Idle Control Valve In Need Of Replacement? (1 Viewer)

[mr jits]

A little history: on two separate occasions now, both while wheeling, my truck has died and wouldn't restart. Plenty of electrical power, but just wouldn't turn over. I would disconnect everything electrically related (accessory lighting, stereo, CB, positive and negative terminals on the battery) and get a jump and the thing would start???
Today after rewiring my ground and power I stopped and took notice of my idle speed due to one of the comments one of the guys had said on the trail yesterday as we tried to get my truck started. He had said that my truck sounded like it was idling pretty low, around 500rpm. It's idled at that speed since I bought it so I'd never thought anything of it. Now I know it should be 650rpm, and I'm wondering if it could be related.
I noticed a severe current drop as well when I flipped on my Warn floods (dual 100w halogen type) of about 3 volts from the indicated 14.5.
I guess I have three questions here: why am I dying at idle, do I need to replace my idle control valve, and should I have that major of a current drop from my accessory lights?

 

[Tenzig Norgay]

I wouldn't replace the idle control valve until I tested it according to the FSM and it was bad. No need to just start replacing things. The 92 alt is a 80 amp version, and doesn't put out a lot of juice. At idle this alt doesn't put out enough to run the heater and lights at the same time without the lights dimming down, so if your running aux. lights, at idle they may not work so good. Think it is normal and many have noticed this, expecially in cold weather. As soon as the rpms go up, so do the lights. Some have even found smaller alt pulleys, which spin faster and put out more juice at idle. So your lights dimming is normal.

I would look elsewhere into why your dying. Tune up? Timing. Fix your idle speed. Look for vac leaks. Don't know the procedure for testing the Idle control valve, but I'm sure some 3fer will chime in.

I upgraded to the 90 amp alt, which is not a direct bolt in and requires some mod of the new alt. This helps with the dim lights at idle, but they're still there. I hear I can rebuild the 90 amp version to put out 135 amps or so, but have not done it yet. Someday, I may have a stereo, lights, CB, etc. and need more juice.

 

[mr jits]

Tune up was about a year ago, but only about 6K miles since. The idle is controlled by the IAC so I can't adjust it. I'm for sure at a low idle.
Alternator was replaced two months ago with an upgraded (putting out 95 amps) alternator.
New alternator is good, I tested it today.

 

[98 SNAKE EATER]

Keep in mind that after you disconnect the battery, the computer needs to relearn due to the reset

I'd drive it as is and see how it feels after a few drive cycles

 

[Frankencruiser]

I would look into your ground wires. With that much of a voltage drop with your lights on I think you might have an issue there.

 

[mr jits]

I'll run through the grounds next.

I made a dedicated to the body ground for the lights and cb, but I'll check the impedance of the lights themselves. Being that they're grounded to the bumper, I may not have enough area for a proper ground.