Sudden Death
04-20-2012, 03:20 PM
#16
Electron Wrangler
Lifetime Rennlist
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Lifetime Rennlist
Member
Don't do it on any car... its simple to avoid...
The 928 has a higher power (voltage/current) spark system than many cars and can have a higher frequency than some due to wasted spark. To hold a spark plug attached to a distributor HT cable you usually need to lean in and brace with your other hand (to the engine/body) - this is an extremely bad idea....
Once you are gripping the spark plug - its pretty difficult to let go if you get repeatedly shocked and this can lead to the title of this thread - particularly for those susceptible to Arrhythmia (and who knows...).
Alan
The 928 has a higher power (voltage/current) spark system than many cars and can have a higher frequency than some due to wasted spark. To hold a spark plug attached to a distributor HT cable you usually need to lean in and brace with your other hand (to the engine/body) - this is an extremely bad idea....
Once you are gripping the spark plug - its pretty difficult to let go if you get repeatedly shocked and this can lead to the title of this thread - particularly for those susceptible to Arrhythmia (and who knows...).
Alan
05-15-2012, 10:06 PM
#17
Rennlist Member
Thread Starter
Jim you're a genius! (that's Jadz928 for those following at home). Kept the jumper in and she fired right up and ran like a champ.
To fill in, the first thing I looked at was fuse 22. It was fine, a little discolored, but okay. I swapped it out anyway with a new spare that I had.
Next, pulled the fuel pump relay and jumpered the fuel pump (I first removed the cover under the back of the gas tank to inspect the pump physically and to hear it better). When the pump was jumpered, it ran fine - a good solid buzz.
Since I did not have a spare fuel pump relay, I couldn't tell yet if that was the issue. After I jumpered the fuel pump, I pulled out the jumper because I was afraid to leave it running like that. The early cars also do not use the 53 relay for the fuel pump.
So to be sure and try to narrow things down, I tried firing the car - it coughed - like it got some fuel, and immediately died. Jumpered the pump again for a brief instant, and again fired it up and it coughed and died.
For giggles, I then checked for spark. Followed Alan's advice from the post above, and there is good spark.
Then Jim called me back and told me to leave the jumper in and start it. I did, and the car started fine and ran strong. So, the issue is simply a relay. I intend to replace the fuel pump anyway, as the heat soak at fuse 22 and behind the relay indicate the pump might be having a problem. I did the CE panel R&R last year, and the problem has not gotten worse, but why take a chance on a fuel pump that may be nearing its end based on what I see on the panel. Besides, it looks like a fairly strait forward job.
To fill in, the first thing I looked at was fuse 22. It was fine, a little discolored, but okay. I swapped it out anyway with a new spare that I had.
Next, pulled the fuel pump relay and jumpered the fuel pump (I first removed the cover under the back of the gas tank to inspect the pump physically and to hear it better). When the pump was jumpered, it ran fine - a good solid buzz.
Since I did not have a spare fuel pump relay, I couldn't tell yet if that was the issue. After I jumpered the fuel pump, I pulled out the jumper because I was afraid to leave it running like that. The early cars also do not use the 53 relay for the fuel pump.
So to be sure and try to narrow things down, I tried firing the car - it coughed - like it got some fuel, and immediately died. Jumpered the pump again for a brief instant, and again fired it up and it coughed and died.
For giggles, I then checked for spark. Followed Alan's advice from the post above, and there is good spark.
Then Jim called me back and told me to leave the jumper in and start it. I did, and the car started fine and ran strong. So, the issue is simply a relay. I intend to replace the fuel pump anyway, as the heat soak at fuse 22 and behind the relay indicate the pump might be having a problem. I did the CE panel R&R last year, and the problem has not gotten worse, but why take a chance on a fuel pump that may be nearing its end based on what I see on the panel. Besides, it looks like a fairly strait forward job.
05-15-2012, 11:10 PM
#18
Rennlist Member
Besides, it looks like a fairly strait forward job.
05-16-2012, 12:03 AM
#19
Rennlist Member
Thread Starter
05-16-2012, 12:47 AM
#20
Rennlist Member
I RECENTLY had a pump relay failure - 2nd time in maybe 5k miles. It was a bit unexpected, so I swapped back in the one that had previously failed - fired up fine. Went for a run - 40mins later, dropped dead in traffic, no pump, relay hot - and no coughing or stumbles, just died completely. Had to jumper the pump to get home.
While I was rooting around with things, I caught a spark flash out the corner of one eye - fuse 22 ! I reckon the poor fuse contact caused a higher than usual current, which killed both relays. I have now replaced 22 and some other fuses (sunroof, windows, headlights) with my blade fuseholder adapters. This enables me to plug in a digital ammeter with blade fuse contacts, and it now shows the pump pulling 7A, which I am happy with. Check your current for something close to this.
jp 83 Euro S AT 54k
While I was rooting around with things, I caught a spark flash out the corner of one eye - fuse 22 ! I reckon the poor fuse contact caused a higher than usual current, which killed both relays. I have now replaced 22 and some other fuses (sunroof, windows, headlights) with my blade fuseholder adapters. This enables me to plug in a digital ammeter with blade fuse contacts, and it now shows the pump pulling 7A, which I am happy with. Check your current for something close to this.
jp 83 Euro S AT 54k
