older carburetated mercruiser 5.7 hard start

[brian3127]

Rochester quadrajet carb.
How many pumps do you give your engine at the throttle to get it started.
I put a spark tester on the engine and the spark wasn't very good so I took the cap off and this is what I found. I ordered a new pickup. I cant get a serial number off the engine it is very tight in the engine compartment.

 

[kenny nunez]

With a volt meter on the + side of the coil crank the engine over. You should read 11-12 volts. If it is much lower then the “by pass” circuit from the outer connector on the starter solenoid is the problem.
To further prove out the problem run a jumper wire directly from the + battery to the + side of the coil. If the engine starts easier then the fault is the starter solenoid.

 

[brian3127]

With a volt meter on the + side of the coil crank the engine over. You should read 11-12 volts. If it is much lower then the “by pass” circuit from the outer connector on the starter solenoid is the problem.
To further prove out the problem run a jumper wire directly from the + battery to the + side of the coil. If the engine starts easier then the fault is the starter solenoid.

having trouble understanding, what the starter solenoid has to do with the hard starting. then engine turns over just fine

 

[kenny nunez]

When the key is turned and the starter is engaged there is no or very little voltage at the + side of the coil provided from the ignition switch, that is the purpose of the ”by pass” circuit on the starter solenoid to provide voltage at the coil.
Just check the coil to make sure there is 12 volts provided in cranking mode.

 

[brian3127]

When the key is turned and the starter is engaged there is no or very little voltage at the + side of the coil provided from the ignition switch, that is the purpose of the ”by pass” circuit on the starter solenoid to provide voltage at the coil.
Just check the coil to make sure there is 12 volts provided in cranking mode.

ok thanks.

 

[tango13]

my carbed 7.4 w/ TB V ignition was having starting issues (cold and hot), and my pickup looked the exact same.

I swapped out the sensor, cap/rotor, wires, and COIL and it mad a world of difference. Everyone will tell you that the coils never fail but I can tell you that the coil was the last component i changed and my hot start problems essentially went away.