Project 3.4 Camaro

Title says it all, wondering if anyone has swapped a 3.4 motor in, but also switched to the 3.4 ECM and harness.

Project 3.4 Camaro

Guess that's a no, well found a guy on 60*'s site that did it on an s10 and sent him a pm, hopefully he can provide me some guidance on what needs to be dealt with on the non engine management side of things, plugging the harness into the 3.4 and ECM is easy..making it play nice with everything else is what will be the hard part.

KuroNeko

do you mean like the 3.4 in the 4th gen camaros?

Project 3.4 Camaro

Yes, generally speaking they are referred to as 3.4s, while the fwd variants are referred to by CC of displacement(ie. 3400), and the 3.4 dohc generally referred to as such, though not everyone follows the rule of thumb, lol. Kind of an inside thing I guess.

I'm just fed up with messing around trying to fix the old harness after my attempted repin I just have not been able to get the thing to run right, also sick of messing around with the timing which is finicky at best, just too many variables for whats wrong and the only way to take them out of the equation is to put something in that I know will fire the engine right up unless there is a mechanical or sensor issue. Plus I want DIS so I can go hybrid, albeit I won't be able to tune at least for now(supposedly someone is working on the obd 1.5s)

Six_Shooter

iTrader: (2)

The 3.4 PCM swap troubles are NOT worth it.

I would run a '7730/'7749 LONG before trying to run the 3.4 PCM.

DeathStarr89

iTrader: (1)

^ Agreed


OBD1.5 sucks


1227730 is where it's at, With a Jbody harness you can be running DIS in a few hours. You'll also be able to tune it in your lifetime.

Project 3.4 Camaro

I really don't feel like going down the road of trying to make things that weren't designed for my application work again, I already attempted a 165 swap and all it did was mess my car up, and it hasn't been right since, its why I'm in this damn mess in the first place, I just want my car back at this point without a major headache.

Six_Shooter

iTrader: (2)

No matter how you look at it, the 3.4 PCM was also never intended for your application, so I'm not sure what makes you think it's going to be any easier.

To be honest, if you can't get the '165 swap working, you're not going to get the 3.4 PCM working, it's more involved, much more involved.

Maverick H1L

iTrader: (8)

Why does everyone seem to forget about the 93 3.4 PCM (16172693)? You know, the ONE year that the 3.4 wasn't hung by the OBD1.5 garbage? A direct swap to that ECM is the 16149396 (according to the Hollander interchange which runs Car-Part.com), which IS tuneable and has a MEMCAL just like the 730, and is found in the cars using the DOHC 3.4, and others. And there is a guide for the swap that I have a copy of and can be found easily otherwise (it's for N-bodies, but still).

Also, keep in mind that he didn't start with the standard 1227302, he got the one-year-only ECM (can't think of the P/N, but he knows it) that the 85s got. Which is one of the reasons why the 165 swap failed, since nobody seems to have any data for the 85's ECM.

Project, I agree with the guys above... Start with a J-body harness and splice in the C100 and the wiring coming out of the passenger's side pass-through by the door hinges, ONE WIRE AT A TIME, and double check your connections with a meter when done. Don't start with an F-body harness.

Project 3.4 Camaro

93 is what I was after, didn't know it was OBDI though, I was after it because I know its the only year the autos didn't have a trans controller built into the ECM.

My original ECM was an 830.
So you're saying I should find a jbody harness, and 93 fbody ECM? What year and engine option jbody should I look for? Also why use the jbody harness and not an fbody one?

Six_Shooter

iTrader: (2)

After doing a quick Google search it appears those two ECMs are a completely different. The 16172693 does not appear to have a MEMCAL, and would be flash only, as I've always seen for all 3.4 SFI PCMs.

So? The wires between the ECM and the engine don't care what ECM is at the end of the wire, through simple pin swapping a different ECM of similar generation be be able to be swapped over easily. Even if it was the edge card style connector, some simple wire splicing would be all that would be needed. I don't see how what the original ECM was has any bearing on getting an ECM swap running.

Why use a J-body harness? While I have gone this route with a couple of my swaps now, they were into vehicles that were originally carburetted, and had the J-body harnesses on hand. In this case I would start with an F-body harness, a 3.1 harness would be easiest, when using a '7730, since the only changes that would then be needed for DIS is the connector to the DIS ICM. All of the wires are in the harness already though.

