TheSamba.com :: View topic

Fri Mar 02, 2007 2:37 pm

Hey y'all. I'm new, and it's kinda crappy that my first post on T.S. is one that doesn't include soft puppys and fluffy kittens. My brother actually recommended T.S. to me, and since another VW forum was utterly useless in more ways than one...I am here.

I recently purchased a 1991 Volkswagen Jetta GL. German built (I know enough of the MKII to know not to buy any other than the German ones), 173k, 5-speed (O'course) 8v motor.

The car was sitting for well over a month, but it started just fine. There was some sputtering upon acceleration and full-throttle situations. I wrote this off as a mildly gummed up fuel system. I ran half a bottle of injector cleaner in half a tank of gas. And then the other half in a full tank. This cleared up the stumbling, sputtering bit the motor was doing.

I replaced the front rotors and pads, plugs and plug wires. The battery was thought to need replacement, but it turned out it had just been somewhat weak from no use and a small parasitic drain on the electrical system. Essentially, this is all stuff that I'm used to from the six cars I've owned thus far. This is basic crap.

Now here's where it starts to go wrong...

Last week, it supposedly ran out of gas in my driveway. I went to start it for the first time of the day (to leave) and it wouldn't fire. The gas gauge read 1/4 and I could hear some gas sloshing in the tank when I bounced the rear end. But no dice..
I ran up to the Shell station and grabbed two-ish gallons of gas in a can and put it in my car. Applying a small amount of throttle, I cranked the car up and it fired no problem. It ran like crap for a just a mo', but it smoothed out lickity split.

The problem is, from that day on, it required a little bit of throttle when the motor was cold to get the engine to fire. When it was warmed up a bit, it'd start without throttle application just fine.

I've taken the Jetta (Affectionately named 'Olga') on 200 mile round trips on the interstate at 70mph. That's 3,500 revs and the car performed flawleslly. I'd never push it past that point, however. I'm not at all abusive and I take care of my cars.

I drove the car to my friend's house the other day to borrow a tool from him, which is a 3.2 mile trip exactly. Went into his garage, got the tool, came out, turned the key and it was acting like the battery had gone flat. Cranking over uber slow, getting weaker. I asked my friend for a jump. When we connected the jumper clamps, the negative battery cable turned out to have severed from the terminal itself. Reconnecting it, I tried starting the car again. It was cranking fine, spinning the motor over at a normal speed, but it wouldn't fire.

Nothing's changed. It's still sitting in front of his house. I've yet to check for spark (It was dark and his back was bothering him), but pulling out the #4 spark plug proved that it was bone dry.
I went over every wire and connection I could find in that engine bay. I checked the fuses. Gas gauge reads that I've half a tank. The battery isn't weak. The car just will not fire.

Discuss.

Sat Mar 03, 2007 1:02 pm

I read something about an in-tank transfer fuel pump. If that had been going out, could it have been the start of my cold starting issues? And my current problem as well? Or would the motor start and run off of the main pump?

Really need to nail this.. :(

Mon Mar 05, 2007 5:46 pm

I am at my friend's house now, and I just replaced the negative battery terminal since the wire snapped clean off of it.

I tried starting the car, for kicks, and it still isn't firing. Not even a tiny little sputter....

I quickly pulled all of my spark plugs and discovered that they are dry as could be. #1 had a very very faint smell of gasoline but it wore off. None of the plugs were moist in any way shape or form.

The negative battery cable snapped off from the terminal itself, which is why the car was cranking over like the battery was flat. I've been told that my ECU might have fried... But how on earth do I test for something like that?
The main fuel pump audibly primes. I know you can't hear the transfer pump in the tank..and no one has yet answered if the car would start and/or run without the transfer pump working.

Tue Mar 06, 2007 8:45 pm

Yes the car will start & run without the in-tank pump,however this will shorten the life of the main pump. You will notice an inoperable in-tank pump mostly when you are low on fuel or parked on an incline. Yes you may have damaged the computer due to lack of ground. You still have not said if you have spark or not.

Tue Mar 06, 2007 8:54 pm

I didn't even bother checking for spark. Nothing for the spark to ignite..

I spoke with a few people. Apparently in these cars, the main fuse rarely breaks before the ECU fries.

So here's what a bunch of my friends and I have worked out....

When I replaced the power steering fluid reservoir the day the car stopped starting, I had to secure my battery from sliding and hitting the new reservoir (Which would crack it) and I used zip ties for that until I figure out an alternative. My dad came out and was looking over my engine bay (As if he knows anything about cars!) and was 'making sure' my battery terminals were tight. Okay, that's fine, except what I didn't know is that the cable was only connected to the terminal by electrical tape. I figured someone merely wrapped the cable in electrical tape...seen people do it tons before.

When I drove over to my friend's house and shut the car off, it severed from what we can tell. Then when I went to leave, and tried to start the car, the lack of main ground (Or it could've been hanging on by a thread so to speak) caused a voltage spike and fried the ECU.

OR

When we connected jumpers (Which is when we discovered the cable had severed underneath the tape) all that voltage fried it.

Regardless, the vote is that my ECU is done for. It's only $50 - $80. I'll live.

And now that you just informed me that the car will start and run on the main pump alone, that rules that out... So now the only plausible cause is the ECU.

:shock: