BosoMKII's project! 56k cut your head off

[BosoMKII]

Yeah well as soon as its running I will let you give me the first offer on it.

I think the reason the new motor isn't starting is because it might not have compression. Checked just about everything else. The timing was way off, but its all sorted now.

Either the coil is bad and that tiny spark isn't enough, or no compression. That about all that can be wrong at this point.

 

[BosoMKII]

Wow time flys. All this seems both really long ago and not that long ago. This project was really pretty ambitious, looking back. I got frustrated with the Corona because I really had no idea what I was doing. I needed a car, I had to focus on school, I wasn't working much, life changes, all sorts of stuff. The Corona project got shelved for what ended up being 6 years!


Years of the car sitting out in the elements. And the elements took thier toll. The paint faded, and rubber dried out.

Meanwhile, life was happening for me. I was working very hard in school, and had little time or money for anything else.

I've since graduated, gotten a job, and got married. Lots of up and downs, mostly ups but with some big downs. So it goes.

At last I am getting back on my feet. I have a little time and a little money to spend on the car, and it's back home with me.

 

[BosoMKII]

The car is back to the bay area!

I set about cleaning it up some. Got the wasp nests and ants out of it. The spiders under the car are pretty persistent though.

Since bringing the car back, I have slowly started working out systems and components needed to get the project going again.

I started with the fuel.

I've gone back and forth about whether use a fuel cell and a single in-tank pump, or the stock tank and dual pumps with a surge tank.

After much reading about aftermarket fuel tanks, I decided the tanks I could afford are too problematic. Plastic tanks are notorious for collapsing and degrading quickly. Aluminum tanks are too expensive.

So I chose to go with two pumps and a surge tank

 

[BosoMKII]

(A few pages/years back you can see a similar fuel setup but with different components. When I switched power to those pumps they sounded like a frelling hovercraft! Maybe that Summit stuff if good for a ProStreet drag car, I wanted a more streetable setup. Besides, I had removed and sold the old pumps long ago.)


One issue with converting a carbureted car to an EFI car is that the fuel tank wasn't designed with baffles inside to provide constant fuel supply to the pump.

Just throwing an inline, high pressure pump in the fuel lines can cause fuel starvation during cornering and hill climbing if the tank is getting low. Also, a small EFI pump can't pull much fuel. It's only designed to push at high pressure. The EFI pump works best when it has a constant supply of high volume, low pressure fuel feeding it.

That's where the "lift pump" comes in. These are old school. They are meant to pull lots of fuel out of the tank at low pressure, but high volume. Like what you would need with a big displacement carbureted engine.

A little bit of research, and I settled on a Carter brand lift pump. This one seemed to be the standard among muscle car guys.

For the inline, high pressure pump needed to feed the EFI engine, I chose a Bosch unit that was OEM for several German cars. The standards are high with marques like BMW, and I knew the pump would supply enough fuel for the 7M-GE

One component of this fuel set up I debated about was the surge tank. Also called a swirl pot. This device was common in high powered race cars back in the 80's and 90's. Even now, they are still common for big horsepower cars. Having one eliminates any potential fuel starvation, in any conditions. For just a stock 7M-GE, the surge tank is total over kill. But I didn't want any issues with the fuel ever. I hope to drive up to the mountains in this car soon, and going up steep and windy roads would tax any fuel setup but a very good one.

 

[BosoMKII]

Hard to see in the photos above, but to mount the pumps I insulated the mounts with chunks of rubber to cut down on vibrations transmitted into the chassis.

I also made a small bracket for mounting the EFI pump, and insulated that with rubber as well as wrapped the pump with rubber. Noisy pumps will not do!

Here is the surge tank during install. Eventually, the trunk floor will be wood, so the block I've mounted the tank on will make more sense in the future

Two fuel pumps, powered by two fused relays.

The battery box. Still to be mounted, but this is where it will live. Power to the pumps straight off the battery.

 

[BosoMKII]

The interior of my car needs a lot of help. The carpets in front were so worn out and impregnated with so much nasty old dirt, I just threw them out. I found replacement carpets here: http://www.stockinteriors.com/CutSewnCarpet.asp?Itemid=6628&MakeId=28&ModelId=499

I haven't ordered yet. Not too important until the car actually runs!

