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Date:         Sat, 25 May 2002 14:28:59 -0700
Reply-To:     Mark Keller <kelphoto@HIGHSPEEDPLUS.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark Keller <kelphoto@HIGHSPEEDPLUS.COM>
Subject:      Loss of power
Comments: To: Mike Finkbiner <mike_l_f@HOTMAIL.COM>
Content-Type: text/plain; charset=us-ascii

Hi Mike,

Sorry to hear you having this problem. I wish I had a magic answer, but I don't exactly. I know your well aquatinted with the list and this issue. I try to repeat some of the previously offered point to consider. As in the past I work with you as long as you want.

The Basic premise is that the ECU gets confused and needs to be reset, then the van runs fine until the "event" that confuses the computer occurs. You've mentioned the "BAD SOLDER JOINT ECU" issue. Other events that confuse the computer invariably deal with a wire harness fault. Some favorite failure points

The main ECU connector; a service bulletin state that the earlier connectors were weak, later connectors had a round spring clip added to increase the strength. I clean all contacts with Tarn-X, rinse, blow dry, then apply OX guard or some such electrical contact enhancer.

In fact a complete TARN-X treatment on every engine compartment connector and ground would be my basic suggestion.

Further I would check each major wire that feeds the ECU, for continuity, not every one just the majors, HALL SENDER, AFM, TEMP 2, and O2, for a good resistance, before replacing any of these items.

The temp II is my first suspect after all of this, they do seem to have a rather short life on my vehicle, especially the VW ones, every 6 monthes to a year, but the Vw ones allow the ECU to go close loop about 2 minutes faster than the aftermarket type.

Next the O2, since something else is a miss the O2 takes a beating by getting coked up with a rich mixture. My first try is that you can possibly remove the O2, heat the tip with a propane torch to remove built up soot, and even check with a digital voltmeter, to verify that its at least creating voltage when you heat it up.

A bad or weak connector to the hall unit. This ia a favorite of mine, the ECU sensor input give an momentary false rpm signal, and the computer adjust, then the confusion cycle. The connector breaks just inside the distributor housing. Wiggle it while running, may be a miss with occur. Other listmembers post that the tach, if you have one will drop, if your looking at it, and it happens long enough to observe.

The O2 sensor cable is shorted from the ECU to the sensor, this is regardless of the sensor being connected. use microphone cable to replace the entire lead.

If you wash your engine, like I do, consider reconfirming the operation of the Idle and WOT micro switches at the base of the Throttle body.

Let me know how it goes pmail, since I'm on digest

Sincerely,

Mark Keller 91 Carat Cowichan Bay, BC

PS I just read your I've got aluminum on my spark plug threads. Perhaps you've had these out or the mechanic before, only takes once to cross thread it. Back to you basic issue, fouled plugs would perhaps be a symptom.

The thing to check though is on the original metal jacket spark plug boot. An old style wire end and a new style end are unfortunately not compatible but will assembly, PUSH the wire into the boot really well, there is a diagram in the Bentley but the basic problem is that one is a large copper/brass end type, and the new one is a small diameter affair. But this problem usually is a miss at idle.

Automatic digest processor wrote: > > There is one message totalling 67 lines in this issue. > > Topics of the day: > > 1. Loss of Power, Backfire > > ---------------------------------------------------------------------- > > Date: Sat, 25 May 2002 04:00:47 +0000 > From: Mike Finkbiner <mike_l_f@HOTMAIL.COM> > Subject: Loss of Power, Backfire > > Had an interesting day. I was headed out for a weekend of camping, and > about 30 miles out of town, my '87 Westy sort of bucked and lost power, then > kept running. Another few minutes, it did the same thing, and sounded like > it backfired. > > Fortunately I was coming up on a rest stop, so I pulled in and let it idle. > It ran OK, but when I put it in gear and pulled ahead to get to a better > parking spot, it backfired and died. > > I have a digitool, and didn't see any odd readings. > > A couple of months ago I had a problem with the van loosing power something > like this, but when you re-started, it would run OK for a couple of minutes. > I added an additional ground wire to the ECUs O2 sensor line, based on > another list member's suggestion, and that seemed to solve the problem for > several 50 mile trips. > > So, I wondered if I could get by with disconnecting the O2 sensor. After I > did, it started and idled OK, but when I started to pull back out onto the > highway, it died completely, and had to be pushed back to a parking spot. > It wouldn't re-start and run. > > After mulling things over for a few minutes, I re-started, and it idled > fine. > > I pulled the fuel filter, and blew through it - no problem. I re-installed, > and it started and idled OK. > > I have a spare ECU, the TA unit that came with it, so I pulled the 2 year > old Bosch ECU and replaced it with the TA. Again, it started and ran OK. > > After running around the parking lot, I drove home. > > Gas is Chevron, from a local, fairly busy station. The digitool readings > for Temp 2 and AFM were pretty normal. I left the O2 sensor disconnected on > the way home. > > The inside of the tailpipe is pretty black. I have been getting 16-18 mpg > on the highway. > > Tomorrow I should pull the plugs and see what they look like, then put the > Bosch ECU in and go for a drive. I really don't want to keep the TA in, as > it seems to have an intermittant loss of power problem, possibly due to a > bad solder joint. > > Any suggestions for other things I could look for? > > Mike Finkbiner > '87 Westy > Moscow, ID > > mike_l_f@hotmail.com > c


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