Maverick H1L

iTrader: (8)

1. Never known the Hollander Interchange to be unreliable. It IS the junker's bible, after all. :edit: Scuze me. It's the LT1 PCM that interchanges (16159278). Can't imagine it being too hard to cut off one injector connector on each bank...
2. It doesn't help if you can't get the right pinout for the stock ECM in the first place.
3. The F-body harness is unreliable, PERIOD. I myself and other members on here have replaced it COMPLETELY due to problems with stalling. I believe it was Firebird_305 that got a NEW GM harness due to this. And don't dare blame my repinning of the C207, C221, and C100 for the harness issues as the pinouts were made IDENTICAL to my 302 harness (such that I could swap between harnesses in half an hour when necessary) and don't blame the hard parts, as those were proven to be able to run quite reliably for years and for hours and 400 miles at a time. The F-body harnesses are JUNK, period, and GM admitted to such in the TSB. If it's been done with a J-body harness and it runs reliably, I say go for it. Besides, the J-body DOES use your coveted 1227730, after all, and won't require repinning at the ECM connectors.

DeathStarr89

iTrader: (1)

I guess i should have made notes when i wired the Jbody harness into my 89.


the '7730 Camaro harness would be a better option, in my case the only shortfall with the Jbody one is that the wire length from the bulkhead plug to the ECM connectors is shorter than the camaro version making it a little harder to get the ECM tucked up into the 7730 bracket.


Just a tidbit of info, people have been talking about cracking the 1.5 ECM for 10+ years, you can datalog it just fine but it's just not feasible to make the modifications needed to be able to tune it.

Project 3.4 Camaro

Well my plan is to more or less convert it to 3.4, get it running as if it were a factory 3.4 in its factory application, and at that point I'll have a solid platform and can do the obd1 swap, a guy on 60* posted up a pretty good deal on the swap harness and ECM needed for that conversion, but my goal atm is getting it to run, THEN I can think about modifying it.
Sometimes its just better to not do more than the necessary amount of supporting mods for the sake of simplification of diagnosis if something goes wrong.

Also I did find a seller on ebay selling something I thought might have the engine harness attached(looked like an awful lot of wires in there and what appeared to be an ECM(apparently it was not) however they informed me they do have one, so I am waiting to hear back on what it is they have exactly. Unfortunately even though I have a 3.4 harness it was butchered before I got it(came with my engine) and even more so after I borrowed some wiring from it.

The biggest pita is going to actually be anything and everything but the harness and ECM, I am going to have to find what needs grounded and figure out where to ground it to etc.
As far as relays go, is the ECM going to care if they're hooked up. ie. if it doesn't have the control of the fuel pump relay will it simply not even try to run?

project89

iTrader: (1)

get a megasquirt 2 and a 12ft harness, and make all ur own connections.

will take u about 4-6 hours to get it installed and u can tune the thing no problem

or instead of buying a 12ft harness use whatever factory harness u want, even the correct 3.4 harness and buy an adapter board for the megasquirt and then it becomes plug and play

project89

iTrader: (1)

http://www.diyautotune.com/catalog/m...pcb-p-363.html

use the correct harness ,and cut the dizzy conectors off and splice on the correct connector for the coil pack
the ms2 wont do the sfi , but the stock ecm switches to batch fire above a specific rpm anyways so it wont matter

if u really want the sfi u could buy an ms3 exspansion board and have full time sfi down the road

Six_Shooter

iTrader: (2)

WHY would you put in an OBD 1.5 SFI harness just to swap BACK to an OBD1 ECM?

Just start with a 3.1 F-body harness, use the 1227730 ECM (with a 3.1 RWD MEMCAL), and be done.

When you're ready you can tune with this ECM easily.

Project 3.4 Camaro

Because said obd1.5 harness will plug right in, have the right dimensions, all the necessary wiring etc. Money isn't my main objective atm, minimal margin for error, followed by simplicity are(which kind of go hand in hand) hence I am getting the harness meant for the engine, and am most likely going to go ahead and get the 730 ECM and swap harness off of the guy on 60*, as the price is right and its been proven, since he had it running his 3.4 swap. I reckon its about as close to plug and play as I am going to get.

Now that the direction I am taking is settled, does the 730 do sfi or no?(If I recall correctly it does not?)
Ultimately it doesn't matter either way, but knowing ahead of time would be nice.

