Logo
FULL SITE MENU

Faulty fuel pump?

K

Keats

New member
9 Nov 13,
1998 Sea Ray 210 Sun Deck with a Mercruiser 5.7 lrt EFI engine. Ser # 0L050996. Bravo III out drive.
My boat has been sitting for the past three years. When last I used it, it ran like new. The engine has about 160 hours on it since new. I added Stabil to the gas tank about a month after I parked it. I did not run the engine at that time. So now I'm getting ready to offer it for sale (my wife is not really a boater person) and I installed two brand new batteries and put 10 gallons of fuel in it today. I had checked the raw water intake pump to make sure it was free because I had one go bad on me in the past. The oil is full and clean.
So I cranked the engine a few times for about 4-5 seconds each time and it did not start. I removed the spark arrestor and primed the throttle body with a bit of fresh gas and tried the key again. It fired right up and ran briefly till the gas ran out. O.K. so at least I know it will start. The only way it will start / run is if I prime the throttle body. I see no fuel being delivered to the throttle body.
Now I'm thinking of all the bad things that can be wrong. Is the fuel filter / water separator clogged? Is the fuel pump shot.? This is a Cool Fuel System and from what I can figure out in the service manual (Mercruiser #24) the fuel enters the fuel pump and is then routed via a 90 degree fitting up thru a pipe that leads from the outdrive to the raw water pump thereby cooling the fuel as it passes thru the pipe? This is based on the exploded drawings in the manual. I can't see the fuel pump and I'm not 100 % sure where it's actually located on the engine. I know that sounds nuts but they really crammed the engine into the engine compartment and it's really hard to see anything let alone work on it.
I'm thinking about trouble shooting the easy things first. Disconnect the fuel line fitting at the throttle body and see if anything comes out when the engine cranks. Remove the fuel filter and replace it in case it's gummed up. Maybe remove the rubber line from the gas tank to the fuel filter to see if the line is blocked.
Removing the fuel pump would be a major chore so I'd like to test it before I try to remove it. Any ideas how to do that?
I checked the relay box on top of the engine and tried to push the "Reset" - red - button. It does not move at all. So I'm guessing that it's not popped out tripping the circuits.
I am not sure which relay is for the fuel pump. Nothing is labeled.
So my question(s) are:
How do I test the fuel pump without having to pull it out?
Where is the fuel pump located on this engine?
Does anyone have a photo of this engine showing the fuel pump?
I'm open to any ideas..
Sorry this post is so long but I'm trying to address everything I can. I'm at a total loss for ideas.
Thanks for any imput.
Keats
Arizona :cool:
 
Don't forget that you'll have a "start-by-pass" circuit that provides power to the fuel pump during cranking ONLY (prior to engine oil pressure coming up).
Perhaps begin by checking this!

BTW, the start-by-pass circuit will over-ride any issues with a Low Oil Pressure Switch during cranking only.
IOW, the engine would fire up during cranking, but would die once the starter motor circuit is released.
(this does not sound like your problem, however)


Kim has shown you the fuel pump harness, of which is a simple Positive and Negative connection harness.
There will be a 4 or 5 pin relay in the system to take the load.
Make sure that the relay is working correctly, both on the power In/Out side and on the triggering side (i.e., magnetic latch side).



.
 
Last edited:
Sunday A.M.
Wow ! thank you to everyone that has offered ideas.
This is a TBI system so no fuel rails or individual injectors are involved. There are two small bowls suspended over the throat of the throttle body and they are wired. I'm guessing that these act something like a fuel reservoir and that they would spray fuel into the throttle body above the butterfly valves as needed. Nothing comes out of either of them so I'm guessing that there is no fuel getting to them. I plan to remove the fuel line fitting at the rear of the TBI and crank the engine over to see if any fuel is getting to that point. If not then it's working backward to the fuel pump, and fuel filter and eventually the fuel tank. I tried to listen @ the engine compartment to hear the fuel pump working when the key was turned on but I heard nothing. I did hear a very slight clicking near the relay box making me think that the relay was shutting off when the key was turned off. I'm still not exactly sure where the fuel pump is. I think it's on the Starboard side below the exhaust manifold but it's so darn tight there, I can't see anything. I'm thinking that perhaps the fuel pick up inside the fuel tank may be clogged from the old gas. Any ideas about trying to blow some air thru the fuel line hose after I remove it from the fuel filter? I don't know if there is a screen of some sort on the end of the pick up and I'd hate to blow it off inside the tank by using the air compressor. Has anyone ever removed the fitting from the top of the gas tank and removed the fuel pick up? Is there a screen / filter on the end of the line?
I'm going to replace the filter/ water separator (looks like an oil filter) and if I can find the fuel pump, maybe I can remove it and then blow out the lines before and after it to make sure there is no varnish in them clogging things up.
I'll try to post a few pictures.
Again, Thank You for all the good ideas.

