Ranger Mods

Hi Guys,
My 2015 PX1 work ute has been intermittently been going into limp mode where it wont/ struggles to rev over 2000rpm. Over the past few months I have been trying to monitor it and note when it seems to fault, so far I have noticed it will only fault on longer drives (30 mins or more at highway speed) and only on warmer days (not night time). When it faults I have no engine light come up on the dash, sometimes if I shut it down and restart it will come good for 10 mins. After yesterdays fault it seemed to be idling at 1000rpm which was unusual.

I finally had it play up with my laptop in the ute so I plugged into Forscan and recorded the following parameters:
Vehicle speed
Fuel rail desired pressure
Fuel rail actual pressure
Fuel temp
Oxygen sensor
MAP sensor
MAF sensor

I have compared this to a previously recorded drive where I had no faults and everything looks much the same.

Has anyone had this fault before or can anyone point me in the right direction on some other parameters to record and compare against?

Cheers!

I'm no expert but to my way of thinking the indications are ( long drives, warm days ) that you may have either a defective coolant sensor or an air temperature of some sort - somewhere - and its telling the ECU that your engine is either overheating or the incoming air is too hot from the intercooler so it goes into limp mode.

Thanks mate, ill add those parameters in and give it another go. Cheers!

I got round to comparing this problematic work ute with my own PX1. Although it was a cooler day yesterday, I took my own ranger for an hour long drive and found the fuel temp would gradually rise up to a max of 41 degrees after 20 mins driving. Then taking the work ute for a drive straight after, I noticed the fuel temp reached 40 degrees after 7 minutes driving and continued to rise all the way to 67 degrees, although it didn't go into limp mode for me, I think this would explain why on a hot day I was getting it go into limp mode!

Looks like I'll be checking the fuel return lines and then possibly a fuel temp sensor after that!

Diesels pump a lot more fuel than they need and return excess to tank to cool the system.

Sort of first rule with diesels if check/change fuel filters.

I have read of failed/blocked/crimped fuel return hoses causing problems as well.

Fuel temp is definitely your issue. It goes into reduced power mode at 82 deg.
Check and make sure your fuel lines are not reversed when going into the fuel filter housing.

Make sure you report back if you eventually fix it, as I am interested to know

Tezza wrote: ↑Sat Mar 28, 2020 9:14 pm Fuel temp is definitely your issue. It goes into reduced power mode at 82 deg.
Check and make sure your fuel lines are not reversed when going into the fuel filter housing.

Make sure you report back if you eventually fix it, as I am interested to know

That makes sense and a solution that I'd never had thought of - it always made me curious that on a Freightliner prime mover I occasionally get called on to drive I noticed during one of its regular services that the fuel return line went through a finned alloy plate attached to the main ECU to cool it.

Kenworth trucks have a fuel cooler in front of the radiator,

There is a fuel cooler listed for some rangers,

I suspect fuel overheat is just a symptom of overall general overheating.

Bala1 wrote: ↑Sat Mar 28, 2020 11:48 am Diesels pump a lot more fuel than they need and return excess to tank to cool the system.

Sort of first rule with diesels if check/change fuel filters.

I have read of failed/blocked/crimped fuel return hoses causing problems as well.

Fuel filters are lines back to tank are ok

Bala1 wrote: ↑Sun Mar 29, 2020 11:02 am Kenworth trucks have a fuel cooler in front of the radiator,

There is a fuel cooler listed for some rangers,

I suspect fuel overheat is just a symptom of overall general overheating.

Engine coolant temp is normal

I have read somewhere of a sticking piston or valve in the injector pump causing overheating problems.

This: Also, don’t ignore a check-engine light, as sometimes, a damaged injector-pump return valve can stick and overheat the fuel, sending the vehicle into limp-home mode

From here

https://magazine.unsealed4x4.com.au/en_ ... tions.html

Bala1 wrote: ↑Sun Mar 29, 2020 11:02 am Kenworth trucks have a fuel cooler in front of the radiator,

There is a fuel cooler listed for some rangers,

I suspect fuel overheat is just a symptom of overall general overheating.

I read here that the crucial temperature is around the 80*C mark before the engine goes into limp mode.
Last year March 16-25, 2019 I took my Danish son-in-law into the Simpson Desert on a camping tour and the daily temperatures were well into the high 40*C ranges and I never had a single issue with any form of overheating my engine coolant never going over 87*C so just how hot does it have to be before the fuel gets to 80*C+ ??

[/quote]

I read here that the crucial temperature is around the 80*C mark before the engine goes into limp mode.
Last year March 16-25, 2019 I took my Danish son-in-law into the Simpson Desert on a camping tour and the daily temperatures were well into the high 40*C ranges and I never had a single issue with any form of overheating my engine coolant never going over 87*C so just how hot does it have to be before the fuel gets to 80*C+ ??
[/quote]

I have seen 106 coolant with no limp mode and I slowed down then stopped, it was hot with a strong side wind towing a trailer at 110kph. I have had to slow down on other occasions when towing to bring coolant temp down.

I was not monitoring trans or fuel temp at that stage, but suspect they both would have been up.

temps depend how I drive, up hills like Palmerston hway FNQ I can easily get 100c coolant towing or not depending on ambient temp. That is maintaining 100kph. If I dropped speed Im sure they would come down easily.

Towing a caravan a few weeks ago at 90kph trans and coolant temp were stable, as soon as I went over 90 they started to rise.

If you drive easy things stay cool, the harder you drive the hotter things get.

On your trips were you towing? What speeds were you doing?

If you drive easy things stay cool, the harder you drive the hotter things get.

On your trips were you towing? What speeds were you doing?


No, we weren't towing, although I have the alloy finned deep auto sump and an upgraded transmission fluid cooler normally I don't tow - other than borrowing my neighbours 6x4 box trailer to go to the local tip.
Crossing the desert dunes my tyre pressures were dropped to 14psi front 16 psi rear, my PX2 Wildtrak has an ungraded GVM to 3500kg and all up weight with 140 l of diesel and 125 l of water, food for 3-4 weeks, two adults and all our camping gear it weights in at 3400kg. My average speeds over the desert would have been sub 30kph and I got a fuel economy of 13.8 L/100K, I think we could have done better but we had the A/C on full time.
My ECU has been "tweaked" by the HPF in Melbourne and fitted with a modified PX1 turbo to deliver more low down torque and better economy (I'm not interested in increased kilowatt power) with a rev. limit of 3850rmp and maximum boost of 22.5psi.
Normal bitumen driving, tyres at 38/40 the cruise control set at 95kph it runs at 1560rpm, 0-3 psi boost and I get an economy of 12.5 l/100k

SOLVED

Comparing the problematic ranger against my own I double checked the fuel lines on the filter and noticed that the lines were connected differently, swapped the lines to match my own ute and the fuel temp has dropped significantly.

Cheers for everyones input!