Toyota Celica Supra Forum banner

7mgte swap...almost to the finish line!

7K views 27 replies 8 participants last post by  Whitey482 
#1 ·
Hey felllas,

I've been working on my 7mgte swap build for several months now and made really good progress thanks to this forum. I am nearly finished and just need some help with making a few wiring connections to get her started. I've done a fair amount of research on the wiring conversion. The main question I have is how to connect the 7m engine wire to the fuse box (junction 3) in the engine bay to power everything? I believe the C1 connector on the 7m was the connection on the 89 car. Are you guys taking mk2 body connectors and making a jumper harness that will connect to the c1 or doing something else? The plugs on junction 3 go straight to relays and fuses obviously. I've done some research on a few ways that folks on here have done it. Now, I had someone do the engine harness conversion for me. And below you'll see details on that.


Background
83 celica supra ptype
7MGTE from an 89 turbo car
All Stock, motor completely rebuilt

Wiring
The ECU wiring and dash side engine wiring is complete. I think.
Fuel Pump - unknown???
Alternator - complete
C1 connector - not complete

Here is what I believe is the C1 connector. Please correct me if I'm wrong. You can see it's next to the igniter and EFI resitor plugs.





Here is a pic of the connections in the glove box. You can see the mk2 dash connector and old ecu connector wired up. HOWEVER, I had someone do this for me. And the B1 Connector is gone. I'm not sure what exactly the person did. I've got a note out to the guy to find out the deal. Now you all know the B1 connector is attached to the 7m engine harness and connects to the mk3 body harness. The problem is the write ups I've researched say to move wires from B1 to other places to get this thing started.



You can see the 5m engine harness connector and 5m ecu plug wired in here




From what researched you can connect up c1 in two ways.

First is moving stuff around according to this post. Scroll about 3/4 the way down and Leon explains moving wires from C1 to B1 i think. But again I don't have a B1 connector anymore. I suppose I could try to trace the wire colors he calls out and see where they go.

http://www.celicasupra.com/forums/showthread.php?59802-RHR-7M-GTE-PnP-wiring-guide/page2

The second way is through this really awesome step by step site from Andy in New Zealand I think. He says to connect C1 to a few plugs on the fuse box in the engine bay. Again I'm not sure how to do this or if this is will work given my setup.

http://web.archive.org/web/20081014034610/http://andy.supras.org.nz/wiring_files/wiring.htm

Also, anyone know what this plug does? Looks like it's a 2pin connector coming off the engine harness near the firewall.



Any thoughts or suggestions would be greatly appreciated.
 
See less See more
5
#6 ·
Can anyone help me out?
Which way did you come in?

My computer took a shit awhile back and I lost all my swap stuff. But these pics were in my Photobucket account. Taken by another member who I bought a used Junkie swap harness from. He took the pics as he was unswapping the 7mgte and going to swap in a 2jz instead.
 
#4 ·
Thanks for your response. I do have the EWDs for both the 83 and 89 cars. I am just stuck on how to cleanly splice into the 83's body connectors to wire everything up. I do not want to hack up my car. I am able to follow some of the steps from the guides posted on here. I get it conceptually. Unfortunately i do not have any spare parts or cars sitting around to steal plugs from. I've got a message out to Jim King on here to see if he has any advice and/or 83 body connectors. Here's where I'm at. If anyone has advice i would greatly appreciate it.

Overall state of the car:

Car cranks, fuel is getting to the rail. I had a boat load of fuel leaks and got those all fixed. However, I don't think it's getting spark.

Wiring issues:

1. Power to coils, ecu and main relay. I'm a little stuck on this part. I've located the C1 connector on the 7m harness. I believe the 5 wires from the C1 plug need to be connected to various plugs in the fuse box in the engine bay. My main issue is I don't know how to cleanly connect these together without creating a hack job on the car's wiring. I think this is where spare 83 connectors may help bridge the two together. I am looking at this diagram. The way I think the diagram reads is from left to right. The pin numbers from C1 are listed on far left column. Then middle column is the 83 connector label. The far right column is pin number from the corresponding 83 connector.



2 safely trigger the fuel pump. I am running a walbro 255 external pump, same location and wiring as the stock one. I've verified it works by jumping the fuel pump test connector next to the 83 AFM plug. Honestly i'm not sure if the fuel pump kicks on when it's supposed to because of issue 1. It very well may and just don't know it yet.
 