Keats
Arizona :cool:
 
I'm going to try a couple of photos here.
Keats
Arizona

Well that did not work. Can't get a photo to load. Sorry..
 
Last edited:
RicardoMarine said:
Ah hah!
So this is not using a Low Oil Pressure switch to continue pump operation?

I'd better give myself a demerit! :cool:
Click to expand...
Just for clarification Rick, With Merc, the low oil pressure switch to control the fuel pump is only used on the carbureted models.

With EFI/MPI's it is first done by relay at "key up" for two seconds then once the ECM sees an rpm signal/reference pulses at engine crank speed, the ECM once again turns on the fuel pump relay until it loses an RPM signal.

The RPM signal first comes from the pick up coil mounted on the distributor shaft/housing then through the ignition control module under the distributor cap and finally to the input of the ECM. The output of the ECM turns on the fuel pump relay.
 
Last edited:
boat_tech said:
Just for clarification Rick, With Merc, the low oil pressure switch to control the fuel pump is only used on the carbureted models.

With EFI/MPI's it is first done by relay at "key up" for two seconds then once the ECM sees an rpm signal/reference pulses at engine crank speed, the ECM once again turns on the fuel pump relay until it loses an RPM signal.

The RPM signal first comes from the pick up coil mounted on the distributor shaft/housing then through the ignition control module under the distributor cap and finally to the input of the ECM. The output of the ECM turns on the fuel pump relay.
Click to expand...

Monday,
So should I not consider the oil pressure sending switch as being in the loop? My engine is EFI ( no carb) so that switch is not involved and I can move on to other areas?
I hope so..
Thanks
Keats Az.
 
Boat Tech..... thank you for that info.

Keats, if you have TBI, it will look similar to this.
$(KGrHqJ,!iYE8tplFZKTBPhK+7jmcg~~60_35.GIF
 
Yea, that it. I saw this schematic and I've also got the service manual #24 that is a shop manual. I found out that the relays are the same so I can swap them out to see if I get anything at the fuel pump. I believe it should make a noise when the key is turned on. If it will after the swap, then it's a faulty relay (keeping my fingers crossed that the relay is the culprit). If I don't get a noise, then it's most likely the pump.
Thanks for the tips..
Keats Az.
 
It appears the pump used on this application may be the same as the older carbed V6 motors. It may be higher pressure but similar in location and shape.

It would be inline with the fuel line between the water serperating filter and the TBI unit. Not sure on this one for EFI/MPI

If this is so??????? then it is simply a 12vdc pump. You could apply 12vdc to the wire leading to the pump. It looks like the GREY wire from the relay is the power to the pump.

You could jump 12 volts to the grey wire to see if the pump works. If it works then relay...if not relay then something further back in the system is open.

Just be very cautious about this and try to avoid sparks and fuel mixing..........!!!!
 
Yes. It's in the run position. I checked that right away. Good idea though. Usually it's something very simple and this would have stopped everything. Thanks for the idea.
Keats
Az
 
I'm heading out to the boat this afternoon. I'll check it again. My wife said she heard a noise that she thought was the pump when the ing. switch was first turned to the ON position. (Not the start position). I did not hear that.
I'm going to take the stethescope with me and put it next the Cool Fuel box with the fuel pump in it. Hopefully I'll hear something. That would mean that it's not the relay or the pump and that would be a great thing. Then it would be tracing the lines back to the gas/water separator filter to see if it's so varnished up that nothing gets thru it. I'm going to replace it no matter what. It's overdue..
If not then it's a clogged line from the tank or from the filter or from the pump to the TBI. I'm going to try blowing thru the lines to see if they are clogged. Last place it may be is inside the tank where the pick up is. Maybe it's caked with varnish around the pick up screen. I sent an e. mail to Moeller in Tenn. to ask their Cust Service the best way to drain the tank and remove the outlet line to inspect it and I'm waiting for a reply.
Thank you for the kind words and advise. I really appreciate it.

