QuestionQUESTION: so heres my question: i have a 97 a4 1.8t with starting problems. on cold starts (at least leaving it untouched for 6+ hours) the car starts perfectly fine. as soon as i drive to the gas station up the street turn it off or go to the store for instance it will not start if left turned off for more than 30 seconds otherwise it will start up fine again. the problem is intermittant since it will take anywhere from 5-20 start attempts to get it started and running. even when started it may run idle for 2 minutes and shut down again or, more commanly, turn over and shut down right away as if someone was turning the ignition off. i have taken it to a number of mechanics and to differnet delaerships and no one can figure out the problem. the common denominator however is that it is electrical. when the car shuts off you can hear the relays click and the dash lights flash (not the common flashing when the ignition is on and the car is just not started but the CEL for example flashes erradically). now the car sat parked for about 2 months and for the 2 week period after it was driven frequently all was well but the problem again is getting progressivley worse. i already had the ignition switch replaced as per the re call. it does not throw any codes while experiencing this problem. lights, wipers etc stay on all the time while this is happening, playing with the key in the ignition does not affect it. the key however seems to have a lot of play while in the on position. i also know this is not the igniton switch since the car is equipped with an aftermarket starter and using that to start the car has the same symptoms. i had the starter disable to isolate this as well. there is moisture under the dash closest to the firewall on the drivers side and on the carpet below the drivers feet. im not too sure if this perhaps creating a short or not. in addition to the switch being replaced i have also replaced the coolant temp sensor, a module which sits on top of the airbox (not too sure what its called right now, its a solid state that bolts on and connects two identical plugs). when the car is started it runs perfectly fine (thought it may be fuel related but no misfiring and fuel delivery seems fine as well it has good power still). when i turn key to the on position and leave it there for more than 5 seconds and try to start from that position the car will not turn over at all. i have recently found as well by turning it on and revving to a high rpm when it decides to shut down if you very quickly turn the key to the off then on position it will restart and slightly backfire. i am doing this now to try to save the wear on the starter. when this is all happening a lot of fumes come out of the exhaust but not burning coolant or oil. was told that cam position sensor seems fine, possibly ecu. uhm... the plastic gaurd that sits below the wiperblades between the windshield and hood is sitting low on the drivers side and perhaps letting water in? dont know if theres anything important there or if thats the reason theres moisture on the inside firewall or carpet on drivers foot. i literally can turn the car on, redline it and it still shuts right down.
any help would be greatly appreciated since this problem has been on going for 8 months now and im seriously thinking about driving the car into a lake and calling it in.
thanks in advance.
ANSWER: Sounds like perhaps your ignition relay is flaky, did your mechanic change that yet? When you say it will not start, it does turn over but does not fire, correct? Or the starter motor does not turn? Let me know, Jan
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QUESTION: to be honest i dont think that was looked at. do you happen to know what relay number it is:? or even beter yet, where it is? i'm assuming its under the steering coulmn somewhere. when i start it starts just fine, but immediately shuts off, best way to describe is exactly if you started your car normally and turned the ignition back off.
ANSWER: I think it is under the lower dash, but cannot be sure and I am travelling out of state; don't have access to manuals... Let me know if you cannot find it; the relay descriptions are normally on a sticker on the inside of the lower dash panel. Jan
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QUESTION: hey, thanks for the all the help by the way. so i took it apart today and tried but couldnt find that sticker. so i fished around town today... one "tech" said it was in position #4. so i ask the parts guy for that realy and he said "well its the relay for the head lights/tail lights" so i was a little reluctant to change it. i then asked him specifically for the "ignition relay" he looked around and said "the car doesnt have one, the ignition is completely controlled by the ECM". so i hit the rown 30 miles away to the next dealer where they told me "i'm not sure which relay it is, you're going to have to tell me the relay position/number/part number". ahhhh.... well... i did find one interesting thing though. it seems the problem is directly related to the check engine light. heres the thing: if you turn ignition to the on position, leave it there for 5-10 seconds and crank from that position and the light stays on, it starts no problem. if you do the same thing and the light goes off and then try to crank it does not turn over. as well, if you start it and it runs for a few seconds, the CEL will flash and go off until the ignition is reset. perhaps a relay for the ECM? ECU? dunno where to get a bentley manual at this time... ???
AnswerI think this will be either fuel pump relay or ECM... I enclose manual section, sorry no pictures, you can buy manual CD online of from Bentley... At some point you will need wiring diagrams etc.
Fuel pump relay and relay triggering, checking The fuel pump relay is located at position 6 of the central electrical panel under the left side of the instrument panel.
Checking fuel pump relay -J17-
Remove shelf in left front footwell.
Remove fuses 28, 29 and 34 from fuse relay panel.
Connect VAG 1527B voltage tester between Ground (GND) and either of the fuse 28 terminals using jumper wires from the connector test kit VW 1594.
Briefly operate starter.
Fuel pump relay must be felt and heard ("click")
Voltage tester must light up
If fuel pump relay does not operate:
Check triggering => page AUDI-B5-FU01-24-005-0124-27.
If voltage tester does not light up:
Repeat test on other terminal for fuse 28.
If voltage tester still does not light up:
Check fuse 28 wiring to terminal 30 (relay position 6), repair as necessary.
Connect voltage tester between Ground (GND) and each terminal of fuse 29, in sequence.
Use scan tool "Output Diagnostic Test Mode" function 03 to trigger fuel pump relay -J17- => Repair Group 01.
Fuel pump relay must be felt and heard ("click")
Voltage tester must light up
If voltage tester does not light up:
Repeat test on the other terminal for fuse 28.
If voltage tester still does not light up:
Check fuse 29 wiring for continuity to terminal 30 (relay position 6) using wiring diagram, correct as necessary.
Connect voltage tester between Ground (GND) and either terminal for fuse 34.
Use scan tool "Output Diagnostic Test Mode" function 03 to trigger fuel pump relay -J17- => Repair Group 01.
Fuel pump relay must be felt and heard ("click")
Voltage tester must light up
If the voltage tester does not light up
Repeat the check using the other fuse 34 terminal.
If the voltage tester still does not light up:
Check wiring for continuity between fuse 34 and terminal 31 (relay position 6) using wiring diagram, correct as necessary.
Checking voltage supply
Remove fuel pump relay -J17- from the fuse relay panel, relay position 6.
Switch ignition ON.
Connect multimeter (Fluke 83 or equivalent) between sockets 28 (B+) and 34, then between sockets 32 (B+) and 34.
Specified value: approx. battery positive voltage (B+)
If the specified values are not obtained:
Check for open circuit using wiring diagram, correct as necessary.
Checking fuel pump relay triggering
Connect voltage tester between sockets 28 (B+) and 29.
Voltage tester must light up for approx. 1 second and then go out. Tester must stay lit while operating starter.
Note:
Only by operating the starter is it possible to make the voltage tester LED go out, otherwise it will appear dimly lit (due to low current draw).
If voltage tester does not light up, check wiring as follows:
Connect VAG 1598/19 test box to ECM harness connector (ECM is left disconnected) => Repair Group 01.
Switch multimeter (Fluke 83 or equivalent) to measure resistance ( Ù ) and check for continuity between relay socket 29 and test box socket A5 using jumper wires from connector test kit VW 1594.
Specified value: max. 1 Ù
If the specified value is not obtained:
Check for open circuit using wiring diagram, and correct as necessary.
If the wiring is OK and the voltage tester does not light up:
Replace ECM => Repair Group 01.
If the fuel pump relay triggering and the wiring is OK:
Replace the fuel pump relay.
Re-insert the removed fuses.
Hope this helps, Jan
