4.6l 3V swap Injector Pulse Issues

10953 Views 65 Replies 9 Participants Last post by outo20022, 11 mo ago

dman642008

Discussion Starter · Dec 5, 2019

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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41 - 60 of 66 Posts

eschaider

· #41 · Jul 15, 2021

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.

dman642008

Discussion Starter · #42 · Jul 17, 2021

mastersmith said:
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.

mastersmith said:
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

eschaider

· #43 · Jul 17, 2021

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.

Adam L

· #44 · Nov 25, 2021

3

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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dman642008

Discussion Starter · #45 · Nov 27, 2021

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

Adam L

· #46 · Nov 28, 2021

I have a 2005 PCM, and I have P0685 and P0690. Anyone try to clear these or anyone having a 3V running and still have these codes present?

05 and 06 had slightly different pin outs from 07 and up.

My wiring diagram doesn't have a pin for 46 on 175B

Writing implement Font Office supplies Material property Parallel

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mastersmith

· #47 · Nov 28, 2021

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.

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dman642008

Discussion Starter · #48 · Nov 29, 2021

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

dman642008

Discussion Starter · #49 · Dec 8, 2021

Alright, I've decided to throw in the towel, I'm over it. I just ordered a Megasquirt system. I will keep you posted on my progress.

mastersmith

· #50 · Dec 27, 2021

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.

eschaider

· #51 · Dec 27, 2021

mastersmith said:
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.

Get smart and throw away the OEM ECU. Go aftermarket and the problems disappear. MegaSquirt is an excellent starting point

mastersmith

· #52 · Dec 29, 2021

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.

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65Stang4.6L3V

· #53 · Mar 10, 2022

What’s up fellas. I have been reading all of you post. Has anybody figured out the problem?

65Stang4.6L3V

· #54 · Mar 10, 2022

Have you guys taken this into consideration about the return style fuel system. Normally, the 4.6l 3V are returnless but if you haven’t done so have you tried the return style?

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mastersmith

· #55 · Mar 12, 2022

65Stang4.6L3V said:
What’s up fellas. I have been reading all of you post. Has anybody figured out the problem?

I bailed on it and sold the 3V. After 3 months and way too much money trying get the 3V to run. I bought a 2011 crown Vic and used the 2V out of it. Had it installed and running in 2 days.

65Stang4.6L3V

· #56 · Mar 12, 2022

mastersmith said:
I bailed on it and sold the 3V. After 3 months and way too much money trying get the 3V to run. I bought a 2011 crown Vic and used the 2V out of it. Had it installed and running in 2 days.

That’s sucks bro. I just bought a 3V for my 65.

sparkydmac

· #57 · 12 mo ago

I think that the factory harness in 2005 and 2006 is tricky in a standalone setup, and everyone that I came across had the same years and the same issue.

I have the meagsquirt running and wish I would have gone that way from the beginning.

1957 Mercury with 4.6 3V, ms3pro evo ecu

1957 Mercury Maiden Voyage

sparkydmac

· #58 · 12 mo ago

65Stang4.6L3V said:
That’s sucks bro. I just bought a 3V for my 65.

Get yourself a megasquirt system.

D

65Stang4.6L3V

· #59 · 12 mo ago

sparkydmac said:
Get yourself a megasquirt system.

D

Sweet Truck Bro. So I have a 2007 4.6 3V with computer, engine harness and pedal. I did look at the ms3pro evo stand-alone management system with harness for $1599. Is that the one you are talking about?

sparkydmac

· #60 · 12 mo ago

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

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