Running a 165 ECM along side a 7427 PCM

[Racprops]

I am building a 93 Custom Van a new drive train.

It is a low RPM Torque Monster SBC 383 that thanks to Roards Veritable roller lifters will produce a torque curve from 1000 to 3000RPMs and power curve from 2500 to 4700 RPMs though a 4L80e and a US Gear Dual Range Overdrive.

It is hoped and believe my special engine will with the 5 gears be able to cruse at around 80MPH and 1600RPMs and get 25+ MPG.

It will not run over 5000RPMs.

I am running 193 Swirl Port heads, stock headers.

All of this will be fed by a 87 Camaro TPI system and controlled by a original 165ECM with its full Lean Burn Cruse custom tuned for best operation.

The 4L80e rebuilt with all the upgrades will be controlled by a 93 7427 PCM acting as the transmission only controller.

This is where I am asking for help: how to set these two controllers up.

My plan so far is to mainly hook both systems up at the same time:

The 165ECM gets all the Camaro sensors, VSS, Knock, IAT, MAF, TPS, Engine Temp, Tach. More of less a full Carmaro set up from a coplet wiring hardness from a 87 Camaro.

The 7427 PCM is the problem, as it will only be controlling the transmission, I am unsure what it needed to operate normally. This is not a drag racer but a RV Cruiser. This will be hooked up using the 93 Stock Van's wring.

So what controls shifting??

I think: VSS, RPMs, TPS(?) and MAP as load sensor. I have read Engine Temp is also need, but why?

I plan on having knock, IAT, and fuel injectors turned off by a programmer.

VSS and RPMs is easy to share being a electronic signal. MAP is also easy to plug into the manifold by its self.

The TPS Throttle Position Sensor is a bug-loo, as it is a sensor managed by the PCM I think I cannot run the PCM and the ECM off the same sensor, so the big question is does the 7427 PCM controlling only the transmission need the TPS??

I am hoping it only needs the MAP to judge load and thus respond to throttle changes requiring a down shift or to do a up shift.

Other wise I will need to figure out a way to add TBI TPS to the Throttle Body of my TPI intake.

Rich

[steveo]

i understand your plan and i know you could probably make it work BUT i disagree with your complicated approach.

my thoughts are if you have VSS, TPS, RPM, and MAP, and disable a lot of codes, you can likely get the 7427 to act as a standalone.

connecting the same sensor to two different ECMs can be problematic. they each send their own reference voltage. it can be a wiring nightmare although anything is possible if you understand analog signalling.

so here's a really big question for you

why not just convert the 7427 to batch fire mpi and dump the other ecm, having one ecm controlling everything?

were you aware the 7427 is plenty capable of feeding a TPI rig? it has been done quite a few times

[Fast355]

i understand your plan and i know you could probably make it work BUT i disagree with your complicated approach.

my thoughts are if you have VSS, TPS, RPM, and MAP, and disable a lot of codes, you can likely get the 7427 to act as a standalone.

connecting the same sensor to two different ECMs can be problematic. they each send their own reference voltage. it can be a wiring nightmare although anything is possible if you understand analog signalling.

so here's a really big question for you

why not just convert the 7427 to batch fire mpi and dump the other ecm, having one ecm controlling everything?

were you aware the 7427 is plenty capable of feeding a TPI rig? it has been done quite a few times

Personally I would delete the OBD1 stuff entirely, EFI Connection 24x reluctor behind a Holley vortec timing cover, convert to coil near plug, get an inexpensive LS swap harness and use a DBC 0411 or P59.

The early GM MAFs are garbage and the only 165 I have ever tuned I went to $12P MAP based code in.

USA made swap harness I am about to use to replace the Proflow 4s garbage ECU setup I am currently running.

https://highperformanceinjectors.com...lhi-connectors

[In-Tech]

Personally I would delete the OBD1 stuff entirely, EFI Connection 24x reluctor behind a Holley vortec timing cover, convert to coil near plug, get an inexpensive LS swap harness and use a DBC 0411 or P59.

The early GM MAFs are garbage and the only 165 I have ever tuned I went to $12P MAP based code in.

USA made swap harness I am about to use to replace the Proflow 4s garbage ECU setup I am currently running.

https://highperformanceinjectors.com...lhi-connectors

Hiya's,
My original thought was to just use the '7427 to handle it all. Man, that wiring harness price is great. Using a 24x crank and 1x cam sensor distributor is perfect. Sequential spark and fuel would be super neat on a TPI. I like it :)

[Racprops]

Gentlemen, I am NOT building a Hot Rod, I am building a MPG low RPM 383 its power curve is from 1000 to 3500 and HP to 4500RPMs.

My money went into the engine and dual transmissions.

It is designed to run at 1500RPMs on the highway.

Upgrading to a hotter PCM is not needed and too costly, I might as well just buy a newer van…IF I was made of money that is and want the new crap.

And everything I can find on Sequential fuel injection show almost no change from the 165’s batch firing, in fact it is said laying fuel onto the back of HOT intake valve helps vaporizing the fuel even for a millisecond.

Sequential fuel injection really only helps with pollution control and even then it is very small.

