where do you start if everything is changed and it will not run to get good logs?

[smithers]

Everything except the injectors has changed, new block 347, different static compression, centri-blower, cam, heads, headers, etc... everything. 2bar SD. LS1B ECM.
It will start very easy, however, one must feather the throttle to keep it running. (barely)
What is the most effective way to get it to idle?

the wideband is near stoich near the idle rpm (for the second it hangs there) after that it stalls or when feathering the pedal up to 2000 unloaded rpm, its lean (off the scale) -
Trims are pegged at +25%. lean
Does one just go across the VE table and add 12.5%? and keep doing this until the wideband has a reading other than lean?

How can you log STITs if you are having to feather the throttle?
Does one just increase the idle position to lets say, 2000rpm and get the VE dialed in so at least its running without human help? would this idea even work?

I would like to hear what other options there are in a case like this?

thanks

[gagliano7]

If you want any help you will have to post your tune and a log if you can. You will probably have to add to the idle base running airflow to get it to idle. http://www.hptuners.com/forum/showth...highlight=idle here is agood thread on idle after cam swap.

[Pekka_Perkeles]

Trims are pegged at +25%. lean
Does one just go across the VE table and add 12.5%? and keep doing this until the wideband has a reading other than lean?

Yes, except in this case I would probably add 20% to the whole table. Doing so the shape of VE stays reasonably balanced for time being.

Have you already populated boost area with some values (i.e. between 105 kpa and 300 kpa)?

You may also zero your RAF to see what it needs at idle. When it idles and AFR is about right, check all typical things, like fuel pressure and so on. Then continue with normal procedure.

[smithers]

I did stumble across Rinkrat456 post, decent read.

I will add 4° timing to the idle tables, add 4g/sec to RAF, add 20% to the VE table across the board.
No boost, not drivable as tune is too far off.
Fuel pressure is fine, its now return regulated. IFR table is flatlined.

[cpolaris502]

The idle tuning how-to is a great thread. I kind of had the same problems as you at first with the idle and that post got me pretty close pretty quickly.

[smithers]

No luck, will not run...
i had VE table all the way into the 200's still LEAN off the Wideband.

[smithers]

Here are the files
I brought the VE back down to where it was before the engine change.

[Pekka_Perkeles]

No luck, will not run...
i had VE table all the way into the 200's still LEAN off the Wideband.

I did check the tune and couldn't find anything which would cause this kind of behavior. I'm not expert though.

For me this sounds like you have some other problem(s) than just the tune. I mean, you have in practice doubled the amout of fuel injected to the engine, and it's still lean. Or is it? Does your wideband show realistic value when it is in a free air?

Also, your left narrowband sensor seems to be dead.

[smithers]

drivers 02 is dead as the wideband is in place, doesnt matter anyways, its in OL.

[planethax]

Inspect the Plugs, Wideband reading lean but could be wrong and you could be overly Rich.

[gagliano7]

How is your fuel pressure?

[smithers]

How is your fuel pressure?

Not sure I quite understand the question.
fine?
I can dial in whatever fuel pressure I want, its return regulated behind two gss-340 pumps. it does not move from 58psi if the reference is unplugged, however it is boost referenced. Using Deka 61s, if you look at the IFR, this is correct for 58psi rail, and flatlined. I could unhook the reference and slope the IFR curve as it was before.
Im perplexed, i have done many tunes, never had this much trouble, though, ive never had a vehicle that doesnt run... just not sure where to start.

[smithers]

well, after a dozen more flashes.. I have notice the following:
I always see 'lean' on my wide band exception for the odd flicker rich when stalling out.
I see the vac decreases as i slowly let OFF the throttle.
Fueling seems to 'drift' to basement lean.
I tried without the regulator, and brought back the sloped IFR that was how it was prior to engine swap.
Why when i am at 875rpm I have to hold the throttle down? why would it not IDLE there. Idle must be off yes.. but in this case what do you adjust to GET it to idle?

[Pekka_Perkeles]

Do you have any old logs from last year covering idle?

In your latest log, the engine is warm and around frames 450 it is at or near idle with 800...900 rpm's. Your injector pulsewidth is 3.5 milliseconds, which I think is rather high, considering you have 346 cubic inch engine with 60 lb injectors.

Could there be some problems with injectors? Clogged somehow?

Just an idea, nothing more.

[smithers]

in Idle prior injector pw was 1.6ms. map was also at 36kpa and TPS was only 4%

It was only near 900rpm with my foot on the accelerator notice the 17%, and yes, 3.5ms is wayy to much for idle, but maybe not for 70pka at 17%TPS. but that probably because the MAP is at 70kpa at 800-1000rpm, why?
what would cause no vac at 800rpm? is this the characteristics of the heads/cam ? is this typical? OR is there something mechanically wrong?
lets perhaps say, there is a FAST intake leak, is this indicitive of how this is reacting? as in, vac when you rev, but no vac close to idle?


I dont know of a means of checking the injectors.

[Pekka_Perkeles]

It was only near 900rpm with my foot on the accelerator notice the 17%, and yes, 3.5ms is wayy to much for idle, but maybe not for 70pka at 17%TPS. but that probably because the MAP is at 70kpa at 800-1000rpm, why?
what would cause no vac at 800rpm? is this the characteristics of the heads/cam ? is this typical? OR is there something mechanically wrong?
lets perhaps say, there is a FAST intake leak, is this indicitive of how this is reacting? as in, vac when you rev, but no vac close to idle?

I think we're now getting somewhere. Those are good questions.

Can you please tell more about the cam. What I've seen, idle kpa can be around 50...60 with not that big cams and 800 rpms. But I'm not familiar with huge cams.

I dont know of a means of checking the injectors.

There are companies than can flowtest them. But maybe it's not necessary this time.

[smithers]

I think we're now getting somewhere. Those are good questions.

Can you please tell more about the cam. What I've seen, idle kpa can be around 50...60 with not that big cams and 800 rpms. But I'm not familiar with huge cams.
There are companies than can flowtest them. But maybe it's not necessary this time.

I know how it SHOULD act, ive tuned several cars, but ive never come across this much 'strange' and dont know where to adjust. Open header still back on my mind causing false readings with the o2s
Any car Ive ever done, at least was running prior.


Cam:
281/289 115LSA with a 114 ILC
ABDC is 74.5° close meaning 1° cam advance

It is a blower cam
specd : 232 240 .595 .608 115lsa
http://shop.brutespeed.com/Brute-Spe...d-Camshaft.htm

I wouldnt think a cam like this on 230cc intake AFR heads on a 347 would cause this extreme (no vac). 50kpa would make more sense.
I live in a place, where I have to order seals, injectors to be tested, unlikely anywhere here. The injectors worked fine before, but sitting in plastic bags for 6 mo ... you never know I guess.

[smithers]

Dug up a more proper prior simple drive around... BEFORE

[wyochimneysweep]

map wired correctly or incorrect map sensor?

[smithers]

rpm drops, kpa increases... what can cause this?
lets make a list...
is incorrect rod length? incorrect install of cam? FAST with bad seals?

if there was an 'air leak' why would vac increase with rpm as the throttle opens?
Or is this just extremely off RAF / VE / spark ?