Intermittent starting problems?

[mrbozo1]

First I will tell you what has been done and if someone has had a similar problem.......please let me know.

The car is a 1991 nsx with 140000 miles. It has problems starting sometimes?
I have rebuilt the starter and then replaced it.
I have rebuilt the ign switch and then replaced it.
I have bypassed the clutch interlock switch and bypassed the relay as well.
I have cleaned all terminals and battery connections.
I have tried a newer battery.
I have checked and cleaned all ground cables that are on the car.
If you put a test lite on the solenoid start terminal the test lite will come on but car will not start.
If I run a jumper from battery to start solenoid car starts.

This has been a problem now for about 1 year. Car sometimes must be push started and then it will be fine for ??????
Car sometimes will start after a few attempts.

Any ideas?

 

[jwmelvin]

Is there a relay that supplies power to the solenoid?

 

[Old Guy]

When you say that starting is intermittent, do you mean that the operation of the starter motor is intermittent or that the starter motor operates but that getting the engine to run (successful ignition and sustained operation) is intermittent? I am going to guess the first!

You talk about running a jumper from the battery to the starter solenoid which fixes the problem. Are you running a jumper to the jump start terminal in the engine fuse box? If this is what fixes the problem, then I would check the condition of the main cable that runs from the engine fuse box jump start terminal to the battery. The likely candidate is the cable clamp on the + battery post. I know you said that you cleaned the battery terminals; but, see if you can twist the clamp on the post. The Honda clamps are notorious for stretching due to over tightening of the clamping bolt. This makes for a bad connection which results in failure of the starting motor. The tell tale is hook your voltmeter on to the jump start terminal and have somebody turn the ignition key to the start position. If the voltage goes from 12 v to something really low, then the battery clamp is likely shot. The solution involves a new battery post clamp.

If you are getting the motor to start putting the jumper on to the small terminal on starter solenoid (black/white wire), then you have a problem in the ignition switch, starter cut relay circuit.

 

[mrbozo1]

The problem is the starter solenoid will not pull in all of the time with the key. If I run a wire from the fuse box in the engine compartment to the solenoid terminal on the starter.....the engine will turn over. When it turns over it always will start.
The car has a new ignition switch.
I have by passed the starter cut relay circuit.
I have also installed a new positive clamp on the battery post.

 

[Old Guy]

I have attached the schematic for the starter circuit. It is exceedingly simple. In your first post you said "If you put a test lite on the solenoid start terminal the test lite will come on but car will not start.". Does that mean that you are measuring the voltage between the black/white wire on the solenoid terminal and chassis ground and that you are getting a full 12 v at that point when somebody turns the ignition key to the start position (that is the only time that you should get 12 v at that connection)? If you are getting 12 v at that point and you don't hear the solenoid attempting to engage, then the problem is internal to the starter solenoid assembly.

I underlined the full 12 v part because if you are getting something significantly less than 12 v, you could have a bad connection in the solenoid circuit. If the voltage is a lot less than 12 v, it may be insufficient to cause the solenoid to engage. This bad connection could be at the ignition switch terminal, the socket for the starter cut relay (how did you by-pass the relay) or the actual terminal at the starter solenoid. If you are getting a full 12v at this point then the problem could be intermittent because of a poor connection internal to the solenoid. When you apply the jumper to the solenoid terminal, it may be moving the terminal slightly causing the connection to make. I have attached the test procedure for the starter solenoid. The starter solenoid has two coils, a pull in and hold coil. If you have a tester, put it on the lowest resistance setting and connect the tester between the solenoid S terminal and the M terminal (see the attached diagram) to check the pull in coil. The connection from the M terminal to the starter motor has to be disconnected for this test. Wiggle the S terminal around and look for changes in resistance. Do the same thing between the S terminal and the chassis to check the hold coil connection. If you see any resistance changes when you wiggle the S terminal or the circuit is open, then you have an internal problem with the starter solenoid.

 

[mrbozo1]

I have tested everything that you have mentioned.......except if I have 12 volts at the solenoid. I tested that with a test lite only....I will check to make sure that I have 12 volts at the black and white wire......unfortunately the car has been starting and has only missed once for one try. As you know it will be impossible to find if it continues to work properly. I will report back as soon as I have the opportunity to check.....once it quits again. Thanks for your input.

 

[Old Guy]

If you tested the solenoid connection with a normal 12 volt incandescent test light (not an LED) and you got normal or close to normal brightness on the light, I wouldn't bother with testing with an actual voltmeter. If the voltage was low enough to cause problems for the solenoid, the lamp dimness would have been really obvious.

Intermittent failures are a pain!

 

[EK4 hatchback]

I had something similar which I eventually found out it is tge starting relay located on the bottom of the glove box. Have you look at that relay? I had a few relay failure that cause problem.

 

[mrbozo1]

I had something similar which I eventually found out it is tge starting relay located on the bottom of the glove box. Have you look at that relay? I had a few relay failure that cause problem.

Yes I by passed that relay and still had the problem?????