Date: Thu, 31 Aug 2017 14:18:18 -0400
Reply-To: Dennis Jowell <dennisjowell@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Jowell <dennisjowell@GMAIL.COM>
Subject: Re: 2.2 engine hiccups at 3300 rpm
In-Reply-To: <CY4PR20MB1303D50C3D56184E1BCF2839A09C0@CY4PR20MB1303.namprd20.prod.outlook.com>
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With ignition on ,engine off, Coax shield outer green copper wire zero ohms to ground, center lead of green wire with O2 disconnected not continuos.
Dennis Jowell
Scotch Hollow Farm
Newbury, Vermont
> On Aug 30, 2017, at 6:15 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
>
> Go check the archives. In the past I did a fairly detailed explanation of what to look for.
> Short version, test the O2 sensor heater, make sure it is getting power. Current meter!
> Sensor lead-connection. The green wire is a coaxial cable. Make sure the outer shield is not shorted to the signal wire.
> Check for stray voltage on the outer shield. Peel back insulation a bit to reach it. Ignition on, engine off, between there and ground real close to “0”. Center lead to ground .5 to .6 volt with sensor disconnected.
> If shield has voltage you have ground problem. Check ground at harness for distributor.
>
> Good luck.
> Dennis
>
>
> From: Dennis Jowell [mailto:dennisjowell@gmail.com]
> Sent: Wednesday, August 30, 2017 6:08 PM
> To: Dennis Haynes <d23haynes57@hotmail.com>
> Cc: vanagon@GERRY.VANAGON.COM
> Subject: Re: 2.2 engine hiccups at 3300 rpm
>
> I did the shut off test you suggested. Yes the hiccup went away for a short while. Now to understand how to test the O2 sensor electrically.
> I'll study my Bently and see what I can come up with.
>
> Dennis J
>
> Dennis Jowell
> Scotch Hollow Farm
> Newbury, Vermont
>
>
> On Aug 28, 2017, at 10:32 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
>
> There are a lot of things that can cause the hiccups or engine miss even at a given speed range. It is extremely unlikely that it is the air flow meter. I recently had a van with hiccups with changing engine load. Turned out to be the wire connection at the alternator that feeds the fuel injection. That one kicked my but for at least a week.
>
> Point is you need to do some real trouble shooting and just changing parts is not the way to go. Changing parts can often mask bad wiring or connectors where just moving things made a change but the fix does not last so next time a symptom appears one just moves on to the next part.
>
> For these hiccups I would begin by suspecting the O2 sensor circuit. The fast easy test for this would be to cycle the ignition off and back on while still moving. If the hiccups disappear for a short while than most likely the sensor is weak or the system has an electrical problem causing the ECU to make the mixture too rich. At this point changing throttle-speed may get the engine above or below that critical choking point.
>
> For all the vans I have worked on I have only actually fixed three with an air flow meter. And those three had the meters opened up and tampered with They really don’t go bad and you can’t reliably test them with an ohmmeter. I have also found that the fuel injection often gets blamed for running issues and that it is not the problem. The ignition system can also cause all sorts of grief even from something as minor as a crack (carbon trace) in the distributor cap or rotor.
>
> Dennis
>
>
>
> Sent from Mail for Windows 10
>
> From: Dennis Jowell
> Sent: Sunday, August 27, 2017 6:16 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: 2.2 engine hiccups at 3300 rpm
>
> Thanks Dan I have a replacement AFM I will try tomorrow
>
> Dennis Jowell
> Scotch Hollow Farm
> Newbury, Vermont
>
>
> > On Aug 27, 2017, at 4:40 PM, Dan N <dn92610@gmail.com> wrote:
> >
> > so it's not altitude related...
> >
> > besides what I suggested to do/check ... I'd think that the carbon tracks on the AFM were worn at the 3K/3.5K rpm spot (that's where the contact sits most of the time) ... if it's the case then you will need and a rebuilt AFM or have yours rebuilt... unless you want to do it yourself...
>
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