Holley/ Starting issue
 

got the motor back in the boat and did my wiring and im having a crank-no start
i think i screwed up my ignition source wire for the Holley.

i have a red/white wire then needs a switched 12v source IN.
i have it tapped into the purple wire - pin 5 on the boat side of the 10pin cannon plug.
i feel like i have this wrong

HELP

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Holley HP EFI i haven't yet. ran into this no start last night in the dark so i stopped well i was ahead and thought id ask and make sure this is a 12V switched source. all the wiring diagrams from Merc that i can find leave a lot to be desired

......how do you have the controller wired

The purple wire to the switched red/white wire sounds correct to me. Make sure you have +12v at the purple wire when the ignition is turned on.

it is soldered unless you mean the whole unit in witch case i used the Holley harness - its on a 03 575SCI


the positive and neg are right to battery 1, the one i use to run on


no meter yet. going to do that today that cannon looks like a real &^*( to probe at well its plugged in. went to start it at the end of the night and it it just cranked so i stopped and thought i would check my wire selection

check for fuel also, does the high pressure pump load with fuel pressure ? we need some more info, where did you splice into the purple wire, where does the purple wire end up on the engine harness, what ignition / coil are you running

has fuel, pulled the filter off the intake and can see it on the injection plate
spliced into the purple wire about 3 inches behind the cannon plug on the boat side - not the motor side
ignition/coil is all factory 575sci replacement items. motor ran on the dyno with all this. the only thing that has changed wit it being put into the boat is a diffrent fuel pump - set at same pressure - 48-50 psi the power and ground wires of the ECU and the red/white signal wire

I looked it up, it has the same distributor and coil as the 502 mag mpi, you could of put your red/white wire connection at the coil....anyway a volt meter is your friend,

going to confirm that tonight

if i was to go to the coil im guessing it would be this red wire?
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should be, did you check the connector where the 3 fuses are located, under a grey cap I think ?

honestly didnt even know that existed. i will check

Update
have good fuel pressure. Pump dosent hold pressure after it primes tho. Weldon 1100a. This normal? Was told they dont use a check ball

Have spark. Injectors are firing Confirmed timing is good. Red/white Holley wire has 12v well cranking. Put in a new ignition module. Still no change. Will crank perfect and when you release the key it will stumble and bark a little out the exhaust. Wtf Help

I remember reading something in the holley manual when I was looking at a holley setup about using the "stock" dist. Are you sure you have the dist. and efi tied together properly...I seem to remember another harness being needed?? Sounds to me that spark is your issue in that you are losing it while cranking and when you release the key you get a split second of fire....that's my guess lol btw could you PM me some info on what holley setup you used? Is it dual throttle body? been looking at options for efi on a roots style blower...thanks and good luck!! I believe the ignition has to be separated from the boat and ran strictly off of the efi I think. I would start there....can't help on the fuel pump losing pressure...does it pump right back up when you start cranking? if not that could be your issue as well.

Oops just reread that you have spark haha...any chance you are losing it while cranking or did you check it while cranking?

yellow/red from ign key is prob wired direct to starter by someone instead of the Mercruiser remote starter solenoid. Have seen this almost a dozen times. What gives this away is the engine firing or slightly firing right after key is let go from start position.

This happens because of the long run from key ignition switch...voltage reduced enough during cranking that it won't start,,,but release starter and voltage now is enough. This is why Mercruiser uses the remote starter solenoid.

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You might be 180* out on timing, make sure you're on the compression stroke #1

where would I see this? Should this be right by the starter?

Checked and confirmed the timing is right One is at one on TDC give it take a degree

Have the jumper harness for the distributor. This motor was running one the dyno less then a month ago Only some wiring and the fuel system is different Confirmed spark well cranking Confirmed injector pulse and fuel pressure well cranking. Made sure sensor readings in the Holley are good. Sees rpm No weird ass AFR or ECT readings.

typically the starter solenoid is mounted on a bracket at the rear of the head

depending on engine it can be mounted in frt, over fuel seperator, or in the rear to the sideof distributor area.

You can also follow the yellow/red from Starter terminal 'S' (smaller terminal just to the right(block side) of the big + terminal.

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Wiring is good Key to signal power out of solinoid

explain what its doing again, do you think you're losing voltage to the ignition when you stop cranking it ??

it cranks and wont fire. When you let go of the key -returns to the on/run position. It will stumble a few times as if it where running

Have fuel have spark have air. Was running on dyno not long ago. Nothing on the motor it self has changed. Only new things are fuel system. Cannon plugged into the rest of the boat Ecu is mounted to the boat. And running off boat batteries Confirmed charge is good and had a booster on it well cranking

That is what usually causes 'starting to fire' when releasing the key from 'crank.'

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where do I test to see this. ? This would be the yellow/red wire I'm guessing?

I have a starter solinoid relay on order just to be sure. It's a P IA to get at so I think I should replace it to be 100%

No one? Everyone out enjoying the water :p

If the motor cranks over the yellow/red wire is fine.

Are you seeing cranking RPMs on the labtop?

Also what is battery voltage on the labtop while you are cranking?

sees rpm Lowest voltage saw was about 10. Had the batteries on a charger and tried using both. Made no difference

10 is too low

Is the ECU wired directly to the battery?

directly to battery one. Same one I run on. Tried with using both batteries and a charger

New batterys No difference

when you made the splice in the purple wire for your ecm switched voltage ( it was a splice not a cut and connect correct ? ) it continued .........I know the answer but I had to ask,...

I had a bad connection on my ignition switch that caused that to happen to me. I had 12volts everywhere but the connection was not good enough. Same thing happened to my outdrive trim function The rivet holding the wire connector on the fuse board was loose sometimes it worked sometimes it did not. Good luck with your project

it was a soldered splice

Does the purple wire have power while cranking? I thought it dropped power while cranking....could be wrong

Did you set the timing at 50* BTDC?
If set less than that lets say 34* then during start it would spark after the compression stroke.

it has power well cranking Its tapped on the boat side not the motor side. It has battery voltage well cranking.

I dont know about the ignition timing of the top of my head. I'll be plugging in tomorrow and checking it Along with the start RPM setting.