Spark is always Sequential.

You all work on older Trucks you should understand my needs.

The 165 has a programmable Lean Burn Cruse that BY ITS SELF can give 5 to 10 MORE MPG as can the TPI its self can add 20 to 30% more MPG, torque and HP over any carb.

The Highway Mode drops in at a nice cruse and fades out under load smoothly.

The 7427 also has a lot of programming settings for control of the 4L80e and I am told I can get a partial throttle down shift instead of the classic full throttle to the floor downshift, like my 03 Ford Explorer with its 5R55s does.

This is a Stealth RV Van…a road cruiser not a drag racer. I plan on 2 to 6K road trips where a 25+MPG VS the crappie stock 14MPG can really matter and I can feel less cheated with today’s gas prices.

[dave w]

Many gearhead-efi members including myself share ideas and information that come form personal experiences, including the school of hard knocks (waisted time and waisted money)

There is considerable truth to the statement: The More you Know about EFI the Less you Pay for EFI.

I'm sure many gearhead-efi members will agree with the above statement.

4L80E with 16197427 ECM Links below:

http://www.gearhead-efi.com/Fuel-Inj...0E-Controller&

http://mattw.dyndns.org/4L80E/

[dave w]

The original writeup was for a 1227749, most of the information in the .pdf also applies to the 1227165

[Fast355]

Many gearhead-efi members including myself share ideas and information that come form personal experiences, including the school of hard knocks (waisted time and waisted money)

There is considerable truth to the statement: The More you Know about EFI the Less you Pay for EFI.

I'm sure many gearhead-efi members will agree with the above statement.

4L80E with 16197427 ECM Links below:

http://www.gearhead-efi.com/Fuel-Inj...0E-Controller&

http://mattw.dyndns.org/4L80E/

Absolutely agree. My LS PCM recomendation was due to actually running them. He has a fantasy of lean cruise adding 5-10 mpg in something the weight of his van with the aerodynamic loada of his van. I have run well implemented lean cruise on many of my vehicles for 2 decades now. G20 and Express van both saw about 2-3 mpg improvement on flat, level road at highway speeds. 5-10 mpg is fantasy land even if the engine were moving a slick Corvette or Camaro. My buddies 71 Chevelle saw the biggest improvement I have seen and it was about 4 mpg. It has a 6.0L/4L80E and a 4.10 rear gear so it is singing along at ~2,500 rpm at 70 mph with very little engine load.

I suggested the 0411 or P59 because it is a far better PCM for what he is attempting to do than a stone age 165 and its matching MAF that even 10-15 years ago was nearly impossible to find a quality MAF sensor replacement for.

Ignition timing and fuel injection timing based off a crank sensor are far more accurate than a distributor. With dual timing maps and inidvidual cylinder retard capability the 0411/P59 results in less wasted torque and fuel. The LS PCMs also offer the ability to alter injection timing with engine temperature which is a big benifit. Can spray the fuel on the back of a closed valve with a cold engine and shift to spray as the exhaust valve closes with a hot engine, minimizing wasted fuel during split overlap. With even a stock L31 I can reduce the pulsewidth for the idle fueling as much 10-15% shifting hot injector timing to spray the fuel with a closed or almost closed exhaust valve. I have also mentioned to the OP that for torque at 1,500 rpm the TPI is actually about the worst single intake for that setup.

[steveo]

totally agree. also despite its reduced precision, the 7427 is capable of highway lean cruise on a budget. there's just no need to try to run two ecms here. if this were my build on a budget i would simply run the 7427 with speed density in open loop and tune leaner AFRs where required.

[Fast355]

totally agree. also despite its reduced precision, the 7427 is capable of highway lean cruise on a budget. there's just no need to try to run two ecms here. if this were my build on a budget i would simply run the 7427 with speed density in open loop and tune leaner AFRs where required.

That would easily work as well. I have done that with both TPI and the old Edelbrock TBI to MPFI intake setup. The old MAFs are junk in my experience. The 7427 is absolutely capable of open loop psuedo highway mode and it works well.

I have also run both the TPI and a dual plane MPFI manifold. Under ~2,500 rpm the dual plane mpfi manifold eats the TPIs lunch in torque production.

[steveo]

on rigs like my big heavy jeep (no highway lean cruise) i just run open loop super lean with lots of timing in cruise range. great economy. just gotta read your plugs to see if you went too far and your combustion chamber temp is too high. no need for a special program for that

[Racprops]

Well interesting ideas, running open loop..how?? Cut the O2 sensor?? tell me more.

I know that these lean burn cruse do not tell how lean, I have tested a 2000 Ford 4.6 step by step from 14.7 to 18.0 and found its MPG peeked ay16.5. Reading the Air Fuel Ratios.

My set up is a low torque 383 running in a second overdrive so at 75MPH it is running a 1500RPMs.

The 165 was good enough for for nearly 10 years in Camaros and Corvettes.

It had a true Highway Mode that will automatically fade into lean curse and fade out as needed.

Plus we are trying to stop the lean cruse from cycling in and out so its duty cycle will be as close to 100% rather that the factory setting around 50%.

