Inconsistent idle with cams

[kwiksilver]

Why does the mother thumper idle roll between two distinct rhythms? The cool lumpy idle and a sickening kind of rolling idle? It only does it when the car is in drive. It seems to hunt to the rolling one and them will go back to the cool lumpy one. Seen it in a few vids but can't figure out how to search it.

 

[Thekid760]

your idle in gear is probably set to low.

I dont think this is tech...

 

[kwiksilver]

your idle in gear is probably set to low.

I dont think this is tech...

Idle in gear is 750. As far as tech I read the rules and couldn't get a clear answer on that. I guessed if someone could ask about weight I would be ok asking about idle. Move it if necessary

 

[Thekid760]

I'm not a mod, just letting you know before they jump on ya.

Tech is anything that involves tools, like: I'm having trouble getting my axle in after gear swap and need help. not: whats the best exhaust.

I think the idle your talking about is a normal cammed idle, that is prob why you bought the thumpers.

the more overlap the cams have, the "lumpier" the idle typically is. this is because more overlap will decrease your engines vacuum, forcing the engine to have to idle higher to be smooth, or it'll stumble as it tries to suck in enough air to keep running.

 

[JeremyH]

LOL at thread title, TTOTD.

 

[kwiksilver]

LOL at thread title, TTOTD.

Lol you're right. Just trying to figure out if I can make it stop somehow. Since it only does it in drive. Timing? Vacuum? Fuel?

 

[JeremyH]

Put stock cams back in...

 

[kwiksilver]

What about a different performance cam? Aren't you into performance? I think I'm a little deep into this to just "put the stock cams back in".

Sent from my Desire HD using Tapatalk 2

 

[Thekid760]

why do you want to go through all of the time/effort/money to get rid of the lope?

 

[Marc s]

The idle is little low and a tune adjustment to the idle integrater/dash pot might need a little help.

 

[Captainstr8edge]

Post a video of what its actually doing.

 

[kwiksilver]

You guys are having fun with this I can tell. What I'm trying to get across is not the lope. There is a change in the way it idles. Almost like the computer is trying to adjust for something. This is my first time messing with cams and efi so its hard to know what's happening. Watching it on torque app seems to be normal. I'm going to datalog it next to see if I can spot what it is doing. My guess is timing to fix the vacuum drop. Thought you guys might know.

 

[Franchi]

I have the Thumprs as well and it very rarely does that, but only at idle, never under accleration. When it does the odd sounding lope, I just give it a tiny bit of gas and it kicks right over the the normal lope. And by rarely, I mean it happens maybe once every two months or so. And my idle is set to 650 currently I think.

 

[JeremyH]

Raise the idle and drive rpms in the tune would be a work around.

 

[screaming_pc]

vct

 

[kwiksilver]

http://www.youtube.com/watch?v=LDVCwbFgFyw&feature=plcp

 

[dirtfan71]

My Hot Rods do the same thing.....really bumps then the lope smooths out for a bit then bumps again. I just thought it was normal.

 

[Marc s]

I just thought it was normal.

It is.

 

[Wes06]

Yea mine has done this too. Smooths out to a slight lope, but then comes back really hard and can just rock the car until it smooths out alitle

 

[JeremyH]

lol