LTG ecotec engine wiring help needed

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want2race
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LTG ecotec engine wiring help needed

Post by want2race » Tue Jul 31, 2018 6:42 pm

Hi Gents

I have been waiting 3x longer than expected for an order of a custom wiring harness. At this point I am beginning to think the seller isn't going to actually deliver anything.

My big concern is I have the LTG engine and all things needed to physically mount it but need the engine harness and pcm to fire it up.

Does anyone have any recommendations on how to do it or where to buy one? I've tried alpha fab and I'm waiting for a reply. Most other people do not return calls or are afraid of direct injection.

Any help is appreciated. I've got a ton in this build and this last part is proving more difficult than it should.

Thanks

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OneBFC
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Re: LTG ecotec engine wiring help needed

Post by OneBFC » Tue Jul 31, 2018 6:55 pm

https://paceperformance.com/i-22326117- ... nsors.html

There are other sources as well if you search a bit.

That is a kit directly from GM.
-Russ
-----------------------------------
The only thing stopping you is FEAR
400+hp Ecotec, 12x7.6 DBDO, 80" 3B Maximus, 2.3 OX,85+mph, water = purely optional
Life begins at 2 BAR, Just a good ole boy

want2race
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Re: LTG ecotec engine wiring help needed

Post by want2race » Tue Jul 31, 2018 7:02 pm

OneBFC wrote:https://paceperformance.com/i-22326117- ... nsors.html

There are other sources as well if you search a bit.

That is a kit directly from GM.
Thanks. I've very familiar with that but failed to mention it. I'm hoping there are other options. Things I don't love about the gm kit -
Requires a pretty specific fuel pump
Needs a vehicle speed sensor input ( can be simulated. Just not ideal
And the price

If I don't have other options I'll probably go with it but hoping someone knows "a guy"

loudmouse
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Re: LTG ecotec engine wiring help needed

Post by loudmouse » Tue Jul 31, 2018 10:55 pm

When I did the LNF Chuck did the harness and Trifecta did the tune. Never again! Each engine combination will be different unless u only use all the factory parts as it was in the car. So the tune must be altered for each boat and Trifecta didn't want to do that. Apparently $400 for a tune isn't enough $$ for them to dial it in. (Canned tune only). At that time no one could tune it but trifecta. Have heard things have changed now. Good luck those lil engines do great when they run right. IMHO I would not consider Alpha in my search.
Last edited by loudmouse on Tue Jul 31, 2018 11:21 pm, edited 1 time in total.
15' Alumitech deckover LSX TT Oxbox 84" JX 4-blade
Gas required Water optional :dontknow:
Built and Tuned by Me
14'X8' JW, Chevrolet 122CID LNF Turbo Engine, Ox box, 80" NGR 3 blade

Life is short, eat your dessert first! :downtown:

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Slidin Gator
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Re: LTG ecotec engine wiring help needed

Post by Slidin Gator » Tue Jul 31, 2018 11:12 pm

want2race wrote:If I don't have other options I'll probably go with it but hoping someone knows "a guy"
I'm pretty sure OneBFC and mouse are guys.

What is the issue with vehicle speed simulation? it is just a 1:1 input off the crank position sensor.
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

want2race
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Re: LTG ecotec engine wiring help needed

Post by want2race » Wed Aug 01, 2018 9:31 am

Thanks Guys.
I shot an email to Chuck but he pointed me in the direction of the GM harness.

The VSS concern- The engine was designed around "torque by gears" so it limits power in lower gears. Ideally what we would need is something with a "3rd gear" like profile so it gives full torque but the PCM might faulter and say "you missed 3 gears.." which isnt ideal either.

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Slidin Gator
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Re: LTG ecotec engine wiring help needed

Post by Slidin Gator » Wed Aug 01, 2018 8:15 pm

want2race wrote:Requires a pretty specific fuel pump
Referring to the documentation from BFC's link, there appears to be an option to use any fixed pressure fuel pump that meets flow and pressure requirements. The PDF from the link below has the following statement regarding alternate fuel pumps (note that 500 kPa is 72.5 PSI):
A fuel flow rate of 32 G/hr at 400 KPa is needed. Because this is a dead headed system, a pressure relief set at 84
psi (580 KPa) must be included in the fuel line between the tank pump and the engine mounted high pressure pump. Part number
13582660 is one example of a compatible pump and it includes an integral pressure relief.

