up buying the correct one at the £80ish.

Both original and copy are fully retracted.

If anyone has a cheap one laying around that wont work that you can send me, Ill give cutting the shaft down a go, as I built a test setup for them so I can strip them apart easily.

mark

I have the copy one lying around ( somewhere), Pm me your address and I will pop it in the post.

[blitzracing]

Ive now pulled the pattern one to bits along side the genuine unit. As already seen the shaft length is about 4mm different, so the cone cant be pulled back as far. The shaft is also of different construction, being hexagonal and without a keyway, so you can put the genuine shaft into the pattern unit to get the length correct. Luckily it would appear that you can cut the end off the screw thread to make the shafts the same overall length, and the two then appear to line up after modifying. As far as I can see from bench testing the two units now work identically, but it will need testing on a car, so Ill pop it back to Harrytsg. If you have RoverGauge or ECUmate the steppers are easy enough to strip apart and modify.

Heres the two side by side:





and the shafts:







After modification:



On the pattern units its also worth checking the circular seal where the connector joins the housing, as Ive seen these leak air into the motor, This one appears to be ok.

[Harrytsg]

To update this thread, Blitz kindly returned the eBay stepper with the reduced shaft length as above. I fitted it to the car and took it for a 10-15 min run, and it worked fine. I also took it out today for a couple of hours of roof off (but heated seats on) fun and again it performed exactly as it should.
No hot or cold idle issues, on slowing to standstill revs hold at 1100 rpm ish, then drop to 900rpm ish, as per normal.
So, I will keep this stepper in, the 'proper' one in the boot in case of emergencies and update when, or indeed, if it fails.
Thanks blitz for looking at and modifying this.

[hififreak]

Hi!

i am reading all Posts troughout this Topic having a small problem with idling

after having Problems with the V8 (idle too low) i decided to remove plenum (cleaning and sealing)...i have detected a very small leak (like dust on a very small area where plenum is mounted!

i thought it could not be wrong, cleaning stepper Motor...i found out, that stepper was broken, didn`t move and there was no noise after turning off engine (reset procedure)

so i bought a new one...from Rimmer Bros!
(there was no part number on the old part....but anyway..)

after mounting it i started engine...cold, revs up to 1300...after a few seconds it fell to about 1000
ok

but if engine is warm-> stopping at the lane, no gear, idle is too high (1300-1400)...goes down to 900 (that should be ok) after a few seconds!


i have read that position of the idle control valve has to be retuned (kind of reset)....but i don't have the ECU Mate and nobody here has that Thing....

what, if i take out the washer and take a thread sealing instead of to bring the part more into the opening of the plenum ?

seems, that ECU has to know ONCE which value at which idle...right ?

it is not the best way of doing it, but at the Moment the only thing....or is there any way to reset ICV without ECU Mate ?!