Thread: Petrol in a diesel ford rager

Originally Posted by No.3

A Mazda man hey?

Originally Posted by No.3

Nope, engine stop is achieved by the fuel pressure modulation valve (what us not-Bosch mortals call a suction control valve) going to full open and dumping rail pressure back to the tank... This was the critter that stuffed my Ranger up - it was not opening correctly to release pressure off the common rail so that when you hit the top of a hill and throttle off, the common rail pressure was being told to drop back by the ECU (modulation valve commanded to open) but the valve wasn't opening - meaning the commanded pressure and actual pressure were different enough to trigger a limp mode alarm (fuel pressure out of specification).

The vehicle didn't have the usual symptoms of fuel injection failure (the issue I had was too much common rail pressure), which made us look a lot further into it spending a lot of time with a datalogger. Biggest issue is with the datalogger on, it played ball and behaved. Take the datalogger off, and it would trip an alarm and go into limp mode within minutes the stupid Ford thing...

Yeah I didn't think the rail being pressurised all the time sounded right.

I'm not too sure what the sequence is on engine start, it must command the valve closed somewhere in the sequence once engine is turned over on starter motor but I haven't looked at that side of it.
I have the datalogger set to (I think) either .75 or .5 second intervals to get around the file size issue after a long run logging. File sizes get a bit redic at anything more than that. That sample rate is too slow to really track what's happening on start though... I'm looking at the performance of the fuel system on open road running not fine detail!

It's a fair warning for the danger of the thing when pressurized though - 2000 bar is enough to cut solid crap right up.

I filled a 2008Mitsubishi diesel motorhome with petrol in Wanaka and stubbornly drove 60km to Makarora before, accepting it wasn't dirty fuel. AA Roadside assist returned me to Wanaka on a truck. Cost $140 to drain fuel from system and replace fuel filter. Honestly it has never missed a beat since, Mechanic told me the electronics caused the missing and performance and also reset itself. Was probably my most depressing night in my life thinking I had been so foolish and the cost to solve it.

Diesel engines rely on the lubrication properties of diesel to keep the high pressure pump in good order. A little bit of petrol through the pump isn't necessarily the end of the world. running on pure petrol for a length of time will end up being expensive.
Diesel is heavier than petrol so will tend to sit on the bottom and get used first.
There is a good chance you continued to get enough diesel through the system to avoid damage to the high pressure pump.
Don't ask how I know!

Originally Posted by No.3

A Mazda man hey?

....isn't the latest Mazda sourced from Isuzu?
The whole automotive industry is more incestuous than Alabama

The mobile mechanic bloke is booked in for this afternoon to come round home and do his thing. Fingers crossed I haven't rooted it. Been a couple of restless nights and the Mrs has been giving me the look for a couple of days. Never going to hear the end of it from her as she lords it over me on that one for the next 20 yrs...

Take your chances with the rail pressurized or not, mechanic at toyo told me to not Crack it , it can retain pressure was the message
Happy for u to try and let us know , and u don't need to , delivery side on filter is AL u need to do

Originally Posted by Nickoli

....isn't the latest Mazda sourced from Isuzu?
The whole automotive industry is more incestuous than Alabama

Yep that would be correct. I hear the latest Amarok is using the Ranger underpinnings as well.

Originally Posted by Sharki

Take your chances with the rail pressurized or not, mechanic at toyo told me to not Crack it , it can retain pressure was the message
Happy for u to try and let us know , and u don't need to , delivery side on filter is AL u need to do

Someone has to crack it when the injectors etc need to come out and be replaced - but the issue there is Bosch specifies the rail as a single use item. Local mechanic has reused them with no issues though... Apparently loosening the fuel pressure modulation valve or SCV will prevent anything bad happening if you have to crack a common rail fitting, in my case I just slap the datalogger on and it tells me what the rail pressure is prior to even touching it with a wrench...

Apparently though, once the key is turned to 'On' (not 'Start') the electric lift pump will prime the system with diesel and they seem to think this will push fuel through (the fuel modulation valve must open as part of the ECU prestart checks ref. the earlier conversation). I'm thinking a few cycles of key to 'On' then 'Off' again should get enough diesel through to the injection pump and injectors to lubricate things?

I put petrol in my SWB Pajero back in the day, called Mr Suckie Moto https://www.suckiemoto.co.nz/

Sucked it out, filled it back up with diesel, no worries, that Pajero lasted me another 10 years, but then it died.

Originally Posted by Nickoli

....isn't the latest Mazda sourced from Isuzu?
The whole automotive industry is more incestuous than Alabama

A bit harsh on ‘bama aren’t you?

Originally Posted by Finnwolf

A bit harsh on ‘bama aren’t you?

....insert whatever inbreeding reference you want....or take whatever offence you want....."that don't bother me none"
FWIW - I've got no ties to anything in the States more than a passing interest; but I do enjoy poking fun at Southern States for inbreeding.

mates Mrs put half tank of petrol in a toyota car....was 20ish years ago so cant remember model,possibly corrolla??? was four door....
she drove from Timaru to half way up waitaki valley..some 150ish KMS before admitting something was wrong..the ONLY symptom was the auto gearbox playing up...wouldnt change down think it was...we drained tank completely,mate was auto wrecker so no drama to him. refilled with diesel and the car never missed a beat..... the mixed fuel gifted to cockie whos place we were on for the burn pile starter....
funny the things that stick in memory.

Well..the mobile mechanic here in Taupo came round. Drained the tank with a pump and dropped the filter etc. Put some fresh diesel in and and away she went. Marty reckons it sounds fine, if not smoother than a lot of other 3.2 rangers. No nasty clacking sounds of surgeons or unhappy pistons. In fact it sounds better than before.
Might have got away with it. Fingers crossed.
Marty reckons you'll never know if there is damage until something shots itself.
The mobile mechanic Marty stock was awesome. Even pointed out a few prevention issues with the ranger motors and the little coolant pipe that can rub a hole on a metal part and dump your coolant and cook your motor. Good to know.
Shouted myself a lotto ticket. Might get some sleep tonight.