Keats Az.:cool:
 
11 Nov 13 Veteran's Day.
I was able to use the stethescope to listen to the cool fuel box where the pump is located and when the key was turned on, I could hear the pump running. That solved the pump and relay issue. Yea !!
I then removed the water/fuel filter and it was full of liquid. I poured it into a can and it smelled very much like a thin varnish. I siphoned some fuel via the tank fitting and it was much more of a gas smell. ( I had added 10 gallons of gas last Saturday.) Next was the fitting at the rear of the TBI. I removed it and the line had liquid in it. I pumped that into a can and it too smelled like a varnish. Still nothing from the TBI into the venturis of the throttle body.
So it looks like the fuel is getting to the TBI but stopping there. I will check the "Bowls" suspended over the TBI venturis and look for a fuse somewhere that may control the fuel.
This is a better situation than I had anticipated. At least I know that I don't need to buy a pump and relay and the fuel lines are clear. If I can get the TBI to spray fuel into the engine, I'll be O.K.
Keats
Az. :cool:P1060674.jpgP1060672.jpgP1060683.jpg
 
I then removed the water/fuel filter and it was full of liquid. I poured it into a can and it smelled very much like a thin varnish.
Click to expand...
That's the smell of old gas...it won't burn. The TBIs could be plugged w/varnish residue. You can try a new water/filter separator. Prime it w/half fuel and half SeaFoam. Try to start it w/a few cranks of the starter and turn the key off each time wait 30 seconds so the starter doesn't overheat and repeat. Doing this will get some of the mix into the injector circuit. Let it sit overnight and try to start it the next day.
 
Sounds like a good idea. I picked up a new filter (Sierra 18-7944) @ West Marine here in Phoenix today. I spoke with the guy about my situation and he said to use Sea Foam too. I bought a can and I'm planning on trying it tomorrow.
I read about pulling the injectors today in the service manual and it said that they pull out and perhaps a slight assist with a screwdriver might be needed. Looks like there is a fine screen at the bottom of the injector per the exploded drawing and I'm guessing that's clogged up pretty bad. I'll try to clean these screens and reinstall everything. It's got to be the injectors now. Everything else is open but nothing is coming out of the bottom of the injectors into the Throttle Body. I know that there should be some very fine holes on the bottom of the injector to atomize the fuel and they probably are gummed up too. I looked on line for an injector kit and sure enough, it's no longer available. the Merc # is 852956A1 and the TBI gasket kit with the O rings etc. is 852957. Not even an after market kit anywhere. I really have to be careful handling the injectors cause apparently I can't replace them.
Thanks again for the advise.
Keats,:cool: Az.
 
This is good news. Worse case is a replacement but at least now I know they do exist.
Thank you very much. I never thought E Bay would have them.
Keats Az. :cool:
 
I pulled one injector today. I've been on line searching for replacements just to see what they run. Found the gasket / o ring kit at Rock Auto. Made by Walker mfg. $3.08 plus shipping. All new gaskets, o rings and filters for two injectors.
I found that this injector is used on big block GM engines from 1988 thru 1995. The injector part # is 17104288. opposite that stamped in # it reads #57 GM. It's made by Rochester for GM. I've found them for as low as $39.99 rebuilt or $48.79 new at Rock Auto. Apparently it's a very common injector. You Tube has videos showing how to do the rebuild. I'm going to check with the "Boss" when she gets home from work to see if she wants me to replace my injectors or buy replacements. I can still try the Sea Foam to see if it clears up the varnish issue.


Keats Az. :cool:

P1060714.jpgP1060710.jpgP1060709.jpgP1060708.jpg
 
kimcrwbr1 said:
http://www.marineengine.com/boat-forum/showthread.php?413544-A-Serious-Ethanol-Problem
Click to expand...

Good link.
If I could get any liquid to pump out of the injectors, then I'd at least have that part of the problem solved. Right now, I'm thinking new injector filters and some Sea Foam into the TBI feed line to get the cleaner into the Injectors to hopefully clean out the gunk. My injectors are bone dry. Not a squirt, not a drip, nothing. Tried the 9V battery test across the contacts very briefly and could hear a very slight ping noise but I'm not sure if that's the solenoid working or not.
Can't get the filter off of either injector stem. Really stuck on. I'm afraid to break the plastic around the extremely fine screen material. I should just replace them with the rebuild kit.
I do appreciate all the great imput from everyone. When I get through with this and I'm back on the water, then I'll be willing to assist someone else with a similar problem. I'm still learning right now..
Thanks again,

