weez58

Bill,

It should be free to post. They haven't collected any money from me anyway.

My point was that I couldn't get thru to Accel to even ask a question. All I ever got was their voicemail. At least this way you might get some feedback from them.

-Bob

Bullshark

Ok, I think I have figgerd it out.
With the old design shutter wheel, an excerpt from it's directions are as follows:

18. Rotate the distributor housing opposite the rotor rotation (Chevy: Rotate housing counter clockwise) or opposite direction as when the engine is turning the rotor. (Either clockwise or counterclockwise).
Continue rotating until the blue LED shuts off completely. This indicates the falling edge of the cam trigger position.

19. Continue to slowly rotate the distributor housing until the red LED shuts off completely. This indicates the falling edge of the
crank trigger position. Stop at this point.

With the newer design, the updated directions read as follows:

19. Continue to slowly rotate the distributor housing until the red LED shuts off, comes on again then shuts off (Stop). This indicates the falling edge of the crank trigger position. Stop at this point.

This is a big difference in setup! the later directions now allow enough time for the ECU to respond to the upcoming crank trigger #1 of the new distributor configuration.

Bottom line, do not setup the newer shutter wheel design using the old instructions. Or visa versa.


Bullshark

wmf62

Bob
that is VERY interesting, now it's got me questioning what i have and what i did.... i wonder whether there is a way of checking the sync without pulling the distributor out of the engine.... probably not....

how do you think getting these confused would affect the operation of the engine? would it cause my hard starting and yet not effect it running?
Bill

ps: i just searched the Accel DFI website instructions, and they don't show different sets of instructions for different shutter wheels/distributor versions...

wmf62

Bob
this is a better picture of the shutter wheel for the distributor i have installed. (i checked my other distributor and it has the narrow window)



do you know where i can find a full set of the instructions for this distributor? they're not on the Accel DFI website...

Bill

Bullshark

Bill
I have a paper copy. The only difference that I can tell is the part I already posted. I could e-mail you a scan of the page if you send me your e-mail address.

Bob

Bill, I just found a copy on the internet. Check out http://www.malloryperformance.com/pd...c_77Series.pdf

wmf62

Bob
thanks for making the effort to find the instructions....

in the meantime i had gone back and compared what you originally sent with what is written in the installation manual (all 200 pages or so) that i had downloaded and printed back when i first did the installation. the instructions contained what you had written, so i went ahead and used those instructions to re-verify my setup while the distributor was still installed in the car. the setup was correct (unless i've consistently made the same mistake.... ; or we are wrong about which instructions go with which distributor). unfortunately, i still have the hard starting when hot problem.....

funny thing is that the installation instructions from their website didn't address both versions of the distributor; and stranger still, the distributor instructions that came with the wide window distributor that i got from Summit are those for what you say is the newer version...

and even worse, i just read the instructions that Accel sent back with the replacement distributor (which has the narrow window shutter wheel) for the one that fell apart, and they are the same as you sent for the wide window distributor....

needless to say, i'm confused; are you????
Bill

and, speaking of instructions, the instructions for setting the # of cylinders in the distributor control box were for dipswitches, and the newer version controller i got (from Accel) had a rotary switch.

wmf62

it was suggested that i try changing from sequential to batch and see if that made a difference. well, i did; and it does seem to start better/easier when hot...

any ideas?
Bill

wmf62

well...... when i cold started it this morning and drove it to breakfast, it was very cold natured; lean spitting and popping until it warmed up. then when i started it after sitting, it was more of the hard starting ....



Bill

Bullshark

Bill, have you seen this Accel Tuning tips paper on their web site?

http://www.accel-dfi.com/pdf/Helpful...hrusterEFI.pdf

http://www.accel-dfi.com/pdf/Helpful...hrusterEFI.pdf

It has some helpful hints that may be food for thought.

I took another look at your cal file, and from a first glance, it sure seems your VE table is low down around startup and idle compared to Accel's 77350PWS example file included in their Calmap Software. Your base timing also looks on the low side. I will take a another look at your Starting Fuel Coefficient and your After Start vs ECT, but I thought it seemed ok if I remember correctly.

Bullshark

5abivt

If you like Send me your files and any info to my email. i'd be happy to go over them and help out if I can. Mikegillvt@hotmail.com

wmf62

Mike
thanks, files sent
Bill

Steve85

Not an expert here but...

Upping the injector constant while not changing injector size or VE table is equivalent to leaning out the mixture. As injector constant increases for a given VE value, pulse width would be reduced. Think of filling a 5 gallon bucket (amount of fuel needed at a given VE value) with a garden hose, it would need to run for 2 minutes (30# injector) now fill it with a fire hose (50# injector) about 1 second.

If closed loop is correcting by 20-25% for a rich condition, then multiply the VE cell value by .80-.75 to pull the corrrect amount of fuel out. Or use the handy auto-calc button, it does the same thing. If it is correcting 20-25% for a lean condition, multiply the VE cell value by 1.20 to 1.25 to add the fuel. Adjusting injector constant is a bad idea.

So with that in mind, the VE tables need to be close to right in order for the correction factors to be effective.

I think I read that you dropped Starting Fuel Coeff. to 85% with no change? I am at 80% at 164* and that's with fairly close VE tables, less than 10% correction closed loop. If your tables are rich to begin with, you have not even begun to "correct" for hot start.

As a quick check hit "page down" to drop the whole graph until Start Coeff hits 50% at hot start (about 164).

Give it a shot, let me know what happens, then work on those VE tables.

wmf62

Steve
thanks for your interest...

i have tried so many things that i've lost track of what/when & where.... i have tried, once upon a time, lowering the start multiplier to as low as it would go, but with no positive effect. the only way i could finally get it to start was to reduce the values in the last couple of cells of the first column of the VE table in a table that was provided by a tuner i hired. but, it was still a 'difficult' start.... (btw, the tuner still doesn't have a solution to what's happening. his .ecm has good driveability but poor starting)

funny thing is i created a VE table using the VE estimator utility (assuming that i got the plugged-in values right) that had high #s in the last column cells and it started as 'well' as the VE table with the reduced values.

and speaking of the injector constant... i'm not quite sure where to set that. the original injectors were custom modified injectors that were supposed to flow 32# at a fuel rail pressure of 43; but in actuality, when flow tested, the injectors supposedly flowed about 40 at 32 (which is the pressure the regulator supposedly was set at when i got it instead of 43).

now i have 'stock' 2005 LS2 injectors with a fuel rail pressure set at about 34 (i now have a gauge in the rail), but i'm not sure what to set the constant to as i'm not sure what the injectors flow at that pressure. i THINK the guy that i got them from said they should do about 27 at 32; does that sound about right????? i believe the stock LS2 injector installation is rated at a higher fuel rail pressure.

F W I W, i remember once-upon a time setting the rail pressure at 34 and then watching the Closed Loop scale at idle, and then changed the injector constant incrementally to about 48 in order to get the Closed Loop scale to run in the +/- "0" range at idle......

i do believe that i will end up destroying the new mini-torque starter i just put on (because someone thought i had starter problems) because of when the rpms raise enough with the engine almost starting and then the bendix releases and then suddenly engages again as the rpms drop to cranking speed again....

and so i remain
Bill

btw... i have also tried reducing the starting advance to 1 from the usual 12 to 18 that most tables use and it seems to reduce the starting effort some, but not eliminate the problem; and it has to crank longer to eventually start

Bullshark

Injector Constant??? Are you guys talking about Injector Coefficients. I wouldn't doink with them unless you have an engine dyno properly instrumented with thermal couples and O2 sensors.