#7 ·
Thanks for the pics. This helps. I wired everything up temporarily. Confirmed I have power to coils, ignitor and fuel injector resistor. Motor still won't start. I am getting fuel as I jumped the Fuel pump test connector and can hear the pump running. But still not getting spark. I reset timing per TSRM by setting cps with crank pulley at top dead center. Cam gears line up to the marks on timing cover too. So not sure what is going on. I am going to double check all my ground points and also make sure my coil wires are hooked up per the correct firing order. I should still get spark even if they are in the wrong sequence. Any other suggestions?

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#8 ·
Hey all just a quick update. The car finally started! Turns out I didn't have the engine harness grounded. So I bolted that up to the intake manifold and fires right up. However the motor won't stay running for very long. I can keep it running for a little while by pressing on acc pedal. But the motor doesnt rev up like it should. Checkd for vacuum leaks and found one on upper intercooler pipe. Then checked isc sensor, tps and made sure resistances were in spec. All checked out okay. But still car won't idle or rev up. Which makes me think there is still a vacuum leak or something else?

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#11 ·
Okay I connected up a hose on the actuator of the turbo. Here's a picture. The engine fired right up, seemed to have throttle response for a short bit, starting idling then after about 10-20 seconds, it slows down, no throttle response then dies. The issue seems to be slightly better. I wonder if my timing is off? Any other suggestions?





You can see the blue vacuum hose. I'm not sure if this is beefy enough as the stock one is much thicker with clamps. I can get it from toyota for like 10 bucks.
 
#13 ·
Of course not! I took off the accordion hose for this picture. The symptoms occur with everything connected including the AFM, accordion hose, all PCV hoses and vacuum lines.
 
#14 ·
I also verified the issue is not the throttle cable - it opens and closes the throttle valve just fine. I even tried opening the throttle valve directly on the throttle body, after getting the car to run for a bit, and still the issues occur.
 
#16 ·
Timed the motor per TSRM. Set engine to top dead center. Aligned the mark on the crank pulley with timing cover at 0, cam marks aligned, looked inside the oil filler oil and could see the intake lobe pointing up, and then put a screw driver down cylinder 1 and verified it's at the highest point. Then I aligned the CPS, which is a kind of pain by the way, and then tried again. Car started, ran, after 20 seconds, no throttle response, died. Same crap again. I was able to rev it up to maybe 3K rpm. Checked codes and threw a code 26 which is an air fuel rich malfunction. Things are starting to make a little sense now. I checked my spark plugs and the electrodes were black. They are brand new and the motor running rich would explain that. Then I noticed one of the wires on the O2 sensor is broken. So I will fix that and see if that does the trick.

Also, I checked all the ECU terminals and made sure voltage was present at the right values. http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=50. There's a neat trick I didn't know about from going through the TSRM here. The ECU plugs have little tabs that you can unlock and fold down, plug it back into ECU and then your test probe and touch the terminals for testing. Pretty cool - had no idea the plugs did that. Everything seemed to check out fine.
 
#18 ·
Good call Gamble. I will do that too. I don't have a compression gauge but I do have a leak down tester I bought from Harbor Freight Tools. That should tell me if there is any leakage.
 
#20 ·
Yeah man I'm off work today and tomorrow. And then pretty free this weekend. Give me a shout

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#21 ·
Well I fixed the O2 sensor wire. Tries again and same symptoms. Threw a code 22. Efi temp sensor malfunction. The ECU coolant temp sensor connector was loose on thermostat housing. So fixed that. Then threw a code 52. Knock sensor so I dunno. My next step is to do a compression test and Leak down test. Go from there. The motor was completely rebuilt, metal head gasket. So really hoping it's not the motor.

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#22 ·
Those locks on the ECU clips are there to lock the pins into position in the plug. Generally only used when replacing a pinned wire that was somehow damaged or defective. What can happen when you plug a clip in without the pins being locked fully in, is that some or many pins may not be in full contact with their mating pins on the ECU. Of course, any pins that you back probe will likely be pushed into making good contact with its corresponding ECU pin. But I would guess many aren't. Otherwise, if all those pins were making good contact, wouldn't all the error codes for everything the ECU detected be displayed at the same time? For example, you got a temp sensor code when the plug was loose. And then after connecting that, a knock sensor code. Why weren't they both detected and displayed at the same time?
At the very least, you should probably disconnect your battery and check and recheck everything. And you should manually verify every pin is firmly seated after you insert any plug with the lock open before reconnecting the battery and retesting everything. You should probably recheck everything else too. Your symptoms all seem to indicate different issues. At least to me they do, and I've been doing this kind of stuff for a lifetime.
ECU's have at least some amount of capacitance to maintain the keep alive memory for a certain amount of time. This is so that it takes a loss of sufficient power for a certain minimum time before it has to relearn things that would have been kept in memory. This can also be a good thing to force a reset after it gets confused or to reset error codes by removing power for longer than that. Suppose that 20 seconds was about that time. Does this then suggest the two things might be related? Poor power or ground can do exactly this type of crazy stuff. Remember that your meter has an extremely high input impedance and therefore puts essentially no load on anything when taking measurements. It's very possible that with any load at all, some voltages virtually disappear. And you can't measure everything at once so... check everything after following these recommendations again.
By the way, certain sensor wires are shielded to prevent the wires from picking up any of the extreme under hood electrical noise and rendering their outputs completely unusable. Examples are: O2 sensor, knock sensor, distributor pickup (which you don't have), crank triggers, cam position sensors, etc, as well as other similar things. Typically these shields are only connected to ground at the ECU and not at the sensors themselves. These shielded wires are very similar to other shielded cables like audio and video cables and others. One important factor in the shield being effective and the desired signal getting through in a usable form is the actual shape of the shielded cable. So sharp bends and kinks can render them unusable.
Hope this helps you figure things out. Let us know what you find or don't find. Good luck.
 
