Mercruiser 3L Fuel Delivery from fuel tank

[Snoopyf150]

My 1987 Four Winns boat, 170 Horizon, has been in dry dock for past 7 yrs. I recently decided to get it afloat again. So I tried cranking it over but it would not start. I pulled the line from FP to carb and it was dry. That said I suspected bad FP. So I charged ahead and installed new pump, carb filter, spark plugs(pulled one and it looked bad). I also drained fuel from tank, had a "turp" smell to it. I also replaced the original anti siphon valve, fuel tank to ZfP tube and related hose. After all this I tried starting the engine with the inlet to FP hose in a fresh gas can. Nada. Checked the carb, it was dry. Would I be. Better off putting fuel in tank and connecting FP hose to it rather than the external gas can? I cannot understand why the pump isn't drawing gas from the gas can. I had the can sitting inside the boat(rear bench removed). I welcome any suggestions/recommendations. Thank you.

 

[alldodge]

My 1987 Four Winns boat, 170 Horizon, has been in dry dock for past 7 yrs. I recently decided to get it afloat again. So I tried cranking it over but it would not start. I pulled the line from FP to carb and it was dry. That said I suspected bad FP. So I charged ahead and installed new pump, carb filter, spark plugs(pulled one and it looked bad). I also drained fuel from tank, had a "turp" smell to it. I also replaced the original anti siphon valve, fuel tank to ZfP tube and related hose. After all this I tried starting the engine with the inlet to FP hose in a fresh gas can. Nada. Checked the carb, it was dry. Would I be. Better off putting fuel in tank and connecting FP hose to it rather than the external gas can? I cannot understand why the pump isn't drawing gas from the gas can. I had the can sitting inside the boat(rear bench removed). I welcome any suggestions/recommendations. Thank you.

:welcome: to iboats

New fuel pump and it will not pump fuel, my first guess is maybe it was not installed or connected correctly. Using a gas can should not be an issue and is better in you instant then using the boats tank. Placement of the can could cause some issues but I don't see any that is apparent from your description.

What engine do you have, 3.0, 4.3 something else? Got any pics of what your setup is?

 

[fishrdan]

The fuel pump should draw from the tank, but if all your lines are empty, it could take some cranking.

If I haven't started my boat for some time, I'll crank it a couple times at 3-4 second bursts to see if it will start or at least cough (like it's getting fuel). If it's still just spinning and has no signs of firing, I'll remove the spark arrestor and put a bit of fuel straight down the throat of the carb, a teaspoon or so... (move all sources of fuel away from the engine) and then crank it over again. This will usually get the engine spinning enough to prime the fuel pump and get the carb filled.

Also, with the fuel lines removed from the fuel pump, hold your fingers over the in-out ports and see if you can feel the pump pushing/pulling while someone cranks the engine over a couple of times. You should feel it pulse as the pump operates.

 

[Snoopyf150]

My engine is. 3.0 L. As far as pump, lines etc. being connected correctly/incorrectly I do understand someone possibly maybe would hook it up incorrectly. Not sure how they would do it without bending preformed lines, but heh stranger things have happened I am sure. But I will tell you, given the setup there is only one way to hook the pump up. I am 100% certain it is correct. The in from fuel tank is connected as such to the in port barb on the FP and the out port(what we call in the jet engine business as an AN fitting(37deg angle) is connected to fuel line that goes to carb.
I do like the suggestion of removing in/ out lines of FP and cranking to see if pump pulse is noticed. As I said the pump is a brand spanking new unit, Quicksiler model. I may try putting some fuel down carb as you mentioned. As they say intelligent minds think alike. I almost did this today but was plumb just "boat tired", working on my baby for past 6 days, and decided to call it a day.
Thank you folks for your comments. I appreciate all of them

 

[alldodge]

We are unable to see what your seeing so checking if it is installed correctly is just a question. Your model year can also have one of two different fuel pumps and one is installed up, the other down

 

[Snoopyf150]

Understood, just wanted to be clear that I installed pump etc correctly. My pump is the one on left above. Today I hooked up the fuel supply line hose from tank anti siphon valve to FP inlet and i put about 4. Gals gas in tank. Then removed flame arrest or and shot some ether in carb. FYI. The choke plate is closed. I then tried to start the engine(with ear muffs flowing water) and nada. Did this on,ff, on, off for about an hour and threw in the towel for now. I am stumped. I still cannot comprehend why the pump isn't spewing gas into the carb. I do appreciate your help and comments as I continue to troubleshoot the issue.