"After start Fuel coe vs ECT" and "Starting Fuel coefficient" are just starting modifiers. The first decays quickly based on the After Start Decay profile. I believe that Accel's standard 350 calibration file settings should be fine in this area. So, I agree with RainDelay, its a matter of getting the proper Base VE and Timing table values tuned in. Timing should be pretty easy also. I would go with the base timing table provided in Accel's 350WS file. That should be more than adequate to get started.

Bill, I know its easy for me to sit here and hip shoot from the chair, but I still think timing is set too low and you are starting/running lean. Disable closed loop until you get things sorted out.

Bullshark

I can't help but think that the slow, lugging cranking at hot is caused by something entirely separate from the ecu sequence. Have you tried cranking at hot with no fuel / ignition????

wmf62

Bob
by 'injector constant' i am referring to the setup page where one can enter the fuel rail pressure setting, the injector flow rate, and other items. i wasn't messing with the injector coefficients; i can get in enough trouble with just the 'normal' stuff...

the cranking is not slow and lugging, it is the same effect that one experiences in a hydrostatic lock, only it passes through it (and doesn't bend a rod... ), picks up speed and then may repeat the sequence several time again before finally starting. i have a current datalog taken while starting that shows the 'problem' very distinctly.

btw, today the cranking problem just tore up the new mini-torque starter i just installed on Sunday....

i asked Accel support what the 350 Chevy PNP .ecm's represented, but they never responded. the PNP's i have with the software don't have a 350WS, but there is a 350PWS, a 350P, a 350PS, a 350PW, a 360PRMS355...

Bill

Steve85

Sorry to hear that....

What is your ignition -> starting -> start-up term RPM? Mine is at 350. So ignition does not advance from start setting until after 350. Without being there I am taking some guesses of course. If this was too low you could be getting unwanted advance before it fires enough cylinders to run.

I think you may want to enter the actual flow rate for the injectors then put the 34 in the fuel rail pressure box. My guess is Calmap should compensate the injector flow rate for the lower pressure.

wmf62

i have never noticed a 'noticeable' change with whatever i have set the rail pressure and injector flow rate to... BUT, i have now set it at 27# and 34psig.....

the starting timing for the .ecm i am using now is 15 (12 in the bottom 2 cells) and the break between cell columns is @ 250 where it then goes to 18. i don't think my delco starter is going above that. the mini-torque that tore up only went 140 -150. i even set the initial advance as low a 1 for a while; took longer to start, but still started..
Bill

Steve85

For my setup the lowest advance I have is 27 in the left most column of base advance (200rpm column).

The start-up term RPM is in the ignition drop down menu. I persume you have the pro-key? This is where the 350rpm is. Timing will not be advanced until the engine hits 350rpm.

So, in my application 15* of timing is pulled from 27 when starting around and above 164 degrees coolant temp.

If you are set at 12 in those base advance cells, and pulling another 15 at hot start (Accel came up with this figure in mine in the ign. start menu, yours may be similar) would put you at 3* tarded.

I know you have been down many roads and I feel for ya. It's not my intention to send you on a goose chase. I'm trying to compare the values in yours with mine which are largely based on Accels guesstimates that have worked well for me in several applications.

wmf62

Steve
no, i don't have the Pro Key... not even sure what it is (other than reading about it in the 198 page manual i printed from the Accel website) or how to get it...

i spent the entire day checking EVERYTHING out, AND i MAY have made some progress; but i don't want to jinx it until i get a warm 'fuzzy' and i have had repeatable positive results...

but even if i have solved the starting problem, i still don't have a clue how to determine the best and most efficient VE and A/F tables.

thanks again for your interest....
Bill

Bullshark

Sounds like you are making some progress Good luck with your witch hunt. Keep us informed.
Don't worry about a Pro-Key, it is not needed for what you are trying to accomplish.
After you get the starting problem behind you, the VE / A/F table thing will be alot easier. I'm sure we can help there.

Bullshark