Engine idle speed

[Malarkus]

Anybody know if there’s a way I can raise my engine idle speed? Got a one wire HO alt and it’s not coming on at idle... about 100rpm short of what it needs. Have a 2018 1500 4x4 tradesman quad cab any insight would be appreciated!

Thx

 

[Tach_tech]

Would require a custom tune to do that.

 

[Malarkus]

When I contacted Diablo they said they only have a pretty limited option for enhancing pedal sensitivity for the 2018. Rep told me they were “close” but since the pcm is locked weren’t there yet. Is there another route I should be going? Kind of a novice when it comes to this.

 

[bassheadhemi]

smaller pulley on the alt?

 

[Malarkus]

have the smallest pulley

 

[bassheadhemi]

have the smallest pulley

even if you have it to start with 100rpm more it probably won't give much out. you should have a shop made one for your specific needs.

if you insist on using this alt, you could go with a larger crankshaft pulley or try run it from a second belt with a larger driving pulley.

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[Malarkus]

bassheadhemi sorry for the delayed response here. I feel kind of stupid asking this but how would I go about running the alternator from a second belt? I was also looking at something on Mechman’s site that said to fabricate another bracket to hold a free spinning pulley that would ride on the back of the belt forcing it to wrap around the alternator pulley better. This seemed like a decent idea to me but a couple questions came to mind. How do I know where to mount said bracket, it seems like it would need to be in a fairly precise location so as not to ride too much or not enough? So eyeballing it is probably not a great option? And the other question I have is how is this going to affect other accessories on the engine such as the water pump? I know I’m probably asking for a lot of information here so any suggestions on how I can increase my knowledge in this area more efficiently are most welcome!

 

[bassheadhemi]

there's different ways to do it but will require fabrication

An ati damper pulley with an extra overdrive pulley attached to it could be used. Either to drive your mechman in a different spot like where the power steering pump was or have another set of dual pulley in the PS pump location to drive the alt in the factory spot. you could also use an underdrive damper pulley for your current accessories to help with the load on the engine at idle. All this will require fabrication and a way to tension those belts.

easier and cheaper would be to have a new alt made that would work for your application. contact singer alternators to see what they can offer


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[Burla]

My theory from researching the weakness of cams/lifters is that the cam is starved from adequate oil at idle. I think tuning up the idle is a good idea all around. Even if you find a work around, I would consider turning up idle a bit when available. If you can push more air into the engine, I think it would respond by bringing more fuel. maybe research air sensor, shot in the dark on that.

 

[Burla]

Looking around the net I see some people have done this with the throttle, and ended up throwing a CEL. I doubt it would be a dangerous cel, but it would be the way of your truck telling you it can't control the idle. bringing more air should change the idle. But I'd rather get it tuned.