HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

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Quick DME/Fuel Pump Question

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Quick DME/Fuel Pump Question

Post  Luke714 on Sun Sep 05, 2010 2:50 pm

Hello,

I'm hoping to fire the engine for the first time tonight, I'm working on wiring the fuel pump right now. For now I'm going to stick with the DME to control it. I'd like to make my own stand-alone harness at some point though. Where do I need to hook Pin 9 of C2 from the LS1 ECU? Directly to the DME relay? This is what I've assumed, but what spade on the relay do I need to use? Is it 85b? If that is the case isn't that the red/blue wire on the 14 pin connector under the hood. However, in the conversion manual it doesn't mention doing anything with this particular wire on the 14 pin.

I just want to make sure..... so that I don't melt either the relay or the ECU.

Another thing I noticed, I can't seem to find the wire for the neutral safety switch on my harness, supposedly it's pin 34 on C1 (according to the manual), but it's empty for me. Does this not exist if the original was a manual, is there a safety for the clutch that I need to jump instead? Engine came from a 2004 GTO.

Thanks,
Luke
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Re: Quick DME/Fuel Pump Question

Post  Admin on Sun Sep 05, 2010 3:07 pm

You might as well do away with the DME right now!
The LS ECU puts out the wrong signal to trigger the DME, which means you still have to add a relay. So there is no reason what so ever to stack relay upon relay like Porsche has done and cause future problems for your self.
That is why this subject has been gone over a thousand times!

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Re: Quick DME/Fuel Pump Question

Post  Luke714 on Sun Sep 05, 2010 3:50 pm

Ok, I can do that. I just found a relay that should work. I also found this article: [You must be registered and logged in to see this link.]

It looks like the old Porsche computer completed the ground to the DME instead of supplying the power. So it makes sense it wouldn't work now that I know that.

Thanks,
Luke
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Re: Quick DME/Fuel Pump Question

Post  944-LT1 on Sun Sep 05, 2010 4:14 pm

I'm hoping to fire the engine for the first time tonight, I'm working on wiring the fuel pump right now. For now I'm going to stick with the DME to control it. I'd like to make my own stand-alone harness at some point though. Where do I need to hook Pin 9 of C2 from the LS1 ECU? Directly to the DME relay? This is what I've assumed, but what spade on the relay do I need to use? Is it 85b? If that is the case isn't that the red/blue wire on the 14 pin connector under the hood. However, in the conversion manual it doesn't mention doing anything with this particular wire on the 14 pin.

If you must...... Neutral

Grounding the DME relay:
The DME relay is just two relays within a single relay box.... Two relays in there! This is why theres an 85 and 85b! 85/85b is ground to the two coils within the DME relay (open one up!).
So, to ground it, make sure to have pin 5 of the 14 pin connector grounded. Check it with an ohm meter to the negative side of the battery. If its already grounded, then youre good. If its open, ground it.

Switched power to ready the DME relay:
Next, 86 is switched power to the coils. When this recieves power from the ignition switch (after going through the alarm control unit if satisfied), it completes the circuit and sends battery power from pin 30 through to the fuel pump coil within the DME relay. This should not have to be tampered with. Leave it alone!

Triggering the DME relay for fuel:
Finally, you must trigger the fuel pump coil within the DME relay. To do this, you must apply 12vdc to pin 87 of the DME relay.

To check this quickly, apply 12vdc to pin 4 of the 14 pin connector. If you apply 12vdc to pin 4, this will be a stright shot (bypassing the relay) to the fuel pump. Caution: this is an unfused route!

So, you can see, this is much more complex than just wiring up your own relay! Laughing

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Re: Quick DME/Fuel Pump Question

Post  944-LT1 on Sun Sep 05, 2010 4:45 pm

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Re: Quick DME/Fuel Pump Question

Post  Luke714 on Sun Sep 05, 2010 5:37 pm

Thanks guys! I took everyone's advice and wired in my own relay, it was simple (like everyone said it would be). Hopefully I'll try starting the engine in the next couple of hours.

Any thoughts on the neutral switch?
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Re: Quick DME/Fuel Pump Question

Post  944-LT1 on Sun Sep 05, 2010 6:29 pm

Neutral safety pin needs ground but I have no idea where it would be or which pin it is for a 2004 gto. Sorry. But, if you wired the LS computer to control the starter and the starter turns over with the key, you may not need to ground it.

??? Need a schematic...


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Re: Quick DME/Fuel Pump Question

Post  Arthropraxis on Sun Sep 05, 2010 6:54 pm

I have a 2004 GTO motor and ECM out of a 6 spd car. The ECM didn't have the neutral safety switch pin filled/no wire coming out of it. I am thinking it is only used on an automatic car.
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Re: Quick DME/Fuel Pump Question

Post  Luke714 on Sun Sep 05, 2010 9:49 pm

ok, those were my thoughts. The starter cranks just fine. All I have to do now is fill the oil, reconnect a ground wire to the MAF I accidentally cut, and fill the coolant.
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Re: Quick DME/Fuel Pump Question

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