Idle issue

[Harrismarine]

OK..here is one for you, I am tuning a LS 6L in a boat, Its an Ls2 bottom end with CNC ported heads and a cam (dont know the grind). Its a maffless tune.
The problem that has me scratching my head is the idle, I couldnt get it to idle below 1700rpm as the map would bounce to 70,80kpa and die.
I finally got it to idle at 900rpm@70kpa but it had to be around 18.0 to 1 to do this, as soon as it gets over 1700rpm it smooths out and the map hits 50ish. and air fuel returns to to normal, nothing I do with the timing helps ,from there it tunes up well, Any ideas folks??
I have also just ordered the V2, any hints to the transition from V1 to V2 would be much appreciated...looking forward to it arriving:cheers: I am also looking at purchasing road runner, again comments very welcome

Mike

[joecar]

Mike,

Air leak...?

Are you saying it would idle only if commanding very lean, and any richer than that it would die...?

Just connect V2 and start logging/tuning... use software 7.5.3 from www.efilive.com/downloads (http://www.efilive.com/downloads)

What PCM are you using...?

Have you being logging from the scantool or from V1 BBL (black box logging)...?

Cheers
Joe

[Harrismarine]

Hi Joe,

No air leaks that I can find and i would have thought it would just idle faster with air leak.
I have to make it lean at 70 even though command fuel is correct Its shows low vacc at below 1700rpm but over that and it returns to normal:doh2:.
Im thinking cam timing maybe??

Using 411PCMs and logging from both.

Mike

[joecar]

Hi Mike,

It could be... can you check/degree the cam...?

[Harrismarine]

Hi Mike,

It could be... can you check/degree the cam...?

Yeah I figure thats the next step:cheers:

Mike

[Harrismarine]

Back on the water tuning this weekend so ill let you know how I get on...big thanks for the fast response from the Guys for sending me the V2 so quickly when my V1 gave out (suspect a bit of misuse on my part caused it:doh2:)

I am still keen to hear comments on the road runner

Mike

[hquick]

Mike...the RR is awesome!
I borrowed one from a fellow member and I had to send it back to him (Damn you Mick!...just 'cause you wanted to do some tuning with your own RR).
I miss it sooooo much.
I'm just waiting for Craig Moates to get back to me so I can order the DIY kit.

[Harrismarine]

Mike...the RR is awesome!
I borrowed one from a fellow member and I had to send it back to him (Damn you Mick!...just 'cause you wanted to do some tuning with your own RR).
I miss it sooooo much.
I'm just waiting for Craig Moates to get back to me so I can order the DIY kit.

I should have grabbed Micks while I was over there then:angel_innocent::angel_innocent:.

Whats the deal with the DIY kit??

Mike

[hquick]

Save $100.
Solder it together yourself.
I have a spare 0411 PCM so I'll go with the DIY kit.