Dynamix

Hi,

First post, so hi to everyone and hope you can help.

Got a 53 plate ST170 and it has recently started to intermitently hesitate generally in the higher rev range, i.e. 5k upwards. Seems to be worse when the engine is under load.

Seems to generally be OK from cold but after driving around for a while the issue starts again.

I have had the IMRC replaced, I thought the transition from long to short runners could have been causing the hesitancy given it was at the higher end of the rev range, no chnage.

I noticed from the docket from my last service they put in the wrong spark plugs, should be 1151999 but they had used 1233897 which I believe are for the standard 2 litre. Had the plugs changed for 1151999 by Ford for free given the error on their part but still no change.

I have once had hesitancy between 3k and 4k Revs, the engine management light does not come on and my mechanic checked and there seem to be no error codes recorded.

I am next thinking of HT leads and coil pack, any other ideas ?

Thanks in advance.

Mark

tabetha

I'd start by cleaning the MAF, then resetting the ecu with the KAM fuse.
tabetha

Dynamix

Thanks for the reply tabetha.

Sorry to be a pain, but I am not very knowledgeable on cars. How easy is it to get to the Mass Air Flow sensor, where is it located and do I need anything special to clean it ?

Can you also explain how to reset the ECU with the KAM fuse ? Is this not the same as disconnecting the battery and leaving it for a given period of time ?

Many thanks.

Mark

Csm

The maf is the sensor with the multiplug attached to the pipe coming from the airbox will be held down with a couple of hex type screw/bolts

Some folk say that a maf works or doesnt work and they require replacment

seve170

alright mate i,ve had the same problem for a long time it comes and goes i have changed ht leads,coil pack,fuel rail,fuel filter,air flow mass metre and crank sensor still no joy so maybe save yourself money until somebody finds out for sure the cause of it! i,ve splashed a s**t load of cash at it with no joy so wouldn't won't to see somebody else do it

seve170

was just wondering if yours won't rev rite up to 7000 rpm

Dynamix

I cleaned the MAF Sensor and did an ECU rest, no change.

Replaced the HT leads with some Magnecor leads and same issue.

Sometimes it will drive fine to the red line. It seems it starts off OK and to begin with you can drive right through the rev range but once the problem starts unless you stop the engine and leave it for a while it will keep happening. Hesitation seems to be at approx 4750 RPM.

If you rev it with it in neutral it seems to get past this point OK even when the problem has set in.

Desperation has set in so before I take it into Ford I am running some BG 44K through it. Does any one have any experience with BG 44K ?

Sorry to here you have the same issue seve170. If/when I get the issue sorted I will post on this thread, I would appreciate it if you did the same.

Cheers,

Mark

seazer

i had the same kind of problem on my rs mate. i tryed everything! literally, i solved the problem by changing the coil (which i dont think needed to be done) ht leads and plugs thats solved the problem.

i think it would be the ht leads though. im pretty sure it wouldnt be the MAF because i was thinking the exact same as you.

if i was you get a set of leads and try them!!!

let me know how it goes

Charles

seazer

sorry mate just seen that you said you changed the leads,if this has happened since its come out from fords take it back and tell them they f***ed up???

try the coil tho defo gotta be cheaper

Dynamix

Thanks Seazer, I will give it a try.

Have got a third party coil I can try just to put it to the test. If it does transpire to be the coil I can then get an authentic Ford spare.

Fingers crossed

j_cros1

Hi, All same has been happening with my st170 but at about 4,000revs. Had it in a ford garage on two occasions now and still not fixed. going back in again in the morning. So far have been told the solenoid valve has been changed as well as the vvt unit. Same thing happens when i get it back. Cheers for info above will let them know.

Dynamix

Update, I am beginning to notice a trend ....

I never normally fill the fuel tank up, I put in about 30 - 35 quids worth as I need it.

When I put the BG 44K in I had to fill the tank right up to get the right mix. I don't do many miles so after a good few journeys it did not put a foot wrong. After about half a tank you seem to get a bit of a flat spot and as the tank seems to empty the symptoms get worse.

I have then filled right back up again, no problems going like a dream, I am now at about half a tank and now just starting to see the symptoms begin to return in a mld form.

I am kind of hoping to see it get worse as the fuel tank empties. It is not good that it is broken but at least I can get to the bottom of what the fault is.

Fuel pump perhaps .... (stroking chin) ?

Sp3no

iTrader: (1)

Fuel pump for sure it is a weak spot on the st170

R5AAL

Fuel pump 100%

I've fitted a few to st170s now, very common problem.

Dynamix

Just got my car back from Ford, they found no fault, surprise, surprise, probelm was to intermitent for them to pick up. Asked them to replace the Fuel pump anyway. So far, so good, only time will tell. I will post again if it has resolved the issue.

st170jim

hi, i have had the same probs, i have been reading up from all the people who have had this problem and it always comes down to the fuel pump.
i had my pump replaced today and happy days its perfect. all my filters were blocked and very dirty and so was the pump. all good now though and i got an upgraded pump from demon tweeks and alot cheaper than the ford pump.



this was what my fuel fliter looked like when i changed it 3 months ago, first signs of dirt in the tank. i will put some pics up of my in tank filters soon.

Dynamix

Glad your motor is sorted, that filter does look pretty dirty !

Mine is still running well, touch wood the fuel pump has sorted it.

To celebreate I treated her to 4 new Michelin Pilot Exalto PE2's. Still had the original Conti Sport Contact 2's on the back, despite the tread being of legal depth they were beginning to crack and down to the legal limits on the fronts.

white2lsr

iTrader: (1)

Any more info on the uprated fuel pump you fitted please?

st170jim

hi yes i will sort some pics out 2nite and post them up cheers

st170jim

the filter on the pump looks like a very old tea bag, the bottom of the tank was full of like a mud, water and general crap. so i had to clean the lines out and replace the filter once again. car pulls even better now as i got an uprated pump and its spot on, much cheaper than ford!

white2lsr

iTrader: (1)

As above

st170jim

lol its a sytec pump, you can buy this from pumabuild. or try searching sytec they are a direct replacement and fit a charm!

St170fella

Hi I came across these threads, and I am encountering a similar juddering problem, however mine only happens at low revs, i.e sub 2k revs. It sumtimes on rare occasions it stutters at 4.5k but very slight. I only seem to come across threads that talk about higher end problems. Iv had a friend plug in an OBD 2 machine but doesn't seem to find any faults. Any ideas what the problem may be?

Sp3no

iTrader: (1)

Sounds ignition related, swap the coil

Oxxmate

mine sometimes judders at low rpms but ive read a few threads on various forums and people say theyve replaced the ht leads and coil pack and what not but still no change. Now i dont know if i should do this or not :S

Jay

kyle_st200

Mine was down to the front lambda sensor apparently common on these