How to make it 'rev up' upon cold start 7747

[EagleMark]

Could be spark advace at idle is -6 to -10 from stock? WIth the cold spark bias you under 0 advance at start up.

Could be open loop AFR -1 to - 3 in that area?

Could be IAC park position off by 5?

Could be BPW of 165? Not sure how you came up with that number for a 401?

With those I think the motor is struggling just to keep running at cold start?

Need to turn Error 42 back on, it's a good one.

Error 43 is turned off as well. Do you not have a knock sensor? If not you should apply the ESC done patch so the forced knock test does not run. You've got 32 degrees advance, plus 5 in PE, plus 5 in the slope gain so your up to 42 degrees total spark advance... then add 11 degrees for forced knock test = 52 degrees and if it fails it adds 22 so your up to 62 degrees advance during the test! Minus 9.84 for the warm spark bias on all those totals...

I didin't see anything weird so I don't think you need to start with a fresh bin. Maybe some of them back to stock, have to calculate BPW!!! What injectors? What pressure?

[ony]

eagle mark, look at the target idle speed verses coolent temp.it looks funny but iam use to 6 cylender bins.

[ony]

never mind i looked agian i have the ao xdf on not the 42.

[ony]

blake the engine start up speed is 499, on my 6clyender it is 1176 rpms. in the scalers

[Blake]

LOL - yeah, make fun of the noob.

[ony]

i dont know what its should be, i have only messed with a 4.3 6 cylender,wish i could spell better would make for faster typing

[Blake]

Could be spark advace at idle is -6 to -10 from stock? WIth the cold spark bias you under 0 advance at start up.

My SA - Spark Bias - Cold is set at 20.04.

Could be open loop AFR -1 to - 3 in that area?

What exact value are you referring too?

Could be IAC park position off by 5?

how do I tell?

Could be BPW of 165? Not sure how you came up with that number for a 401?

I've played with it at 135. I think it was a little better at 165. I have not ran the numbers in the spreadsheet.

With those I think the motor is struggling just to keep running at cold start?

Yes, it barely starts and barely idles for the first couple of minutes.

Need to turn Error 42 back on, it's a good one.

Ok.

Error 43 is turned off as well. Do you not have a knock sensor? If not you should apply the ESC done patch so the forced knock test does not run. You've got 32 degrees advance, plus 5 in PE, plus 5 in the slope gain so your up to 42 degrees total spark advance... then add 11 degrees for forced knock test = 52 degrees and if it fails it adds 22 so your up to 62 degrees advance during the test! Minus 9.84 for the warm spark bias on all those totals...

I do not have a knock sensor. I apparently need to read up and the timing. I've only messed with the actual timing table (don't remember messing with any other's)

I didin't see anything weird so I don't think you need to start with a fresh bin. Maybe some of them back to stock, have to calculate BPW!!! What injectors? What pressure?

This particular setup is a Howell TBI that was originally specd for an AMC 360 V8. I have never removed or really looked at the injectors. It's running a junkyard chevy truck harness that I took completely apart - only running the bare minimum wires) Stock motorcraft dizzy that I welded (I welded it before really paying attention to any of the 'phasing' threads, so I'm sure that is probably screwed up, I dunno, seem to run ok). The truck runs fine once warmed up and netted 10.5MPG on a single hwy run at 70mph. This MPG is average for the type of truck it is.

Any overall comments are helpful. I'm gonna mess with the bin in TP with some of your suggestions and will report back.

Thanks!

[JeepsAndGuns]

The rev up at start is the one and only thing I miss about the 7747. I can not get my 7427 to do it. I have changed several paramiters and can get it to do it for a while, but then it randomly decides not to do it.

Back when I had my 7747, mine would rev up and stay reved up for a good while. If I didnt set there and let it come down to idle, then it would stay reved up for as long as I drove, untill I set stopped long enough for it to come back down to idle. I was using the bin file ARJT. I ended up finding a table labeled "position after motor reset Vs barometric" (address is 0x606) I changed all of those to 0 and tried it. I would now get the 1 or so second rev up, then it would drop down to idle.
It might be worth a try to get a copy of that bin (ARJT) copy over your tables and what other important changes you have made and try it. I know it atleast worked on my 401.
You can get a copy of that bin in the $42 thread. http://www.gearhead-efi.com/Fuel-Inj...Information-42

[EagleMark]

blake the engine start up speed is 499, on my 6clyender it is 1176 rpms. in the scalers

499 is correct for his bin and a common number. Not sure why your's is higher? May be a V6 thing.

ENG Start Up Distributor Reference Pulse Periods. Setting affects start spark, fuel etc.... basically how long all the start up paremeters are in affect then engine is running.



Replies in red.

My SA - Spark Bias - Cold is set at 20.04.
Cold spark bias. This value is subtracted from the Total SA. It's purpose is to bias the Coolant compensation spark table. Again, to allow for a negative advance in this table.

This is why your negitive spark.

What exact value are you referring too?
"Open Loop - AFR vs Temp"
This table details corrections to the A/F ratio, based on engine temperature. It includes startup enrichment (choke).
Also Choke - Cold AFR vs. VAC kPa effects commanded AFR while in Open Loop.

how do I tell?
IAC - Park Position

IAC park position. IAC is immediately moved to this position after engine stop and IAC reset completion. This is the IAC position for engine cranking and start.

I've played with it at 135. I think it was a little better at 165. I have not ran the numbers in the spreadsheet.
BPW is not an adjustment, it is a calculated setting. I've done a lot of testing on this and adjusting more then 10 away yeilds a curve in fueling ie rich idle and lean up top.

