nhromyak

UGH!

My oem Howell Bin looks really weird... strange numbers for volts vs. BPW, AE (5.0) vs delta MAP (at 0) etc. etc.

I have been getting a very bad fluctuating idle.


Q1
Are either the AXCN or AHNT bins good to use as a starting point?


So I thought I would change the constants in the howell bin to reflect the AXCN (manual vette) bin, using the SUper_8dMv1.ecu and TunerPro.

NO LUCK with a steady idle.

Q2
Are the VEs going to affect idle at the lower RPMS?


I have been trying to tune my VEs but it has been more than difficult to get the idle set . Idle keeps wondering between 550 - and 800. When the idle fluctuates.

When idle fluctuates, my ignition base timing keeps changing.

I have corrected (I think) my IACs for temps.

q3

Will it idle at 650 with this cam?
(408 BBC - 210/216 @.050)
I get ~15 - 17 inches of mercury at idle.

What I have tried
I have since added the AXCN VE tables and multiplied them all by .8475.
With this I was getting 132 - 140 BLMs at almost all RPMs.

Another issue with the AXCN
NOW I just saw my O2 going below .100 (like .082 really).... this is LEAN RIGHT?
This happens on DECEL. I think I enabled the DFO using the AXCN - so now it's stalling when I come to a stop. (VSS is disabled).

UGH, I can't take it anymore. I have been working on this ALL day, and burned 15 chips, and have gone back 15 steps!

Help... please....

RBob

iTrader: (1)

Part of what you are up against is that the bins you are using are for a dry flow port injection system while you are using a wet flow TBI system.

A1: I don't think it will matter much which bin to start with with the exception of auto vs. manual. Use the one your vehicle is.

A2: yes, the VE table is used during idle. To start out flatten the VE's in the idle region. May also want to eliminate (zero out) the idle timing correction tables. That is why the timing is changing during idle.

A3: I'd say that it should idle at that RPM, 15-17 in Hg is decent. Disbale the DFCO until the tune is better. Try and get the VSS operational.

Q1: what is being used to drive the 4 TBI injectors?

RBob.

nhromyak

Thank you SO much for answering all the questions. :hail:

I have a mechanical HEI, not computer controlled. Someday...
Hence, I used some stronger springs to try and combat this spark walking. I have also checked the distributor free-play.

I wasn't sure if I should make all the VEs the same becaues of the fluctuating idle seemed to be so variable (500 rpms at 40kpa up to 800 rpms at 30 kpa).

A1: I presume the stock 7730 drivers are driving the (presumed) Holley 4 injectors. There are four wires on the harness to the injectors (two are pink or red, a blue, and a green).

Then from the injectors four wires are tied together.

Now to search for the " idle timing correction tables."

Thanks!