Also, I ordered a 3.4 harness off of ebay the other day, hopefully I'll have it by the weekend, assuming the seller sees my message about shipping it to the right address...

DeathStarr89

iTrader: (1)

7730 is MPFI, The stock SFI controls revert back to MPFI on OBD1.5 and OBD2 after like 2K RPM anyways. It's just a way to smooth out the idle. There is no performance gain.

Project 3.4 Camaro

Yeah I already knew that about SFI, just wasn't sure if the 730 ran SFI or MPFI is all, thanks.

project89

iTrader: (1)

i belive the ebl will do sfi

Six_Shooter

iTrader: (2)

But the 4th gen harness is FAR from a plug into. It may plug into the engine components, but to connect it into the car will require much more work than pinning your current harness correctly, or swapping in a 3.1 3rd gen harness. It will also require PASSKEY/VATS parts, that complicates the swap farther, trans type plays a HUGE part in making the ECM happy. To use a manual or non electronic tranny, you would have to use a manual 3.4 PCM, and even then you'd lose TCC, on the non-electronic auto. It's just WAY more hassle than it's worth.

Good. The '7730 swap will be much better and easier than the 3.4 SFI PCM swap. Easily tuneable, and if the harness you are getting is from a 3rd gen, it will be as close to a plug and play as possible. I can imagine a few differences at the body side connector. I know there was when I swapped a couple J-bodies between engine types.


Not the original EBL, nor the P4 based EBL. There is an SFI-6 coming out though, that will be SFI.

Project 3.4 Camaro

My original harness for my car is completely fubar, and I've pulled just about everything electrical, Idk what you mean by pinning unless you mean pinning the 3.4 harness to plug into a 730 ecm which is not necessary as i will be buying a conversion harness, not that worried about the transmission side of things, if I stay auto I'll run a 93 auto ecm, or a manual one, and put the tcc on a switch, but there is a good chance I will be going manual once I get the rest of the car sorted. As for vats there are vats disable modules that only cost like $30.
As for integration, I'm going to have to do some integrating no matter what route I go, almost my entire electrical system is gutted atm, and a lot of is not going back in.

project89

iTrader: (1)

disable the vats urself with a 25 cent resistor form radioshack

Six_Shooter

iTrader: (2)

It doesn't work that way, if you don't have the VATS module.

Just seems like a lot more work to swap in something in the 3.4 SFI PCM, for NO gain, when the '7730 will run the engine QUITE well, DIS and all.

Project 3.4 Camaro

My harness arrived today, but unfortunately were in a cold spell so I only got a couple things plugged in, but at least Its in there and I've figured out the approximate routing of it.

I know that the 3.4 in stock application has an o2 for each bank and that the ecm will expect 2 o2 inputs, would it work if I just splice off the signal to make it think that there are 2 o2 sensors that are in sync with each other? Also, does anyone know if the 3.4s had MAF sensors, or were they just MAP? Because I know 3x00s are both, so I am uncertain.

Six_Shooter

iTrader: (2)

No, you can't splice the O2 sensors, they measure the efficiency of the converter between the two, not how much oxygen content is in the exhaust.

Like I've been saying all along, not worth the effort...

Could this be why you had trouble with your previous ECM swap attempt? Lack of research BEFORE starting?

Project 3.4 Camaro

I take it the 730 uses a conventional single o2 sensor circuit? Could someone lay out for me how the 730s operate, ie. map, or maf, sfi or mpfi, dis or dizzy, vats or not, etc. Would help me assess which ECM to go with, but atm I am just wiring the engine harness as its the same setup regardless.

And to answer your question, no. I know of 2-3 other people that had the exact same problem, and statistically speaking, considering a maximum of probably 10 people have done that swap, and at least 30% have failed, knowing that most people wouldn't attempt that if they thought it was above their ability level, and they all checked their work multiple times, came up empty, and came up empty on diagnosing as well, its fairly probable that there is some other underlying fault in the swap, probably related to the application, as its pretty much the only variable. And that is both in the past and irrelevant.

