First post, been lurking for a while.
Hoping for some tips / ideas with regard to the following issues on a 1.9 JTDM 16v (159SW):
- Irregular idle RPM, worse if fans/AC turn on. Not misfiring irregular, just hunting up and down between ~750-900rpm. Occasionally at traffic signals it almost feels ready to stall on take off.
- Hesitation between 1750 and 2200rpm
- Occasional wastegate / blow off valve like noise around 2200rpm if shifting
- Power feels down / restricted
In April, mainly for preventative measures, I replaced the EGR, installed a "blanking" plate (genuine gasket, 4 holes on the intake side) and cleaned the MAP and MAF. Car was running really well after that. Also ran a bottle of Redex Gold through the tank.
Had an issue in May, where the car stalled at a set of traffic lights, then ended up needing towing. Would stall as soon as put into gear. Was taken to a local Alfa specialist, plugged into examiner, loads of EGR faults. They said the reconditioned EGR that I'd installed was faulty, replaced it, cleaned the throttle body and it ran again.
Since then, it's just not felt right. Symptoms described above. So far I've tried:
- Checking for error codes using FiatECUScan (no faults)
- Recleaning MAP
- Verifying EGR and swirl flap operation using FiatECUScan (can hear swirl flaps. EGR makes a faint noise?)
- Replacing air filter
- Checking for split turbo hoses and vacuum hoses (I can't see/feel any splits)
On the last point, I did note that there was some oily residue on the outside of the hose from the turbo to the intercooler, and that the intake hose to the turbo isn't exactly tight, I can shift it by hand quite easily.
Took the car for a good run today, as DPF was 85% blocked. Regenerated fine, now at 18%, 75km after last regeneration. Didn't make any noticeable difference to drivability.
Noticed the injector correction values are a bit over the place. At idle, injector 1 is at +5mm3/inj, though goes down to +2mm3/inj if held at 2000rpm for ~ 30sec. Injector 3 is at -3mm3/inj, though goes down to -1mm/3inj if held at 2000rpm. Injector 2/4 both read between 0 and -0.5mm3/inj.
I'm presuming those injector values are not healthy?
At the moment my plan of attack is:
- Take vehicle to a bosch injector specialist, have them test the injectors properly and recondition if required
- Replace diesel filter
- Try running car without MAF connected, to see if it improves (and if so, replace MAF)
- Clean my spare EGR, and fit it to see if it improves (and if it does, take it back to the Alfa specialist to replace the EGR under warranty)
- Tighten the turbo intake hose with a jubilee clip
If none of that works,
- Clean MAP again or replace MAP?
- Replace vacuum hoses?
- Replace boost control solenoid?
Does this seem reasonable?
Any other suggestions / ideas to try?