Need to know about what HP engine is, size of injectors, fuel pressure to support that HP with those injectors and I forget the math because we have a spreadsheet to calculate BPW setting.

Yes, it barely starts and barely idles for the first couple of minutes.
You can see why all these things will effect that.


I do not have a knock sensor. I apparently need to read up and the timing. I've only messed with the actual timing table (don't remember messing with any other's)
"SA - Main Spark Advance" Is the only spark table I see effected. Going back to a stock spark table will start better, may not run as well, but will be much safer with no knock sensor. Your WOT spark advance is about 10 degrees over stock.

This particular setup is a Howell TBI that was originally specd for an AMC 360 V8. I have never removed or really looked at the injectors.
Should be the 5.7L 61lb/hr injectors.

Stock motorcraft dizzy that I welded (I welded it before really paying attention to any of the 'phasing' threads, so I'm sure that is probably screwed up, I dunno, seem to run ok). The truck runs fine once warmed up and netted 10.5MPG on a single hwy run at 70mph. This MPG is average for the type of truck it is.
The reason for the phasing is your cap and rotor could cross fire wrong cylinder with all the spark advance of an EFI system. The chevy small cap distributor cap and rotor have a channel to direct spark and prevents cross fire.

Since it's already done just set distributor 5 degrees advance and in the bin set "SA - Initial SA" to 5 from 0.
Initial spark advance. This value should be what the physical distributor timing is set to. This value gets subtracted from the Total Spark Advance. (but is physically added back in by the position of the distributor relative to piston tdc). This is also called 'static' timing.



Thanks!

[Blake]

Well I made a couple of tweaks as recommended and ended up with this bin. http://blakeoffroad.com/vps/Attachme...gy-401_001.bin

The 401 sat for two days in the cold then I started it up on this bin. It seemed to start a little better, but has absolutely no hint of revving up. The IAC was very loud after it started and was loud as I drove it around the block.

Ideas?

[EagleMark]

Open your bin in Tunerpro and then click on Compare and load a compare bin, ASDU. Open spark table and click the scale icon, use the icon next to it for difference, use the graph icon. See the difference in tables and how much spark your missing from idle?

Loud IAC sucking air noise is a sign that all the air is going through IAC and none or not enough past throttle blades. Turn the screw in 1/4 turn and give it a shot.

Data logs would really help!

[JeepsAndGuns]

You have done the min idle speed and tps adjustment on the TB havent you?
If idle is fine, but IAC is screaming, thats a good sign that the blades are closed too much.

[EagleMark]

There's 2 big misconception on how to do throttle blade min air setting and none of the internet write ups mention it. If you read this thread and the min air procedure you can figure it out!

First it must be done with engine warmed up and wait for it to go closed loop.

Second the final RPM should be 100 below what idle is programmed in bin, that's not a secret but did you read how IAC logic is totally differant with B10 wire grounded? So how would it work in park? It doesn't! Must be in drive or at least have B10 not grounded. In gear is better as it has the auto trans load on engine.

In the end when engine is totally warmed up and driven around a little, the IAC should be about 20 counts.

I've gotten very good at doing this because of all the off roaders around here that need rock solid idle. Cheat! Totally warmed up engine in gear and note IAC count of say 80, so throttle blades need more air, turn in screw 1/4 turn and then turn off engine for 10 seconds, restart so ECM calculates TPS postion to 0% that you just moved 1/4 turn, you can not see this value in a scan tool, this is why I added the TPS% hack, it should never be left on after this! Start engine and wait for it to go CL put in gear and watch IAC counts... now 40, rinse and repeat.

On a engine from the factory this should not be needed until around 100k on a auto and 50 60 K on manual, manual throttle moves a lot more then auto and wears faster. As they wear the throttle blades close. Another time it's needed is if throttle body was rebuilt or if installing it on another engine conversion. I'm sure there's a measurment way, some guys use a piece of paper to slide by throttle blades and bore. But in the end this procedure is accurate because your using the IAC counts.

Point of why all this is so important is the injectors are above throttle blades! If they are open properly then the fuel and air are mixed and flow through the intake, if not fuel and air does not mix well and dribbles into intake, now the intake is soaked and until you drive or rev engine for awhile nothing is right because of all the extra fuel in wet intake.

[Blake]

Thanks for all the help!

I've been following Bill's FAQ's over on BP (Is he on here???) as pretty much my only source of info. I've followed his "initial setup procedures" many times, on many different rigs. Most of the time the rig was cold and definitively not in closed loop.

I'll try the above and report back....

[EagleMark]

It's not that hard, if you need help let us know.

Here's a corrected clip.

Take the paper clip and open it up and form it into a big "U" shape. Insert the clip ends into the ALDL in the 'A' and 'B' pins.

With engine totally warmed up!
Turn on the ignition, but don't start the engine. Wait 30 seconds. Now, go remove the connector from the IAC.

Start engine.

With engine totally warmed up and in CL, if auto in drive (be careful, block wheels, parking brake on, friend to hold brake, this could be dangerous!)
Some vehicles will not idle as low as this procedure indicates, get as low as you can!

You are now going to adjust "minimum air". There is a Torx screw on the side of the throttle body. This is what needs to be turned to adjust minimum air, or more commonly known as "idle speed". It comes from the factory with a protective metal cap over it. If the cap is still there, use a small punch to knock it out. Set the idle speed to 100 RPM below what is set in bin for warmed up temp, rotating the Torx screw clockwise to raise rpm, and counter-clockwise to lower rpm. Once the idle rpm is set, turn off the engine.

Clear codes, start engine and should idle fine. Check IAC counts after it is driven a little. May have to turn off and let IAC go back to parked position, then restart.

Drive and enjoy!