Just because you don't know what they are, doesn't mean I don't have good reasons for every decision I make. A 3.4 harness, 3.4 engine, and 3.4 ECM, will very much work together, a fact proven in every v6 fbody manufactured from 93-95. That is why I am going with a 3.4 harness, and when I made the decision WAS planning to go with a 3.4 ecm, if I had to weld in o2 bungs, and swap back to a cam with a trigger on it, and get a new cam position sensor since the one on it is broke, I would've because there is no doubt that it would've worked.
Now is that to say I won't opt for a 730, since it appears to be a simpler, tuneable yet equally viable option that I didn't know of when I made my choice, no, it isn't, and now that I know about it, I probably will go that route. So please don't insinuate that I just blindly dive into things without knowing anything about them.

Six_Shooter

iTrader: (2)

A few minutes of research would reveal, that the '7730 (and it's siblings) have been used in MPFI, TBI, 4, 6 and 8 cyl, Batch fire, Speed Density (MAP), DIS and dizzy, VATS and no VATS, all depending on the applications that it was used in.

Wires are wires, they have no greater effect on how a system runs than what the price of butter in China is. I find that people that have issues with electrical, swaps or simply repair, just over think what the electrons do and confuse themselves. I've used the same harness to run an engine using both a '7747 (TBI ECM) and a '7730, first with an adapter harness, then by repinning, in one application, used a pigtail from a '7427 to run a Crossfire system that I made the harness from scratch, first using a mechanical trans (TH350) then swapped in an electronic trans (4L60E), just to mention a couple swaps that "couldn't be done," they run flawlessly.
If you're speaking of the '165 swap, I can guarantee you that more than 10 people have swapped that ECM into other vehciles with great success.
What possible "underlying problem" could wires present? All you need to do is feed the ECM happy signals to get happy signals out. Most of the signals to and from the ECMs are the same for the '80s and early '90s ECMs that GM used, with only a few small changes, mostly due to obvious mechanical changes, like offsets for DIS systems, that differ from dizzy.

I can't imagine what good reason there would be to use a 3.4 PCM in a 3rd gen, when it's not supported for tuning, at least not very well, the added sensors NEEDED, the added complexity to turn around and swap to a different, easier to swap in ECM.
Who's insinuating? I'm blatently saying it, your posts show that you don't do ANY research before jumping in, if you did, you wouldn't be asking the questions you are, and I'm confidant that if you did some in depth research before buying anything or turning a screw, you'd have much greater success than you have, much quicker.

Project 3.4 Camaro

Any number of variables might have caused my issue with the 165, though I suspect the problem was the ECM itself, but if you know a reason for injectors pulsing too fast when an engine starts firing up that can be explained by wiring I'm all ears, because I couldn't figure it out, bl85c couldn't figure it out(and hes the one that wrote the instructions up in the first place) and the instructors at my school couldn't figure it out.
Tuning isn't a current concern, its a future concern, I have limited time to get my car running, and even more limited time to work on and research it. And I think I pretty well laid out why I was initially planning to use a 3.4 pcm, really not that many extra sensors, cam, 24x, o2, knock, and maybe 1 or 2 others, and the provisions for them are there already, o2 sensors withstanding, and with a swap harness, really not any added complexity, plus as I said, I initially planned to use a 3.4 ecm.

Project 3.4 Camaro

Bit of an update:
I took a bit of a hiatus while waiting for some more cash flow after having to shell out $300 for some really BS BS I don't need to get into.

Anyway, I have the '730 and adapter now, and am running down the wiring. My lights are wired up for the most part, just horn, wipers, and fuel pump left on the chassis side of things, not having the switch panel is holding me back on that, also hooked up the juice for the the starter solenoid enable, and the always + coming off of it that is going to power up pretty much everything but the few relays I will be using. I did notice some rather substantial damage at said power wires down at the solenoid, I will have to do some patching there.
Switch panel is getting ordered on thursday when I get paid again.

I've connected up most of the engine harness, I need a new injector harness and or connector though. Other than that, just the CTS, fans, knock sensor, o2 sensor and oil pressure and or level SU. Power and grounds need hooked up too, but the grounds will take all of 5 seconds to bolt down, the power wires I am still tracking down, have found the one for the ECM, and am just about certain the other power leads are in the same connector, but unfortunately I cannot seem to find a pinout for it, and forgot my DMM at work =/
Also going to need to do a little patchwork to the engine harness, its a little rough around the edges. I'm probably about 1/4 to 1/3 of the way there, hopefully everything plays nice when it comes time to fire her up.