4.3 mercruiser tks no start help!!

antvan21

Recruit
Joined
Aug 8, 2022
Messages
2
We took our 2006 tahoe q4 out yesterday.. it started up and ran fine then after got to our swimming area we would drift then start it up and move a few times but after the 4th or 5th time it wouldn't start just cranks and cranks..

After messing with it while on the water there was a couple things that I noticed.. one was that I didn't hear the fuel pump priming after I stopped cranking the motor and the other was no oil pressure on the gauge while cranking..
I did test the fuel pump and it works fine so
My thought was it could be the oil pressure switch but I'm not sure if that keeps it from starting or just kills the fuel pump?

Another idea I had is it could possibly be the coil and or ignition sensor in the distributor..

I just ordered the oil sensor, coil, and ignition sensor and I already have a new cap, rotor, plugs, and wires so I plan to replace those parts and do a full tune up..

I guess my main question is is there anything else I should be looking at? And would that oil sensor cause a no start even if there's still fuel in the carb?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,065
Start with look at the fuses (TKS has a 15 or 20 amp fuse on the motor)
Then is the man overboard kill switch tripped?

Your fuel pump will not prime when key is turned to ON. It runs when cranking coming direct from the starter. Will keep running after oil pressure builds.

Since it was running fine prior, then just wouldn't start, and fuel pump did test good, I would look for spark.

Run thru the TBV troubleshooting guide
 

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antvan21

Recruit
Joined
Aug 8, 2022
Messages
2
Start with look at the fuses (TKS has a 15 or 20 amp fuse on the motor)
Then is the man overboard kill switch tripped?

Your fuel pump will not prime when key is turned to ON. It runs when cranking coming direct from the starter. Will keep running after oil pressure builds.

Since it was running fine prior, then just wouldn't start, and fuel pump did test good, I would look for spark.

Run thru the TBV troubleshooting guide
Thanks for the quick reply guys..
I didn't know about the fuse so I'll definitely check that out..
 
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