Need help, very slow crank after reinstalling heads

im about at a loss and hope someone can help me through this. Recently went into my 1998 3.4 to replace the headgaskets. It’s all put together again now but for some reason the starter just cranks very very slowly. I’ve replaced the starter even though the old one tested good. New battery, checked all connections and grounds, replaced starter relay. Verified timing and even pulled the plugs back out and it still just cranks real slow...

 

How did you test the old starter? Did you test the new one the same way?

What I'm really getting at is, did you bench test the starter? With the same battery that's in the truck? It spun ok there?

 

Last week I took the old one to the auto part store, they tested it and it read fine. I put it back in then tried everything else. Today I went and bought a new one and put it in and does the same thing

 

I gotta think either poor grounds or corroded battery terminals.

Remember the starting circuit grounds through the bell housing to the engine block back to the battery.

Battery fully charged

 

Go over all the connections and cables with a fine toothed comb and I can almost guarantee you'll find your answer. You can even remove the wiring harness for the starter and do it in a more comfortable place. I've read one guy lately found that the wires came loose from a connector or were corroded inside the crimp where he couldn't see, and that was causing a no crank / weak crank ticking sound. Gotta dissect that stuff sometimes.

You might also want to change the name of your thread - I came on here with the intent of helping someone getting vehicle recovery services out to a stuck vehicle because of the title.

 

There are 3 grounds on the 3.4. The main one is on the engine block. Follow the negative lead down to it. The second ground is on the passenger side head rear, the third is off the negative cable and goes to the chassis by the battery.
The issue you are having is high resistance in the ground circuit(s)... this IS NOT tested with an ohm meter. You need to preform a voltage drop on the affected circuits. An analog volt/ohm meter is the easiest to use. Set the scale to DC volts, depending on the meter the scale can be 0 to 3 volts or 0 to 100 volts or ??? depends on your meter. Put one lead on the positive battert post and the other on the post on the starter and crank it and look at the reading. If the meter swings the wrong way, reverse the leads. There should be no more than 2 volts showing omn the meter. If there is there is too much internal resistance in that circuit. Do the same on the ground connections.

 

Alright I’m going to go over all the connections again now and put a meter on it. Let you know if I have luck

 

@tcBob

 

Just tested the leads, got .16 volts to the starter and no voltage reading from the grounds..

 

There ya go

You really gotta change the thread title to something like "Starter slow cranks after engine work" up in the thread tools option at the top of the thread - pretty sure that's why a moderator was tagged in this thread though.

 

My bad, I changed the title. Should I have gotten some voltage reading between the grounds and the negative terminal when it’s being cranked?..

 

You should not have voltage on the ground side... if you got 0 volts that's a good thing

 

damn... you guys are beating me to the answers....

 

Well the meter is showing good all around. As far as I understand the only thing that would keep a starter from spinning full speed is the electrical to and from the battery. Guess I’ll have to try running new power and new grounds

 

What is the static battery voltage and the cranking voltage?

 

Probably means you're being more productive than us today lol