Home Technical Discussions Volkswagen Rabbit, Jetta, Scirocco, Convertible: 1975-1984...

Volkswagen Rabbit, Jetta, Scirocco, Convertible: 1975-1984 (A1) new issues w/83 rabbit gti that doesn't wanna run


Permlink Replies: 9 - Pages: 1
Last Post: Apr 14, 2014 5:34 PM Last Post By: tcovenant2000
bunnylebowski

Posts: 9
Registered: 06/21/13
new issues w/83 rabbit gti that doesn't wanna run
Posted: Jan 30, 2014 9:22 PM
  Click to reply to this thread Reply
so, while working on my 83 rabbit gti trying to get it to run, I noticed something. when I turn my key to accessory, before I start it, the rpm dial shoots way up as far as it'll go. it never did that before. & what's even more disturbing, is that after it cranks, & turns over it'll run for three seconds, maybe 5, & the fuel pump relay is clicking like crazy...click, click, click, click....super fast. I know that it's the fuel pump relay, because I put my fingers on it while i started it to be sure. yikes!!!! any ideas out there?!? please!?
tcovenant2000

Posts: 1,746
Registered: 12/09/03
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Jan 31, 2014 8:29 PM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
Now it's making sense. Now I know where the problem is!
You've a problem with the coil wire. I'll try to explain.

The hall sensor creates a signal that goes to the electronic ignition to tell the transistor when to turn on and off. This signal is amplified by the transistor in the electronic ignition and sent to the coil. It is also sent to various relays which need to sense speed. It's also sent to the fuel pump relay, which needs to know that the engine is running. In addition to all of this, it also goes to the cluster to feed the tach.
The fuel pump relay is designed such that when you turn the key, it runs for 3-5 seconds and then stops...unless it senses a signal from the coil indicating that the engine is turning over. Since the coil is getting good signal, but the relay is intermittent, the car runs for the 3-5 seconds and then stops when the fuel pump relay stops. The relay sees a coil signal sometimes and CLICKS, but this click doesn't last 3-5 seconds, only a few milliseconds. So the fuel pumps can't run long enough to keep pressure up and the car dies.

so:
Wire comes from electronic ignition to - terminal of coil. This appears to be fine, since there's good spark.
From - of coil it goes to the underdash where it is fed to the cluster and various relays.
The MOST common cause of your symptoms is simply a loose nut on the - terminal of the coil (there are three, the BIG one and one marked + and one marked -), or dirt on the terminal lugs, or the wire has broken right at the lug.
Locate the right terminal and use a small wrench to check the nut. If it's loose or missing you've found the problem. If it's loose, remove it anyway. If it's not loose, remove it. Carefully clean all the lugs for all the wires and put the wires and nut back on and snug it. Don't crank on it.
Try to start the car. If it works, then shut it off and torque the nut. If it doesn't work, remove the nut, remove the lugs from all the wires. Strip them back about an inch and cut off the old wire. Add new lugs and put it back together.While you're there, clean the + side lugs and torque the nut when you put it back on. Again, don't crank on it. Just get it good and tight. You can break the coil...especially if it's elderly.

95% chance you'll be driving in half an hour.

Thomas
bunnylebowski

Posts: 9
Registered: 06/21/13
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 3, 2014 1:14 PM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
thanks so much! I will check that out & let you know!!
tcovenant2000

Posts: 1,746
Registered: 12/09/03
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 11, 2014 6:24 PM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
Did you ever get it figured out?

Thomas
bunnylebowski

Posts: 9
Registered: 06/21/13
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 13, 2014 9:29 PM   in response to: tcovenant2000 in response to: tcovenant2000
  Click to reply to this thread Reply
so, the coil that was in there wasn't metering out as it should have been, so I bought a new one slapped it in, &...she ran like a dream!!!....until I went for a test drive. then it did the old fuel pump clicking like crazy, brake light in dash board flashing, battery voltage skyrocketing, then she died. when I first fired her up, I turned on my lights, heater fan, wipers, to see if that would cause a problem, it didn't. only when I started driving did go back to its old problem, not while idling. think it could be a problem w/the relay plate? cause I do have an extra one, & was thinking about swapping them out...or not? what do you think?
tcovenant2000

Posts: 1,746
Registered: 12/09/03
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 15, 2014 9:33 AM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
Something is loose. Relay? Ground? Hard to say at this point. I'd still want to check the - relay wire anyway. Worth taking 10 mins to remove the lugs, cut a half inch off, strip and put new lugs on.
Sounds like vibration is causing it.
Thomas
bunnylebowski

Posts: 9
Registered: 06/21/13
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 16, 2014 12:43 PM   in response to: tcovenant2000 in response to: tcovenant2000
  Click to reply to this thread Reply
I'll do that right now & let you know. thanks so much!
tcovenant2000

Posts: 1,746
Registered: 12/09/03
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Feb 19, 2014 5:59 PM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
Oops...I meant stripping back the - COIL post wires...not - relay. I think you figured it out. :)
Thomas
bunnylebowski

Posts: 9
Registered: 06/21/13
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Apr 13, 2014 6:50 PM   in response to: tcovenant2000 in response to: tcovenant2000
  Click to reply to this thread Reply
so I stripped back the coil post wires as you suggested, & to my disappointment, didn't fix it. I can get her running still, & idles wonderfully when stationary. but after I start to drive, it power surges, revs, decelerates, & the fuel pump relay starts click click clicking away. sometimes it will die, but sometimes if I stop moving it'll go back to normal. I'm beginning to get frustrated. am I overlooking something? please, any more advice would be super appreciated...thanks, hill

ps... I can take a video of our problem, if that would help explain my dilemma !!
tcovenant2000

Posts: 1,746
Registered: 12/09/03
Re: new issues w/83 rabbit gti that doesn't wanna run
Posted: Apr 14, 2014 5:34 PM   in response to: bunnylebowski in response to: bunnylebowski
  Click to reply to this thread Reply
I think you've got an issue with the coil wire to the fuel pump relay. One way to be certain is simply to jump out the fuel pump relay and drive it around. If it runs well, then your problems are fuel pump relay related. The FPR needs a good ground (those grounds are located at the 5th injector mounting bolts), +12 from Battery, +12 from switch and the coil signal.
Oh! Your symptoms can also be caused by a bad ignition switch. Just thought of it...it's not uncommon that ignition switches do that.

Thomas

Point your RSS reader here for a feed of the latest messages in all forums

Popular Discussions:
Volkswagen Rabbit, Jetta, Scirocco, Convertible: 1975-1984 (A1)
timing marks
Rabbit, Jetta, Scirocco, Convertible: 1975-1984 (A1)