So this month I hope to swap out the dead 350 and its 4L60e with my custom 383 and its 4L80e and dual range overdrive.

This dream and project has taken 26 years to do.

Frankly I am afraid to fire it up, and to have to wait until some 500 miles to break in a rebuilt engine, transmission and NOS (New) Dual Range Overdrive to start seeing if this is a great idea and the van gets 25MPG+ or a total waste of my dreams, time and money.

And the frustrating fact that when I started this quest, my ideas were still valuable for a fair number of Vans, trucks and cars might be able to use some of my ideas.

Vans, Trucks and cars have move so far from these systems that only 20+ older Vans, Trucks and cars might be able to use.

So I maybe one of the very few that can benefit from all of this.

As I am compiling the ECM (Engine Control Module) running the fueling systems and a PCM (Power Control Module) to control the transmission systems I am seeing how complex the control systems have become.

The ECM uses ONE O2 sensor, a throttle position sensor, a MAF air flow sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor.

A new car now have: 4 O2 sensors, a crankshaft position sensor, cam shaft position sensors (one per cam) fuel pressure, a throttle position sensor, a MAF air flow sensor, and a MAP sensor, an incoming air temp sensor, an coolant temperature sensor, RPM readings, and a knock sensor, oil pressure sensor, and maybe more:

How many sensors are in a car engine?
There are around 15-30 sensors in a modern car engine if you don’t include the solenoids. You can find over 70 sensors in a modern car if you count every sensor in the whole car.

And ALL this stuff has barely made driving a car any better..not in MPG any way.

ALL this tech and cars still get about the same MPG.

And Trucks, Vans and SUVs still seem to get the same crappy MPG thay got with old carbs and no overdrive.

My 1974/78 Chevy G20 Vans running a 350s with 4 barrel carbs and simple 3 speed transmissions, and the same rear end a 3.43 gear: 14MPG.

My 1993 Chevy G20 Van, now with Fuel Injection, and a 4 speed transmission with a .70 overdrive into a 3.42 rear end gets…wait for it…14MPG…WTF??

Is this a fix?? Is my van PROGRAMED to get poor MPG??? Is this possible??


Well I have TWO Ford Explorers, one a 02 with a 4.0 V6, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.

And a 03 with a 4.6 V8, with a 5 speed transmission with a .70 overdrive and a 3.73 rear end.

Both get the about the same reported MPG, with the V6 getting 19MPG and the V8 18MPG at 65MPH.

As I have seen cars get great MPG at around 1500RPMs so I tested both SUVs at 1500MPH which is 50MPH.

And WOW both SUVs showed 28 to 32MPG at 1500RPMs…

But speed up to 60MPH and WTF now they are getting 18MPG…they both lose around 10MPG just going 10MPH faster.

But then things return to a normal loss of 1MPG per each 5MPH faster so they both get 16MPG at 75/80MPH…again WTF.

How odd is this?? My 2000 Grand Marques and 03 Crown Vic with a 4.6 V8 only does the normal loss of 1MPG per each 5MPH faster…so they have a steady loss of MPG with faster speeds.

There is NO drop of 10MPGs at any speed change of any 10MPH.

I believe instead of using the computers to make as much MPG in cars and Trucks, Vans and SUVs especially are using the computers against us.

I hope to show that we can get better MPG.

I rest my case.

Rich

[steveo]

And ALL this stuff has barely made driving a car any better..not in MPG any way.

that's where you're dead wrong

modern vehicles with variable cam timing controlled by neural networks and precise spark and injection control make vastly more power and achieve incredible efficiency for a given displacement

[1project2many]

The 165 was good enough for for nearly 10 years in Camaros and Corvettes.

Well, you've just arrived at the heart of the issue. The 165 was "good enough" even though vehicles with a more recent design were getting a better ecm. OEM choices are based on economy and profit. That's what business is. But you're in a different space.

Think of it this way... the 5.7 / 350 was "good enough" until the LS engine was introduced. But you're using a 383 instead. Why? And if you're using a better version of the factory engine what is stopping you from using a better version of the factory ecm? The 7427 has more features and more tunable tables. The LS pcm has more tables and features than the 7427 and it has a faster processor.

If you want to run dual pcm's, follow the instructions in the pdf previously posted.

[Fast355]

Well, you've just arrived at the heart of the issue. The 165 was "good enough" even though vehicles with a more recent design were getting a better ecm. OEM choices are based on economy and profit. That's what business is. But you're in a different space.

Think of it this way... the 5.7 / 350 was "good enough" until the LS engine was introduced. But you're using a 383 instead. Why? And if you're using a better version of the factory engine what is stopping you from using a better version of the factory ecm? The 7427 has more features and more tunable tables. The LS pcm has more tables and features than the 7427 and it has a faster processor.

If you want to run dual pcm's, follow the instructions in the pdf previously posted.

The 165' was also only used for about 3-4 years. 85 had a 1 year only ECM with a seperate maf burn off aka "burnout" module as I like to call it for its ability to commonly fail which then killed the MAFs by baking the sensing wires during a prolonged burnoff session and then in 1990 GM moved on to the far superior speed density 7730 ECM and the underhood 7727 equivalent.