3.2 engine swap help

goldsc78258 · 08-13-2006, 04:28 AM

I fnished putting the engine up on the car (911 1977) yesterday, the oil system is conected and sorted. I ran into trouble when I tried to find the conections for the fuel lines that come from the underbody, I can't find the ends on any of the stores around here and the regular aeroquip or arl's won't fit (different flares). Any suggestions? in the mean time we ran direct fuel lines from the pump and went on to sort the wiring, I followed the instructons in ore of the threads and thought to have the wiring down, but when I tried to start it there is no spark all. Anybody done an engine swap on a 77? do you have pictures of the wiring front and back? Any ideas why there is no spark? Please help.

Thanks in advance

LakeCleElum · 08-13-2006, 06:10 AM

Here's a good write-up by a fellow Pelican-ite:

http://www.pelicanparts.com/MotorCity/marcesq/

DW SD · 08-13-2006, 06:47 AM

You should have attached the DME harness to the fuse panel upfront. Any mistake there could foul up the operation.

Can you hear your DME relay clicking on? Stage I should come on in the relay with the ignition. I had attached power to the wrong ciruit at the fuse panel and realized that the circuit I selected turns off when cranking (radio and other accessories act in this fashion).

Stage II on the DME relay powers the fuel pump. The computer needs to see the crank position moving before it lights the fuel pump. Is your fuel pump coming on during cranking - use a test light?

I'd make sure you get power at the DME relay (that turns on the computer). From there, the computer will turn on the fuel pump, injectors and time spark. I think if you have no spark only, it could be bad grounds, bad coil, no rotor in the distributor, OR??

Doug

goldsc78258 · 11:39 AM

LakeCleElum, I did see that article and folowed the instructions.

Doug, I will check some of the things that you have mentioned and will post back, I have to leave tomorow and won't be back till sunday, I don't know if I'll have time.

Anybody have a good idea of where every cable that goes to the front should be atached to? If you do please let me know

In the mean time feel free to chime in with some more ideas, I really want to get this car running

Thanks

goldsc78258 · 08-14-2006, 03:39 PM

Evening bump
C'mon guys I really need help with some of the wiring

DW SD · 08-14-2006, 04:42 PM

www.addictionmotorsports.com
Jim's website has good information for this conversion.

Doug

DW SD · 04:48 PM

It is this page to which I was referring for the 14 pin connector: http://www.addictionmotorsports.com/WiringHarness.htm

Jim made a conversion harnesses so he didn't have to cut up the original harness on the engine or the connectors. I actually took apart the 14 pin connector and moved the wires around and then checked each gauge to make work properly.

UPFRONT:
The four DME harness leads goes to 1. 12V+ always on, 2. switched on with ignition, but remaining on when cranking and to 3. the fuel pump 12V+ and 4. the tach.

I don't know the colors for each of these wires.

Doug

goldsc78258 · 08-15-2006, 02:20 AM

Doug, thanks again. I've got the front wires as follows
1. thick red wire to 12v 2. thick black to switch on but remaining on 3. yellow to crancking on the ign. switch 4. purple and balck to tach 5. thin black to the same power on ( I think this is the coil) 6. I can't remember the color of the one to the pump (maybe green and something?)

Fred

IROC · IROC's Garage

I don't think the yellow wire is required. All you really need to ensure is that the DME has power and that the two black wires (one that supplies 12V to trick the DME into thinking the car has an alarm and the one that supplies power to the coil) are wired correctly. You'll need to locate a fuse that supplies 12V during cranking and running (very important) for the coil wire.

The red/green wire is for the fuel pump. Depending on how you've got the fuel pump wired, this may or may not be required (I don't use it on mine).

Mike

goldsc78258 · 08:23 AM

Anymore suggestions? I'm back and ready to solve this

Thanks

DW SD · 08-21-2006, 08:24 AM

Seems like you had the wires connected properly. Is the DME relay coming on? You should hear it click?

When cranking, are you getting power to the fuel pump?

Are you sure your fuel pump works? What happens if you jump power to the fuel pump, do you hear it run and can you hear your pressure regulator bleeding off pressure? I can hear mine open and close - when I jump power to the fuel pump.

Doug

goldsc78258 · 09-05-2006, 04:27 PM

I've got everything conected the way it is suposed to be but no spark. anymore ideas? I out of them

Fred

DW SD · 09-05-2006, 04:31 PM

Do you hear the DME relay click, when you turn the key? without the computer turning on you won't get spark and you won't get the pump turning on (unless you have it hard wired not through the computer and DME relay).

Doug

goldsc78258 · 09-05-2006, 05:07 PM

Doug I can hear the primary relay opening but I have nothing on the wire that goes into the pump maybe the seconday relay is not opening. Let me know what you think. maybe the computer is bad? or the realy?

Fred

DW SD · 09-05-2006, 05:13 PM

Could be the computer. Once the computer sees activity from the crank position sensor (engine is cranking over), it turns on the next relay which turns on the fuel pump.

The computer also provides spark. Good sign if you are hearing the relay.

I'd suggest this: Put a test light on the positive to the fuel pump and crank. If you get 12V during cranking then you know the computer is turning on stage two of the relay.

If it is doing that function, I suspect that the computer is not broken.

Also do you smell fuel at the tailpipe? it should be strong.

Report the findings back.

goldsc78258 · 09-05-2006, 05:15 PM

I did, and don't get 12V on the fuel pupm wire. bad computer or relay

DW SD · 09-05-2006, 05:25 PM

Can you swap computers with someone? I think you can send the computer out to be tested.

A bad computer would cause no spark, of course, too. A bad DME relay (stage II) would only kill the fuel pump.

However, maybe someone will chime in as to how to test the wiring to the computer (via pin outs). If the DME relay is turning on stage one, the computer, I believe the computer should be turning on and giving you spark.

Doug

goldsc78258 · 09-06-2006, 03:52 AM

Don't think I have anybody here in San Antonio. is there anyway that the computer can be tested? I think stage 2 on the relay is bad but if that wouldn't cause the loss of spark then I think it is the computer.

Fred

goldsc78258 · 09-06-2006, 09:33 AM

Nothing, I did changed the DME realy, Could it be the computer went bad? the car was a running car before I did the swap, and I don't think I did anything to cause it to burn. but you never know. anybody have exactly where the front wires go(just to make sure)

Fred

goldsc78258 · 09-07-2006, 10:14 AM

Doug finally got it running!!

Thanks for taking the time helping me thru this

Fred