Tried to start the Z again and did fire up but not on all cylinders. Took the reading from the TPS 0.5v low to only 3.6v high, how important are those extra .4 volts to make it to 4? It will start every time now but seriously lumpy.

 

Next step to do the ecu diag?? haven't done one before but sounds straight forward.

James,

 

Had a similar prob and had to turn it as far as it would go and still only getting 3.9 V and mine seems to be running ok , I would be interested to hear what could cause the drop of 0.5ish volts even on full clockwise adgustment

It could be that the TPS unit itself is damaged/failing - it's only a potentiometer and the carbon tracks tend to wear out (just like a noisy/erractic volume control on an old amplifier). I hear that replacements are pretty cheap in terms of Z parts !

James - lumpy as in hunting?

 

Might be worth slackening the throttle cable that you adjusted back off a little, from memory you do want a tiny bit of slack in there, then readjusting the TPS - you shouldn't need it on full clockwise adjustment to make it read correctly.

 

Other than that - definitely do an ECU diagnostic, it's a piece of cake, really is (aside from being a bit of a grovel to get to the ECU or consult connector).

 

Check any connectors you might have dislodged - especially the TPS one, and all the injector connectors & coilpack connectors, as you must have had the centre throttle cover plate off..

 

HTH

What a wind-up !!

 

No, not hunting, revs are even but just not on all 6 cyl. I have slackened off cable already. Will do diag next.

 

On one of the starts just then I noticed the "POWER" light on dash flashed about half a dozen times !!??? hasn't done it again.

 

Sorry to keep on but just winding me up as was running perfect before! and I just can't see the connection between missing a cyl and the TPS?

 

Thanks...

Cars have a habit of doing this!..

 

The power light flashing is the auto box fault warning light - if you pull the auto error codes you'll find an (old) stored code.

 

If it flashes every time, it's failing the diag every time - but it's not, so it was probably just a random failure..

 

Hmm... If all else fails - hit it with a big hammer!

 

Kidding..

 

ECU diag, and try wiggling things like the PTU connector, coil pack connectors - those are common 'missing cylinder' problems..

I have hit my car with a big hammer................

TPS fault will show on an autobox diag, sounds like this might be the problem with the autbox diag. It really is a doddle to do the autobox diag, instructions are on twinturbo.net.

I thought TPS would also show on an ECU diag. Code 44 ???

im not saying it doesnt ;)

oh sorry mate, I misunderstood :D ;)

ok, its just he hasnt got to fetch the floor apart to do an autobox diag so I thought I would make his life that little bit easier because im such a nice person :p ;)

Originally posted by Clarkey

ok, its just he hasnt got to fetch the floor apart to do an autobox diag so I thought I would make his life that little bit easier because im such a nice person :p ;)

 

You can do an engine diag without getting to the ecu fwiw.

theres 2 pins to short out on the diag link in the drivers footwell. read out on the engine warning lamp.

Hi,

 

If you are conserned about the TPS you can actaully disconnect it(the connector that has the throttle %) and the engine will default to base idle. YOu can do this while the engine is running, it takes 5-10 seconds to settle down... sometimes more.

 

Sorry can't remember my default voltage, beacuse mines also out a little. 0.4volts on the % Throttle will make the idle sit in the wrong place.

 

"but not on all cylinders"... it it's really not firing on all cylinders it's not the TPS. Check all the coil pack connectors... push them down to start with.

 

Jez.

From what I can make out, the TPS actual voltage returned isn't important. What's important is that it increases at the correct rate up to the max... The ecu must calibrate itself against the TPS after a reset hence so long as your voltage starts low and builds steadily to high then the throttle will read 0% - 100%... the ECU makes a compensation.

 

Just my 1/8th of a p

 

Cheers!

 

RobH

Thanks for that. So will divert my attention away from the TPS. Bloody hell -didn't touch anything else! but will go round the usual points in detail, I'm thinking PTU connections (cos got new PTU 2nd edition) or one of the coils. I must have disturbed something without realising. Will also run ECU diag.

 

Cheers.

Coils sounds good to me...

 

Just pull em off in turn to find the dodgy one...you might want to check your plugs while you're at it - might be something as base as that...

 

Cheers!

 

RobH

ok so to work out a misfire going from simple to hard do the following

 

remove each coilpack connector in turn (they will probably break but dont worry about it ;))

 

you will get to one where you pull it and the revs dont drop, this is where you need to concentrate. Clean up the coilpack connector (easy), clean up the injector connector (somewhat harder :p). If that doesnt work then fetch the PTU out and clean up the conectors on that, if that fails then try changing the plug, if that still doesnt work then you might have a wiring problem which will be a nightmare ;)

 

I can't see how a TPS couldcause a misfire, and have you reset the ECU? You never know, it might just work :p