1981 245 EFI Conversion

[limezest]

To Do List: EFI Conversion

• plumb fuel system
• mount AFPR
• fab crank trigger wheel
• fab crank trigger sensor mount
• install wbO2 gauge
• install IAC
• mount ignition coils
• mount relay / fuse box
• wire IAT
• wire CLT
• wire TPS
• wire crank sensor
• wire cam sensor
• wire fuel pump
• wire starter
• wire alternator
• wire injectors
• wire ignition coils
• wire wbO2
• plumb vacuum to brake booster
• plumb PCV system
• plumb vacuum to MAP sensor
• check timing
• plumb air intake
• blockoff for cold start injector
• blockoff for mech fuel pump

To Do List: Maintenance Tasks

• shocks (front)
• shock tower hats
• shocks (rear)
• fill diff
• change trans fluid
• change oil
• replace brake lines (front)
• replace brake lines (rear)
• bleed brakes
• ball joints
• tie rod ends
• sway bar endlinks
• hatch lifters
• radiator hoses
• heater hoses
• timing belt
• fix exhaust leak
• engine mounts
• valve cover gasket
• drive belts
• tires (wheels?)
• repair hatch wiring
• overdrive

About 10 years ago my dad bought a Yellow 245 wagon. He and I both love wagons. Sadly, it's sat in front of their house for the last 5 years in a non-running state. It wouldn't idle, but it would start and then sputter and die. I figure a rotting harness and a dozen vacuum leaks, along with my overall distaste for k-jet make this (i think) a good candidate for a megasquirt EFI conversion. Body has ~150k mi on it, so there's plenty of maintenance we'll do along the way. Back when it ran the M46 had trouble getting into overdrive, so I expect to rebuild that overdrive system. I did a bit of reading about it, I'm sure there are helpful posts in here as well.

Had it towed to my carport

Vacuumed out the interior

Pressure washed the engine bay

Removed the radiator, fan, and started pulling the ignition and intake system

So what's the plan? I bought an MS3X from somebody's wrecked LS truck, so I'm going to use as much of that harness as I can and remove the connections I don't need. Yes, MS3X is overkill for this project's first phase, but after we get it going N/A, we will decide whether it's getting a +T or if we'll do an engine swap.

The fabrication needs are as follows:

• Ignition
  • Firewall mounted LS coils, wasted spark full sequential
• Timing
  • Fabricate crank trigger wheel and hall sensor mount (this is probably the most complex fab task of the project)
• Fuel
  • Block off k-jet ports (sts block-off plates en route)
  • Fabricate return-style fuel system with ebay fuel rail

I've made and tested this cool little mount for a bmw throttle position sensor:

And I have a later model efi intake manifold with the injectors. I'll need to make a block-off plate for the (now absent) cold start injector.
Plenty more to come, I'm sure I'll have lots of questions as we get further along with the project.

 

[bobxyz]

Wow, that yellow exterior and brown interior look great! Where are you located, or where did the wagon come from originally? Looks like it was well cared for.

Hopefully your overdrive issues are just a sticky solenoid.

If you swap to a EFI Intake manifold (LH2.2 or LH2.4), you can use the factory fuel rail. IIRC, LH2.2 has a 2.5bar FPR on a drop-down leg, and LH2.4 has 3bar on a more compact rail. If you pull one from a later 940, it will have a schraeder [sp?] valve for a pressure gauge (but still hard to access).

To start with, you can use a LH2.2 distributor with a hall pickup instead of adding a trigger wheel, or pulling the engine and adding a 60-2 flywheel/flexplate.

Depending on the length and condition of the MS3 harness, you might be better off starting with a new 8' harness (~$100).

Do you need to pass an emissions test? If so, MS might be more difficult than a factory LH2.2 or LH2.4 retrofit.

Edit: and oil your hood hinges if you haven't done so already.

 

[Scaramanga]

Great looking car! More pictures please

 

[limezest]

I'm in Maryland, and this vehicle is registered as historic. No emissions tests on vehicles registered historic. It will never be a daily driver. I realize I'm opening up a can of worms with the MS conversion, but I'm excited for the challenge.

The intake I bought on ebay had a flexible line to the cold start injector, and i'd rather blockoff that port. Plus, AN fittings look clean and gives me one more thing to tinker with.

I understand that a hall pickup is an option and it's my fallback if I can't design a missing tooth wheel that can be installed on the crank pulley. We're going to do the timing belt, water pump, and cam/crank seals, so I'll have the front of the motor torn down anyway.

More pics coming soon, and i'll be sure to oil those hinges!

 

[limezest]

Quad lights

Has tach dash

Broken hatch wires

Intake with new rail

Need to cap off this port

 

[limezest]

belt is due for replacement and front seals are clearly leaking

pulley off and checking fit for crank trigger wheel

installed tps on throttle body

rough draft design for crank angle sensor bracket - I think the easiset answer is to pick up on two front oil pan bolts to come down and out

 

[limezest]

Ordered today:

wipers
accessory v-belts
valve cover gasket
timing belt kit (seals and tensioner)
water pump
intake manifold gasket
oil filters
front shock mounts
sway bar endlinks
motor mounts

 

[Souped]

You 3d print that crank trigger?

 

[limezest]

I did, just so I can check fitment. Plastic is not particularly ferrous
I've seen other posts describing what needs to be clearanced for it to fit behind the crank pulley, but I need to measure for myself.