Also the center console needs refreshing. It's in pretty good shape except all the chrome over plastic has peeled away, leaving all that ugly yellowish plastic. I can't afford to send the part away, so I decided to try painting it myself. You should be feeling some foreboding after reading that last sentance....

I cleaned with Simple green and water, and gently hosed it all off and let dry.

Using JB Weld to strengthen the cracks in the plastic. Everything is old and brittle

Masking off, very carefully! Trying to do a good job. The dull grey-silver you see in the middle is paint over plastic. It matches the plastic on the gauge cluster, so I want to preserve it.

All masked off

Under coat of gloss black. I was reading on hobby websites about how to get a good chrome spray, and they all had good results by spraying gloss black first.

And after a few coats of chrome....

Oh no! Over spray! I thought I had masked off really well.

If I can clean up the over spray with a bit of paint thinner, then this will look better. If not, then I have to re-do it.

Also, I had a really hard time with the chrome spray. I didn't get a smooth coat. Overall, not a success.

The opening in the console is for a clock on some better-optioned car. Mine came with no tachometer and a clock where one would go. I wonder what the tachometer and console clock upgrade cost in 1973? $20? Cheapskates! I think I will install a clock in that space myself.

 

[BosoMKII]

My wife is a fashion designer, and is a pro at making anything out of cloth.

She brought me a big bag of very high quality black leather from her work, like what would be used for a high end hand-bag.

Here she is helping me make a new shift boot

An old tshirt

More of the shift boot to come. She has been too busy lately to help more

 

[BosoMKII]

The shifter in the W58 had been cut down by someone who had hoped to make a short shifter. Neet to fix that!

Here is the original shifter. It has a bushing inside, but no threads. The W58 shifter is too fat to fit into the opening at the bottom of the Corona shifter, so my brother welded on a bolt that fits into the opening.

I will post the final product once the shift boot is done and I put it all back in the car. Soon I hope

 

[BosoMKII]

Many wires. Such harness. Wow.

I have no idea what I'm doing...

 

[BosoMKII]

Needed to get the ECU into a factory-like position, which meant making a new hole in the firewall. I avoid cutting or drilling anything on this car as much as possible, but some is necessiary.

A $20 hole saw blade for my drill and a $9 dollar guide bit makes this circle-shaped lack of metal a very expensive hole.

But the result is worth it. I do need to insulate the wire harness as it passes close to the exhaust manifold, but that will be easy.

Next I have to make small brackets and drill holes in the firewall for bolts to secure the ECU. There is space for the ECU to be mounted flush to the firewall at the back of this small parcel shelf you see it currently resting on.

 

[BosoMKII]

Not many updates today. I spent the day pouring over wiring diagrams and searching for the wires I think I need to make this all work. That's slow going!

Here is the surge tank all plummed.

New starter wire run. The Supra runs the starter signal through the harness. Easy to just keep it that way, but cutting the origninal Corona wires is emotionally difficult to commit to!

Crimp connectors are ugly, but they do work very well.

 

[BosoMKII]

The thread title cracks up up. 56k? Does anyone have that internet speed still? That's how long ago this saga started.

I am pulling these updates from another thread I started on Japanese Nostalgic Car. We will catch up to the future soon.



Here is the bolt welded onto the remainder of the W58 shifter, then sprayed with a "galvanizing" spray paint. Probably didn't need it.

Rubber insulators from the W58 and Corona as well. I'll use some rubber mat to cover the rest of the hole in the trans tunnel.

More wires. The dangling thing you see under the dash is the fuse box. All of the car's electricity passes through here. Seemed like a good place to tap for power to the ECU.

 

[BosoMKII]

The wiring that I am doing:

This photo shows the B1 connector. This supplies power to the many components. The 7M only needs a few to run.

In the middle there are two 12 gauge wires that need power. One is the black/blue (can't be seen in the photo) that just power straight off the ignition. The other is the black/orange that powers the injectors and some other important stuff. That wire gets switched 12v power. Meaning if the key is in the "on" position, this must have power. I tapped the Corona's 12v ignition wire for that.

Also in this plug are the small black/red and green wires. The black/red is ECU power, and the green powers the fuel pump relay. They also get fused, switched power.

Next is the M1 connector. These are all the sensor feeds to the instrument pannel. I think all I need to do is run a wire from a few of these to the Corona equivalent. I.E. the black wire is the tach wire, so i'll just plug into that for my aftermarket tach. The yellow/black is water temp, black/yellow oil pressure. I am nervous about taking the gauge cluster out because the plastic is so old and brittle. But I want the fatory temp gauge and oil warning light to work like stock, so I'm going to have to!

