Quite long ago, I came across a suggestion to add a ground wire from the
ECU box to the body (under the bench, right side). I didn't have any
problem but I did that anyway... so all my vans have that ground wire.
You may want to try that.

On Sat, Apr 22, 2023 at 12:38 PM Alistair Bell <ragnarhairybreeks@icloud.com>
wrote:

> It’s a bit of a long story so I’ll trim out a lot of what I did…. Take it
> as read that I did redo grounds, terminals, check basics, did Bentley.
> Yadda yadda, you know.
>
> And a perhaps related issue that I fixed a few years ago… that was an
> annoying stumble and jerking, have to floor then pedal to get going… that
> only occurred on summer trips on logging roads. Never in town, and didn’t
> happen every trip.
>
> Did all the stuff you can imagine to track that down. Wasn’t successful.
> But it went away after I did two things. Did the capacitor fix in AFM ( was
> not classic vanagon syndrome but I thought why not) and I reflowed a solder
> joint on one of the power transistors in the ecu. Did that after van died ,
> dead, one day. After a fair bit of work I found a bad joint in ecu.
>
> That was 4 years ago, the ecu fix.
>
> This last winter I started to have occasional bucking again. This time
> around town. Not quite the same as before. But was getting worse. Only
> happened after 15 min driving. Also the van felt sluggish all the time.
> Sluggish pick up from stop. Felt lacking in power at low rpm.
>
> Got worse and a week or so ago got so bad I had to pull over. Van idled
> high, about 1500 , tach bouncing at 3500!
>
> Something really wrong. Let the van sit for 20 minutes and I could make it
> home. Only bucking at the end of that short drive .
>
> For some reason I suspected the ecu again.  So I pulled and looked. I’m no
> expert, but I found what looked like an iffy solder point on the board.
> Reflowed that one, and some others that probably good but thought why not.
>
> Ecu back in and van started. Test drive for 30 min and all good.
> Drivability great. Nice throttle tip in, smooth, no sluggish start, no
> bucking.
>
> Happy guy.
>
> Next morning , start and back up in drive to turn, dies. Cranks but no
> start. Jeeze…..
>
> Catches for a sec, dies.
>
> Crank crank
>
> Finally I reseat the ecu connection and it starts.  Idles high agajn and
> Tach bounces. I swap in spare coil, same .
>
> I fiddle with ground wire to ecu, the ecu harness, the connector. Starts,
> runs great.
>
> All this last week it’s run sweetly. Really nice. I mean like a new van.
>
> So what’s the deal? I did look carefully at the ecu board where the main
> connection comes in. I couldn’t see any issue. My ecu ground wire might be
> the issue. On my van it disappears behind the rear bench side wall and I
> can’t get at it without pulling the bench. This weekend I will look at the
> harness side of the connection and see if I see anything. Also I’ll sister
> a new ground.
>
> Obviously I’m not confident about my “ fix “ so far. But I tell ya, the
> van is running better than I can remember it running. You know that jerking
> sometimes at low speed , trailing throttle? Ad if you have the tps mis
> adjusted? I was also getting that on occasion before the fix. Believe me ,
> I have done lots to try and have my tps working well. Rebuilt throttle
> body, it’s in great shape, switch good etc. been a bug bear of mine that it
> seemed to not be working at times. I now think it’s was always fine, it was
> the ecu.
>
> I know there will be comments about this, did you check this or that etc.
> but please believe me I’ve gone thru a lot of time and part swapping to no
> avail.
>
>
> Ab
>