

| Subject: | Re: Cold start 3 cylinder stalling and bucking idle insanity!!! |
| From: | Daniel L. Katz |
| Date: | Fri, 4 Feb 2005 14:55:29 -0500 |
adam: set your analog meter on a sensitive voltage setting and check for a needle movement as you shunt across from engine to body, especially from engine to ecu case, with the engine running - this is the acid test. also, while cleaning the terminal surfaces is a good idea, the weak point on that bonding strap is the crimps, and it is possible to have several ohms or more contact resistance at the crimp itself - easy to check with strap disconected using a good meter. as a quick and dirty test, you could use a good set of jumper cables with jaws that really bite to temporarily make a known good bonding connection between body and engine, and also bewteen oxygen sensor housing and body (ecu) to see if that helps. we have an '84, which has a zillion individual wires from the ecu that are grounded next to the braided strap you are working on. there was a big contact resistance on the engine side crimp of the copper braid (8 ohm !!!!), and so i crimped and soldered a new ring terminal on each end the braid, and then also bundled all those individual ground wires together, freshly stripped, and crimped and soldered them using a single new ring terminal. dan On Thu, 3 Feb 2005 00:54:04 -0500, Adam H. Behle <tikiman2@COX.NET> wrote: >I forgot to add that I also cleaned the grounds with a dremel/wire brush on the left head and >firewall, but it had no effect. > >On Wed, 2 Feb 2005 23:44:51 -0500, Adam H. Behle <tikiman2@COX.NET> wrote: > >>It seems like more and more Vanagonites are having this problem more than ever these >days. >>My 87 Westy with 156K miles has the evil cold start bucking and stalling problem as well. It >>feels like it is running on 3 cylinders and stalls repeatedly. Once it is warmed up by careful >>manipulation of the gas pedal for about 5-10 minutes, all is well-great power, throttle >>response, 17 mpg. Exhaust smells a bit rich, but it has for quite some time. >> >>This is what I have done so far: >>Replaced air filter, fuel filter, oil, oil filter, and spark plugs. Found and replaced 2 broken >>vacuum lines. Checked throttle switch per Bentley and found it to be ok. I have a nicely >>humming idle control valve which was cleaned anyway. Swapped out the idle stabilizer >>control unit with a friends' and got no change in behavior. Replaced temp 2 sensor last >year, >>but still need to re-check it. All this has resulted in no change of cold idle stalling/bucking >>behavior. >> >>It seems like the fuel pressure regulator could be suspect, or possibly the "new" temp 2 >>sensor. The oxygen sensor doesn't participate in the cold idle loop anyway, so that is >>probably not to blame-right? It was replaced about 40K miles ago. My air flow sensor had >the >>"capacitor fix" when I was hunting down Vanagon syndrome a few years back. Turned out to >>be the ECU, which was replaced. >> >>So...I am at a loss for what to do next before giving up and bucking over to my mechanic. >>Any last ideas??? I'm not ready to give up just yet! >> >>Thanks, Adam
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