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4.6l 3V swap Injector Pulse Issues

15K views 65 replies 9 participants last post by  outo20022 
#1 ·
Hi Everyone. I am doing a 4.6l 3V swap from a 2006 Mustang GT into and old truck. I have the stock harness and pcm which has been re pinned and reprogrammed with HP Tuners. PATS has been turned off, this has been confirmed.

I can't get it to stumble sometimes but not all the time.

I have Crank Signal and Spark while cranking.

I have 12V to my injectors in key on and while cranking.

When I starting cranking upon a new key cycle I get one pulse with 1 shot of fuel.

If I connect my test light to the control side of the injector and battery positive I get one pulse while cranking then nothing.

I have a stand alone fuel system and an adjustable regulator that is set to 42psi and it stays constant while cranking.

I have new coils, New Plugs. Injectors do test out with a 9V battery. I have 5V reference at MAF. MAF is stock replacement.

I have checked grounds on connector C175T and have continuity on pins 10, 47, 48, 49, 50.

I have disconnected all injectors and ohmed them out to confirm that nothing is shorted.

Not sure what tells the injectors to fire or what is failing in the sequence. Any help would be appreciated.

TIA D

- - - Updated - - -

Sorry not sure how to edit thread. But I CAN get it to stumble randomly if I can get fuel in it.

D
 
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#31 ·
Well, I will second the poor service from flagship 1. I order a replacement PCM two weeks ago that was supposedly in stock. Called last week to find out what the status was. after waiting for about 20 minutes on the phone with an lady who could barely speak english, I was told it was "In processing" and I would be notified when it shipped.... Then today I get an email saying the unit is on back order.:unsure: So I asked them to cancel the order (hopefully I can get my money back) and ordered a PCM from another supplier. So hopefully I have a new one to try next week.
 
#32 ·
Sorry to hear your bad luck, they really shouldn't be in business. If you can call your credit card company and say it never showed up, and cancel it. I had to call them multiple times a day and be a pain in the *** in order to get an RMA issued, and then they sent it after 3 months of hounding them. Once they got the bad unit back they never credited me and I had to dispute it with paypal.
 
#34 ·
There are, what Greg Banish at Calibrated Success calls, Universal Truths, if I remember correctly. Two of them are excellent grounds and adequate voltage. Something you should know is battery adequacy is neither measured nor determined by when you bought the battery. Battery adequacy and for that matter electrical system adequacy is measured by power available at the battery and in the car.

A good, charged battery should show between 11.9 to 12.5 volts at the battery, the higher the voltage the better. A good electrical system in a running car should show between 13 and 14.2 volts. If your numbers fall outside those guidelines you need to find out why and fix it.
 
#36 ·
There are, what Greg Banish at Calibrated Success calls, Universal Truths, if I remember correctly. Two of them are excellent grounds and adequate voltage. Something you should know is battery adequacy is neither measured nor determined by when you bought the battery. Battery adequacy and for that matter electrical system adequacy is measured by power available at the battery and in the car.

A good, charged battery should show between 11.9 to 12.5 volts at the battery, the higher the voltage the better. A good electrical system in a running car should show between 13 and 14.2 volts. If your numbers fall outside those guidelines you need to find out why and fix it.


Ed
I agree good grounds and adequate voltage should always be the goal, but in my case (and I believe the OP is in the same boat) we are not even getting the engine running long enough to activate the alternator. with the voltage drop from the starter 11-12 volts while cranking should not be an issue.
 
#37 ·
Has anybody on here successfully swapped a 3v into something else using the stock PCM/Harness, or a Ron Francis? I am at a loss of what to try next. Could there be something in the cluster/BCM/PATS/other modules that the PCM needs to see?

After doing some more research, unplugging both cam sensors puts it into some sort of "failure" mode and will then fire the injectors and spark on both cycles, thus why it will run for a couple seconds but has a bit of a misfire. Also to note, with the cam sensors unplugged, I can press the gas pedal and get a response (engine revs like it should). It still shuts off after about three seconds though.

with the cam sensors plugged in, it will only run for about a half second, and has no response to the throttle pedal.
 
