Wierd Hesitating

[andy3i]

hi

i have a st185 that has just started hesitating (sort of juddereing) when i accelerate fast, but this is only doing it whilst the car is moving if it is stood still it revs fine, foot to the floor an revs without any problem,

iv noticed that if im carefull an dont rev too hard whilst driving then it runs fine an boost perfect,

iv replaced the plugs for some Iridium 1s an also the fuel filter an gave the air filter a clean(k&n)

iv checked for error codes but still nothing,

i would live with it but it has got to the stage where im worried it may happen if i go to overtake someone an the last thing i want is this happening whilst in the middle of the road,

has anyone got any ideas ie

maybe a sensor an if so which 1?

[andy3i]

iv thought of another way of maybe explaining it

its like when i push hard on the throttle whislt driving the boost gets held back but if i gradually build up the power its fine

but as i said when its stood still i dont have this problem it boost straight away however i push the throttle

[andy3i]

ok well iv been going over this in my head whislt watching britains got talent an i was wondering if it is the throttle postitions sensor?

does anyone know how to test this ?

please help i can see myself not sleeping tonight thinkin about this lol

[GT4 BOOSTER]

most throttle sensors are set bang in the middle on the adjusting screws .

[andy3i]

ok just been out an checked that an yep bang on but would it throw a code up if it was starting to play up a little? or do codes only get thrown up when sumet has totaly gone?

[Calisto]

It sounds a bit like my MR2 before I got her sorted.

Cleaned the throttle body, new sparks, new headgasket, compression test done, new lambda sensor.... as I had an error code. After having done all that, she runs like a dream.

[andy3i]

head gasket is fine done head gasket test an had new sparks etc, not cleaned the throttle body so that may well be a job for tomoro then,also been thinking that maybe it could be a bit of the cat broken off an moving under hard acceleration but doesnt move when driven gentle

[GT4 BOOSTER]

could be the butterfly inside throttle body is a bit late opening , give it a good clean.

check the throttle cable isnt slack too .

[andy3i]

ok i`ll give that a go an see how it goes

[andy3i]

ok well just been out an whipped the intercooler off an tested the tps which was easy to do i got the specs etc off this site

http://www.gtfours.co.uk/default.htm?http%..._to/fcd/fcd.htm

mine had no 0.5 or 0.7 readings at all so quick adjustments an fired it up sounded alot better which i thought was wierd an reved perfect an also the rev counter is working spot on now too

not had chance to take it for a drive yet as my m8 has come round but i`ll let you know if its working or not

[mad1969]

sounds like you got the same problem has me ?? ill be checking all the above tomorrow and checking back to see if you sorted the problem

good look

[andy3i]

rite took the car for a quick drive round an after few mins it boosted fine foot to the floor an pulled as it should but now it seems to struggle at lower speeds if im going slower then its a bit jerky an at 1 stage i needed to rev it to stop it stalling but after i did that it seemed better so now the intercooler is coming off again to clean all throttle body

but im looking at 2 options either leave intercooler un loosen the clip throttle boby side an spray carb cleaner through the gap or take it all off an clean it with petrol so if possible could you let me know which option you normally do?

cheers

andy

[andy3i]

:D :D well all sorted now thanks to this fella

only kidding but he was a great help stopped me from kicking the crap out of it lol

well to get it running well again i have

Iridium plugs

spark plug leads

fuel filter

adjusted the tps

cleaned rotor arm an cap

sprayed a whole tin of carb cleaner through it(loads of smoke but can see your face in it now lol)

an its running just how it was when i got it so im sorry to say that im not sure which it could be to be honest

but it didnt run any better with plugs an leads an clean rotor an cap an fuel filter but least they are done now :)

so im putting it down to the tps an carb cleaner both very cheap an easy ways to try 1st

carb cleaner from pound shop (obviously £1)

tps adjustment about 5 mins but helps if you have a third hand to tighten it in place whilst you hold it in the perfect position with your multimeter giving you the reading