Hello.
Newbie here. Don't know if this is how to post about my problem.
Evo 1.3 multijet turbo. I have cleaned and tested injectors. Recut injector seats due to very bad seal leaks. The car Ran ok for 40-50 miles after work carried out. Then had eml come on. Fault code p0089. Rail pressure regulator. Car in neutral revs great at any rpm. But when put into gear cuts out after a few seconds.
Tested the pressure regulator and have erratic voltage on signal wire. Bought another pressure regulator and same problem.
After its cut out, it will not restart and there is no noise from lift pump in tank until I have switched on and off several times.
I'm thinking that it might be pressure relief valve, (fuel return to tank) high pressure pump or tank pump. Or ECU.
Has anybody got any thoughts on this.
I would appreciate any help and advice.
Thank you.

Sounds to me like you have a faulty injector, sticking and loosing pressure. You need to have a injector leak off test carried out. Dirt or swarf in fuel lines after filter could cause injectors or pressure regulator to stick. All fuel components need to be 100% clean.
I'm assuming the fuel filter is ok and fuel is good.
If you think the lift pump is suspect I'd recommend you check the relay first, remove the plastic cover on the relay and inspect the contacts.

Thank you Thefox.
Yes it was injector problem.
I replaced pressure reg. Fuel filter. Checked lift pump.
Fitted second hand high pressure pump. But still no better.
Then I went back to injectors.
Cleaned again and this sorted the fault.
Sorry I didn't thank you earlier.
First time I've been on this site since problem.
I bought a wifi diagnostic for about £20 on eBay and it was the live data on rail pressure that helped a lot.
Thanks again.

Ps. I did have same question on another part of this site. I also replied to it myself with how I went through process and fixed the car so others might benefit..

Hi mate newbie I hope you are able to help me -I am getting p0089 and thinking of replacing or cleaning the fuel pressure regulator on the rail, my question is do I need to depressurise the rail before unbolting the regulator from the rail? If so where / how?Fiat 500 1.3 diesel multi jet running great apart of cutting off under load going to limp mode check engine comes on and then drive ok but gutless.

Thanks in advance

Dan

Ö do I need to depressurise the rail before unbolting the regulator from the rail? If so where / how?Fiat 500 1.3 diesel multi jet running great apart of cutting off under load going to limp mode check engine comes on and then drive ok but gutless.

Thanks in advance

Dan[/QUOTE]

Hi

https://www.fiatforum.com/fiorino-iii/456920-fuel-pressur-regulator-2.html

Personally I would unplug fuel pump and run till it dies.. the filter element is selfpriming..so no dramas there

Charlie