

| Subject: | FIXED runs well for a minute or two |
| From: | Jim Felder |
| Date: | Sat, 22 Jan 2005 16:27:36 -0600 |
Sam, Milo and Ken, Thanks for your help. It was ultimately the advice in this post to do look for poor connections that did it. I unplugged the connector to the black box on top of the air filter (AFM?) a number of times when troubleshooting the problem ( the car running richer and richer until it stalled) along with the O2 and TempII sensors. When I would disconnect the AFM block, the car would die. BUT when I disconnected not the block going to the AFM but to the next connector, the one that the anti-bucking pigtail is plugged into, it actually ran better. Unplugging and replugging this connection, which I never touched during removal or installation, evidently cleared up a contact problem and the car ran fine after that. I put about 10 miles on the interstate, ran great. Thanks for your help and support, Jim ( On Jan 22, 2005, at 1:34 PM, Sam Walters wrote: > Perhaps the ECU, which isn't usually the problem, or perhaps the idle > stabilizer. > > Attached are some files from the list archives which will help with > diagnostics. > > Sam > > -- > Sam Walters > Baltimore, MD > > 89 Syncro GL > 85 Westy Weekender > > All incoming and outgoing email scanned by automatically updated copy > of Norton AntiVirus. > > On Fri, 28 May 2004, Michael Rule wrote: > > >>> HI Hans (and anyone In The Know), >>> >>> Can you help me out please and give me an idea of what the TSII >>> does? Might help in the future if my basic trouble-shooting >>> skills offer no help in the fuel-delivery department! > > > It measures the engine temperature. The ECU uses this information to > provide a richer mixture when the engine is cold. > > If it fails shorted, the engine won't fire when cold. > > If it fails open, the engine will start fine when cold but will flood > out > and die when it warms up. > > On my aircooled bus, I worked around a bad Temp II sender for a while > by > disconnecting the wire when it was cold, then grounding it when it > warmed > up a bit. I've heard since that it's better to connect it through a > test > light than to just ground it, to leave a little resistance in the > circuit. > > It's amazing how suddenly an aircooled engine with an open Temp II > sender > will die when it gets warmed up. I had it cut out at 55 mph like I'd > turned off the switch. > > > David Brodbeck, N8SRE > '86 Volvo 240DL wagon > '82 VW Vanagon Westfalia Diesel > > Maintenance troubleshooting tips > > If you've verified that the senders are OK, it may be a wiring issue. > > - Sounds like your ECU is in 'warm' mode even when the engine is cold. > > - Step one is to reseat all the electrical connectors in the engine > bay, > sometimes you can isolate this kind of problem by wiggling connectors > to > see if it changes the idle. Making sure the main connector to the ECU > is > nice and tight can't hurt either, since all the sensor wires come > together > right there. > > - I assume you've already cleaned up the big ground connection on the > left > side head, if not, do so! > > - Also check the condition of the ground braid from that ground point > to > the firewall. It's fairly cheap to double-up this connection with a > second > ground braid. > > - The most common failure point in the cold-start to warm-running > transiation seems to be the Temp Sensor II (water temp sensor, on the > thermostat housing). Sounds like you've verified that the sender is > OK, so > make sure the connector is in good shape, and that the wires are well > crimped into the connector. > > - There's also the Temp Sensor I (air temp sensor, inside the AFM), > make > sure the connections to the AFM are nice and tight as well... this one > rarely seems to fail (based on reading various posts to this list), but > I've had similar cold start symptoms when I've forgotten to reconnect > the > AFM connector after having the air box out. > > - Vacuum lines are also real important! Make sure they are all tight > and in > good condition. Twenty years takes it's toll, it may be a good idea to > just > replace 'em all. My van came with a wide variety of dry rotted, loose > or > collapsed vacuum hoses, most of which have been replaced now (ongoing > process, it doesn't seem possible to find *all* the sizes you need at > any > one FLAPS... or two... or even three). > > I've turned my '85 from a rough runner to a smooth one just by > cleaning up > the big ground connection, adding a new ground braid, and replacing old > vacuum lines. It's cheap maintenance, and made a world of difference. I > hope yours is as simple a