Cancel out cam sensor?

[turboculosis]

Well I've been trying to chase this off idle stumble for some time and had no luck in getting rid of it completely.As I tried to disconnect the cam sensor to verify if it was set incorrectly,the idle got worse and stumbled even more.Is it safe to say that it's not the cam sensor setting that's causing the stumble?FWIW@idle--
TPS:.42/4.60 WOT
IAC:18-19 "P" and 22-26 "D"
MAF:9 g/s
BLM's:130(@off idle stumble-down to105 then jumps up to 150's)
FP:40 line off
Vac:10-12(suspect small vacuum leak)
O2's:irratic (jumps all over)

TIA

 

[turboculosis]

top......

 

[striker_29]

Its probably ok, you can try turning it counter clockwise about 3/16 and see if that helps any. If you suspect a vaccum leak, i would be all over that as it will cause what you are describing. Good luck, it can be hard to diagnose. Believe me I know.

 

[azgn]

start the car and unplug the cam sensor.....if the idle improves, maybe you found your problem

 

[turboculosis]

Thanks...

As for tracking down the vacuum leak,I'm going with all new hoses and a new vacuum block gasket.The hoses that are on now feel very flimsy and soft.Also noticed traces of seapage on the vac. block gasket when I removed it.As for disconnecting the cam sensor while motor is idling,I tried that too.All I noticed was a loud ticking noise from the cam sensor and worse idle.I put her in gear for sh!tz and giggles to see if the stumble went away and that also got worse.Thanks for the replies guys,I REALLY appreciate them.Also thanks to Neal Steward as he is also helping me with this...

I will post back as soon as I make any progress with this...

 

[zam70]

I'd raise your fuel pressure a touch....see what it effects.

 

[NC87GN]

Looking at your MAF's I see a problem. Your MAF should be 4-6 g/s in gear with a stock unit and idle at 788-825 rpm "HOT". This does make a big difference in idle quality. If your IAC and TPS numbers appear norm but the idle is high, you may need to do a reset. I'm assuming stock long block...

Mike Banas
87GN

 

[turboculosis]

Originally posted by NC87GN
Looking at your MAF's I see a problem. Your MAF should be 4-6 g/s in gear with a stock unit and idle at 788-825 rpm "HOT". This does make a big difference in idle quality. If your IAC and TPS numbers appear norm but the idle is high, you may need to do a reset. I'm assuming stock long block...

Mike Banas
87GN

Does 4-6 g/s MAF readings still apply to an LT1 MAF?The 9 g/s I posted earlier is in P/N.I'll have to check when in gear.

 

[turboculosis]

Originally posted by zam70
I'd raise your fuel pressure a touch....see what it effects.

I tried that too.All the way up to 60 hose off and down to 30 hose off.The stumble did improve when the FP was at 30hose off .Only at a quick stab at the throttle, but when I eased into it the stumble was still there.

 

[NC87GN]

2-4 g/s with a translator plus.

Mike Banas
87GN

 

[turboculosis]

Originally posted by NC87GN
2-4 g/s with a translator plus.

Mike Banas
87GN

Thanks.I'll reset the iac & tps and will shoot for 2-4 g/s MAF reading.My idle rpm's via Directscan reads 850-900, and programmed idle is 900 at this point with the 9 g/s MAF reading.I'll be definitely looking into this....

 

[TurboDave]

Originally posted by NC87GN
2-4 g/s with a translator plus.

Mike Banas
87GN

Only with the Extender chip, otherwise they should be at normal levels. I would suspect something closer to 5-7 should be normal.

 

[blackbuick87]

With my Translator + LT1 MAF I am always at or around 6 gps

 

[The Radius Kid]

I would try changing your base setting on your Translator to -10 for the 3" Maf.
See if playing with that helps.

 

[turboculosis]

Ok.I reset the IAC and TPS and got 7g/s on the MAF.Programmed idle is still 900.Idle is around 850-900,now there is a slight surge at idle and stumble is still present.My LT1 MAF is screenless btw.Maybe this is why the stumble,and that I can't get the MAF #'s to go below7,even with the IAC screw backed out till it doesn't touch the butterfly lever.I also tried messing with the settings on the translator and the idle is best but not perfect if the BASE setting is on 3.5MAF.When I have the setting at 3"MAF the car just dies. wierd.I also tried unplugging the translator and putting on my father's stock MAF and idle was even worse.I still have to try out a good working ECM with 2.5A peak holders.I've been told that these injectors don't work too well with 4A peak holders.I'm not sure what I have in the ECM at this point(bought the car with it),but worth a try.Whatcha guys think?...

 

[blackbuick87]

It is not uncommon for cars to run better on the 3.5 MAF setting with the 3" MAF for some reason. Mine does the same thing.

I would try swapping in a MAF with a screen and see if that helps any. UNGN and others have removed theirs, but I have not heard of anyone doing it with injectors as large as yours

 

[Steve Wood]

Not sure why the maf numbers would change much with IAC adjustments. I would think the Translator settings would be more appropriate.

The programmed idle is what the chip is programmed to control the idle speed to. No matter what adjustments, you make, it will not change. On the programmer can set that. Actual idle speed should conform to that number with minor variations.

 

[turboculosis]

Originally posted by Steve Wood
Not sure why the maf numbers would change much with IAC adjustments. I would think the Translator settings would be more appropriate.

The programmed idle is what the chip is programmed to control the idle speed to. No matter what adjustments, you make, it will not change. On the programmer can set that. Actual idle speed should conform to that number with minor variations.

Your right.I forgot to mention the 7g/s MAF reading was due to putting the translator BASE setting to 3"MAF.At this point I reset the IAC and TPS accordingly so that it wouldn't stall.Now it has a slight surge at idle.Before that, the the MAF # was 9 g/s and translator BASE was set for 3.5"MAF.Which made it idle better and no surge.Sorry for the confusion guys.Now I'm confused.....