#42 ·
Finally, here it is giving it some throttle with the cam sensors unplugged
There is a guy that put one in a ford ranger and he used Ron Francis wiring harness.

Why is it that when you make it go into a default mode by unplugging a sensor it will run longer? It makes no sense. It's like there is maybe a wiring piece missing? It's almost like the key gets shut off or the timing table is confused.

The cam sensors control PWM for the injectors, if I remember correctly. So why do we lose the injector pulse? The injectors are 12V constant and the ground is controlled by the ECM, so where is the break down?

BTW glad to hear you got your refund.

D
 
#41 ·
Depending on how much time you have to devote to this you might want to look at an aftermarket ECU like an MS3Pro PnP or MS3Pro EVO <= clickable. They will start the engine, run the engine and get you away from the problem pit you are currently stuck in. If you use one of the PnP units you can use a factory wiring harness. The MS3Pro PnP supports variable cam timing on as many as four cams so you can keep the VCT feature the engine already has.
 
#43 ·
Injector pulse width is always modulated by the ECM. The cam sensors report to the ECM the cam position for the variable cam positioning messaging to the cam phasers, which is also exclusively handled by the ECU.
 
#44 ·
Joining the fray here with you guys. I’ve been battling the same symptoms. I get one fuel injector pulse unless cam sensors are unplugged. It will fire on starting fluid, haven’t tried giving it throttle with the cam sensors unplugged, but that was motivating! I started with a custom harness, tried two different ECU’s finally broke down and spent some coin on the Ron Francis kit, a 3rd brand new ECU, and used their tune… same disappointing result. I bought the Ford reference value manual and pinned everything out. I’ve got some weird ones out of spec like the knock sensors and IRMC. A more ambitious version would have changed them out already… just burned out on throwing money at this thing 🤣 how do your reads look against mine?
 

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#45 ·
Welcome to the club, sorry. A couple of questions for you. 1) What year PCM do you have? 2) Do you have any engine codes?


I wonder about wire 1140 Pin 46 in harness 175B, mine has no wire there and is the ISP-R location. This is to be hot in start and run, and is what is tied to the fuel pump relay coil hot side when the key is turned on.


It's almost like it fires and then shuts off, but the fuel PW is way too high and is flooding the cylinders so the PCM shuts it down to prevent cylinder wash.

This is kind of where I'm going next.

D
 
#47 ·
hopefully between the three of us, somebody can get this figured out... I've been working on paint/interior and wiring the rest of the truck, but hoping to start trying to get it running again soon. My 06 also does not have anything in pin 46. I believe that pin was used on the 07 up models. Looking at my wiring diagrams the 1140 circuit is the "Run" circuit that triggers all of the PCM/ fuel pump etc... relays. Are you guys using the factory "BEC" (fuse/relay box)? I am not.
Previously I had all of my grounds going to a single stud. My plan now is the separate some of the ground circuits to be more like the factory. Specifically all the the (570) black/white grounds. I will splice them all together and terminate them to a different location than all of my generic grounds. Same thing with the 1118 power circuit for the coils/injectors/pcm. I will splice them all together this like the factory was. Other than that I really don't know what else to try. I'm really wishing I would have just went with a coyote at this point.
 
#48 ·
Mine doesn't have Pin 46 either but maybe that is the piece we are missing. Once you modify it from the factory setup this may be required. The setup is acting almost like start and then shut down, but why? At this point, there have been multiple harnesses and PCM's tried by all of us and we are in the same place, I think that Pin 46 is worth considering.

Ford Racing swap harness and PCM uses a 2007-2009 engine harness and incorporates Pin 46, I would think that 2007-2009 uses it as well, in the factory setup.

I may be wrong but I think it's worth a shot.

D
 
#50 ·
So I started working on the engine again today. I changed the ground circuits a little bit to match the factory (isolated the Black/White 570 ground circuit) and that didn't change anything. So I swapped in another harness that I picked up a while back. Also no changes. I did get another ECU with the harness, but at this point I'm not sure I want to spend the $100 on credits to tune another ECU to remove PATS. I'm close to throwing in the towel as well, and dropping in a Coyote .... or even a 2V in this thing.
 