 

[limezest]

@bobxyz thanks for the notes!

Before I go too much further down this crank trigger wheel road, I did some reading into the LH2.2 distributor option, and that does look a lot simpler. How can I identify the right distributor with the hall sensor? What would my trigger wheel config look like in MS? Would I have only a cam sensor configured and no crank angle sensor? MS would calculate RPM from the cam angle only?

 

[Souped]

I did, just so I can check fitment. Plastic is not particularly ferrous
I've seen other posts describing what needs to be clearanced for it to fit behind the crank pulley, but I need to measure for myself.

That's a pretty sweet tool to have in your tool box, even if it's just for test fitting.

I just removed the hall effect distributor from my '83 this past weekend. You can have it for shipping, if its what you need. It's a Bosch distributor, should be the same for 2.2, IIRC.

 

[OldCarNewTricks]

That's a pretty sweet tool to have in your tool box, even if it's just for test fitting.

I just removed the hall effect distributor from my '83 this past weekend. You can have it for shipping, if its what you need. It's a Bosch distributor, should be the same for 2.2, IIRC.

On my 83, I have the factory LH 2.0. If that is what you have, as well, I would probably recommend the OP find a 2.2 distributor, as the hall pickup is available for much cheaper. (Round plug sensor for 2.0 on RockAuto is $403! )

 

[bobxyz]

Before I go too much further down this crank trigger wheel road, I did some reading into the LH2.2 distributor option, and that does look a lot simpler. How can I identify the right distributor with the hall sensor? What would my trigger wheel config look like in MS? Would I have only a cam sensor configured and no crank angle sensor? MS would calculate RPM from the cam angle only?

I don't know the Bosch part number(s) for LH2.2 distributors, but they're the ones with a 3-pin black connector coming out the side (and no vacuum can). The connector is a bit of an oddball - Dave Barton 240turbo.com should have new ones if needed.

In MS, you want to use "Trigger Return" Spark Mode, with the hall sensor connected to the crank input, and a pullup resistor added.

There's a link in this post to a picture of Trigger Return distributor: https://www.turbobricks.com/index.p...irt-with-no-crank-sensor.367952/#post-6320271
(but you'll need to use the latest MSextra documentation for the configuration screens).

This is another somewhat dated writeup: https://www.diyautotune.com/support/tech/install/volvo/megasquirt-your-240-740-940/

Maybe someone with a running MS + LH2.2 setup can post:
1) their TunerStudio config screen, and
2) a picture of the distributor alignment mark vs. the rotor position at TDC

 

[limezest]

I understand how the ecu can get RPM from the hall sensor style dizzy, but I must be missing something - I do not understand how the ECU can get something unique from four vanes that pass thru the gap in the hall sensor.

Okay more thinking and reading: I get how you can use the trailing edge of the vanes and an offset angle to define spark timing, but im still stuck on "how do we know cyl 1 tdc from cyl 2/3/4?" maybe one of the vanes is smaller?

 

[bobxyz]

All 4 vanes are the same. To get this to work, you need the distributor, rotor, single coil, and spark cables to get the spark to the correct cylinder based on which cable is plugged into which disti cap tower. MS simply delays firing the spark from each vane, and the disti steers the spark to the correct cylinder.

 

[limezest]

Oh! Thank you for the clarification, that helps a lot.

We're doing wasted spark coil near plug with a crank trigger wheel and we'll figure out how to get full sequential (if desired) at a later date.

I just picked up a relocation kit for these LS coil packs. It'll look something like this, but with half as many coils:

 

[limezest]

So I met up with a friend today who has more experience with this stuff than I do and he recommended that we try and figure out a way to read cam angle from the aux shaft via the distributor. I love yoshifab's 4g63 CAS adapter, and i'm sure it would be perfect for my appliction, but I'd rather not drop $400 on it. It is the perfect solution for my current problem, but I'm trying to do this on a reasonable budget. I'm toying around with a replacement 12-1 shutter wheel design for the LH2.2 dizzy.

Installed the injector blockoffs

Pulled the intake manifold and the fuel injector lines

 

[elborikua]

Great stuff. Sounds like rocket science to me. Maybe one of these days I will attempt it on my ‘78.

 

[esmth]

I just picked up a relocation kit for these LS coil packs. It'll look something like this, but with half as many coils:

im pretty sure im running the same coils and brackets

 

[limezest]

removed k-jet fuel distributor assy, drained diff. The pcv box is so crusty!

gotta figure out fuel lines from here

we have m14x1.5 male concave for the output from the fuel filter - confirmed correct
m14x1.5 female concave for the return - i think this is actually m12x1.5. m14 is too large

matching fasteners are:

Male 14 x 1.5mm Metric Convex Seat to 6AN Male, Aluminum - Pegasus Auto Racing Supplies

This metric convex seat has 14x1.5mm male threads with a convex seat on one end and a 6AN male (9/16-18 thread) on the other.

www.pegasusautoracing.com

- note, this was too big. I think it's actually m12x1.5

Female 14 x 1.5mm Metric Convex Seat to 6AN Male, Steel - Pegasus Auto Racing Supplies

This female 14 x 1.5mm metric convex seat to 6AN male has a swivel on the female metric end to avoid damage to the seat.

www.pegasusautoracing.com

- this one fit great onto the filter, confirmed correct.

I suspect the factory engine harness wiring has something to do with why it wasn't running.