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Discussion Starter #1
To familiarize you guys with my current situation, the stock 5m in my mx73 Cressida (1986) blew a chunk of the block out on the freeway for reasons I'm not aware of.

i just so happened to have a spare 6mge in my backyard, so it was a good excuse to swap it in.

I've finished putting the 6m in, and cant get it to start. I have Fuel, but no spark. The car cranks, and i have 11.6v at the battery (after some cranking). I removed the wire running from the Igniter to the distributor and held it 1/4" from ground. With my gf cranking the ignition i got two sparks at first, then it just stopped arcing. When we went to try cranking it again, there was a loud shriek/squeal sound coming from what i assume to be the coil? anyways, it was in that general area, and squeals at KOEO (key on engine off) The sound scarred me enough to drop the wire and it fell to the intake manifold where it then started to smoke. the key was removed from the ignition along with the negative battery cable.
The next day i reconnected the battery and tried again. the event occurred in the same sequence.
1) connect battery
2) crank the engine=no start
3) turn key to the ON position and the squeal come back

I also have a check engine light that stays on EVEN with the key OUT of the ignition. I have never had a check engine light on the previous engine.

I've tried to trouble shoot this problem by looking up info on this forum, Toyotacressida.net, and ALL DATA online. I've had no success and I'm out of a much needed car.

I'm afraid I've damaged either a computer/module or worse. Maybe I've connected something incorrectly?

I didn't have my DMM with me to test for voltage at the Igniter, but all the fuses are good in the engine bay fuse box/ driver's side kick panel. I don't really know where relays or computers are located on this car.

Any tips would be greatly appreciated. I know my way around a DMM, and 5/6m, but am muuuch more familiar with the mkii Celica Supra (I've had 3). This is my first Cressida, and currently my only car.
 

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I could sell you one with a money-back guarantee , which is my standard policy with used electronics. Pm me with a part number if you want to give it a try.
 

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I seem to remember having nothing but a check engine light (with key in off position) after a breakdown once. Turned out my battery-engine ground bolt had shaken loose and fallen off. Make sure all your grounds are good... just a thought.
 

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Discussion Starter #5
Update

I seem to remember having nothing but a check engine light (with key in off position) after a breakdown once. Turned out my battery-engine ground bolt had shaken loose and fallen off. Make sure all your grounds are good... just a thought.
I have 4 grounds in the engine bay area.
1) Battery negative terminal to block
2) Battery negative terminal to stock fender ground location
3) Engine to firewall (near VIN)
4) Auto Trans to Trans mount

I could sell you one with a money-back guarantee , which is my standard policy with used electronics. Pm me with a part number if you want to give it a try.
Build date is OCT 1984 (mx73 Cressida)
how much is an ECU?
Igniter/Coil?

This helped me out greatly. the following reading were followed from this TSRM


Took these readings today....
Coil Primary Resistance: 0.4 ohms
Coil Secondary Resistance: 10.8k ohms
Wire from the Igniter to Distributor Cap: 3.09k ohms

These are from the Distributor
Pick Up Coil from pin G to G: 166.2 ohms
Pick Up Coil from pin Ne to G: 166.8 ohms

And i have source voltage (12v) at the Igniter with the key in the ON position.

A little update on the troubleshooting:

I turned the key to the ON position and got a backfire through the intake. I wasn't even cranking the engine, just KOEO. I was cranking the engine a few min prior to the backfire, so I assume there was fuel in the chamber, and that squeal i hear is the coil firing at full tilt and ignited the mixture in the chamber?

I've isolated the strange noise to be at the Coil/Igniter.
When i was testing power to the green Coil connector, the key was in the ON position. After getting my 12v reading, i proceeded to plug the green connector back when i heard the sound as soon as the terminals made contact.

Is it possible to have the Coil within specs, power at the Igniter, but still have a faulty assembly?
And if so, what causes them to go bad?

Thanks to Falkon45, i located the ECU and took some measurements based on this pinout:


I got the following readings KOEO (key on engine off) by back probing the harness with the harness still connected to the ECU:
Eo1: 10.05v
E02: 10.05v
IGt: 3.3v
E1: 9.43v
L1: 9.43v
L2: 9.43v
L3: 9.43v
Battery voltage at the time of testing was 12.2v
I can't necessarily guarantee it, but i thought this pinout was for an mkii supra 5mge ECU, and my Cressida ECU had a few extra wires that were "blank" in this pinout, so I'm not sure if this information is 100% accurate.

And for the model of ECU (if it matters), the car was made OCT 1984 according to the door sill

And this picture is just for any of those who wanted to see the engine (taken last week)
 

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Discussion Starter #7
I'll look into that when I get home from school. But even assuming it's off a tooth, would it cause a backfirethrough the intake without even cranking the engine? The key was in the ON position, and I was NOT cranking. I've never heard of that, so I'm a bit confused. Also, I heard the squeal noise right before the backfire, so I could only assume the coil was sparking. Leading me to believe that there is some sort of glitch in a module or something along those lines. Does the Igniter contain any computing componants that may have been damaged in the engine swap process?
 

