Engines crank but no start

[joelewis73]

So I just replaced my VP 305's with 350's and having the same issue on both engines. 5.7 GiPEFS is the engines I am working on. I have been beating myself up for 2 days now trying to get them to start. I have checked all forums and done extensive electrical testing to ensure there is power available where it is supposed to be. I pulled both kill switches which are NC with the fork installed and both are not showing continuity when they are supposed to be closed so I pulled them and jumped the switches out so they are out of play.
I have 12v at all relays, when i turn the key to on I get two beeps but only hear fuel pump start from the port engine but not the stb. I already replaced all the relays since I found 3 bad ones out of the 4 there and one of the fuses was blown.
I can jump out the fuel pump relay and the pup will start.
I am at my wits end and know it is something small that I may have forgotten to connect when i put the new engines in...Send me your inputs and I will try them...
Forgot to mention that a friend of mine is a mechanic and asked about crank sensor. I have everything hooked up and no extra wires anywhere, there is not a crank position sensor listed in the manual either. There would typically be one on the timing cover but not on the engines i pulled out and not on the ones I installed...Have no idea what is going on now.
Thanks
Joer

 

[alldodge]

When key is turned ON power feeds the purple wire to the main power relay. Should be 12V there, a ground and the relay will supply power to the pink/white

There is full time 12V on the fuel pump relay and when the Main relay turns ON and powers up the ECM, it will apply a ground to J1-23 to energize

When cranking do you see 300 rpm on the tach?

The Gi doesn't have a crank sensor

 

[joelewis73]

Thanks been reading alot of the post you have been remarking on and following what you said but I M MISSING SOMETHING...have fuel flow on port eng but no spark. Waiting for myn daughter to come turn it over while im in the bilge to see if I have a spark but out of timing.
Stbd eng i cant seem to get the fuel pump to kick on at startup. i have done all the things listed above and still loss..I found bad wires in the relay mount so i fixed that and have the 12v everywhere as you showed but I am not getting anything from the pump. the pump is good I have jumped it out and it turns on just missing something. Trying to look at both engines at the same time energized to see where I am...swapped the ecm from the port to stbd eng but no go on fuel pump. want to get fuel pumps right then chase down why i dont have spark.
Thanks
Joe

 

[Scott Danforth]

how exactly did you stab the dizzy when you swapped motors? did you follow the procedure in the service manual?

do you have fuel pressure (not just that the pump hums), however actual pressure?

 

[joelewis73]

I rolled the engine to TDC or close as possible...Finger over #1 spark plug hole and lined up timing mark on balancer to mark on block. Identified which post was #1 and set up all the wires in accordance to firing order.

Port engine sprays as it should when turning over but no spark to ignite. i tried shooting a short shot of starting fluid in but did not fire of that either..
thanks
joe

 

[alldodge]

have the 12v everywhere as you showed but I am not getting anything from the pump. the pump is good I have jumped it out and it turns on just missing something.

Have 12V, jump the pump and it works but not on motor. The ECM applies a ground to energize relay. Place meter on the Yellow/Black wire on relay. Turn ignition ON, meter should be a 0V when ECM grounds and then go to 12V when ECM ungrounds.

If this is not happening, then there may be a problem with the ECM

Check for 12V on pin 87 Pink/White on the main power relay (MPR).

If 12V is present check coil same color wire

If 12V is present check pin J2-32 same color wire

 

[joelewis73]

Have 12V, jump the pump and it works but not on motor. The ECM applies a ground to energize relay. Place meter on the Yellow/Black wire on relay. Turn ignition ON, meter should be a 0V when ECM grounds and then go to 12V when ECM ungrounds.....WAITING FOR DAUGHTER TO HELP`

If this is not happening, then there may be a problem with the ECM

Check for 12V on pin 87 Pink/White on the main power relay (MPR)....CHECK 12V PRESENT

If 12V is present check coil same color wire....CHECK 12V PRESENT

If 12V is present check pin J2-32 same color wire...CHECK 12V PRESENT

Done most of this from other post you have replied to...but keep it coming i am determined to be in the water this weekend..Been a long 2 months rebuilding this boat

 

[joelewis73]

Port engine fired up...did spark test had spark and finally got it running. Did spark test on stbd engine have spark but still chasing this fuel pump issue...swapped out ecm from port to stb and same issue so eliminate ecms.
Checking qires in harness man this is nasty...

