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93 Passat GLX starting problem

I've been having a problem with my 93 Passat GLX starting. About a month and a half ago I would hear this clicking noise from under my dash. Finally, a couple days later on my way to work, the car just died. The shop I brought it to said they drove it off the tow truck. They said my fuel pump relay was bad. Makes sense. The clicking was the relay. They replaced it with a generic relay of 10 Amps. This car has a 15 Amp circuit for the pump. I drove it for about 3 weeks, each time starting fine. I stopped into a store and came out and it wouldn't start. The engine cranks and everything. Sounds just like it would when it starts but never catches. So I walked down to a NAPA to get another relay. I don't know much about electric `circuit so I was questioning the 10 Amp fuse instead of the 15 Amp. They didn't have one. I get back to my car and put the relay back in. Tried it again. Boom. Started. I drove it for about two weeks and the same thing happened. Tried reseating relay. No luck. This time I went about three or four days without the car. I jumped into it one night just for the hell of it. Boom. Started. Drove it for a couple days, then it wouldn't start. I thought that perhaps I was not getting power to the primary circuit in the relay. I got a multi meter out, removed the relay and tested the primary (I believe pin 85 and 86). It looks like I have voltage there. I don't recall if it was 12 volts or not. I thought that I might have a ground problem, so (in the parking lot of Home Depot. It decided to get me there but didn't want to leave) I spliced into the ground wire (brown) on the fuel pump and fastened it to a screw that holds the lid on. Boom. Started. It got me out of that problem but again, a few days later wouldn't start again. It doesn't seem to have anthing to do with temperature or humidity. It hasn't started on Hot dry days or cool rainy ones. Seems everytime I climb into the trunk with the multimeter and have a friend try cranking it, it starts. I'm trying to figure out if the pump is getting current. I set the multimeter on Ohms with the audible setting. Puting one probe in the hot wire and one in the negative, it sqwaked. I think that means the ground is good. Is there anything else that you can think of that could be this intermittent.

I tell ya, when the car starts. It runs great. It's just starting.

Anyway. Thanks in advance. I know. Tough to look at electrical problems without looking at the car.

Later.

Mike.

Reply to
Mike Smith
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If you are burning relays, the pump or the circuit to it is bad...

Reply to
Eduardo Kaftanski

I only had the one relay go bad. The car is almost 11 years old. I guess that can go bad over time. I replaced the 10 Amp one with a regular VW one. Like I said, I'm not much of an electrical trouble-shooter. I got thinking about this since my first post. I haven't had this problem since I had the orginial relay problem. I haven't been burning relays out. I am starting to think there might be a problem around the fuse panel. Just that I haven't had the problem since the relay went. I think I heard a noise when it burned out. Perhaps I have a connection that arched or something. It just seems weird that the car runs fine once it starts. Is there a difference between initiating a circuit and one that is already started. I was wondering if the primary circuit on the relay might not be engaging the secondary one.

I don't know. Any suggestions....

Reply to
Mike Smith

I have seen two A2s that had a similar problem. On both cases after I tightened the main fuel pump terminals in their plugs = no more problems. It may not be your case but easy and cheap to do. :-)

**** Now do you hear the fuel pumps running after/during you crank the engine over? You can always hook up a switch to power up the fuel pumps if you encounter another non-start problem. It should work if the problem is in the relay. :-) later, dave
Reply to
dave AKA vwdoc1

Because it is so intermittant, I would wiggle the ignition while you have the volt meter connected and see if it the ignition switch is flakey. The ignition switch gives the initial power to the fuel pump relay in order to start it. You know, the small buzzing sound.

Reply to
Peter Parker

snipped-for-privacy@zero.com (Peter Parker) wrote in message news:...

