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Join Date: Jul 2006
Location: S. Florida
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be very careful jumping terminals on that *%#! pos yellow relay.

i totally burned up 15" of 2 wires in the harness when i jumped it the same way as the red relays in front... they ARE NOT the same.

i know what 2 pins to jump on mine but i'm not gonna tell you which ones to jump because it's a time consuming liability i want no part of if it goes wrong.

and if you know your car and take care of it >>> guess what, you don't need it. throw it into orbit, blast it with a 45 ACP, or flatten it under a sledge hammer with extreme prejudice... thats my opinion.
Old 05-24-2010, 01:43 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #21 (permalink)
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Quote:
Originally Posted by mark houghton View Post
You've got an earlier version of the infamous yellow relay, with the brown wire coming out the side, so the terminals you jump across may be different that what we've directed. No problem, as you've apparently done your own homework on the work-around as to which to short across. Have you confirmed that your pumps run with the jumper in place and the relay completely removed?
Yep, did that test over the weekend. Thanks. When I turned the key the pumps ran full time. I used a test lead from my voltmeter and threw it in the trunk as a last resort if I get stranded.

Quote:
As to the overboost pressure switch, here's a diagram that may help point you to it's location (open the link and click on the diagram)
Pelican Parts - Product Information: 930-606-101-00-M100
Thanks for the diagram.

I drove the car last night without issue. Stopped twice and started up twice and ran beautifully.
Old 05-24-2010, 03:07 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #22 (permalink)
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Quote:
Originally Posted by JFairman View Post
be very careful jumping terminals on that *%#! pos yellow relay.

i totally burned up 15" of 2 wires in the harness when i jumped it the same way as the red relays in front... they ARE NOT the same.

i know what 2 pins to jump on mine but i'm not gonna tell you which ones to jump because it's a time consuming liability i want no part of if it goes wrong.

and if you know your car and take care of it >>> guess what, you don't need it. throw it into orbit, blast it with a 45 ACP, or flatten it under a sledge hammer with extreme prejudice... thats my opinion.
Thanks and I can appreciate your warnings. Letting the smoke out of anything electrical is not fun.

I checked the layout of the pins on the side of the relay before doing any jumping.

Since I've owned the car for 1 year, I have noticed 4 different pump operations when I turn the key to ON and before I start the car:

1) Pump runs about 1/2 second then turns off for about 1/2-1 second, then runs again for 1/2 second, repeating this sequence until the car is started. It hasn't done this one lately.

2) Pump runs full time until the car is started. Does this rarely.

3) Pump runs about 1/2 to 1.5 seconds then stops until I start the car. When this sequence happens, about 1 out of 10 times it will not start (ie., pump doesn't run when cranking the engine). When it doesn't start, then next OFF-then-ON restart try either does this one again or 4) below.

4) Pump does not run at all. This only happens after 3) above happens and the engine doesn't start.
Old 05-24-2010, 03:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #23 (permalink)
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Weird $hit, man. My original yellow relay only turned on the pumps in response to air being drawn across the metering plate and thus activating the micro switch there. That's how it's supposed to work, to assure that your pumps don't continue to run in the event of an accident (where your motor is off, but fuel is squirting everywhere anyway. NOT GOOD, can you say fire)?

At one point I replaced the yellow dude, and now I get a short .5 second pump burst when first turing on the key. That's it, until I crank the engine and the pumps kick on.

Yours sounds like it's giving up the ghost, with 4 different operating scenarios. Your options are to replace the relay, or just keep it jumped and run without it - realizing that you would no longer have the overboost protection. If you're industrious, you can install an impact/collision switch that will kill power to the pump relays in the event of an accident.
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Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 05-24-2010, 04:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #24 (permalink)
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OK, so leaving work today the car wouldn't start. When I turn the key to ON I got a short (1/4 sec) running of the fuel pumps, then studder start then die.

But I was prepared with my wires. I checked the voltage on pin 85 of the yellow relay and before starting it was zero (Air flow =0), then it went to about 12V when cranking (Air flow not equal 0) just as I would have expected.

So I measured pin 87a to ground and here's where the weird stuff is happening. During the next no-crank I measured something like 7V which means that the Speed relay has a large voltage across its contacts. The next crank the car started and the voltage when to about 1.2V.

This is still too much for a relay contact. I should be reading less than 0.5V or so.

When a relay closes and you get 7V across it, there's a good indication of oxidized contacts. So where is this speed relay?

I don't think it's the over pressure switch since that wouldn't change from start to start.
Old 05-26-2010, 03:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #25 (permalink)
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The speed relay is under the driver seat.

The k -jetronic box is the big one, the enrichment relay is in the middle and the speed relay is closest to the door.

I had a fuel pump cut out problem and it went away after I cleaned all the pins on the bottom of it.
Old 05-26-2010, 04:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #26 (permalink)
 
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Well, since the last update, I cleaned the pins on the speed relay. Still had the problem.

Then I shorted the relay in the speed relay. Seemed good at first, then still had the issue.

Finally back at the yellow relay. Sometimes when I touch or twist the yellow relay, the car would run fine, or sputter and cough, or die.

So I disassembled the yellow relay and determined the contacts in the relay itself are oxidized.

With my ohm meter across pins 30 & 87a, just touching the armature of the relay causes resistance readings from a few ohms all the way up to 500 ohms. I think I've found the problem.

I'll clean the contacts and check resistance again.
Old 06-05-2010, 07:28 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #27 (permalink)
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With ohm meter across pins 30 & 87a (normally closed contacts), I actuated the relay by hand and measured the resistance after each actuation:

3.3
32
183
0.3
0.8
3
3.8
4.6
0
0.8
9.4
4.5
2.8
35

These reading are all over the place. With 32, 183, or 35 ohm contact resistance, this would be one of the no-start situations.
Old 06-05-2010, 07:36 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #28 (permalink)
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Used 1000 grit wet-or-dry sandpaper between the contacts, then sprayed with contact cleaner.

Now repeat actuation test and measure resistance:

0
0
0
0
0
0
0
0
0
0

I think I nailed it. Time to reassemble and test in the car.
Old 06-05-2010, 07:53 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #29 (permalink)
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Reassembled relay and installed in the car. It started 2 times in a row. Yea! Time will tell if this was the issue.
Old 06-05-2010, 08:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #30 (permalink)
OFF THE BOOST PIPE NOW...
 
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Just caught up on your work. Good job on the diagnoses and write up!
Old 06-08-2010, 04:17 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #31 (permalink)
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