fix! > > > At 04:37 PM 6/16/2004 -0700, you wrote: > >> Ok, time to put on your thinking caps. Can anyone solve this by >> sheer brain power alone? >> >> Details: >> 1985 1.9l Westy w/Auto Trans and Air Conditioning >> 145k miles >> Compression fair (around 120-125 each cylinder) >> Recently replaced Digital Idle Stabilizer >> Recently replaced AFM >> Timing @ 5BTDC >> >> Symptoms: >> >> When warm runs fine. Get 17-18mpg on the highway @ 65mph, so I don't >> think there is any gross mechanical problem with the engine or >> mis-tuning. >> >> When cold (60F), it starts right up, but quickly (either immediately, >> or within a minute or two) the idle is rough and the engine will die >> when in Drive, and sometimes even when in Neutral. I have to keep >> one foot lightly on the accelerator to keep it from stalling. Within >> about 10 minutes of driving, the problem goes away. >> >> I've tried setting the idle higher when cold (with a few turns of the >> idle adjustment screw). This solves the stalling problem when cold, >> but then when the van is warm, the idle is way too high (1500+ rpm). >> >> I've gone through the Bently and done most of the electrical digijet >> diagnostics (resistances of temp senders when cold and hot, etc.) >> without finding anything amiss. >> >> Ideas? > > > Tim Demarest > tim.demarest@pobox.com > This might not be running lean at all but just the oxy sensor saying > so. Is > the tail pipe black and are ther plugs sooted > what ECU are you using stock or HP European version > check the basics > throttle switch > fuel pressure both at ilde and at 2K > pin test per Bentley > timing at idle and total advance plus timing responce to the throttle > opening > check the vac advance and retard canisters for leaks > compresion cold and hot the tesiting I did on the engine stand showed > you > had 180 PSI cranking with all the plugs out > if you need a unfooled around with AFM let me know > Robert Lilley spent alot of time and effort with the increased fuel > pressure > idea and I would think this would be a problem with cold starting > starting > due to the extra rich fuet miture > I will CC this to him > > going faster miles an hour with the heat on > Bob Donalds > Boston Engine > <FI system diagnostics Keller.zip>2.1 Idle stabilizer explained > > Jeff, I had a problem with erratic idle on my 88 GL, as you describe. > With the engine warm, I disconnected the idle stabilizer valve and the > erratic idle stabilized. Supposedly the idle stabilizer is cut out of > the circuit when the engine warms up, but if there is a fault in the > idle stabilizer circuit - either the ISV(up on top of the engine or the > Idle Stabilizer Control (ISC) - a black box located just forward of the > right hand brake light (remove the tail light for access)- this erratic > idle can occur. > > If this is the source of the problem, you can drive quite safely with > it > disconnected until you can get the right repair. > > The idle stabilizer circuit does three things. > 1) Kicks up the idle until warm-up after a cold start > 2) Kicks up the engine RPM to avoid stalling when the power steering > turn limits are reached ant the power steering pump is loaded. > 3) Kicks up the RPM to avoid stalling at stoplights, etc, in traffic, > when the air conditioner cycles on and off. > > Good Luck. > > John Rodgers > 88 GL Driver Drillock on O2 causing FI problems > > Classic symptoms of a problem with the OX sensor wiring or the sensor > itself. > The ECU just IGNORES the OX sensor signal until the coolant temp sensor > tells it the engine is warmed up. > THEN it uses the OX sensor signal to adjust the fuel mixture for best > ratio. If the signal it sees is screwy it will badly mess up the > mixture > trying to correct it. It won't do this until the engine has been > running > for a few minutes. > > Many times this problem is caused by someone splicing a generic OX > sensor into the OEM wiring. > The splice becomes a problem either right away or some time down the > road. > > Another common cause of OX signal errors is the GROUND for the OX > signal. This is the small brown wire that comes out from the same small > bundle as the hall connector to the distributor. The brown wire has a > small ring connector on it and it gets attaches in various places as > different people work on the engine. It should be removed and cleaned > to > shiny metal. Then it should be screwed down to the engine at a place > where it is against shiny METAL. Commonly it gets screwed down against > the plastic of the oil breather tower and this is not a good place. > > Mark
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