Ok. So here's an update. The car started working pretty reliably. For the most part I think there was only two times it didn't start in about two and a half weeks. I was starting to get comfortable. Anyway. The two times that it didn't start, I gently and I mean reaally gently wiggled the wires that were coming down into the fuse/relay panel. The car would start great. So I was figuring that I got a problem in the fuse panel. I brought it over to my friends and we dropped the fuse/relay panel. Tested the car. It wouldn't start. I jumped in the trunk with a multimeter. I tested for continuity between the Red/Yellow (power wire) and the Brown (ground). I got a beep out of my multimeter. I figured the circuit is good. I had my friend try starting it. I tested power to the Red/Yellow wire and used the Brown for negative. No power. I used the scre hole (unpainted metal) for the ground and had him try it again. Still no power. I tested the plug where the relay plugs into (relay number 12) I got power on one of the small terminals and power on one of the larger terminals. I forgot which ones exactly are the hot ones. The terminal numbers are 86 and 85 for the primary (small) circuit and 87 and 30 for the secondary (larger. to power the pump). I tested these with a indicator light. I used the ground block that is the the upper left of the fuse/relay panel. I figured that somehow the relays primary circuit wasn't closing and giving power to the secondary circuit. I made a small ground and attached it to the primary circuits terminal (the little whole in the terminal) and attached it to the ground block. I put the relay back in and tried it. The car didn't start. When I put the key in the accessories position I could hear the pump making noise. I realized that wasn't normal. I never emeber hearing the fuel pump by putting the key forward like that (just before it cranks) I removed the ground from the relay and plugged it back in. I remounted the fuse/realy panel. Pushed the car out of his garage because it still wasn't starting. Was planning course of action (where to tow it to). Decided to try it again. Boom started. I drove it aobut 10 - 15 miles to charge the battery up. Got back to his place and turned it off. It started again. On my drive home when I hit bumps I'm sure that I could here a relay clicking (above all my tools rattling around). I reached under the dash and relay in position 21 (third from the left on the top) was really hot. I got home. Turned it off then started it right back up. Got up this morning, no go. Wouldn't start.

I had purchased the Bentley Manual (W42 WD BOOK VW 05) for a wiring diagram. It has some stuff (ie. Fuel Pump, Air Conditioning, etc) but I don't see a Fuse/Relay Panel layout.

Is there anything else that might short out and prevent the fuel pump from getting power? I had my ignition switch replaced about 6 months ago and that seems to be fine. Anything with the O2 sensor or Oil presssure switch? I just wondering if if thinks there might not be enought oil it might try to stop the car from starting.

So there it is. I know. Sell it. I gotta get it running to do that.

Any info (and this forums been great in the past) is much appreciated.

Mike.

Reply to
Mike Smith

Did you jumper the fuel pump relay terminals so the fuel pump would run continuously? Relay should be at Fuse Box position #12 (lower right corner??)

FP Relay will or should operate while cranking the engine and at least for a second or two after you release the key. Now it may not run if does not get a signal from the ECM. Did you check fuse #18 (I think) powers both the fuel pump and Oxygen Sensor Heater. So that could be your problem if you have a problem with the wiring to the 02 sensor. Try unplugging the 02 sensor and see if that helps you out any.

I don't think the paper Bentley will have the wiring diagrams for the GLX nor VR6 engine information. :-( Some of the older Bentley CDs should have the info though. If you keep an eye out you will find them on Ebay from time to time.

later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

OK. The shop I finally brought it to replaced another relay. This one was position 21 (third on from the left on the top.) They said it has to do with ignition and fuel. I only got to talk to the guy at the from desk so he wasn't real clear on what they did. I was looking in my bentley manual (W42 WD BOOK VW05). I don't see a relay layout for the Passat GLX (2.8L). I see the Corrado (up to Jan 93/from Jan

93), the Passat 2.0L, and the Syncho. All the diagrams I have wither show that as open or an ABS relay.

Does anyone know what that one is. Again, position 21 (third from the left on the top).

Thanks, yet again.

Mike.

Reply to
Mike Smith

Do you have the old relay? What are the numbers on it?

There is a J271 relay in the wiring diagram, but I am not sure if it fits in position 21. It is a power relay for the ECM though so maybe?????

BTW is the Passat running well now?

later, dave Reminder........ Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you are a mile away from them, and you have their shoes. Frieda Norris

Reply to
dave

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