1999 454 Mag MPI just quits - videos

I love those 3000's they are sooooo quiet.
BTW Santa showed up today, so between the raindrops, I might get the Pro Mariner in tomorrow.
Santa 2.0 should show tomorrow. We will see if the part numbers match up. If they do, I just found the cheapest OEM distributor on the planet.
 
370Dancer said:
I love those 3000's they are sooooo quiet.
BTW Santa showed up today, so between the raindrops, I might get the Pro Mariner in tomorrow.
Santa 2.0 should show tomorrow. We will see if the part numbers match up. If they do, I just found the cheapest OEM distributor on the planet.
Click to expand...

I bought a disti from marineengines4less.com that was pretty good quality and like 1/8 of the price of the merc version. The ignition module went bad in year 2, but that’s a common problem on our old boat so I don’t really blame them.
 
Strecker25 said:
I bought a disti from marineengines4less.com that was pretty good quality and like 1/8 of the price of the merc version. The ignition module went bad in year 2, but that’s a common problem on our old boat so I don’t really blame them.
Click to expand...
Great minds think alike. I'll see what I get.
 
Hmmmm.
Replaced the Distributor yesterday from the marineengines4less.com guys.
Tried PlayDate's trick of using 12v from the battery to the coil primary, had the tach disconnected.
Used the new harness from the ignition module to the ignition coil. Moved my spare MEFI3 to the stbd engine. Ran fine. Moved my MEFI4B and harness adapter to the Starboard engine. Ran fine. So I know I have 3 good MEFIs. Put the 4B back on the port.
I then broke the law, and did 3 things at once.
I put the NEW NEW NEW (3rd one) Ignition Coil from the Distributor pack on
I put the hose clamp back on the Engine harness adapter (which has been off since 2017)
I moved the ground for the MEFI 4B harness adapter from between the 50 amp breaker and the engine block to on top of the 50 amp breaker (direct contact with the bolt head, and cleaned up the ring terminal real good.
Engine fired immediately, and ran for at least 15 minutes without stopping. sonofabitch! restarts any time I want it to. doublesonofabitch!
I think I kinda took the 4B harness ground wire out of the mix when I initially swapped the 4B with my spare 3. BUT, grounds are grounds.
So either the coil (a Merc OEM that came off the STBD engine last week when swapping crap) went bad (doubtful), or the pins just weren't making good contact until I put the aftermarket one in? , or the harness not being clamped at the plug has been the issue all along ?!?!?
Anyways, I set base timing, and it's still missing (I think, still too much rattle in the plate as before). I suspect I will still not get past 2800/3000 rpm, but haven't given it a shot yet.
At my leisure, I will back in the other coils and the old distributor, and see if they are ok, and it was the harness plug all along.
Just documenting all this for future MAG MPI owners. All these motors are getting very long in the tooth.
I did get a new ProMariner charger out of the exercise, though!
Thanks for listening.......
 
370Dancer said:
Hmmmm.
Replaced the Distributor yesterday from the marineengines4less.com guys.
Tried PlayDate's trick of using 12v from the battery to the coil primary, had the tach disconnected.
Used the new harness from the ignition module to the ignition coil. Moved my spare MEFI3 to the stbd engine. Ran fine. Moved my MEFI4B and harness adapter to the Starboard engine. Ran fine. So I know I have 3 good MEFIs. Put the 4B back on the port.
I then broke the law, and did 3 things at once.
I put the NEW NEW NEW (3rd one) Ignition Coil from the Distributor pack on
I put the hose clamp back on the Engine harness adapter (which has been off since 2017)
I moved the ground for the MEFI 4B harness adapter from between the 50 amp breaker and the engine block to on top of the 50 amp breaker (direct contact with the bolt head, and cleaned up the ring terminal real good.
Engine fired immediately, and ran for at least 15 minutes without stopping. sonofabitch! restarts any time I want it to. doublesonofabitch!
I think I kinda took the 4B harness ground wire out of the mix when I initially swapped the 4B with my spare 3. BUT, grounds are grounds.
So either the coil (a Merc OEM that came off the STBD engine last week when swapping crap) went bad (doubtful), or the pins just weren't making good contact until I put the aftermarket one in? , or the harness not being clamped at the plug has been the issue all along ?!?!?
Anyways, I set base timing, and it's still missing (I think, still too much rattle in the plate as before). I suspect I will still not get past 2800/3000 rpm, but haven't given it a shot yet.
At my leisure, I will back in the other coils and the old distributor, and see if they are ok, and it was the harness plug all along.
Just documenting all this for future MAG MPI owners. All these motors are getting very long in the tooth.
I did get a new ProMariner charger out of the exercise, though!
Thanks for listening.......
Click to expand...