#52 ·
I am bailing on the 3V as well. I picked up this beauty for a few hundred bucks at the local copart. 2011 with under 100k miles. If I had the time, I'd do a stand-alone. But for the time and budget of this project, it doesn't make sense. I bought this entire car for less than the cost of a standalone system.
Car Automotive parking light Automotive side marker light Tire Land vehicle
So if anybody needs an 06 PCM or harness, I've got two of each.

On a side note. I've already got the 3V mustang gas pedal mounted in the truck. Any body know if the mustang and Crown Vic pedals are interchangeable? Looks like the same connector.
 
#60 ·
Thanks. Yes that’s the one, with coil drivers and,
CLT IAT MAP sensors it cost around $2000. I also had to adapt a cobra cable throttle body to the intake. I could have bought a DBW controller but it’s $500-$600 more. If you’re not doing your harness send it to Art at wire diet as he knows his stuff, plus his guarantees they will start the first time.
D
 
#63 ·
Well, finally got it running. I broke down and got the Ron Francis kit, brand new ECU, and had them prepare a tune for it, but was still having the same issue with no injector pulses even after getting everything all hooked up. I worked with their tech department, sent in my ECU and they were unable to diagnose the problem. They mentioned that they have had troublesome 2005 and 2006 ECU's so they got me one for a 2007 and re-pinned the harness for the 2007. I hooked everything up again and I was finally getting signals, but still no fuel. Did a quick pressure drop test and only one injector was barely spraying (they had been sitting for 10+ years) New injectors and fired right up. My gut tells me that the 2005 and 2006 ECUs PATS programming are just slightly different than 2007-2010 and most/all the aftermarket tuning software that people are using to delete the PATS are using language programmed for 2007-2010 since PATS deactivates the fuel injector signals. Hope this helps anyone who's struggling with it.
 
#65 ·
Adam,

I am happy for you in terms of getting it up and running again your battle is only half over, though. The Ron Francis kit is an excellent kit and does a stunning job of cleaning up the wiring in the car. Entry-level kits are about $300 give or take and vehicle-specific kits are $500 or a whisker more. I am not sure about the replacement ECU cost but let's say it's around $300. That puts you halfway to the aftermarket system price-wise, but with all the limitations and undocumented programming vagaries of the OEM ECU.

From an emissions and vehicle registration perspective, the Ron Francis kit will either have difficulty passing the referee's visual inspection or will fail the inspection in the more demanding testing some states do. If you manage to pass the visual inspection (I don't think you will) when they hook up or try to hook up the emissions computer to your OBD II port (if it's still there) the whole show will come to an abrupt halt.

If you are going to roll the dice from an emissions inspection perspective the aftermarket plug-and-play alternatives give you a much better starting point and at least a recognizable OEM OBD II port for the inspection station. In states like Kalifornia, you are simply dead meat — it has to be 100% OEM or have a CARB certification like Whipple and KB do; otherwise from an emissions certification and vehicle registration perspective, you're on the outside looking in once again. BTW that's also true when you use an OEM ECU from a different model year or an ECU from a different vehicle model within the same model year.

The worst part is when you are all done you are still saddled with all the original engine speed limitations caused by the slow OEM ECU not to mention all the undocumented (by Ford) programming methodology for the ECU.
 
#66 ·
Hi I have an 03 gt with an 08 gt 3 valve , I’m running the stock 03 gt computer? No real issues after a lot of time getting the right parts and setup? Just curious about all the problems that you are dealing with .. my car has ford hotrod cams longtubes bbk catted x-pipe, all else is basically stock .. I have everything connected sensor wise for the 03 computer to run without codes , only issue is the way I have the dpfe set the computer thinks the egr is closed .. reason is do I can get the car inspected here in NY … after I’m deleting the egr with a tune.. but will go back to stock for future inspections.. the car runs pretty good as is ..
 
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