Bill's EFI Drama AKA A Game of Name that Component!

[mentalite]

On 1/2/2017 at 1:21 PM, Zed Head said:

EuroDat had a problem and improvised a fix.  There are also several other manufacturers that used AFM's, like Toyota, BMW, Mercedes (edit- maybe not MB, they used the D-Jet), Volvo.  All licensed the EFI technology from Bosch so probably used very similar parts.

Thanks for this, Zed.  That's quite a fix EuroDat came up with but beyond my skills I'm afraid.  I'll troll for temp sensors but I still will search for a known good AFM to put in.

[siteunseen]

12 hours ago, mentalite said:

It's funny you say this.  The ground wire that ran from the bottom of the AFM and the mounting bracket was WAY loose.  And there is a rubber gasket under it which doesn't make sense to me.

The rubber goes in between the base mount and the AFM to lessen the vibrations.  The ground goes under the base mount, if I remember right, it's been a few years. 

[mentalite]

Before I finish hooking up the AFM I thought I'd double check the ground wire location which doesn't make sense to me.  These photos show how I have done it, which is how it was before I took it off.  It wouldn't be the first time that something wasn't wired correctly, right?  I'm still confused because the ground wire doesn't touch the base but is between the rubber grommet and the washer (as seen in the previous post photo).  I suppose it still makes a connection with the bolt which in turn makes contact with the base.  The other end of the wire mounts to the top of the base when installed.  This doesn't make sense to me either because it seems to merely be grounding itself to itself.  So....my concern that something isn't quite right and it's better to ask one of you experts before I put power to it.

   

[Zed Head]

You're missing the little rubber grommets/standoffs/vibration insulators.  So you actually have more and redundant grounding.  Nissan engineers were just being fastidious in ensuring that all part functions were accomplished, with that dedicated ground wire.  Powering up shouldn't cause any problems, at least as far as grounding is concerned.

[cbuczesk]

mentalite - I see a Hammer Nutrition bottle on your table. Are you a biker?

Chuck

 

[mentalite]

7 hours ago, cbuczesk said:

mentalite - I see a Hammer Nutrition bottle on your table. Are you a biker?

Chuck

 

Sure am.  Until the last three months or so when it seems I've lost my motivation.  I ride the road, mountain bike, and cyclocross but the road less and less.  I'm weary of close calls.  You?

[cbuczesk]

I raced mostly mtb but also raced road and cross. Did it for about 20 years. I raced for Team Sourbeer, Yellow Breaches Racing, Gettysburg Bicycle and Mountain Bikers of Michaux. I stopped a couple years ago when tennis and golfer's elbow in BOTH elbows! I'm almost better so I hope to get back on the bike in the spring. I'm close to Mont Alto/Teaberry (southern Michaux) so I'll probably ride there a lot. What's your name?

Chuck Buczeskie

 

 

[mentalite]

Hi guys.

Slowly working my way through the system trying to get everything right.  My aux air regulator is definitely bad.  It is nearly closed all the way when cold so my initial idle is way too low in this cold weather.  If I loosen the clamp on the hose leading to the throttle body and use a screwdriver to let extra air in, the idle immediately picks up.  Finding a new one seems like it will be a chore so I guess I'll clean/lubricate this one in hopes of freeing it up.

I went for a drive today and now have an issue with the idle not dropping down when I take my foot off the gas.  If I push in the clutch and coast the RPM will stay up around 2K for several seconds then drop down to normal.  Under load it will continue to stay at 2K.  The dashpot seems to retract quite slowly when releasing the throttle.  Is this a potential cause of these symptoms?  I've lubricated the pivot points of the throttle linkage.

Thanks.

[Zed Head]

Is your throttle return spring intact?  They rust and break.  There's a second spring on the throttle body itself but it's not very strong.

[mentalite]

4 hours ago, Zed Head said:

Is your throttle return spring intact?  They rust and break.  There's a second spring on the throttle body itself but it's not very strong.

It's there, Zed.  Quite rusty but it is providing tension.  The throttle snaps back quite nicely when operating it by hand in the engine bay.

[Zed Head]

Apparently the BCDD can cause RPM to hang high.  It's described in the Emissions chapter.  

I had a problem with a hanging throttle blade due to gunk in the throttle body bore.  Nissan actually put out a Technical Service Bulletin about and had a fix involving cleaning the throttle body and rerouting the PCV hoses.  The dirty blowby from the crankcase fouled the blade.  In my case, it only hung up when the engine was warm.  I fixed it with carburetor cleaner and a little abrasive pad work where blade seats when closed.  It only takes a small opening to let a lot of air through.  

You can distinguish the BCDD problem from the throttle blade problem by pulling the throttle pedal up with your foot when it happens.  If it goes away then it's a blade opening problem.  The BCDD lets air by when the blade is closed so that cause won't be affected.

[Captain Obvious]

What he said.

If the RPM's drop properly when you pull the pedal up with your foot, then it's a linkage issue or a throttle plate issue.

If the RPM's hang even if you pull up with your foot, then the BCDD is the prime suspect.