On Thu, 07 Jun 2007 22:29:27 -0700, wrote:

>On Jun 7, 11:40 pm, "dave AKA vwdoc1" > wrote:
>> > wrote in message
>>
>> oups.com...
>>
>> > it's the ECU!!! i am sure
>>
>> WELL that is one possible cause, but I say check all of the wiring from the
>> ECM/ECU plug using the Bentley testing chart. If the ECM/ECU is not getting
>> power and ground then it will not work. ;-)
>> Bentley $44.07 http://tinyurl.com/22obwb or the long linkhttp://www.amazon.com/Volkswagen-Jetta-Golf-GTI-1993-1999/dp/08376036...
>>
>> The ECM should be the LAST thing to suspect and change!
>> Ign switch is one of the first I look at.
>>
>> > i dont have the vag-com.. it could have saved me a lot of time...
>> > but yeah i did check the fuses and relays first thing.. i just can't
>> > recall seeing the check engine light on recently, either when cranking
>> > or running, but like you said i think it could be a bad bulb, mine had
>> > been overworked.
>>
>> Some use the vag-com clones found on Ebay for around $20. I am not sure
>> that they work but for $20...........why not try one! ;-)
>>
>>
>>
>> > i did clean all the connectors, spayed CRC cleaner on every each one
>> > them... i only disconnected and clean the inside a few connectors that
>> > i suspected getting showered by the coolant, and ones that go to
>> > camshaft sensor, crankshaft sensor and coolant sensor
>>
>> > i found out that in case of a faulty coolant sensor, the ECU will use
>> > the default 80 C or 176 F, so it's not the coolant sensor. also on
>> > 2.0L engine the camshaft sensor only works for advanced/retarded
>> > timing and the engine can start with it disconnected, so neither the
>> > camshaft sensor
>>
>> > i was able to download the bentley manual for BMW 3 series and check
>> > the Jetta crankshaft sensor following the instructions, the resistance
>> > across pin 1-2 is 570 ohms compared to 1280 ohms specs of that of the
>> > BMW. checked with napaonline and they are different part numbers,
>> > albeit looking exactly the same.. while i have no idea if 570 ohms is
>> > still within specs, at least the sensor was not completely dead,
>> > yes?
>>
>> > i reached under the rain gutter and tapped the ECU a few times with a
>> > wooden stick, then cranked the engine and noticed a significantly
>> > slower crank, some sort of resistance that caused by chamber
>> > combustions, though weak and uneven.... also another good thing was
>> > that the dash shift indicator worked correctly. tried cranking about
>> > five times more but still no start.
>>
>> > so i pulled the ECU off the compartment, unpluged the harness and
>> > examined the wires and prongs, made sure nothing was broken or loose,
>> > put everything back, and the first thing i noticed was the dash shift
>> > indicator turning wacko again.... i tapped the damn ECU again, and
>> > this time it's like beating a dead horse..
>>
>> > i'd probably look for another ECU at a junk yard, dont know if i'll
>> > have much luck finding used VW parts in houston TX... haha...
>>
>> ebay has a '95 ECM going pretty cheap right now http://tinyurl.com/2g9rl7http://cgi....e-ECM-95-Volks...
>>
>> You NEED to make sure all the ECM's numbers and letters are identical to
>> yours.
>
>
>hi dave
>
>i'll look for it on eBay, thanks for pointing that out.. i've haven't
>bought anything from eBay for like two years, but i'd been an eBay
>junkie before...
>
>long before it died my jetta would behave like a barometer, running
>erratically on a humid day, misfires, hesistation.. etc. now it only
>makes sense if a failing ECU is resposible for that.. why did VW
>engineers decided to hide the engine computer under the rain gutter is
>beyond me, did they set up their home computers in a barn too?
>sheesh!!!
>
>now what is responsible for a failing computer? beside short circuit,
>i'd say water, heat, humidity, shock.. and so on.. and also some
>pointers led me to the Split Fire spark plugs that i used in the last
>tune up. when i pulled them out, 3 out of 4 look corroded and fouled.
>some people believe that the unsual shape of the electrode creates too
>much electro-magnetic noises (RF interferences) that eventually
>damaged the engine computer chip. i am not so sure about that but i'll
>stay with Bosch or NGK platinum from now on
>
>til i find another brain for my jetta..
>
>thanks
That idea about excessive rf with Splitfire is about the stupidest
thing I have heard. But I am not an electrical/electronics engineer.
What kind of noise do you create with bad/leaking spark plug wires?
What kind of noise do you get when a trucker drives by with a cb
running at 50 watts? What do you get when you drive under power lines?
What kind of RF do you get when you are around a nuclear explosion?
Well I know the last situation makes for a bad day with many things
electronic. But if you don't have your iodine nearby it probably
doesn't matter if the heat did not get you.

The brains of most engine management computers have some basic RF
shielding built in. I believe my Toyota repair manual says do not
mount a CB radio next to the computer though. I am sure that also
means no shortwave radio nearby.