 

[Snoopyf150]

I will tell you that before I removed the pump I read thru the Mercruiser service manual for any considerations or special procedures. The only thing it said was to facilitate pump removal, loosen the mtg bolts and hold onto pump. Then have someone crank the engine until FP arm real eases from cam lobe. Oddly enough, when I removed the mtg bolts the pump came right out. I did not have to crank the motor. I installed the new pump the same way the old one came out. Did I get lucky when I removed old pump or was that possibly the start of my initial "hidden" problem?

 

[jimbo_jwc]

Read into some of my post. I went thru most of the problems you will probably have as my was a 1987 3.0 L that had about 40hrs when I got the PO couldn't get to start either but new battery came with it because of problems and he was tired of working on . You can fill the float bowl from top of carb ,clean points with emery and try.

 

[alldodge]

has been in dry dock for past 7 yrs

Your looking for gas and it could be you have bigger problems and its starting to have me think that something is missing or broke. If you don't know for sure, pull the distributer cap off and crank the engine, see if the rotor turns

 

[Snoopyf150]

I did clean up the points but will go at them again. Good point on rotor. Again intelligent minds think alike. I removed dist cap yesterday and cranked the engine. Rotor turns. Also checked cap surfaces for carbon build up. Nada. I tried checking for spark at plugs, grounding one but had a tough time cranking engine and trying to stretch from front seat close enough to plug to see if there was a nice blue arc. Unable to see if arc was present in daylight. Will try again Sunday with a helper to crank the motor while I watch the plug tip. Please keep comments coming. It will be a check on me to see what I did or if I missed doing something. I am still miffed by no fuel in carb from fuel pump. Thanks

 

[Snoopyf150]

Forgot to mention I will probably remove the new pump Monday(I am currently out of town) and do a review of it and where it goes in the engine block. Tx

 

[alldodge]

Rotor is turning so timing chain is working. The issue I'm thinking about is if the pump arm is actually moving. The 3.0 does not use a pump rod off the cam (if memory serves me correctly) for the old design pump should work. It does not make since that there is no gas, you have spark yet it will not fire with starting fluid.

 

[Snoopyf150]

I don't have a good visual on spark at plug yet. As I said I was in the "drivers seat" with plug #1 grounded trying to crank the motor and watch for spark. During daylight hrs difficult not being I'd top of plug. I will get better read on this tomorrow. And yes the pump does not have pump rod, just pump arm. What is also odd is I had this engine running in 2008 when I last winterized it. Unfortunately because of my job(lot of travel, especially in summer mos.) I Have not had the boat back in the water since then. Now I am retired and determined to have this boat see water this year. As I said in my first blog, I tried starting the engine and discovered I was not getting fuel at carb. It was then I began checking over the engine very closely. Changed the pump, carb filter, thermostat, alt belt and plugs. Checked, cleaned points, checked rotor movement(rotates with crank),cap condition( no carbon buildup). With this I felt cam was good. I then went after the anti siphon valve at tank. In an attempt to remove it because of age and oxidation, it broke off inside the tank supply tube. So I replaced the tube and valve parts. I did drain old gas from tank and gave since put fresh gas in tank, after being unsuccessful in trying to draw from a gas can inside the boat. That is my journey so far and I continue on not wanting to give up.. Again, thank you very much for all your technical feedback and suggestions. If i haven't tried any of them, when I see your reply I go after them.

 

[Snoopyf150]

Also I plan to remove in/out lines to pump, crank the engine and check for pump pulsing before I decide to pull the pump. At least it will give me a warm fuzzy if pump is working ok.

 

[fishrdan]

- If you squirt a little fuel down the carb and it still won't fire, start looking for a spark problem.
- The engine could be flooded (too much fuel) so try starting the engine with the throttle wide open,,,, ready to back off to idle QUICK!
- Gas (fuel) only for priming, don't use ether or starting fluid.
- Poor mans / solo / unscientific way to check for spark, hook up a timing light on the coil wire and see if the timing light blinks when engine cranked.

