Injector driver upgrade

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Crimson93Ty

PITA new guy
I dug through the archives and found lots of links to syty.net information but all the links come up 404 when I click on them.???
Anyway, is this still the right injector driver when upgrading?
HUFA76429P3
Fairchild Semiconductor
I found them for about a $1.50 each and went ahead and got 4 of them in case I fubar one up.
Edit:
well here's what the amperage rating was on the one I ordered..
TO-220 20a, 60V, 0.027 Ohm
Does that sound right? It seemed like all the HUFA76429P3 docs come up 44 amps.
 
Last edited:
Loeryder

Loeryder

New member
Re: Injector driver upgrade

"You've Got Mail"
I just sent you the doc I have on upgrading injector drivers.
goes through it step by step.

Hope this helps,

Anyone else wants it just let me know and I will fwd it on to you.
 
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Crimson93Ty

PITA new guy
Re: Injector driver upgrade

When you guys are doing the injector driver upgrade, are you doing the mods so you can use 1 driver for each bank?
It looks like both banks are being run off the same driver off pin C11 and C12.
Here's the pics of the ecm:
749inj.jpg

749bottom.jpg

This shot shows the locations of the 2 injector drivers and the 2 sense resistors from the bottom of the board. Note that I have also added a jumper wire to the connector. The 749 has 3 injector outputs, 2 on one injector driver and one on the second injector driver. I've taken an unused pin (C10) and used it as a second injector output for the second injector driver to reduce the amount of current passed through the connector pin
Click to expand...

I like the idea of splitting up the duty and using one driver for one bank and one for the other.

And then I found this on Chitown:

This is what I believe to be correct. Yes all injectors fire at the same time. Saturation method The Sunbird turbo uses two drivers. Two injectors on each driver using peek and hold method. and had different wiring...(info edited out) some pins the Sy. Yes the Sunbird turbo used c10 and c11 as injector outputs. Whereas the Syclone used c11 and c12 which are joined inside the ECM.

On the Sunbird:

c13 and c15 were jumpered to add a .1 ohm resistor to the source and to ground for one of the injector drivers to operate in peek and hold. d5 and d6 were also jumpered to add another .1 ohm resistor to the source and ground for the second injector driver again to operate in peek and hold. This would probably be the ideal situation. In my experence low-ohm injectors which are usualy driven peek and hold are more stable at small pulse widths so idle is usually more stablen with larger injectors with low z injectors driven peek and hold.
Click to expand...

Are the sy 1227749 ecms and the sunbird 1227749 ecms different?
I have a sunbird ecm I will be modding. I gues I could compare them.
 
9

93ty475

Donating Member
Re: Injector driver upgrade

the mod pictured above was done for a v8 app...it's my understanding that we run off of just one of the two drivers....but while you're there, just replace the 2 mosfets pictured at the top right and up your ecm fuse by 5 amps....don't forget to reinstall the ferrite beads that are installed on the first of the three legs of the fets.... it's also my understanding that the rest of the mods you see pictured above are not necessary for running 6 low imp. injectors in a syty..... here's some more reading to further confuse you....


below are the directions i followed when i modded two of my syty ecms some time back....the info is on this site, you just have to look for it....

http://www.syty.net/forums/showthread.php?t=1417

Here are the steps for the swap...
The best way I have found to r and r the fets is as follows.

1. Scrape away the coating on the bottom side of the circuit board around
where the fets are soldered to the ECU.
2. Remove the solder from the leads of the fets and printed circuit board
3. Remove the bracket that is holding the fets and other devices to the heat
sink. First remove all the screws holding the plastic retainer, then pry it
off slowly and carefully. Try not to break it.
4. Make sure you have most if not all the solder holding the fets into the
printed circuit board removed. After you remove the plastic bracket you
should be able to wiggle the fets out of the printed circuit board.
5. There is a little bead that is attached to the fet but may stick to the
printed circuit board. MAKE SURE YOU INSTALL THESE onto the new fets. If you
do not the car will run real bad and you will get the CES light flashing
from all the noise. These beads prevents the high frequency noise from
reaching the CPU circuitry.
6. Place the fet into the holes on the circuit board that the olds one came
out from. DO NOT FORGET THE BEADS!
7. Center them up and reinstall the plastic retainer to hold them in place
while you re-solder them.
8. Cut off excess leads length, reinstall cover and re-wire the ECU to run P
and H and you will good to go.
 
Last edited:
dgoodhue

dgoodhue

BuSTeD 4.3
Re: Injector driver upgrade

Crimson93Ty said:
Are the sy 1227749 ecms and the sunbird 1227749 ecms different?
Click to expand...

They are the same ECM, but they are run in different modes via the source code in the bin..
 
MRKING

MRKING

New Parts for Old Trucks
Re: Injector driver upgrade

Loeryder said:
Anyone else wants it just let me know and I will fwd it on to you.
Click to expand...

I would also like the same Jason if you dont mind . I am really leaning torwards 74 #ers and have to locate a source for the new drivers .
 
