Engine idle issue

[bigvalkriefan]

Strange, this just started. Whenever I put on my turn signal sitting at a light the engine idle will pulsate in time with the blinker. It's only about 50 - 75 rpm and I don't notice any other problems. Anyone experience this and is it something to worry about?

[John Schmidt]

How old is your battery?

[R J]

What is your idle RPM at the time before ya hit the blinker?

Really sounds like your battery or alternator is ready to give up the ghost.

You can check it with a volt meter. 

Engine OFF, reading across the battery s/b around 12.5
Engine ON,  reading across the battery s/b around 14.7

[Ricky-D]

Strange, this just started. Whenever I put on my turn signal sitting at a light the engine idle will pulsate in time with the blinker. It's only about 50 - 75 rpm and I don't notice any other problems. Anyone experience this and is it something to worry about?

The issue is the low idle speed you have the motor set at.

It should be at 900 rpm's up to 1k rpm's

The reason for what you notice, is the draw on the electrical system, being enhanced by the blinker, and manifesting itself in the spark output from the ignition system.

You might want to get a new battery also!

***

[DFragn]

Curious...Does it do it at cold to warm engine conditions or only at full op temp. Or all the above?

[Ricky-D]

What is your idle RPM at the time before ya hit the blinker?

Really sounds like your battery or alternator is ready to give up the ghost.

You can check it with a volt meter. 

Engine OFF, reading across the battery s/b around 12.5
Engine ON,  reading across the battery s/b around 14.7

The generally accepted test figures for 12v batteries (like ours) is:


State of Charge   Specific Gravity   Voltage
      
100%                   1.265               12.7   
75%                     1.225               12.4
50%                     1.190               12.2
25%                     1.155               12.0
Discharged            1.120               11.9

Note that 12.5 volts is just a bit over 75% of full charge.

***

[bigvalkriefan]

Battery is about 2 yrs old at least. Engine idle is set at 800-850 rpm's. I will up the idle to around 950 and also check the battery. I will let you know the results.Thanks!