Last is the C1 connector in the engine bay near the ignition coil. All this needs is fused 12v constant off the battery.

This is the power distribution block I am using to get power to the front of the car off the battery cable. Alternator feed to battery, starter power off battery, and the C1 power all come from here. These are cheap at any stereo store.

Just a few more wires to go! Then some odds and ends, but this car should run soon. In theory.

All of this info I took from the website below. If this engine actually runs, I am going to send flowers or something to this guy for creating an (almost) idiot proof write up.



http://www.supracharged.com/tech/wiring/

 

[BosoMKII]

In these photos, you can really see the effects of time and neglect. The whole engine bay needs to be detailed. I had it so clean all those years ago!


The Corona throttle linkage pushed the throttle plate open, and I needed to adapt that to the Supra throttle body. I used a few parts I had laying around from my old Datsun 240Z and the original Corona linkages and rigged a system with a chunk of aluminum bar. Works perfectly!

 

[BosoMKII]

The Corona brake booster has a leak, and so the brakes don't work. Had to fix that. The problem is brake boosters for a 1973 Toyota Corona Mark II don't exist. Needed a replacement option.

Took my chances with a booster from a junkyard MA70 Supra Turbo, and the booster fits! Barely. Didn't have enough time to bleed the brakes today, so we have yet to see. However, the bolt patterns are the same for the two different boosters. Thickness is the same too, but as you can see the Supra booster is much larger. Had to take the manifold off to install.

 

[BosoMKII]

I go the engine to crank!

Stupid mistake, I didn't have the engine block grounded. What an amateur mistake. Oh well, this whole project is a learning experience for me.

Engine didn't fire unfortunately. No spark.

I have 12 volts at the ignitor and injectors, so at least I got that right.

 

[BosoMKII]

Swaped ignitor coils. No change.

Turning my attention to testing the wire harness.

All the wire diagrams I can find seem to be for older 7M engines. I have a "grey plug" harness from late 1989 on, and the online wire diagrams seem to be all for the older "yellow plug" harness. So wire colors and pin-outs aren't matching, which is making diagnosis difficult.

Learning a litte bit every time I work on the project. I'll get it eventually

 

[BosoMKII]

In my quest to figure out why the ignition hasn't been sparking, I've gone back to basics.

My first lesson was in getting the starter to engage and crank. I hadn't grounded the engine block, so no circuit. Using the factory service manual available online I looked to see where other grounds were from the factory, and added them.

Cyl head to firewall

Intake manifold to body

(Please excuse the wiring mess. I will clean it all up once this car runs)

I had also read that the igniter grounds through its chassis, so I added an extra wire just to be sure.

None of this solved the no-spark issue!

While I was at it, I checked fuel pressure. Plenty!

 

[BosoMKII]

Still no spark, so back to the engine harness.

Up to now, I've been using descriptions of the wires and plugs I found online. I linked to them earlier in this thread. The problem is, both of the tutorials I have been using are for the older, "yellow plug" ECU and harness. 1985.5-1989. I have a "grey plug" engine, harness, and ECU. Late 1989-1992. The two are different enough that many pinouts and wire colors don't match up!

So I found a service manual for a 1990 Supra and printed out the ECU pinout and check procedure. Turns out having the correct wiring diagrams really makes a big difference! Who knew?

For example, the tutorial said to hook up to a small black w/ red tracer wire at the B1 plug. That wire is for the ECU ignition signal, but on the later ECU the wire is light grey. You can just make it out in the photo below

After I got power to the proper pins, SPARK!!!

I know this by pulling the lead wire off the distributor and holding it near the body while cranking. Sure enough, there was arc between the connector and body!

Car won't fire though! So close!

Now that I am getting pretty good at wires and checking stuff, I delved into the check procedure in the manual

Promising. But why won't the car fire?

I checked to see that the ignition rotor is pointing at the #1 spark plug wire at TDC, good there.

Maybe this? (find the red oval)

 

[BosoMKII]

The above photo of the ECU shows a badly burnt out resistor. Could that be my issue? (assuming I've got all else hooked up properly)

I made so much progress today that I am happy despite continued frustrations.

If anyone else is as frustrated as I am, here is a giant cupcake to cheer you up.