gte shunting

[dathers]

When im coasting up to the traffic lights in gear in my nova gte(E16SE),it somtimes starts shunting/jerking,if you turn the ignition off it stops so it aint a worn gearbox,it doesnt do it all the time but quite regular.
Any ideas?
Dave

[Aragorn]

maybe silly suggestion

but if yout trying to coast down below idle speed in gear it will jump and shudder cos its trying to stall

are we talkin about 2-3000rpm coasting or 900-1000rpm coasting

ie what gear and what speed

[dathers]

come on,give me credit,ive been driving 10 years mate.
between 1000 and 3000rpm it will shut.
Ive just been readig TIS and it mentions about setting the coasting air valve with a vac gauge to 675mb instead of 650mb,so ill try and borrow a vac gauge from somewhere and set it right.
Dave

[Dicko]

if u had an egr vavle i would say it was that :P

but coasting air valve is gonna be ya problem, unless u have an airleak after your air meter. other possibility is throtle position sensor, i think u can ajust these by 1 or 2 degrees cant remember now, but these usualy cuase this problem at anything except idle!

[ade]

nah - its yer timing. My 1400sr does this - doesnt matter what gear I'm in or what speed I'm doing - except mine actually cuts out. I can do 60mph down hill in 5th and if I lift my foot of the accelerator it judders, slow down and shift to 4th at about 40-50 and it astill judders. In lower gears unless I pull out my choke it stalls.

It idles eratically too reving and dropping and spluttering. Its not happy...

:cry:

I'm getting my local vauxhall garage to crypton tune it later today so I'll let you know what happens - this should sort it.

Got my thermostat and temp sensor changed yesterday cos they were reading 3/4 rather than 1/4.

When was it last tuned/serviced?

Ade

[novaboy_southwest]

how much do vaux charge for crypton tuning

[ade]

TONS!

Just dropped me car off - getting it rushed through (theyre v busy) theyre going to clean carb, checkl emissions, set up carb and set timing

?60! (mainly labour for 1 hour!)

:(

Have no choice though - rang a few other places - most about ?10-?15 cheaper but cant book me in till next week. Mine needs doing NOW!
:x

[Dicko]

this is an injection egine ade AND if the timing was that far out it wud b seriously low on power!!

[novaboy_southwest]

i take it most garages crypton tune and another thing people tell me to stay away from places like kwik fit and other chain garages is this wise i got one experiance from kwick fit went in to have new pads ( can do it my self) but in a hurry and could not be arsed to do it and they said sliders have siezed which i knew and the servo was not working as it was not building up pressure so i got in car and puped brake pedel and it was building up pressure so i said put the new pads on as they were in middle of doing it paid up and left in the middle of getting new and big brakes at mo and will do it my self they mite end up saying (kwick fit) summit else is wrong when i know it aint

[dathers]

Ive just give it a service,also had most of the injection sytem off and give everything a really good clean out,and there is no split pipes or leaks anywhere.
New plugs,leads,dizzy cap,rotor arm and coil.
The timing is bob on and the performance is not suffering at all,it drives really smooth,like it should do for a 74K miler,it just judders sometimes on coast down.
Ive arranged to borrow a vacuum gauge tomorrow to test and setup the coasting air valve,TIS says set it to operate at 645mbar/9.35psi or a higher value if it still jerks,TIS calls it lean bucking.
Ive also disconected the vacuum pipe that operates the EGR valve and blocked the pipe off,this helped slightly.
And routed the cam cover breather into a vented bottle instead of into the throttle body and blocked the hole in the TB off,this gave a much smoother idle.
Ill let ya know if setting the coasting air valve solves it.
Im also gonna set the throttle position switch and the throttle stop as per instructions in TIS.
Bloody handy is TIS.
Dave