A pump with excessive capacity may result in cavitation at low flow due to the pump repeatedly stopping and starting instead of
controlling to a speed/pressure. Alternatively, a fuel system operating at a fixed 500 KPa could be used and may be triggered by
the Green/Gray wire in cavity 2 of the Fuel Pump Power Module (FPPM). Note that excessive fuel heating and potential startability/
drivability issues may result from a constant high pressure
https://paceperformance.com/pdf/326894

This thread might provide some more insight into fuel pump options
viewtopic.php?f=48&t=71166
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

want2race
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Re: LTG ecotec engine wiring help needed

Post by want2race » Thu Aug 02, 2018 1:21 pm

Slidin Gator wrote:
want2race wrote:Requires a pretty specific fuel pump
Referring to the documentation from BFC's link, there appears to be an option to use any fixed pressure fuel pump that meets flow and pressure requirements. The PDF from the link below has the following statement regarding alternate fuel pumps (note that 500 kPa is 72.5 PSI):
A fuel flow rate of 32 G/hr at 400 KPa is needed. Because this is a dead headed system, a pressure relief set at 84
psi (580 KPa) must be included in the fuel line between the tank pump and the engine mounted high pressure pump. Part number
13582660 is one example of a compatible pump and it includes an integral pressure relief.

A pump with excessive capacity may result in cavitation at low flow due to the pump repeatedly stopping and starting instead of
controlling to a speed/pressure. Alternatively, a fuel system operating at a fixed 500 KPa could be used and may be triggered by
the Green/Gray wire in cavity 2 of the Fuel Pump Power Module (FPPM). Note that excessive fuel heating and potential startability/
drivability issues may result from a constant high pressure
https://paceperformance.com/pdf/326894

This thread might provide some more insight into fuel pump options
viewtopic.php?f=48&t=71166
Thanks. That fuel pump piece was helpful.
I read the doc on Pace performance. Looks like I can buy the parts for $1700 vs the full kit for $2300. Still not an ideal price but might be easier to get things turning! :cheers:

br,lc,LA
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Re: LTG ecotec engine wiring help needed

Post by br,lc,LA » Thu Aug 02, 2018 7:27 pm

The VSS signal is very easy to manipulate. You splice the crank signal and feed a Dakota Digital SGI-5. Then feed the ECM with the Output of the SGI. You adjust (divide) the signal in the SGI so you get a 0-5mph feed when engine is idle... I read about near 0 mph at idle and it tops out ~20mph which would equate to a manual transmission in 1st or 2nd and putting power to the ground.

I have wired my 1.4L LUV myself (Chuck did the first but I rewired completely last year) and I am starting to get things ready to build my own harness for the LTG which isnt much difference in the wiring except for the DI system and additional fuel pressure sensors.

It is very easy to tune out the need for GM intank fuel pump as I have done on my LUV. Bad New Racing handles my tunes now and Jerry is a great guy and still willing to work with the aftermarket guys outside of the car vs Trifecta who wants to sell a can tune.

Wiring these ECMs by tearing into a stock harness is very easy if you have any wiring experience and can map out the schematics, but just to give you a heads up the LTG is about an inch thick 3 ring binder full of wiring schematics just for the motor. Schematics are easy to get your hands onto via GMSi... $20 for 3 days access to download them all.

One more tidbit... you want an E39A ECM out of a buick regal - Buick Regal had a manual trans and you can overwrite the ECM with a manual tune if you end up with a automatic one when you buy it used. The E92 pinout is essentially the same as the E39A, but not sure who has cracked the E92 for the LTG yet... Im sure HP and EFILive can do it but their websites done advertise it yet.
12x7'6" American Airboat
1.4L GM Ecotec - Stock Turbo
2:1 Century Ecotec Drive
80" 2-bld WW Stump Puller
"Nothin' as Fine as Hearing a Turbo Whine"

want2race
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Re: LTG ecotec engine wiring help needed

Post by want2race » Wed Aug 22, 2018 12:35 pm

Thanks!

I have a question in to Bad News for the tune.
Anyone have any details on the alternator control? It looks like the wiring circuit is controlled via the body control module and harness on most cars. No mention on the OEM standalone harness.

