Please Help need advice with timing issue on 1994 Sea Ray

[warshark25]

Hello all I recently purchased a 1994 Sea Ray 220 Signature Series with a mercruiser 5.7. I am having issues with predestination/pinging when in the water anywhere after 1/3 throttle. If I stay under 1/3rd throttle the boat is fine as soon as I try to give it some go it starts pinging like the timing is too advanced. I checked the timing with a light it is a 8* BTC at 750RPM, new AC delco plugs and wires, compression is good 140-155psi between all cylinders. spark plug gap is at .035. New fuel and carb has been rebuilt. Is there a way to check the ignition module or maybe I am not doing to correct procedure to check the timing properly. Thanks for the advice!

 

[tank1949]

Hello all I recently purchased a 1994 Sea Ray 220 Signature Series with a mercruiser 5.7. I am having issues with predestination/pinging when in the water anywhere after 1/3 throttle. If I stay under 1/3rd throttle the boat is fine as soon as I try to give it some go it starts pinging like the timing is too advanced. I checked the timing with a light it is a 8* BTC at 750RPM, new AC delco plugs and wires, compression is good 140-155psi between all cylinders. spark plug gap is at .035. New fuel and carb has been rebuilt. Is there a way to check the ignition module or maybe I am not doing to correct procedure to check the timing properly. Thanks for the advice!

It it a TB 5? If so, please make sure knock sensor on stb side of motor is connected and functioning.(it may not have knock sensor option) Read in manual about setting base timing w/o knock sensor functioning. There is a wire that you should disconnect to set base timing. If you don't have knock sensor, attached timing light and aim at timing tab and harmonic balance while friend increases throttle. Monitor advance using timing light. You may have tab incorrectly labeled?

 

[warshark25]

It is the TB IV set up. would this also have a knock sensor? Thank you, I will have to purchase a manual for it.

 

[warshark25]

Would a faulty module possibly allow too much of an advance curve?

 

[Mad Props]

If TB IV you don't have a knock sensor... You should check you're timing advance with an advance light or get some timing tape.

Its pretty rare that the modules go bad, that being said, they do go bad and I just replaced my whole ignition system because of it.

I would also wonder when the last time you did a carb rebuild is... You can have issues with knocking/pinging if your engine is running hot which can be a result of running lean. Wondering if your jets are slightly clogged.

I'd start with checking your timing advance and then do a carb rebuild.

 

[warshark25]

Okay I will Take it out and put it in the water tomorrow I have timing tape ill put on it tonight. Its just odd runs and starts fine up to again about 1/4 throttle anything after she sure isn't a happy boat. Actually I replaced the fuel pump, filter,fuel lines and rebuilt the carb this past Sunday it was pretty gummed up looks like the boat did more setting around than anything with the last owner..

 

[warshark25]

P.S. on the water at idle or low speed the temp sets right about 165-170 never goes over 170*

 

[Mad Props]

I doubt you would see a temp change on the water temp gauge when running lean... you'd need an egt gauge or wide wideband o2 gauge to know if that was the issue... if you did a recent rebuild on the carb and are sure everything is set correctly then maybe its just the timing...

Check it out and let us know

 

[warshark25]

Good morning, sorry for the slow response. I took it out on the water. The idle was set at 850. I lowered it to 675 set the base timing at 8* BTC as I raved the boat it did give an increase of timing to about a total of 30* at about 4,200 RPM. It still has the pining/detontation issue which beings to mess with it at 2,100RPM and also does not seem to have any power once that rpm is reached under load. During free rev it feels like it has good throttle response but again not so much under load, thank you

 

[Scott Danforth]

your most likely running lean. check your fuel pressure and if that is not low, look into the carb.

 

[warshark25]

About what PSI should I Be looking for? ill Make a T fitting right by the carb to check pressure. Thank you

 

[achris]

4 to 7 psi.

 

[warshark25]

Okay I was able to finally test the pressure it hangs around 6psi until I give it more than 1/4 throttle then it drops to 2-4psi. Is there a check valve or anything in the tank that may be not allowing enough fuel volume through? Thank You

 

[achris]

It's normal for the pressure to drop. Pressure is the resistance to flow, and when the engine's running, the carb needle is open, allowing fuel in, which is reducing that resistance...

As long as you have pressure, it's good.

Chris...