Mercruiser V8 ,backfire,no power after 2200

[Bt Doctur]

1997 Ser: OK150672 chevy V8,TBI
Original report was : coming back from west point topped off tank, soon thereafter developed a backfire and popping above 3200.Normal service included fuel sep. filter,cap,rotor, plugs,set base timing.Still have a popping above 2600.
30Gal of 93 octane added remaining of fuel load ,2 bottles FI cleaner
Gauge`s reading well within range but did notice the dist. base near the module was too hot to touch??? All connections from tbi to module checked for corrosion and tightness.Stable to about 2200 then with a touch more on the throttle ,the tach starts jumping wildly and you feel /hear the miss,backfire and popping back thru carb.
Help, trying to salvage my customers fishing trip

 

[Don S]

Re: Mercruiser V8 ,backfire,no power after 2200

Check for water in the fuel??? They may have changed the filter, but if there was water in the system and more in the tank............... well, one more time.

 

[Bt Doctur]

Re: Mercruiser V8 ,backfire,no power after 2200

"They" is me Don.
double checked again when we got in. nothing but clean fuel.

 

[Bt Doctur]

Re: Mercruiser V8 ,backfire,no power after 2200

bump

 

[Don S]

Re: Mercruiser V8 ,backfire,no power after 2200

About all you can do is get the Service manual and follow the steps in troubleshooting and testing. Without doing that, all you do is hit and miss (usually miss) and it takes longer to find the problem, if you find it at all by just guessing at things.

 

[Bt Doctur]

Re: Mercruiser V8 ,backfire,no power after 2200

Wouldnt be half bad if i had this in my wife`s van but I`ve never worked a fuel injected system yet.since the throttle position causes the tach to act up along with the pop was wondering about the throttle position sensor or with the heat generated at the dist base plate something in the dist affecting the timng.
Is there a online version to download,Don?

 

[Don S]

Re: Mercruiser V8 ,backfire,no power after 2200

Manual 17 isn't available online. Might give ebay a try.

 

[IMPChris]

Re: Mercruiser V8 ,backfire,no power after 2200

I am having the same problem with my mid 80's Merc. Alpha 1. However the problem only happens under power. I have Rochester carb. not fuel injection. When the motor is in nuetral it will run smooth at any RPM, but under power it dies and backfires at about 2,100 RPM. I have already checked fuel it is OK. Mechanic also recomened checking alternator if it does not put out charge the motor could possibly missfire. My Alternator is OK I am still at a loss. I am interested to hear what you find as well.

 

[Don S]

Re: Mercruiser V8 ,backfire,no power after 2200

Best to start a new thread with your question.