Powerjection III Install and Review

You need an IAC like TheSilverBuick for sure. And yes they whistle like crazy! I hate that noise. The chamfer on top of the passage is there to try and quiet down those things. I have found that lengthening the passageway (even just an inch) will make a world of difference in the sound. I usually take a vacuum nipple (the one that's on the rear of the TB for the Brakes/PCV works well) and tap it into the hole and then you wont hear that bitch anymore.

The butterflies MUST move simultaneously at a 1:1 ratio. Most importantly because the injectors fire the fuel above the butterflies. This makes for amazing atomization but if the primary butterflies open while the secondarys stay shut, then the fuel will puddle on top of the secondarys and just drip into the manifold causing all kinds of issues.

 

Yup that's the IAC.
Haha that's my move! Covering the IAC lets you adjust the properly adjust the butterflies without the EMS/IAC screwing with ya. After the butterflies are set up properly then you want to uncover it!

If there is still a loud sucking sound and the IAC shows closed in the software then the IAC is either dead or stuck (jammed) in the throttle body. This was part of the new firmware (that sounds like you ... dont ... have).

Let me explain... When you shut the key off the IAC motor resets to a home position... the way this happens in V2_0 is the motor goes from the current position to 0 (closed) then to the cranking position. When the IAC fully closes against the TB it gets stuck sometimes... In V2_1 it works opposite... The IAC start from the current position, fully opens, then goes to the cranking position..

Back on track here... Jason, sounds like you need the new software and your IAC might be stuck. Until you get the linkage from Bryce, just bend the linkage rod down in the middle so the butterflies will adjust as I described. I can get you the V2_1 software and firmware, but not until I get home tonight. I can also walk you through the upgrade process...

 

Correct.

 

So if you want to upgrade to the larger LS series IAC motor here is what needs to happen. I got this from one of my good customers that works for Koyo bearings...

IAC modification stuff:


Heres what I can offer if it helps, the IAC was in a throttle body from a 1999-2002 LS 5.3, 6.0 engine family.
Heres a link (looks like its on many GM applications):
shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_IDLE-AIR-CONTROL-VLV-Delphi_25988022-P_757_R|GRPFUELAMS_906724639___#


Some part #s:
Delphi: CV10017
AC: 17113598
BWD: 31036

I Did the following modifications in our machine shop at work:
1) Enlarged the top hole From: 3750 To: .5625 (you will just break into the center fuel passage which is plugged anyway, I just added an O-ring on each end to prevent air leaking between the throttle body and fuel bowls)

2) Enlarged IAC pintle opening From: .375 To: .500 to match the LS IAC

3) Enlarged the lower IAC to manifold Hole to .500 and added blending radius

4) Put a .060 radius on the I.D of the pintle opening in the throttle body to prevent the IAC from potentially sticking

*5) Pulled the pintle out of the IAC and placed a .030 shim between it and the motor body
(this modification is the only way I was able to override the software limit of keeping the IAC open @6 steps, mine now fully closes giving the most dynamic airflow range) So when engine is warm idling in Park, no air passes thru the IAC.

NOTE: I currently have the IAC Cranking Position set to 180 and have no issues starting the car at 25 temp!

 

Thanks. I uncovered the IAC and set up all the parameters to the ones you have listed and the cars idle goes up finally when i start it up. But now, it's having a harder time actually starting. It seems to turnover and seem right at the edge of starting but it never catches. I'd love to get the new software, let me know when you're available. Thanks.

 

What do you have the Fuel Prime set to? Does it help if you prime the engine a couple times (key on, key off, repeat) or if you put your foot on the peddle?

The 2.1 software can be downloaded from here: retrotekspeed.com/product_images/product-dashboard_file-52.exe

And if you shoot me your Email, I can send you the firmware. I cannot attach either here...

Here are the update Instructions...

First uninstall your current dashboard and download and install the new dashboard from here: retrotekspeed.com/product_images/product-dashboard_file-52.zip


Then open the flash utility in C:\Program Files\Stage III Dashboard Software V2_1

The password is: 1972
Select your comm. Number
Open the 12400006.ehf file
Hit "update"
After the update completes shut off the key for 1 minute so the EMS can save the information

Turn the key back on and open the 2.1 dashboard
Hit File > Open calibration....
Select one of the new calibrations found here: C:\Program Files\Stage III Dashboard Software V2_1\StageIII Calibration Files
Make any needed changes (including tach input selection if running a CD box)
Shut off the key and wait 1 minute.

