can anyone tell me where you can adjust the map settings in tunerpro because I keep getting code 33 on my 91 camaro 355tpi. My cam is only pulling 8psi of vacuum and it my motor stumbles and almost dies. there are no vacuum leaks. I was wondering if there was somewhere in the prom that I could set the map lower so it didnt throw this code?

 

If this is $8D mask,
You can turn off the code from being set by clearing the bit at location 24A, bit #2 ($04)

 

Hey thanks for the reply. Is there a table that i need to change somewhere or will just disabling the code in the switch fix it all. I thought you might have to make adjustments somewhere to compensate for the lower vacuum?

 

I believe disabling flag will just address the SES light and code appearance.
Will not address the reversion that may be occurring with that low vacuum and overlap.

Is 8E a MAF application?

JP: Cannot the 02 constants be adjusted to help out? Does that 8E allow OL for idle taking the 02 sensor feedback out of equation?

 

Doesn't say what mask or bin he's running.
O2 settings won't do anything until its in control but will not work well if the idle is not stable. Chugging at too slow of an idle speed makes things harder to correct without trying multiple things.
Are we talking OL or CL idle at this point?
What are some specs on CR, DCR and the cam in that motor?
That is low vacuum for being a stick, What is the idle speed you are setting when not in gear?
Could be the IAC and/or stall saver stuff causing problems when the load is applied. RBob is good with tweaking the stall saver settings in a bunch of posts concerning it.
Need more description on overall running conditions to really speculate the best way to attack the problem.

 

Im running the AUJP bin with 8d mask. My CR is right around 10:1, the cam i have is XR276HR-10. Duration @ 0.006": 276° / 282°, Duration @ 0.050": 224° / 230°. Max Lift w/ 1.5RR: .502" / .510". Im trying to run about 800RPM idle and with the IAC hooked up it wont idle steady just surges almost stalls revs up then almost stalls again. If the IAC is unhooked it will idle until the o2 sensor takes over then it dies. The IAC is working but the cam is only pulling 8 PSI vacuum. The car also has a manual transmission i thought about running the 305 manual bin and just copying over the tables for the 350 but wasnt sure.

 

Isn't 8 psi of vacuum equal to 16" Hg of vacuum? Which is quite a bit, so something doesn't add up. It is usually best when dealing with GM EFI to use KPa for manifold pressure and vacuum.

Try setting the idle speed a little higher at 850 RPM. I'm running a similar cam in a 331 ground on a 108 LSA/LDA and it idles at 13" Hg at 850 RPM.

Should also defeat the stall saver as JP mentioned.

The high MAP could be from the nearly stalling of the engine. Looking at the code the error threshold is based on the ratio of barometric to MAP. Which in AXCN is already high at 85%. Not sure about AUJP.

Can also increase the RPM threshold to disable the test. It is better to do that then to just un-check the malf flag. Usually GM code will still act upon a high MAP error and go n-alpha on you.

Just be sure that once the tune comes together to reset the RPM threshold for the MAP high test. It may be needed some day.

It is going to take some work getting the VE and SA tables dialed in for that cam.

RBob.

 

You need to tweak the timing at idle, in case you havent done that, that will increase your vacuum with that cam ,and you may have to tweak the O2 settings to get it to idle decent in closed loop. One of my former setup idled good with a bigger cam and lower comp after some work, Idle was at 75kPa if I'm not mistaken...........

 

I ran the 276HR for a couple years, should be able to get higher vacuum at idle.
The idle SA will give you the best starting point. I ran around 26* with the iron heads and it liked it.
When first starting (cold) with AUJP, the closed throttle idle spark table is not used. The main spark table (100 Kpa column) is used until warmup.
Stock table has 20* throughout the idle range that matches the Closed throttle idle SA table. Make the two match somewhat when done.
Bump up the table so you have a bit more in the idle RPM area.

Be sure to reset the the idle air screw on the throttle body to get the IAC counts low (20-40 steps) while idling too.
Then go back and reset the TPS. Should give you a good starting point.

If running stock AUJP, the idle is capped at 800 RPM (hard coded value) so setting it higher in the closed throttle table won't yeild anything higher.

The code is probably being set during a stall or close to stall condition.
I would re-enable the code once you get the timing bumped up and the idle stable.
Jp

 

sry yeah i meant it only gets 8 Hg of vacuum. also what were you running for your initial base timing on the dizzy?

 

Also would running a manual tranny on an auto bin cause some idling problems? am i better off going with the 305 manual bin and copying over the tables?

 

Using 6* BTDC. Note that this setting has to match between the distributor and the calibration. With that, the engine running timing is WYSIWYG.

The base setting affects limp mode, malf 42 lockout, and cranking. Could go from 6* to 10* BTDC and be OK.

RBob.

 

What base timin did you run with the cam? Did you use 6*BTDC?

 

I was actually between 8 and 10 but also had the bin matched to that setting so the table was correct to the actual value.

 

were you running the 110 lsa or 112 lsa? Also when you changed the initial timing in the bin did you have to add any timing to the main spark tables?

 

Is it possible that the map sensor is actually bad?

that reading is really low.....

 

well thats the reading im getting off my vacuum guage.