No fuel in carb despite several attempts to crank

[Happygolucky]

Hallå fellow boaters, after sitting for about a week I went to check on the boat (Bayliner Ciera 1997) Trying to start engine (5,7 l mercarb, mechanical fuel pump) cranking repeatedly several runs but no firing up. (I did pump the remote in order for the acc. pump to squirt but no result fireing up)
Sprayed some starter gas down the carb and had it to ignite momentarily, telling me at least there must be spark. So for some reason the fuel pump doesn’t seem to get the fuel to the carb, therefore I went on to hook up a priming bulb in order to manually pump some fuel and that made the engine start at once!
So..what is my problem most likely? I can think of the fuel pump, anti siphone valve, or could it even be the venting of the tank!.??
I do have problems when filling up, with a lot of “ burping” and having to go crazy slow with the trigger on the filler handle.
Lately I’ve also noticed that sometimes when pushing throttle/ remote to accelerate there’s no response if you go to quick.. hmm
Any thoughts or ideas someone have on this is greatly appreciated!

Henrik

 

[alldodge]

After sitting that long it's not a tank vacuum
Use a gas can and length of fuel line. If it fires up and keeps running then it's the antisiphone valve or the tank pickup

If that doesn't work then it's the pump

 

[Bondo]

Ayuh,...... I'd start by changing the fuel filter, 'n examinin' the contents of the old one for anything but clean fresh gasoline,....

 

[dingbat]

I do have problems when filling up, with a lot of “ burping” and having to go crazy slow with the trigger on the filler handle.

Remove the vent line from the hull and blow back through it.

Sometimes fuel gets trapped in the “loop” blocking the vent. Cause I g the problem you describe

 

[Happygolucky]

After sitting that long it's not a tank vacuum
Use a gas can and length of fuel line. If it fires up and keeps running then it's the antisiphone valve or the tank pickup

If that doesn't work then it's the pump

ok so no vacuum then , an external tank was a great advice to rule out the valve & pickup ! thanks!

 

[Happygolucky]

Ayuh,...... I'd start by changing the fuel filter, 'n examinin' the contents of the old one for anything but clean fresh gasoline,....

had the filter replaced in july but checking it sounds like a good idea!
Thanks!

 

[Happygolucky]

Remove the vent line from the hull and blow back through it.

Sometimes fuel gets trapped in the “loop” blocking the vent. Cause I g the problem you describe

ah yes have had gas squirting out the vent when fueling up so some blowing is’nt a bad idea! Thanks!

 

[Happygolucky]

After sitting that long it's not a tank vacuum
Use a gas can and length of fuel line. If it fires up and keeps running then it's the antisiphone valve or the tank pickup

If that doesn't work then it's the pump

btw what’s with the “Merc Adult “ link ? I just get the message:

Oops! We ran into some problems.​

You do not have permission to view this page or perform this action.”

how do I get the permission required??

 

[alldodge]

Might just have been a hiccup, it's working for me. Select the one in my sig and should take you there

 

[Happygolucky]

Might just have been a hiccup, it's working for me. Select the one in my sig and should take you there

No hiccup, I used your link and get the same denial everyvtime

Might just have been a hiccup, it's working for me. Select the one in my sig and should take you there

no hiccup , the Merc link in your sig doesn’t work (for me) but I think I found the answer ”..The adult title has been charged to MUST HAVE Technical Information for DIYers.”..!

 

[Scott Danforth]

click on this one. https://forums.iboats.com/threads/must-have-technical-information-for-diyers.335378/

 

[alldodge]

No hiccup, I used your link and get the same denial everyvtime

no hiccup , the Merc link in your sig doesn’t work (for me) but I think I found the answer ”..The adult title has been charged to MUST HAVE Technical Information for DIYers.”..!

Your right, I forget that Mod's can see deleted threads. I need to update my sig

 

[Happygolucky]

After sitting that long it's not a tank vacuum
Use a gas can and length of fuel line. If it fires up and keeps running then it's the antisiphone valve or the tank pickup

If that doesn't work then it's the pump

So I’ ve now run engine on external tank ,blown through the fuel tank vent and also replaced ASV. fuel is getting to carb so that’s no issue anymore.
However Engine behaves hesitant when giving throttle going from idle to planing speed . From what I read this could be related to carb’s power valve acting up ?!
Or is it caused by poor of idle mixture/ idle speed adjustment , also I can see the initial timing is some 17 deg. ( not 10 btdc as it should..) From what I read this could make hot starts more difficult but my problem is cold starts. Anyway just ordered a distr.clamb wrench and will start with the timing and then redo the idle mixture settings from scratch ..
Any thoughts,,?