Fire it up!

Here are the new instructions to go along with the new software: retrotekspeed.com/product_images/product-installation_pdf-52.pdf

 

At what point do I need to plug in to the ECU? Also, my email is theone61636@aol.com.

 

??? Plugging into the EMS and turning the key on is this first thing! ... Always. hahah. Sorry, I guess I assume that's a givin thing.

Email/Hex file sent.

 

Got it loaded and running. I had to change the throttle position to get it to start. The IAC seems to be doing it's job, I just have to keep messing with it to get the car to start. Right now, i have the cranking position at 50 and it SEEMS to work okay. I'll keep you posted as i continue to work with it. Thanks again.

 

50 is a very low IAC cranking position. That's about what I use for my SBC 350. I would guess that yours should be closer to the 90-110 area. Try increasing it by 10 steps at a time and see what you come up with.

 

My initial setting was at 110 and it wouldn't start at all. It still acts a little weird...when i crank it, it will fire up to around 1500 rpm and immediately shut back off. I have to feather the gas to keep it running until the it finally starts to run.

 

That could be caused by a couple of different things like:

• Loosing key power while cranking
• Decel RPM threshold ( I know you said that you turned that off)
• Intermediate PW
• Not waiting for the fuel prime before cranking..

Why don't you just save your profile and email it to me so I can look it over. I think that will save a lot of time posting back and forth trying to figure out whats going on. You could also make a log file and send that as well. That way I can see if there is anything that looks out of the ordinary.

 

Jason or Cody,

What was the diagnosis/remedy after reviewing Jason's profile file?

Bruce

p.s. This has been the best thread I have come across concerning Powerjection tuning. It's been invaluable to me. Thanks Cody.

 

I haven't heard from Jason since my last post ...

No problem Bruce, I am here to help. Haven't I talked you you before?

 

Sorry guys, I haven't really been messing with it.I was tired of the IAC continually giving me problems so I plugged it again and went back to the way I had it. Maybe when it's gets warmer out I'll mess around with it some more, but I really am tired of having to mess with it. I also wish you th esystem was fully programmable. Having self learn is great and all but it would be nice to be able to tune every aspect of the system, to include spark.
I'm already saving to make the switch to an MPFI setup that I can tune. Just a as side note, I downloaded the new Holley Avenger EFI system just to see how it works and I tell you what, it's awesome. Every parameter has the ability to be tuned, great visuals, and its self tuning. I was toying with the idea of buying the EMS and wiring and trying to hook it up to the PJIII t/b but the cost is prohibitive and it would make more sense to just go MPFI.

 

Cody,

You have talked to me several times on the phone when you were still with Retrotek. You helped me tune my PJIII on my Cobra. It's idling well and runs strong. I still have to restart the engine 2 or 3 times when it's cold (40 degrees and below). I have the IAC settings the same as your above example. So, I'm not sure if I should increase IAC cranking position from 70 to 80 or lower the After Start Enrichment and/or the C-Temp Enrichment from 120 to 115. What do you think?

 

That's the same problem I have when I try to utilize the IAC. It will fire up and then immediately cut off. I have to feather the throttle to keep it running until the IAC table catches on. On a side note, last night I got bored around 9pm and decided to go tune and I made some changes to the fuel curve, torque setting, and AE and the car accelerates so well now it's amazing. I also have it idling at around 850rpm (seems to fluctuate between 790-870) with the AFR at 16 wit hno problems.

 

Cody,
Also, I contacted Bryce about that adjustable linkage and he says "This linkage that you talk about is mythical." He told me to just bend the arm. I've looked at the rod and it doesn't look like bending it would do me any good. Do i need to move the rod to a different hole on the linkage arm? Also, I'm going to shoot you some logs for you to look at and hopefully be able to iron out the whole starting issue. Thanks.
-Jason

 

This thread kind of wants me to sell my kit and go for a holly dominator efi system..
but if i actually get around to installing this you guys would have figured just about every hiccup in the system lol

 

That's what i would go for it i could do it all over again. You should download the software and mess around with it. Pretty amazing all the stuff u can do with it.