Keats Az.:cool:
 
Friday P.M.
I found a place in Glendale Az. that rebuilds/cleans fuel injectors. (Bluepitt Kustoms 602-973-9088) They charged $12.00 each and they install new filters and the small O ring. Took mine there yesterday and dropped them off. About two hours later they called and said they were ready for pick up. So I went there this A.M. and they were looking good. Huge difference in the filters. Mike, the owner and I talked for a while and he said that they were gummed up with varnish. He had them sitting in a ultrasound cleaner and got the varnish out. He said that he tested each one and they were equal and sprayed very good patterns. He then took me into the shop and hooked one of my injectors up while in the ultrasound machine bowl and he attached a couple of electric wires to the posts and hit the test button on the machine. I could hear a distinct rapid clicking noise (much better than I was able to hear with the 9v battery the other day). The injector was spraying like crazy. He added that they took a bit longer to get going cause of the varnish build up.
So $24.00 dollars later I was on my way. Tomorrow I'm going to get the new gaskets via USPS from Rock Auto and I'll be able to put it all back together.
Next is trying to siphon out the fuel tank. Mike said that fresh fuel on top of old varnish fuel would be of no help. He recommended draining the tank completely and using 5 gallons at a time in one of the cars. At least it should not go to waste. We'll see how that goes.
Looks like it's all coming together finally.
Keats Az :cool:
 
;) 16 Nov 13
Horray !! Success today. I finally got it to start and run. I installed the rebuild/cleaned injectors with new O rings and a new gasket on the throttle body and hooked everything up and then replaced the fuel/water filter. I turned the key and nothing.. No spray at all. I got out the volt meter and probed the connector and I had voltage but it would diminish as a few seconds ticked off. Each connector had the same reading initially and then dropped down a few volts. Hmmm?
I knew that there was fuel being delivered to the injector bowls so if they were getting current, they should be spraying. Back to the manual and everything I read led me to believe that all was correct and the engine should be starting.
Then I decided to go back to basics. I pulled out the Sea Ray owners book and read about engine starting procedures. The only thing that I had not done was to drop the outdrive down first. I had it in the full up position for towing. O.K. that was something to consider.
I went back to the injectors and removed the connector and applied 9volts across the injector pins and they each sprayed when the voltage was applied. So I knew that they had fuel, and were clean enough to spray so the only thing left was to drop the outdrive. I brought it down and dammed if the injectors didn't start spraying. Holy Cow.. Could it be something as simple as that?

I reconnected the coil wire and tried again and sure enough I could see them spraying into the throttle body and the engine started right up.
Apparently there is a safety feature involving the outdrive position that locks out the injectors. Nothing in any of my books or manuals says anything about this. There is no mention that the engine will not start while the outdrive is raised for trailering.

Any way, all that's left now is to drain the tank and refill it with fresh fuel and then try it out.

I hope that all of the problems I've encountered and overcome that I've written about here may be of some help to another boater with a similar problem.
Thank you to everyone that replied with all the great tips.

Keats Az. :cool:
 
I installed two brand new batteries and put 10 gallons of fuel in it today.
Click to expand...
If there were only a few gallons of old fuel in the tank before the 10 fresh ones you won't need to drain the fuel tank especially w/new filters installed. Just top it off w/5 gallons of 93 octane or some racing fuel...very high octane.
 
Not sure about the spark. I had the coil wire pulled so it would not fire yet. I wanted to see the injectors spray first. Last week I primed the engine directly thru the throttle body and it fired up immediately so I knew the spark was good then. I had no idea that the tilt safety switch would cut off the injectors. I went over all of the trouble shooting variables in the shop manual etc. but there was nothing to indicate that having the outdrive tilted up would prevent the injector from spraying. Still can't figure out why I got a voltage reading at the injector connectors but the injectors would not spray. The 9Volt battery was enough to get them spraying so why not the 14 volts that I read when first tried.?
Who knows. ? Anyway, I'm thinking that the engine won't start to prevent excess strain on the U joints if the transmission was engaged with the outdrive fully up.
As for the old fuel, it's three years old. The fresh fuel is a week old. I'm sure it's probably still burnable but I really don't want to take a chance of fouling the lines etc. Gas is $2.95 a gallon here in the Phoenix area so I'll just put it into my old van and try to use it up there. I'll put new fuel into the boat and then everything will be fresh and ready to run.
Thanks again for all the imputs. I do appreciate it.
Keats Az. :cool:
 
Back
Top