 

[alldodge]

Swapping ECM's can get expensive, be careful. Put unknown ECM on known good side but not the other way. Might be a bad connection at the ECM

Place the Strb on Port to see if Port still fires up then you know its not ECM

 

[joelewis73]

That is what I did...swapped one for the other...Did not thinki t was ECM issue...im missing a wire somewhere

 

[joelewis73]

You can see the battle I am fighting with this stb fuel pump. Started looking closley at the mounts the connectors are toast and I have changed them for now until the new ones I ordered come in tomorrow. Amazon next day is great especially when its free. So I will keep following the signal to see where it leads me. I appreciate all the help this is a tough task and when you put the problems out here and such veterans of boat chime in there is nothing that cannot be fixed....
SO what ahppened with the Port engine i kept thinking that there was no spark and since I was there alone did not want to give it a whirl..MY buddy chris stopped over to help since I threw him a bat signal over the phone all he could say was you are so close.....he is like the boat whisperer...he takes the #1 plug out and hands it to me to check for spark on the block...got a decent size spark and I was in awe that it was there because i was not for certain i had a spark....Anyways he is like it is gonna run right now....he grabbed my starting fluid shot a couple shots in and startied watching as I turned the engine over...I am being cautious with the starter not wanting to have to buy another one for getting hot I stop like every 5-6 seconds....he tells me to let it go longer...btw he is rich and said if he screwed t up he would buy a new one...so i hit the start key one more time and he hit the starting fluid...it fired up and roared as if we just woke and angry lion...it throttled back after the ether was burned off and continued to run on the gas i put in....\
He smelled the gas and said it was still some o9ld gas I need to work out which will happen in the am. Going to buy 20 more gallons of marine fuel from the boat dock and add 10 more to each tank. I am going to run another gallon or so out of the tank to see what I get...i assume that the more fresh gas I put in the more diluted the bad gas remaining will be. I pumped 45 gallons out of the two tanks and I thought I had pretty much gotten all of it but apparently not...Be off in the am searching for this issue with the fuel pump one more time...keep filling my head with ideas and I will keep looking fior it.
THanks
Joe

 

[alldodge]

i assume that the more fresh gas I put in the more diluted the bad gas remaining will be

Putting good gas in bad gas makes more bad gas. It can be diluted but can cause continuing issues. If gas removal was not taken direct from the bottom it can also have water

 

[joelewis73]

I pulled almost 50 gallons out through the pickup. When I put gas in i used the fuel pumps to pull one gallon out of each tank to see what was coming out. Not that much water came out and very little sediment. I am going to pull a couple more gallons out through the pumps today and see what it looks like. still chasing this one pump though...Today is the day I can feel it.'
Thanks
Joe

 

[joelewis73]

Thanks to you guys I now have fuel pump. It ended up me replacing about a foot of wire from the relay back to the pump, eco ground and the two hot leads. The wires were too corroded and were not making good contact. I could read the voltage but the ground was not kicking in but the ecm was beeping and telling me everything was good. Now it is except I am chasing gremlins in the ignition side. Turn key and get fuel pump on but turn key to start and nothing. BAck to the bilge with meter to find out what happened. I moved the ground today so maybe that is the culprit will swapp it back and see what happens.
thanks
Joe

 

[joelewis73]

I am such a dumbass...I was reading all the voltages through all the relays even the starter relay when i stopped taking readings and started replacing wires..I was just sitting here tracing the voltages in the diagram and realized I forgot to reconnect the starter relay...Sitting in a bilge for days on end under a tarp with a fan blowing and drinking rediculous amounts of water seem to have fried my brain...I will try again in the am...

 

[alldodge]

I fell your pain, rest now

 

[joelewis73]

Ok back at the boat this am. Plugged in starter relay pushed another gallon of gas out of the tank is clear and bright no water no sediment so I am ready to start. Fuel pump comes on , engine turns over but injectors not spraying fuel into carb. Gonna check the wiring in the harness on those now. Send me any ideas to check.
Also the oil sending unit has the blue wire as per the diagram but there is not a blue wire to connect it to. I read continuity from sending unit to the wire but it is not connected to anything. What pin should it be connected to? NOt going to start this without a oil pressure gage on the dash.
Thanks
Joe

 

[alldodge]

When cranking do you see 300 rpm on the tach?

oil sending unit has the blue wire as per the diagram but there is not a blue wire to connect it to

Goes to the oil pressure gauge at the helm thru pin 8 of the 10 pin connector. It has nothing to do with start or run

 

[joelewis73]

Alldodge i realize it does not affect start or run but the PO did away with the plug and it is all hardwired together. THe blue wire coming from the oil sender is not connected and there are no more wires to connect it to. I am running against bad wire after bad wire and am going to find a new wiring harness. Just wanted to know the color of the wire it should be other than the blue one since there is not one in the wires from the cluster. I will have to pull the console and see what color is connected to it....

I got it started was the same issue I found yesterday bad wire after bad wire which is another reason I am going to find a new harness. The boat sat in the water for 8 years and now that I have brought it back to life everyone under the moon is telling me about how many times it sank and was refloated by the marina...Not that I care since everything I am doing is practically brand new...

I chased bad wires again all over the place today in side the wiring harness but alass now have two running engines. All the gas is clear and bright so tomorrow I am going to put it on the hose and runn them both for an hour or so to check everything out before I put it back in the water on tues. I appreciate all the help you guys have given.
Thanks again
Joe

 

[alldodge]

Search on Boat wiring harness and Mercruiser wiring harness. Can find harnesses for boat and motor side, and the 10 pin harness will be same for VP