ewan

Hi my st 170 wont rev past 5000 rpm it just stutters like its hitting a rev limiter and pops and backfires i have put a de cat on it no cure, changed plugs, oil,air filter, oil filter, fuel filter, no cure, now i am totally baffled! any help would be mutch apprieceated!, Thanks in advance

tabetha

Is your rev counter accurate ?, ie is it really revving to what it should but the tacho is lying ?
tabetha

Sp3no

iTrader: (1)

Check your inlet manifold runner control is working and not stuck in one position, if its still working then try a new coil and then fuel pump. Are you getting an EML

ewan

Hi guys thanks for the replies, Yeah my rev counter is defo working because the car ran fine for a few days then started doin it again making me think its some sensor. And when the car is properley warmed up sometimes it wont even rev past 3000 rpm. Really annoying!. And the car also feels like its lacking power before it even starts juddering and poping

COLEYST200

iTrader: (3)

Coil pack trust me it common problem get one from a tat yard Ł10 and do the leads at the same time

martysmartie

iTrader: (1)

A collapsed cat can cause these sort of problems, this can be confirmed by banging it, if it rattles then it needs replacing.

I would have thought if it's coil pack OP would have noticed it misfiring.

Martin

COLEYST200

iTrader: (3)

In his first post he said he has a DECAT on it so thats not the problem

white2lsr

iTrader: (1)

Fuel pump control module is my bet

ajc.78

I would put money on it being the fuel pump I have had 3 on my st170! symptoms were as you describe each time they went

al

martysmartie

iTrader: (1)

Sorry mate haha, missed that.

Martin

COLEYST200

iTrader: (3)

Mate dont say sorry im not right yet

ewan

Hi guys thanks again for the replies no i have no engine management light on. My first thaught was the fuel pump but when it ran good for a few days that made me think it was a sensor. But when i go fast around a roundabout or corner it dies and judders untill i lift off the throttle. Theres a few things i can think of but i am not wanting to throw money at it hoping to cure it.

ewan

Hi i checked the inlet manifold runner control today the cable is pulled when started like it should. But i noticed that when the engine is turned off you hear air de compressing from some where a hissing for about 5 seconds is that normal?. Also when you turn your ignition on should the engine management light light up for a few seconds then go out again?. Because mines doesent. Any help would be mutch apprieceated. Thanks again

Bailes1992

Yeh completley normal, just where the engbines probably int he middle of compressing air and it's escaping somewhere, nothing to be worried about

ewan

Ok thanks right diving to and from work today and the car wouldent rev past 3000 rpm it would reatch 3000 rpm then judder vilantley and eventually when i put my foot to the floor the car got all choked up and would die. But if i accelerated a little gradully the revs would go higher then whilst stationery it wouldent rev past 4000 rpm never used to do that then it died and when i tried to start it the engine would just shake and judder sitting below 1000 rpm and would not rev when i accelerated it would die. Please help me Thanks

ajc.78

good evidence it is the fuel pump. trust me I had the same problems because the fuel pump problems do not put on the eml so it is hard to diagnose but I had all the syptoms you have when my pump went. driving fast roud a roundabout is a good way of testing if it is the fuel pump and I would still put money on that being your problem.

al

ewan

Hi all pluged in a code reader today and im geting the fault code p0141 for o2 lambda sensor bank 1 sensor 2 whitch one is this? the pre cat sensor or the post cat sensor? the first or second?. Also do you think that a faulty lambda would create this problem? Thanks in advance

martysmartie

iTrader: (1)

It could well do yes, I coulden't however tell you which one it would be, they can also be extremely tight due to the heat!

Martin

oldford

P0141 O2 Sensor Heater Circuit Bank 1 Sensor 2
Sensor 2 is the post cat sensor. If you have more than one post cat sensor, then this is the one in the exhaust from cylinder 1.

Check wiring if 12 volt is present for the heater.
Post cat sensor only measures if the cat is still working. It has nothing to do with the engine splutter.

ewan

Ok mate thanks do you think i could be geting this code because i have a de cat?. And are you saying you dont think a new lambda sensor will cure it? cheers Ewan