Thread: OBD2 data logger/black box device...

Ok, the Ranger issue I have is getting more awkward. Dealer service team recommended replace rail, pump, injectors (aerated fuel returning to the tank off the rail) - got 2nd opinion with a local outfit that have a good rep and lo and behold, vehicle performs flawlessly. No real reason to replace the fuel delivery gear from what they can see - and beyond that without the fault occuring in front of them not a lot they can do... While that potentially saves $8K it doesn't fix the issue with it going into limp mode intermittently.

So I've been looking for an OBD2 data logging device to hang off the ODB2 port in the vehicle and basically record the last say 2 hours recording and overwriting over the oldest stuff. This is IF we get the fault again we can look at all of the info off the thing and try and zero down exactly which system and what parameter is getting out of whack to cause the fault code that trips the thing into limp mode.

Problem is there don't seem to be any devices out there that are compact, designed to hang off the OBD2 port semi-permanently and will go into sleep mode with the vehicle is turned off (OBD2 port stays live so a device that won't 'go to sleep' can flatten the battery...).

Used to see these a lot - Plusquip OBD11 Black Box Recorder (EQP-104)

which just plugs in and automatically records the values and you download and empty the devices memory regularly. But - can't seem to find one (only option for those I can find is Ebay which appears not to be an option for getting it to NZ).

Anyone know of anything else that will do this job? Don't really need the fault code reader as we are interested in the engine sensor data on the lead up to the check powertrain light illuminating and tripping the limp mode... Cheers

check out forscan free to download on comp or $10 to phone , has a good rep on ranger face site

Originally Posted by m101a1

check out forscan free to download on comp or $10 to phone , has a good rep on ranger face site

Ahhh yep, that works off the Bluetooth or WiFi dongle type thingie that plugs into the ODB2 port. I'm looking at the OBDLink MX+ dongle as some of the pages selling it (but not all) report that it has a data logging function. I've pinged an email off to a few of the outfits flogging the thing to confirm that it does do data logging, but getting actual info on it otherwise isn't easy. The only reviews I can find don't mention it's use for data logging but that doesn't mean it doesn't just the reviewer hasn't tested that bit...

I've played with a few OBD readers, if your going to datalog I'd use this one
OBD Link MX+ https://www.obdlink.com/products/obdlink-mxp/
Uses its own app
You can get them of Aliexpress

Not cheap but very high refresh rates
Cheaper ones have slower bandwidth and results in a chonky chart.
This ones rated quite highly and is chalk and cheese when compared to the likes of a $30 vgate.
if your just reading & clearing codes the vgate is fine.

Couple of good apps for logging is torque & Carbit

Also pays to have a dedicated device plugged into car full time for logging, PITA reconnecting BT everytime you jump in.
Now the fuel issue with air in the fuel return line...is their air getting in on the suction side of the pump? worn/ cracked hoses, loose fuel filter fittings (water sensor on bottom is a culprit), hoses all the way back to tank in good nick?
Dongle logging might show signs with SCV duty% going up and rail press going down with air entering on suction side.

Oh and not the first time I've heard of dealers loading the parts cannon....

Originally Posted by Stump

I've played with a few OBD readers, if your going to datalog I'd use this one
OBD Link MX+ https://www.obdlink.com/products/obdlink-mxp/
Uses its own app
You can get them of Aliexpress

Not cheap but very high refresh rates
Cheaper ones have slower bandwidth and results in a chonky chart.
This ones rated quite highly and is chalk and cheese when compared to the likes of a $30 vgate.
if your just reading & clearing codes the vgate is fine.

Couple of good apps for logging is torque & Carbit

Also pays to have a dedicated device plugged into car full time for logging, PITA reconnecting BT everytime you jump in.
Now the fuel issue with air in the fuel return line...is their air getting in on the suction side of the pump? worn/ cracked hoses, loose fuel filter fittings (water sensor on bottom is a culprit), hoses all the way back to tank in good nick?
Dongle logging might show signs with SCV duty% going up and rail press going down with air entering on suction side.

Oh and not the first time I've heard of dealers loading the parts cannon....

Hi, thanks for that will try the MX+ unit (was looking at it already so your comment just confirms that one is the one to try). Cheap enough vs close to NZ$8K for replacement parts that might not fix the thing... I'll definitely check out those two apps as well, I think it's going to be a pesky fault like an intermittent loom issue or a sensor getting overheated and reading erratically - one of those great faults that doesn't make sense until it's found.

And you're right on what we are thinking with the air leak - when the independant checked the return fuel for aeration with the clear line it wasn't excessive, just the usual foaming after depressurizing when it comes out of the common rail piping. I'm suspecting that the fuel system is heat-soaking and it's getting a seal that is opening up after a period of time when the temp gets up or something like that - with the mechanics unit on it in live data mode, the commanded pressure and delivered pressure to the fuel rail were fine only a minor amount of variation, RPM sensor and fuel temp were all AOK. Fuel temp didn't get over 39degC in 3 hours of driving so no apparent issues there at all, nowhere near the 85degC needed to trip the ECU into self-protect mode.

The independant mech reckons the injectors and injection pump are fine, no telltale tiny shiny's in the fuel dropped off the filter and it starts and runs better than the one that has just had the heads done and all new injectors pump and radiator and was back in for it's check over and retorque. So I dunno - feel like the dealer really couldn't be arsed in actually diagnosing the thing. Doesn't make me happier with their service, actually right out the other end to be fair (kind of like I'd be dead before I take a vehicle back to them and it's not because I think they are too dear like most people go on, they actually aren't. It's all down to quality of the job).

@No.3 - Flick me a PM. You can have a loan of this one.

So follow up to this, got the data logging function on an app called Forscan Lite (basically a US car with CANBus type systems specific app) and using a MX+ version of the datalogger above. Very interesting in preliminary testing, haven't been able to get the thing to fault and go into limp mode on me but it looks like the pressure control valve is the likely cause of my vehicles issue. Seems the valve isn't opening quickly enough to drop the pressure out of the fuel rail when it goes off throttle - meaning exactly as the demanded pressure drops and the injectors on the common rail stop firing at full rate, the valve is not opening to dump the pressure out of the common rail so the common rail pressure is shooting for the moon... Interesting, just need the thing to fault to confirm what is happening at the time.

I'm impressed with the OBDLink MX+ though (I ordered one the same morning that the gentleman above offered me a loan of his - bugger), it does everything it says on the label.