I was hoping it would be a good update, hoping for the best when you take her out and see how she runs
 
And, while we are waiting for me to see if all is good, I have another question, that 2 solid hours of searching can't answer.
WHO owns the shoulder bolt and spacer that locks the throttle cable to the throttle bracket that is attached to the intake plenum? I cannot find it on engine diagrams, or SeaStar/Teleflex/Dometic(big surprise) sites or searches. Mine conveniently fell between the exhaust manifold on the port side to places unknown. I have used my greasy grimy arms, a water hose to blow all under engine crap to one corner, an extended magnet (apparently it must be stainless and plastic), and my 1080P cylinder cam to try to see where the bolt and it's plastic spacer went. Can't find 'em. I'll buy them, but there is NO online reference.
 
10-96430 shoulder bolt and a black spacer about 1/2", but that may not be needed if the bolt is short enough. It's not called out on the diagrams.
One Ebay seller has the bolt @4bucks free shipping in about 2 weeks, Marineengine.com has it for 1.80 plus 9 bucks shipping in about a week. I can't leave the dock without it, or something like it.
I may hit the specialty bolt section of big box store to try and match it up, or build something that will fit while I wait for the real deal.
shoulder bolt.PNG throttle cable.PNG
 
Made it to 3200 just now, but still struggles after that. Pulling the brand new plugs tomorrow am to see which one(s) aren't firing. I have conflicting oil pressure readings too.
The port is 5-10psi at idle and never gets over 20psi according to my Fox Gateway with the supplied pressure sensor. The analog gauge looks better, more like the Stbd gauge. The Stbd engine is 36 psi at idle, and 40 something on plane. Gonna move that sensor tomorrow as well and see if the low pressure moves with it.
 
She's running as above the last time I tried. Got my oil pressure sorted, and put some magic juice in the oil to see if I could push it into acting right (Hy-Per Lube). However, the tides have been low, damn low, and @#%#$ing low for the past week with the NE blow. Just getting back to "normal", so off I go again to try for all cylinders up. Should have a report by the weekend.
There's still a miss, I feel. And, it may be mechanical (like valves). I re-did a compression check, and everyone at dead cold no lube, all plugs out are 130-140, with little to no leak down over 30 seconds. Still, something is still making that plate chatter. I had one plug carboned up. Lightly, but noticeable over the others. #8. The least likely suspect. Tried a quick temp check on the exhaust ports from a cold start, and #5 looked low compared to the others, but not for very long. We will see what the next couple of days bring.
 
Update:
Ran out this morning. Up on plane first try.
Pic 1 is about 2 minutes in at 3500 RPM All seems nominal
Pic 2 Port Engine starts to lose RPMS I can adjust up but it continues to lose
Pic 3 Quick check of fuel pressure shows that it hasn't moved (1 volt = 25lbs)
Vid 4 Trying to video what is happening. I could get up on plane multiple times over the 45 minutes I was out there. Each time, port would start to stumble and if I come back down to 2000 rpm, it smooths out and runs fine.
Vid 5 One of the repeat sessions. It was getting quicker and quicker as to when it would fail.

Got back to the dock. Everyone's idling fine, and normal. Shut 'em off. Wait a minute. Port doesn't want to start. like vapor locked, or out of gas. Give it a bit of throttle, and it starts. Rough for a few seconds, and then smooths out but is definitely missing. throttle up (in neutral) and I can hear the popping. Stop the engine. start the engine. Starts right up. Go inside and make a cocktail.
Both engines' spark advance was 31-32 at 2000 rpm, both engines spark advance was down to 28 or so at 3000 plus, except the port engine was losing rpms.
I couldn't find any other parameter that was glaringly different, except (calculated) fuel consumption which in one of the pics you can see was 10GPH higher on the port motor. I believe that is because the ECM is keeping the injectors on longer than the starboard. Not necessarily using more fuel.

