Sporadic Starting Problem

[stroker]

Happy Turkey Day All!!!! I have a 91 LS400 and am having an annoying situation now and then when starting the engine. Most times it starts on the first kick and every once in a while when you hit the key to start it, it sounds like its binding up but then immediately turns over but takes some turning to start. I have cleaned the battery terminals and cables and checked the charging rate, both running and not running. Meter reads good both ways.. Sometimes I hear a click and sometimes I hear a brief whirring which to me would be the fuel pump kicking in.. Once running it purrs great and has excellent acceleration....Is the fuel pump on its way south or could it be something as simple as the fuel filter. This just started after replacing the steering rack and pinion which I wouldnt think would be related since my P/S pump was not leaking. It was just the boots and seals that were bad. Thank you all for your input.. Bob

[curiousB]

Well if it’s a fuel pump or filter I would expect problems while driving as well not just at starting. For instance at high engine load (heavy acceleration or high speed) a weak fuel pump are plugged fuel filter would starve the engine for fuel and result in poor performance. If you don’t see that then I’m a little suspicious of the fuel system being the fault.

There is a fuel pump relay in the circuit as well. That could create problems. For instance if the fuel pump relay had badly worn contacts that could create fuel pump intermittency where sometimes it works and other times it doesn’t.

You can buy a fuel pump pressure gauge for under $20 (harbor freight had them for $9.99 a while back). Connect the fuel gauge in the fuel rail and see if you are getting reliable and consistent pressure each time you turn on car. If not then its either relay, fuel pump, fuel filter, or fuel pressure regulator.

Your note seems to suggest it could be a starter motor problem too. I’m not sure what you mean by binding but if the engine isn’t smoothly turning over then your problem might have nothing to do with fuel rather a problem starter motor or starter motor solenoid. A worn solenoid is a common failure for the starting system.

[vyhanh]

I second the suggestion that it can be the starter !

[landar]

I second the suggestion that it can be the starter !

I will "third" the starter. Your single 'click' gives the starter solenoid away.

How old is the battery?

[stroker]

The click I mentioned is when the key is first turned to the on position not the start position (sometimes a click, sometimes a very brief whirring sound). To me that is the power going to the fuel pump. I understand a click in the start position would be probably be the solenoid. I have no problem with power and acceleration, very smooth even at wide open throttle. The battery is about 4 years old but reads just fine. I understand the starter draws a huge amount of amps to turn but most times it turns and starts in less than one revolution of the engine..Still confused !!! Bobby

I second the suggestion that it can be the starter !

I will "third" the starter. Your single 'click' gives the starter solenoid away.

How old is the battery?

[stroker]

Landar.. Your are the winner so far. Had the electrical system checked a local AutoZone and lo and behold, the battery was putting out 148 cold cranking amps which is less than half of what it should be under a load. Put in a new battery and everything seems to be back to normal.. I was thinking way above what the problem really seemed to be.. should have thought about the dumb stuff first.. Thanks again and I'll update you in a few days.. Bobby

I second the suggestion that it can be the starter !

I will "third" the starter. Your single 'click' gives the starter solenoid away.

How old is the battery?