Your basic fuel/air adjustment is out of whack. With the O2 sensor engaged the ECU can make some compensation. --------------------------------------------------------------- Tom Young '81 Vanagon Lafayette, CA 94549 '82 Westfalia --------------------------------------------------------------- ----- Original Message ----- From: "insyncro" <insyncro@HOTMAIL.COM> To: <vanagon@GERRY.VANAGON.COM> Sent: Saturday, February 07, 2004 8:45 AM Subject: Re: ECU question, w/ O2 disconnected
> I disconnected the O2 and right off the bat it ran rough at idle and blew > black smoke while at highway speed with the same amount of hesitation. > Where to next? AFM? > > dylan > ----- Original Message ----- > From: "Dennis Haynes" <dhaynes@OPTONLINE.NET> > To: <vanagon@GERRY.VANAGON.COM> > Sent: Saturday, February 07, 2004 11:19 AM > Subject: Re: ECU question > > > > This type problem is almost always related to the O2 sensor circuit. > > Does your sensor have the heat shield/deflector in place? Is the wiring > > good? Is the O2 sensor heater working? The ECU tries to go closed loop > > at ~120 and 1 minute running. If the O@ sensor output is not sufficient, > > the ECU will keep richening the mixture to get the signal. If not > > working, yet, it will go rich enough to choke the engine. Disconnect the > > sensor for a test. If the problem stays away, then the problem is there. > > When the sensor is disconnected, the leakage of the input circuit of > > about .5 volt fools the ECU into thinking the mixture is ok so it does > > not make any adjustment. > > > > Dennis > > > > > > -----Original Message----- > > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf > > Of Dylan Friedman > > Sent: Saturday, February 07, 2004 10:07 AM > > To: vanagon@GERRY.VANAGON.COM > > Subject: ECU question > > > > Hello List, > > The patient is an 87 Syncro van, that has some hesitation after warm up. > > I > > have checked the grounds, ICV & ICU, temp sender and the AFM. Still no > > change. If I turn off and reset the computer all seems to be fine for a > > short period of time, but starts slight hesitation soon after. > > > > My question is concerning the ECU computer. How often do they good bad? > > What is the best way to check it? > > > > Can I rule out fuel delievery problems because it runs fine after a > > reboot? > > > > Thanks > > > > dylan > > |
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