Half this keeps pushing me back to fuel delivery, and the other half pushes me at ignition. Seems like if it were mechanical, it wouldn't get better, then worse, than better, then worse.

https://www.dropbox.com/sh/6b13yk6qucji6fn/AACEqi_zV3XSNLDojRinL_t5a?dl=0
Fire away.
 
Popping is usually a sign of a lean condition and or timing related.

Refresh my memory... Did you run this on a separate gas can direct to the engine to eliminate fuel supply as an issue?
 
douglee25 said:
Popping is usually a sign of a lean condition and or timing related.

Refresh my memory... Did you run this on a separate gas can direct to the engine to eliminate fuel supply as an issue?
Click to expand...
Not popping like a backfire. popping like a miss. Sorry for that confusion. Yes, I ran it on a portable tank, although that was about 10 pages ago. Just to refresh everyone (and me):
Fuel circuit:
Tank to shutoff solenoid - original 1/2" fuel line and fittings - about 6 inches long
Shutoff solenoid - replaced in 2010 or so. Still have originals. tried bypass and normal
Shutoff solenoid to low pressure pump kit - new 3/8" fuel line, wrapped in heat blanket
Low pressure fuel pump kit - filter and pump new, added June of 2019 (have had other pumps there)
low pressure fuel pump to fuel water separator - new 3/8" fuel line, wrapped in heat blanket
fuel water separator - new 11/2020 - full of fuel
water separator to high pressure fuel pump - new 3/8" high pressure fuel line wrapped in heat blanket
high pressure fuel pump - new 06/2019 just because
fuel pressure regulator - new 06/2019 just because
fuel pressure regulator return to fuel water separator - new 3/8" high pressure fuel line wrapped in heat blanket (no I didn't move it to the fuel fill yet, Scoflaw...)
high pressure pump to fuel rail - original fuel line and fittings - new o-rings
fuel rail to injectors - all new injectors 06/2019

Ignition circuit:
12v batteries - new 2018
12v battery charger new 11/2020
ignition switch at helm - new 06/2020 (stbd was acting up, so I replaced both)
cable harness to engine - original, but re-clamped at connector and may have helped no start to here.
12v relays, fuses to ignition coil - all nominal operating normally
ignition coil - new 11/2020 and may have helped no start to here. 3rd ignition coil tried.
ignition coil to distributor module harness - new came in distributor kit
ignition coil to distributor secondary - new 06/2019 - I have a new set of wires that came with kit. May put those on just because
Distributor - new 11/2020 - to rule out the pickup coil and to have a good starting point
plug wires - new 06/2019 - may put new set on.
spark plugs - new 11/2020 - need to pull them tonight to read since this morning's test

Sensors:
IAC - New 06/2020
MAP sensor - New 06/2020
water temp sensor- original
Throttle position sensor - original, but have swapped out with spares from original engines-no change
Fuel pressure - added 06/2019 for full time monitoring
Oil pressure - added 06/2020 as part of Fox Gateway upgrade to NMEA 2000 monitoring
IAT sensor - new 06/2020 because they're cheap
All sensors are monitored in real time with Fox Gateways, and appear to be running nominal compared with good running Stbd engine

ECM:
I have run the port on the starboard, and the starboard on the port, BUT not out and trying to plane. Thinking about taking my spare MEFI-3 and putting it on for a test run, or swapping the 2.
No Codes.


I know this looks like a parts changer diagnosis, but I did have multiple issues with this engine, and it's bolt-on parts.
Alternators - new 03/2020

I am about to start moving parts to the Stbd engine one at a time to see if anything makes that one mess up.

scoflaw said:
Do you like golf? Might be less stressful.
Click to expand...
"This is my golf" I'm not stressed. I'm intrigued (and relentless), and so friggin' close.

I do have one more for you. The oil pressure went way down on the port engine during the trial run this morning. up near 40 on the cold start, and by the time I had gone through a few get on planes, it was more like 4-7 at idle. Gotta go check the level, and see if I'm losing oil somewhere. no smoke in the exhaust, and no mess in the bilge. no sheen in the water by the exhaust ports.
 
Went downstairs, port started right up, idled fine. Oil pressure mid twenties. As soon as I give it any throttle, it's up to 37-42 psi. go figure.... the analog gauge always reads near 40, so maybe a false reading on the gateway one. Whatever is going on sure seems heat related.
 
You must log in or register to reply here.

Forum statistics

Threads
113,095
Messages
1,425,836
Members
61,017
Latest member
IslandGirls1020
Back
Top