Hello from Spain.
After 6 months stopped, today I started the 1990 V6 3.1 and it ran perfectly. I stopped it and then it didn't start again. It made a clack clack clack under the intake manifold when I turn the key, where the injectors are, as if it didn't have enough battery. So I put in another 72 amp battery one that I know works. It started on the first try. But the second time he did as before. The alternator and starter motor are new. I have connected the battery cables to another running car and it has started fine. What could it be?

 

Sounds like a loose connection somewhere, most likely at the battery or the starter. The noise you are hearing is likely the starter solenoid.

 

I Will check It. I am sure that the noise is not in the starter motor. It is just under the intake manifold near the fuel injectors and the fuel preasure. Can I upload a video?

 

Tonight I have charge the battery. It was full. But It did not start

 

The same day the starter failed I changed a fuel tube before. For that reason it started on the third attempt, but without making the noise that I mentioned before. Could it have affected the gasoline pressure valve that goes to the injectors? where now he makes the "clack clac"

 

hello. The noise actually comes from the starter motor. I'm sorry. I have installed another battery. the alternator voltage at idle is 14.7…with the lights and air conditioning it is 14.5 and if I accelerate it remains at 14.7 Is it too high and have I overheated the batteries and they no longer work? If the voltage is too high, how to fix it? thank you

 

Ok, so,

Given these facts, you absolutely have a bad connection in one (or both) of the battery cables. 14.7 is not too much, and is not your problem. You say 14.7 at the alternator, hopefully there is 14.7 at the battery too?

The thing is, you can have a battery connection that'll pass enough power, till called upon to provide the most power the car ever draws (the starter) and then fall on it's face when asked for the BIG amps the starter requires.

Start by cleaning & inspecting BOTH sides of both battery cables, then do some voltage drop tests across those wires as your assistant attempts to start the engine.......

 

Could this cable be the problem? The cover was off and the copper was visible. Maybe with the vibration touched the casing. now it has duct tape

 

You haven't yet answered my question, you don't get to keep asking questions without answering the questions of those that are trying to help you


(HINT! , , , if you DO have the same 14.7 at the battery that you say you have at the alternator, then that wire is FINE!)

Remember, , , , this symbol ....."?" ......means I asked you a question. Next time I ask you a question that goes ignored, your on your own......

 

I am sorry for no answer. In the battery It was 14.7 too

 

Awesome! Since you had 14.7 at the battery then that wire is good, it's the wire that brings the alternator's power to the battery for charging

From everything I've read, it does sound like one of your battery's wires might have a bad connection, either at the terminals that bolt to the battery itself, or at the engine block (negative) or at the starter (positive)

 

Hello. I have checked the connections and I have only found the one in the photo wrong. I've put in a new battery and so far it's not giving me any problems.
Thank you for the help you have given me