C

Crimson93Ty

PITA new guy
Re: Injector driver upgrade

Get them from Mouser. $1.50 each.
I called them and the web site info is incorrect. As long as you use the correct part number, you will get the correct 44 amp mosfet.
HUFA76429P3
 
C

Crimson93Ty

PITA new guy
Re: Injector driver upgrade

That's the way the above pics are done. If I understand correctly, the syty only uses ONE of the drivers to do all of them. The pics above do the wiring and some board mods to run one driver for one batch and one driver for the other. I've got my stock ecm and a sunbird ecm(same). I'll do one the easy way and just put in the 44 amp mosfets and if I get that working correctly, I'll do the other one the way that sounds like it uses the facilities of the board better and use one for one batch and one for the other and run another wire.
I copied this from there:
There are two advantages to running the Sunbird wiring when using P/H injectors. They are injector life and driver life due to overheating unnecessarily. By using SY/TY wiring and P/H injectors, the full battery voltage is applied to the injectors all the time drawing more current (5 amps or more) than even the high peak current (around 4 amps) and never allowed to go into low current (around 1.3 amps) hold. As Grumpy pointed out, this causes excessive heat to be introduced into the injector solenoid coil and driver transistor, especialy at higher pulse widths where the peak portion of the pulse is a very small percentage, not to mention what the extra current does to pintle action. This is also why the SY/TY guys need a bigger ECM fuse. This will drastically reduce injector and driver life. Heat kills. There is no advantage to running this setup, only potential problems. The proper way to run P/H injectors is to run Sunbird wiring and the proper size sense resistor. For a 4 cyl. setup, a .1 Ohm sense resistor is needed. For a V-6 setup, a .067 Ohm resistor is required (this can be achieved by paralleling three .2 Ohm 1W resistors). For a V-8 setup, .05 Ohm resistors are needed. HTH
Click to expand...
From HaulinA$$ from the 3rd Gen forum. I'm definitely going this route.
 
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9

93ty475

Donating Member
Re: Injector driver upgrade

crimson,

what are your goals? any details on your build?


skywab,

interesting reading over there...been lurking for a while now...don't remember catching that thread....correctly wiring for p&h has been mentioned here before but most just brushed it off because of relatively good closed throttle control when wired the easy way....some here have even reported their 749 running "cooler" after a simple driver change...i have been daily driving (low 12 psi boost) my syclone with no problems...it idles tons better now than when it was on stock saturated inj....maybe because the program that started my truck is based of a 50 ultimate bin that all use quasi-async fueling....there are many trucks running this way which is not to say it's correct but it's working....haven't heard or read (here in syty land) of any driver's or injectors burning up and grumpy at third gen says he's tested "several to destruction"....i've been collecting and have 7 spare 749 ecm's as of now and might sunbird wire one for comparison sake soon....
 
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Crimson93Ty

PITA new guy
Re: Injector driver upgrade

With the 4L80E, I want 800HP and whatever torque it will make. I'm just getting the basics done first though. I'll get the ecm set up, the 4L80E set up, the driveshafts set up, the brakes set up, the rear end set up and only then will I do the engine and tuning. The only thing that is gonna be out of order is I'm gonna do an air to air since my CCHE is leaking but that will be the only thing on the engine until I build the drivetrain to tolerate it. I'm not gonna play games breaking stuff or risking my safety.
 
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93ty475

Donating Member
Re: Injector driver upgrade

sounds good....it might be a good idea to look into a billet crank and maybe even a bowtie block....you might get away with the billet crank and a properly prepped stock "4 bolt" block....read up on "ed hess" as he went 9's in a heavy syclone a few times on an o-ringed, 4bolt stock block running a billet crank....good luck
 
C

Crimson93Ty

PITA new guy
Re: Injector driver upgrade

Got my drivers today and they are the right ones! Double bonus!! I'll let you guy know how it goes.
 
Foot Performance

Foot Performance

Donating Member
Re: Injector driver upgrade

Crimson93Ty said:
I dug through the archives and found lots of links to syty.net information but all the links come up 404 when I click on them.???
Anyway, is this still the right injector driver when upgrading?
HUFA76429P3
Fairchild Semiconductor
I found them for about a $1.50 each and went ahead and got 4 of them in case I fubar one up.
Edit:
well here's what the amperage rating was on the one I ordered..
TO-220 20a, 60V, 0.027 Ohm
Does that sound right? It seemed like all the HUFA76429P3 docs come up 44 amps.
Click to expand...


i am looking to do this to an extra pcm i have layen around and wondering if you have the part number to the riesistor and were you got it

http://home.comcast.net/~p-928/749mods.html

i used this infor for the drivers i dont know about the resistor becuase it sayes it is for a v8 so are the driver and the resitor wrong ???

thanks
brandon
 
H-TOWN-TYPHOON

H-TOWN-TYPHOON

You're killin' me, Smalls
Re: Injector driver upgrade

Last Activity: 03-23-2006 10:58 AM
Offline


good luck getting an answer on that

try mouser.com, alliedelec.com, etc.

or search for user fivetodrive. He has some of the drivers available.
 
Foot Performance

Foot Performance

Donating Member
Re: Injector driver upgrade

I new i was tryen to revieve but that thread has resistor specs i didnt know if v8 and v6 would differ
 
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