cannot get my 454 mercruiser to fire

[IanBat]

I did change the sensor, I think I forgot to mention that earlier but I think it could be the flooding because I was constantly using the throttle when starting the thing everytime I changed a part and never even thought that was actually the problem. Hopefully i'll have it started this weekend and if not you'll probably see some more threads. anyways thanks for all the advice I really appreciate it

Be careful about over fuelling/pumping......

 

[sdarc]

Be careful about over fuelling/pumping......

Yep. Potential for hydraulic lock in the cylinder. Makes a real mess of the engine. Unfortunately I have first hand experience.

IF it realy flooded as much as you say, pull all the plugs before to clear out the fuel while cranking.

Also check the float level in the carb. Maybe the stabilizer loosened up some gunk.

 

[probie24]

Yep. Potential for hydraulic lock in the cylinder. Makes a real mess of the engine. Unfortunately I have first hand experience.

IF it realy flooded as much as you say, pull all the plugs before to clear out the fuel while cranking.

Also check the float level in the carb. Maybe the stabilizer loosened up some gunk.

I was thinking that as well. thanks for the input. I work in a body shop and one of the mechanics told me as well to remove the plugs and crank it to remove the fuel and dry out the plugs. then replace and try to fire it up. if I get it to fire run it for a few then change the oil because there could be fuel in the oil and he said that that could wipe out the seals in the valves and cause a huge prob. sounds like I got a time consuming job ahead. gotta love boats:smt001

 

[CV-23]

Not a fan of starting fluid but when used right.....they start! I have to be careful with my 454 when hot. It will flood so I crank it in neutral and give just a bit of throttle when it starts. Most QJets leak a bit of fuel into the intake while sitting for a while....same on my 5.7L CV-23, Mike.

 

[testlab]

We have a product here called "Start ya Bastard" an aerosol starting fluid. Very aptly named.

I learnt my lesson with the carb'd big blocks. When cold crank them 15 to 30 secs to get the fuel back into the carbs. Then one pump and set half an inch of throttle.

When warm never pump the throttle. Never let the kids play with the controls. Just crank with a closed throttle until it catches or coughs then add a touch of throttle. With TBV ignitions I find they start fine without at idle setting when warm.

 

[rondds]

Good Luck!

 

[IanBat]

We have a product here called "Start ya Bastard" an aerosol starting fluid. Very aptly named.

I learnt my lesson with the carb'd big blocks. When cold crank them 15 to 30 secs to get the fuel back into the carbs. Then one pump and set half an inch of throttle.

When warm never pump the throttle. Never let the kids play with the controls. Just crank with a closed throttle until it catches or coughs then add a touch of throttle. With TBV ignitions I find they start fine without at idle setting when warm.

Aerostart is great fun when the engines out of timing.............Not


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[Studman]

had the same kind of problem, ended up being the main wiring harness plug
take it off and make sure the metal plug ends inside are not spread out making a lose connection
just use the sharp end of your test light to bend the connectors back to the nice round shape they are suppose to be
then make sure you put the plug end on and it's all the way seated
hope it helps

 

[rondds]

If he's got spark, the sensors, harnesses and electronic wizardry are not the problem.