Looking at all options (building or the factory offering) and none have any provisions for the alternator wiring.
My first thought is to replace it with a single wire alternator but since I have the factory one I would prefer to keep it

br,lc,LA
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Re: LTG ecotec engine wiring help needed

Post by br,lc,LA » Wed Aug 22, 2018 3:37 pm

What ECM? E39A
Or tell me the car and year model you purchased the engine from...

For E39A
G13 - 2 pin alternator plug should wire direct to ECM X2 (Black) pins 55 and 53 - your circuits are 23 and 25 - wire colors vary by year and car

Ill check my wiring for cars that have stop/kill programming to assure the case is the same, but normally that affects the starter not the generator rectifier wiring.
12x7'6" American Airboat
1.4L GM Ecotec - Stock Turbo
2:1 Century Ecotec Drive
80" 2-bld WW Stump Puller
"Nothin' as Fine as Hearing a Turbo Whine"

want2race
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Re: LTG ecotec engine wiring help needed

Post by want2race » Wed Aug 22, 2018 6:45 pm

Fantastic! Thanks very much for the help!

br,lc,LA
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Re: LTG ecotec engine wiring help needed

Post by br,lc,LA » Wed Aug 22, 2018 7:32 pm

You confirm E39A... which is a Regal and ATS 2013-2014... E92 is very similar... stay away from Camaro and 2015+ ATS E80 ecms

Best harness to start with is a 2014 Buick regal manual trans... bout $300 new from dealer... much easier than dealing with torn pullout harnesses the salvage yard destroys them

And good luck so I'm right behind ya building mine next year... 500hp+ all forged and EFR7163 turbo
12x7'6" American Airboat
1.4L GM Ecotec - Stock Turbo
2:1 Century Ecotec Drive
80" 2-bld WW Stump Puller
"Nothin' as Fine as Hearing a Turbo Whine"

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Slidin Gator
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Re: LTG ecotec engine wiring help needed

Post by Slidin Gator » Thu Aug 23, 2018 12:32 am

Nothing to do with Airboats, but WTF.
br,lc,LA wrote:Best harness to start with is a 2014 Buick regal manual trans... bout $300 new from dealer... much easier than dealing with torn pullout harnesses the salvage yard destroys them
Damn, that perked my ears up. Had a 74 Buick Regal, the Pickup Truck of cars! Stripped out the trunk and could easily fit a dozen beagles in for a day of hunting and still have room for a beer cooler. I assume they liked the Sammy Hagar 8 track blasting "I Can't Drive 55."

It was an automatic but those turbo 350's don't need no stinkin wiring any way. I don't imagine the wiring harness would be of much use either way, but I can confirm there were no usable pieces remaining when I left it behind in Bayou Vista, La.... Went through quite a few motors on them boats too, I sunk the green one so much from Lake O to Texas I lost count, running anything from that 5 to 25 hp. Still using parts of the trailer on my buggy...

Image
I grew up thinking I-10 was the Mason Dixon line.
1986 Airboat Engineering Inc., 14' Marsh Master. Refreshed narrow deck, SV O-540, 72” NGQ. A Bob Stossel original.

want2race
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Posts: 8
Joined: Wed Mar 28, 2018 9:17 am

Re: LTG ecotec engine wiring help needed

Post by want2race » Thu Aug 23, 2018 7:45 pm

br,lc,LA wrote:You confirm E39A... which is a Regal and ATS 2013-2014... E92 is very similar... stay away from Camaro and 2015+ ATS E80 ecms

Best harness to start with is a 2014 Buick regal manual trans... bout $300 new from dealer... much easier than dealing with torn pullout harnesses the salvage yard destroys them

And good luck so I'm right behind ya building mine next year... 500hp+ all forged and EFR7163 turbo

Thanks

Anything else you recommend?
I found this harness-22870879
And I think ill add an ethanol sensor. Do I need another harness for the obd2 port as well?

Appreciate your help

br,lc,LA
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Posts: 683
Joined: Wed Feb 16, 2005 10:29 pm
Location: Louisiana

Re: LTG ecotec engine wiring help needed

Post by br,lc,LA » Thu Aug 23, 2018 10:53 pm

Thats the right one... it's not plug and play... you need wiring diagrams and it's a lot of cutting and splicing
12x7'6" American Airboat
1.4L GM Ecotec - Stock Turbo
2:1 Century Ecotec Drive
80" 2-bld WW Stump Puller
"Nothin' as Fine as Hearing a Turbo Whine"

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