Sunday, January 25, 2015

Adding Vacuum Ports to the EFI Throttle Bodies

Since it appears that URAL will not be selling the current software/cable used by dealers to synch the EFI models, it was time to do a modification to allow one to synchronize the throttle bodies.

There's been, by the way, no official announcement either way re a bare bones version of the dealer tool which allows dealers to upload EFI maps, synchronize the throttle bodies and see engine details rendered by the ECUs.

So, like a carbureted motorcycle, the idea is to measure the amount of vacuum being "pulled" by each throttle body and ensure it's even both at idle and at around 1800-2000 RPM.  Unbalanced carburetors or throttle bodies tend to run rough and/or poorly so this is an important thing.

Marc L., a fellow Uralista with a Battleship Blue 2014 Gear-UP hosted both Darrell S. and myself at his home in Westminster since he had a drill press.

We all were ready to go by 10AM this morning and soon we had the throttle bodies off both Marc's and my rig.  I watched Marc drill the mounting hole for his throttle bodies and I then mimic'ed him in drilling my own throttle bodies.  Close supervision was supplied by Darrell to ensure I didn't bugger up the job since this was the first time I'd ever used a drill press.

Holes done, it was time to run a tap through them to introduce 5/32" threading into the hole for the vacuum ports we'd bought previously to screw into.

Note:  The throttle bodies are made of a very soft aluminum so a very light touch on the drill press was called for and slow/smooth but very effortless threading of the tapping tool.

Marc demo's the use of the tapping tool, trickiest part was at the
beginning since you have to ensure you're straight up/down and sideways.

The vacuum ports were threaded in with a very small dab of blue Loctite material to ensure they stay in place in the throttle bodies.

Freshly mounted vacuum port, this is the left side throttle body

Re-assembly was basically a reversal of the steps taken to unmount the throttle bodies.  The process highlighted the need for a 2.5mm Torx wrench (these are the stock screws) used to secure the fuel injection module and the bracket holding the throttle cable.

We elected to replace the Torx screws with allen headed screws by the way, and Darrell was kind enough to make a hardware store run to obtain them for us as we did the drilling and tapping.

So now, I need to buy an extra long 2.5mm allen wrench with a T-handle, it makes the removal of these two screws much easier!

Once we got the rigs re-assembled, we set off together, Marc and I, to warm up the rigs by doing about seven miles of riding.  

We returned to Marc's house and put the Harmonizer tool on Marc's rig.  No adjustments required!  Lucky dog.

My rig was next and Scarlett proved quite stubborn in terms of getting her idle where we wanted it and still balanced!  Finally, after much travail, we got it to balance but with the tach on the Harmonizer reading 1200 rpm, a bit high.

I had the left side idle screw completely off the stop and still we couldn't adjust the idle any lower.  Both Darrell and Marc remarked that before we made changes, the rpm had been reported at 1200 by the Harmonizer.  We are suspecting perhaps a small leak on the left side throttle body butterfly valve.  I may have been, all this time, running with idle a bit high?

There's been reports, you see, of some 2014 rigs needing updated butterfly plates as the ones they had are "sticking".  Mine weren't sticking when I examined them but something to keep in mind, the fact that some of the early 2014 rigs needed replacements of these disks.

We said our goodbyes to Marc around 2:30PM and I was home after boring slab riding by 3:30PM in medium traffic conditions.  An overcast day with temperatures in the low 50s for a high though it was cooling down as I neared home.

Note: Scarlett's idle RPM was being displayed as 960 rpm at idle by my cheapo tachometer I got from ebay which I'd determined in the past to read 100 rpm low.  Sure enough, I got home, put the Harmonizer on Scarlett and her idle was around 1060 rpm after an hour of highway riding.  So the idle is fine for now, she sounds good, and pulls strong through all the gears.

I'll monitor things some more I think before I start the process of replacing the butterfly valves on the throttle bodies, under warranty of course.  

Previously, Yet Another Colorado Sunset


Richard M said...

Kind of a bummer that they decided not to have a customer software tool. Was there too much resistance from dealers to make a user tool?

Charlie6 said...

Nothing official from the mothership RichardM, just off the record stuff. Apparently the dealers voted and majority of them don't want the tool available to users since some of the apparently charge their owners to upgrade mappings and balance the throttle bodies....we shall see, in the meantime, we carry on

igor said...

How is your idle now? Did it ever feel like the motorcycle was going to die (and did?). I am just wondering if this will improve or I need to get to the dealer for intervention. Seems like my 2015 Patrol idles too low and sometimes even dies..

Charlie6 said...

Igor, the idle is fine. It never felt like it was going to die, before it would run a bit high.

I'd get your rig to the dealer and have them put the dealer tool on to check the ECU's and their balance and idle. It shouldn't idle down to the point the engine cuts out. I really like v1.07 "offroad" version of the EFI mapping. There's still some popping and slight hesitancy when going slow in first, especially when engine is cold but I think that won't get fixed till a throttle position sensor is built in.