About this stepper motor..

[Barreti]

I noticed at the Growl that my stepper motor wasn't tight up to the seal - I can get my fingernail in there are move the seal.
I believe it should be airtight though because I used PTFE tape on the threads - am I wrong?

The seal is new because the old one fell apart as I took the stepper off, so it must have previously been pinched tight.

The stepper is working because its dropping the revs in stages as it should, although it seems very slow before it drops the revs from 2k when I stop at junctions etc.
Often taking about 30 seconds or more so I sound like a damned boy racer revving the car

Does it matter the stepper is not fully tightened home - positioning wise?

I cleaned it by just sitting it in something - don't remember what now, could this be the cause of its sluggishness and it needs dismantling and cleaning a bit more thoroughly.

Thanks chaps.
Ian

[yellowgriff]

Carb cleaner is good to use on it (HALFORDS)... dont think that a mm is going to make a difference as long as it air tight...

[Barkychoc]

You probably can't tighten it right up due to the PTFE on the threads - I can't see it being a problem the PTFE makes the seal instead of the washer.

[spend]

Make sure the plunger seat (the motor winds it in/out) is fully retracted before fitting.. and the housing is not full of crap from previous bodgery..

[blitzracing]

If the motor is wound in or out a bit and as long as its all perfectly air tight, its not the really a problem as long as the shaft behind the cone is clean. Otherwise if the stepper body is wound in or out more, the postion the cone settles in to control the idle with be moved correspondingly on the shaft, so you may hit a tight spot if its dirty. If you want to make sure its retracting fully, disconnect the stepper with the engine running and hot. Let the engine cool, and then remove the stepper and reconnect it. Now get some one to cycle the ignition on / off (dont start) while you observe the stepper cone. It should wind back smoothly once as the ignition is turned OFF.

[Barreti]

Thanks for the tips guys. I'll pull it apart this weekend, see what I can find.

[FlipFlopGriff]

Barreti said:

Thanks for the tips guys. I'll pull it apart this weekend, see what I can find.

NO!!!!!!!!!!!!!!!!!
FFG

[Johno]

Barreti said:

Thanks for the tips guys. I'll pull it apart this weekend, see what I can find.

Cobwebs and polish dust

[Barreti]

Cheeky buggers

Watch out for the "where do I get a new stepper motor" thread next week !

[Johno]

Got my old one here if ya want it . . . Also take a look at SC Power's site as they do a restrictor which helps with the sticking at 2k rpm. Also have a look at the bleed screw by the butterfly which controls the amount of air the stepper has avaiable to it. Restricting the inlet volume will help to stop it holding the revs up.

[Hoover.]

[quote=Johno] SC Power's site as they do a restrictor which helps with the sticking at 2k rpm. quote]

ohhhh now I thought it was only my car that did this..... obviously not.... I'll be checking it out

[LordGrover]

Hoover. said:

Johno said:

SC Power's site as they do a restrictor which helps with the sticking at 2k rpm.

ohhhh now I thought it was only my car that did this..... obviously not.... I'll be checking it out

Mine does this, well 1,500 RPS anyway, but only after resetting the ECU. Within a couple of hundred miles it settles down again - the revs drop to c. 900 RPM within a few seconds of stopping now.

[blitzracing]

Johno said:

Got my old one here if ya want it . . . Also take a look at SC Power's site as they do a restrictor which helps with the sticking at 2k rpm. Also have a look at the bleed screw by the butterfly which controls the amount of air the stepper has avaiable to it. Restricting the inlet volume will help to stop it holding the revs up.

An high RPM might not just be a bad stepper, as the ECU has various tricks to prevent catalysts damage if something is wrong, and I think holding the RPM high is one of them. You really should never need a restrictor if all's well with the fueling and the stepper is OK.

[Barreti]

Hooray for Pre-Cats !!

[Johno]

blitzracing said:

Johno said:

Got my old one here if ya want it . . . Also take a look at SC Power's site as they do a restrictor which helps with the sticking at 2k rpm. Also have a look at the bleed screw by the butterfly which controls the amount of air the stepper has avaiable to it. Restricting the inlet volume will help to stop it holding the revs up.

An high RPM might not just be a bad stepper, as the ECU has various tricks to prevent catalysts damage if something is wrong, and I think holding the RPM high is one of them. You really should never need a restrictor if all's well with the fueling and the stepper is OK.

Completely agree BR. It's like cooling issues with TVR's, the answer isn't to buy an alloy rad, it's too work out why you've suddenly got a cooling problem.

[spend]

Barti had better start splicing into the wiring in his lambda sensors and checking the voltages then...


Might take Ian a while to get some bosses welded the manifolds and find some lambda sensors though

[Johno]

After the grief he had fitting the current manifolds I think suggesting he cut's holes in them to add something unneccessary may cause a blown fuse

[spend]

You didn't even mention that he had to add catalysts, so that the fault could be attributed to them

Now Barti's mastered cut'n'shut glassing the World is his oyster

[Johno]

I took it as read Spend hence 'unneccessary' comment . ..

[Barreti]

Ahem....
I'm still blinking here you know, keeping my on you lot

Not only can I 'glass, I can weld a bit now too. Never did I dream TVR ownership would be such fun

The world is my lobster, but I'll draw the line at adding Cat bits thanks