Power loss potentially after service.5yr SAFC tune now indistinguishable from stock

[Pattey21]

Hi gents,

Came back from a two week holiday and did a service on my R33 s2 Rb25det.

Changed Oil, cleaned afm with electrical cleaner and swapped back from pod to air box and snorkel with trust filter. I run a air box 99% of the time.

I was giving it a boot at night on Monday and noticed it wasn't as quick as it normally would be with less of a punch in the mid-range. Basically felt like it would on a hot summers day, rather than 10pm at night heading into winter.

As it's SAFC tuned I can see the AFM reading as a percentage and normally in summer it would hit 76-80% and in winter 82-87% 

It was hitting low 80's this night but just felt slow.

Started fault finding, re-cleaned afm, checked fault codes, Checked for loose hoses etc

No obvious boost leak, still hitting and holding 10psi and turbo is not any less responsive than usual. Removed air box filter lid/filter/snorkel for a run and only marginally quicker but didn't seem like it was the issue.

Replaced the fuel filter too, no difference. 

I then removed all corrections on the safc so it was essentially just running stock and I couldn't tell the difference.

Kept doing runs with 0 corrections and then adding the corrections it was tuned for and I can't tell the difference. 

So now I'm at a bit of a loss, I don't have a wideband to see if the corrections are effecting open loop AFRs  or if the fuel pump is dying. Had a walbro put in at the time of tune 5 years ago.

Basically it's had the same setup, 10psi, MBC, return flow and full exhaust with SAFC tune for 5 years and all of a sudden it just feels like it's slower like it's lost its tune/less ignition timing.

Any ideas, whether could be fuel pump dying, still a marginal boost leak or a problem with the SAFC?

Just want to try anything before getting it on the Dyno.

 

Cheers

Patrick

 

 

 

 

 

 

 

 

 

 

 

[hardsteppa]

I would suggest getting a wideband gauge if yr using an safc. I think my aem one was under 300? Have had it a few years on car and still going strong. Otherwise yr shooting in the dark adjusting safc, and in the danger zone. .not the good Kenny Loggins type either

[Dose Pipe Sutututu]

Check your base timing too

[Pattey21]

Thank you for the responses guys, seems it was my VCT solenoid.

 

Cheers

[MagicMikeZ32]

Solenoid or wiring to solenoid?

[Pattey21]

On 5/4/2018 at 4:07 PM, hardsteppa said:

I would suggest getting a wideband gauge if yr using an safc. I think my aem one was under 300? Have had it a few years on car and still going strong. Otherwise yr shooting in the dark adjusting safc, and in the danger zone. .not the good Kenny Loggins type either

Thanks for your response.

Yeah this is basically the next step.tried 

[Pattey21]

Was a sticky solenoid

[MagicMikeZ32]

Nice one, how did you get to the bottom of it?

[Pattey21]

First measured voltage at VCT plug. Requires 2ppl, as car must be in gear.

Voltage was there, so removed vct and made sure it would actuate(audible click) and visually see the Piston move using the battery. It didn't the first go but then after re-applying 12volts it did.

 

So cleaned it up, re installed with plug on and made sure I could here it audibly click/engaged.

 

Ideally I could have done that from the beginning but nevertheless it solved my issue.