 

[Scott Danforth]

Most likely dirt in the carb idle circuit. Nothing a good teardown, cleaning and re-assembly wouldn't cure

 

[Lou C]

There is an off idle or transition system in most carbs that adds a bit of fuel between idle and cruise; it may be that the carb needs a good cleaning as well as a new accel pump. The Mercarb I think is a slightly modified Rochester 2bbl which is a pretty simple carb to take apart & rebuild.

 

[tank1949]

Hallå fellow boaters, after sitting for about a week I went to check on the boat (Bayliner Ciera 1997) Trying to start engine (5,7 l mercarb, mechanical fuel pump) cranking repeatedly several runs but no firing up. (I did pump the remote in order for the acc. pump to squirt but no result fireing up)
Sprayed some starter gas down the carb and had it to ignite momentarily, telling me at least there must be spark. So for some reason the fuel pump doesn’t seem to get the fuel to the carb, therefore I went on to hook up a priming bulb in order to manually pump some fuel and that made the engine start at once!
So..what is my problem most likely? I can think of the fuel pump, anti siphone valve, or could it even be the venting of the tank!.??
I do have problems when filling up, with a lot of “ burping” and having to go crazy slow with the trigger on the filler handle.
Lately I’ve also noticed that sometimes when pushing throttle/ remote to accelerate there’s no response if you go to quick.. hmm
Any thoughts or ideas someone have on this is greatly appreciated!

Henrik

I had similar problems with a 95 Proline and my Sea Ray. Old fuel and debris clogged up Proline fuel pickup, before it could get to water/fuel separator. I had to purchase a cheap automotive 12 volt pump and cycle fuel sever times, after removing pickup tubes' screen, to clean tank. Pulling tank was no option. My SR's issue was a defective pickup tube. I installed two on each of my dual tanks, just to have an option. I just swapped hoses and sucked from second and open line. I have no idea what is causing the bad pickup tube to clog. I have experience mud-dobers clogging up vents.

 

[Happygolucky]

so I’ve been trying to find a solution to why the engine’ behaving so difficult
to start, hesitations at acceleration , initially I was suspecting it was related to carb and fuel.. To do things in the right order I got a timing light (and eventually the special distributor clampdown tool )
As my first checking of timing at idle showed some 17 deg advance , I set the TB V into base timing mode (by grounding the purple / white wire) loosened the distributor and adjusted it to 10 deg.btdc. All seemed well , shutting down , ungrounding and restarting was no problem ( once engine is up to temp it always has been starting instantly.)
A few days later I went down to the boat again to make sure the boat would start smoothly… did not ! After several attempts to get it to fire up I decided to recheck the timing -
Doing so I realize that the distributor was not not locked down sufficiently as I could twist it without touching the locking bolt.. hm so perhaps timing might have been shifted during my cranking.
So once again I go through the routine (as per the manual );grounding , starting and adjusting the distributor to 10 deg btdc. After finishing the process (“Base timing wire“ disconnected )I thought I would check the total timing so I revved the engine to about 2500 rpm and expected to see the timing mark moved away from the “zero” mark but to my surprise the timing remain at the Initial setting.
No advance what so ever !
Now this makes me suspect it is the ignition module that has been causing the poor acceleration /difficulties to cold start thus not a carb/ fuel problem after all !?
I have yet to check if it could be related to corrosion in the connector or if the Module itself has broken down.
As I understand these TB modules are no longer available and the solution is to replace with a Delco distributor !?
Any thoughts on this ?

 

[alldodge]

Yes the module controls advance and are NLA as new. Sometimes they can be found but issue is if they work

Both TB4 and 5 had issues with pickup module in distributor with grounding. This is way Merc changed from 2 wire to 3 wire module which added a new ground wire. Not saying this may be causing the issue but has been a problem with many others

 

[Happygolucky]

Yes the module controls advance and are NLA as new. Sometimes they can be found but issue is if they work

Both TB4 and 5 had issues with pickup module in distributor with grounding. This is way Merc changed from 2 wire to 3 wire module which added a new ground wire. Not saying this may be causing the issue but has been a problem with many others

From my understanding of the pickup module : if it fails to produce pulses ,no spark is generated which would cause rough running rather than lack of advance!?! I’ ve seen some threads on the net where people report having trouble getting their TB V out of the “base timing “ mode .. which I believe to be my problem.. but cannot find any further info on this being a documented problem .

 

[alldodge]

Agree with your statement, my comment was along the possibility if the module is not providing a good signal back to the module then it just "might" be causing issues

I don't know, just a WAG and not meant to cause a change just a comment