If the points and condenser have not been changed, change them. Might not be a bad idea to swap spark plugs too. Also.... If the raw water pump in the drive hasn't been replaced lately (7 year lay-up), it needs to be replaced before firing up the engine.

FWIW, I've had spark plugs so gas fouled that they wouldn't fire. Swap the plugs and the engine fires right up.....

 

[Fun Times]

I don't have a good visual on spark at plug yet.

Poor mans / solo / unscientific way to check for spark, hook up a timing light on the coil wire and see if the timing light blinks when engine cranked.

Using the timing light trick to both the coil wire then to a few plug wires will help give a good indication of where to go from there.

What is also odd is I had this engine running in 2008 when I last winterized it.
I discovered I was not getting fuel at carb.
I am still miffed by no fuel in carb from fuel pump.

You are working way to hard before and after retirement. To make this as easy as possible...First carefully remove the fuel line at the carburetor inlet, have a container and some rags at the ready to catch flowing fuel, crank the engine and see if any fuel is getting to the carb.....If yes, check the little fuel filter by removing the big nut at the carb where the inlet line connects to, if clean then you have an internal problem inside the carb.....Most likely a stuck needle and seat to begin with from sitting. In rare cases and as a test, you can sometimes get away with finding the general area of the needle and seat and giving the top area a light tapping to help unstick a stuck needle and seat. Cranking the engine while tapping may help as well. Then you'll know if you think you need to go deeper into the carburetor or not as far as a rebuild.

Your 1987 3.0 engine model offered 2 styles of carburetor that you'll need to ID to help give you an idea of your carbs internal workings.
Here they are for you,
CARBURETOR (MERCARB)
CARBURETOR (ROCHESTER)
http://www.mercruiserparts.com/selec...?doc_nbr=41261

Hope this helps, good luck.

 

[Snoopyf150]

Tx for all the comments, recommendations. I tried the "unscientific" method to check for spark with coil and timing light. Light did not blink. As far as plugs, they are new. I pulled #1 and #4. Neither of which were fuel logged. They had a slight film of fuel but that may have been from what I put in carb.i tried grounding no. one and cranking, but did not notice any arc at tip either. I am headed toward changing the coil and pats and condenser.thanks again for your support, much appreciated.

 

[Snoopyf150]

Thanks for your comments and recommendations. I did try the "unscientific" method of checking for spark at coil with my timing light. No blinking from light. I also was able to get a better check of spark on two plugs. NADA. My next move before I change points and condenser(want to rule out everything possible) will be to check for arc arc at points and clean coil terminals(really aren't that bad but as I said trying to cover all bases). As far as plugs, they are new. They are not fuel logged and I checked gap again. It is at .035". Barring any weather issues today here in NE I will have at it again.

 

[Snoopyf150]

Oops. Didn't realize my reply was posted on page two when I repeated it. I did the carb line check during crank last week. Got not fuel out. I did change the carb small filter. Today I spent doing ignition checks. What I found, according at least to Mercruiser shop manual troubleshooting, is the coil is bad. I am not convinced on this as some of the meter results weren't conclusive. I am thinking take it to local shop and have it checked out.

 

[Snoopyf150]

Just wanted to send along an update on my fuel delivery, engine starting problem. Drained all old gas and put in new to start. Then checked for arc at points, NADA. So I did an ohm check and voltage check of the coil. Results told me coil is good. I then put a spark checker in line with #1 plug. Something I could see very clearly. Cranked the engine, no spark in checker window. At this point I narrowed "no spark" to distributor. So I pulled the points and condenser. I obviously did not get a good visual on the points before even though I did try cleaning them best I could with file and emery cloth. Long story short it took me all of 2 secs to convince myself issue was with points.so I replaced them and condenser and proceeded to try an engine start. Put a little gas in carb to give the. Motor a slight edge for fuel. Turn on key cranked the engine and oujla it started on the second try. Shutdown and restarted with no problem. Let it run to engine temp. Did slight acceleration on throttle and then SD. I am convinced the points were bad enough with pitting to prevent starting. I want to thank everyone for their comments, recommendations and support. I feel very fortunate to have joined the boats forum and receive an overwhelming amount of help and support for my problem. I hope I can "pay it forward" sometime. Thank you all again. Snoopyf150