Cold starting problem 90HP Merc

[gussie]

This is a 2002 Merc 90HP. It will not start cold until fuel is sprayed directly into carb throats.

I cannot determine if the fuel enrichener is functioning properly.

First, made sure that fuel is being delivered to carbs, and to enrichener from fuel line with just squeezing bulb and also cranking. Note: bulb squeez delivers large squirt of fuel, cranking with fuel pump delivers only very small squirts. In any case, I tried squeezing bulb continuously while trying to start to no avail.

Removed line from enrichener, pushed in on ignition key and held, heard click in enrichener, small dripping of fuel from line, then stopped. The fuel coming from enrichener line could be increased slightly by squeezing bulb. The enrichener always clicked when ignition was pushed in. Fuel coming out of enrichener was occ. slight dripping and intermittent.

If the small button, on top of the enrichener, is pushed, should it deliver squirts of fuel?

After manually introducing fuel into engine and allowing to run and get warm, it starts fine.

I would greatly appreciate any help you could provide, before I go out and spend money that will not fix my engine.
Thanks

 

[Silvertip]

Re: Cold starting problem 90HP Merc

The enrichener will not deliver fuel when you push the key in unless the primer bulb has been squeezed until it is firm. The essentially pressurizes the fuel system and when you push the key in, it injects the fuel. If the system isn't pressurized the enrichener can't work.

 

[Don S]

Re: Cold starting problem 90HP Merc

This ought to help trouble shoot it.

 

[gussie]

Re: Cold starting problem 90HP Merc

Thank you very much for your replies. Thanks Don for the block diagram. I see that, when I push the key in and I get the click, I do get a small amt of fuel, but probably not enough.

Even though I get a very nice flow when I squeezed the bulb, and this large amount of fuel is present at the inlet side of the enrichener, maybe I?m not maintaining pressure. The fuel line and the bulb was purchased new last fall in an attempt to solve this problem. The bulb feels firm after squeezing it several times. Maybe the enrichener is not fully opening.

Is the enrichener a simple electronic valve, where voltage is applied and it opens to allow the pressurized fuel to flow?