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dont be confused, check the distribuitor first, if u r trying to find out what happened u r off topic, main thing right now is to check the timing.
 

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damn. i have that same issue but with no noise. everything is fine, but just no spark from coil. good coil, good igniter, good grounds.. good ecu i would think.. good luck
 

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I was also thinking distributor / ignition timing, but when he said there was no spark directly from the coil it made me think otherwise. Could be a fluke though, and would not be a bad idea to verify the timing first.
 

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Discussion Starter #11
I'll check my distributor again. Maybe I hooked it the wrong way?
I put cylinder one and TDC, and installed the distributor with the rotor facing the number one cylinder sparkplug wire. It was at about 7 or 8 o'clock on the cap if I remember correctly.
 

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Discussion Starter #12
Okay so I just checked timing and it all looks good.
Replaced the igniter and coil and I don't get the squeal noise anymore. But the car still won't start. I crank it once, get nothing. Turn the key to the ON position (not the START position) and the engine rotates a small amount and stops. I belive the coil fires and ignites what fuel was left in the chamber from cranking earlier.
This happened everytime with the old igniter and coil also. Only this time, the squeal noise is gone.

Could it be a bad ECU?
Also, the pinout I used for the ECU doesn't seem to match up. There are blank spots on pinout that my ECU has occupied.
 

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What intake did you use with the swap the 6m or 5m. Also Make sure you did not plug the coil plugs in wrong. Look at the single black wire under the coil/ignitor that runs under the fuse block. It tends to get pinched when a engine is swaped in.

The spark at ignition turn on is caused by a short after the coil wiring.
 

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Discussion Starter #14
What intake did you use with the swap the 6m or 5m. Also Make sure you did not plug the coil plugs in wrong. Look at the single black wire under the coil/ignitor that runs under the fuse block. It tends to get pinched when a engine is swaped in.

The spark at ignition turn on is caused by a short after the coil wiring.
I have the stock air box with the 5m AFM, Rabid Chimp tubing and the 5m Manifold. I have a printout with the vacuum lines from ALL DATA online.

So basically i need to trace the wires that leave the Igniter to the harness for a short, or the black wire that runs under the fuse block?

I want to test for signal at the ECU from the Igniter, but the pinout graph I used doesnt line up correctly to my ECU

Thanks for the help btw. What you said about the short does make sense.
 

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Discussion Starter #16
I'll look at it on my computer when I'm out of class. It's difficult to read diagrams on my phone.
Thanks for the link
It's an 85 mx73 Automatic
 

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Discussion Starter #17
Basically i decided to inspect and clean the entire harness at the connectors yesterday. when i got down to the injectors, i noticed a ground that was just flopping around underneath the intake manifold. I feel pretty juvenile for overlooking it on my instillation, but it was hidden underneath the Intake Mani, so i guess it could have happened to anyone in a rush.
So i bolted her down and the check engine light went away. She gets spark when cranking now, but the Ignition Timing is way off. Ironically it started to rain today and really put a hamper on my progress.

I fished out the ground and rerouted it to be on the outside of the manifold:

 

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Discussion Starter #18
Okay the car starts and stays running, but I have a missfire in cylinder #2 and #3. Timing was set with a timing light today. And the engine shakes a lot.
When the car warmed up a bit, I sprayed some water from a spray bottle onto each header runner, and 2 and 3 didn't evaporate very quickly at all. So I then pulled both spark plug wires and idle didn't change. They arc to the block though, so I DO get spark up to the end of te spark plug wire.
How would I test for fuel?
Any and all suggestions would be GREATLY appritiated.
 

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You need to check to see if the wires for 2 and 3 injectors did not pull out from the insulator/clip. I run into this on few engines that were installed by other people. They gave up thinking the engine was toast.
 

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So my 5m wasnt starting for a good month
I had put the jumper cables on backwards and ended up replacing the Coil, the Igniter, the ECU then brought it to the Toyota Dealer so one of their "professional" mechanics could look at it. He said there was no power going to one of the relays in the fuse box and he was sure the fuse box was fried. I got the car towed back home and had my dad take a look at it the next day.

We went through the diagrams and checking each relay and fuse to see if they were working or not. We found out there was a spark when you bypass a few things. anyways turned out I had blown my igniter with the whole jumper cable thing and also for some reason one relay that sits outside the fusebox was faulty (had a lose wire, and that was causing the car to start sometimes but not other)


So yea be sure to check all relays, fuses etc. in the ignition circuit.

I dont know if that will help at all
 
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