#23 ·
Sounds like fuel pressure is dropping to me. If compression is bad, it would have issues even starting, and wouldn't run 10-20 seconds before slowing down and stalling.
 
#24 ·
Hey all just a quick update. While troubleshooting, I broke a few wires and then kept noticing loose and brittle wires all over the place. Clearly the whole engine harness had been torn into in the past, repaired probably countless times. Half the shit was either cut or spliced. I am fairly certain the motor issues were attributed to this harness. So I decided to buy a whole new replacement engine harness. I found one from a very nice dude on the 82-85 celica supra facebook group. He had a very clean, unmolested harness from an 89 car that also came with the ECU. SO I picked that up for a pretty good deal I think and there are only two wires broken which goes to the thermostat housing. One that controls the AC fan switch. That connector was completely missing. It's a big 'ol blue one that looks like a knock sensor. So i ordered one up from Toyota. The other is the water temp sensor for the gauge. Just need to re-solder that one and should be good to go.

Anyway, so I'll have to do the wiring conversion all over again. I am following Lee's guide http://www.celicasupra.com/forums/showthread.php?59802-RHR-7M-GTE-PnP-wiring-guide. Seems pretty straight forward. The cool thing is this new replacement harness came with the male B1 connector! I'll reuse the cutout plug from the 5m ECU from my old harness, and the K plug that was originally on the 5m harness. So the only male plug I need for the sub harness is the m1 connector. I picked me up one of those from a good dude from supraforums. I'm all over the place trying to piece this thing together. One of the steps calls to de-pin the blk/orange wire from the B1 and pull it all the way out of the harness so that you can plug into the mkii coil or injector resistor connector. The blk/organe wire is critical as it powers the 7m coils, injector resistor and a whole host of other sensors. Seems like a huge pain in the ass unwrapping the whole harness for one wire. I'm wondering if you can just tap into a switched 12v source from another place up near the ECU plugs. If I end up unwrapping the harness and pulling the wire through, i will probably re-wrap it with some expandable sleeving. Here's what i was thinking. http://www.corsa-technic.com/item.php?item_id=292.

So the plan is to get the sub harness built, figure out what to do about that one wire (either pull it through and re-wrap everything or find another power source). Install the new harness on the motor, re-do the ignition timing and hope for the best. Hoping to make some good progress this weekend.
 
#26 ·
Gamble, I hear you man. Wiring is not my forte but at this rate I'm going to be an expert. Takes a lot of patience and research. Both of which I'm not the best at. Ha!

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#27 ·
Over the past week or so I've been trying to source replacement terminals to complete build the subharness. My goal is to have no solder points. Mark Sherman over at Vancouver toyota has been a huge help pointing me in the right direction.

Here's a couple sites that sells a plethora of Japanese connectors.

http://cycleterminal.com
http://www.corsa-technic.com
http://www.bmotorsports.com/shop/

I found the B1 and K connector terminals. However having trouble finding the terminals for the M1 connector. I've dug through these sites trying to find a match. No dice. Terminal is pretty small and slides into a locking type connector. Tip 1.0mm wide and accepts a 20-22 awg wire. .





It would be super helpful to have a cross reference guide of common mk2 and mk3 connectors, terminal types and current mfg, size and where to buy. I may create one when I'm done. It's been painful sifting through the toyota wire harness repair manual, get an idea of the terminal size and type and then go try to match it up at one of the sites

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
#28 ·
I haven't posted here in a while to give a full update on my swap project. I got the car running, timed and everything seems to be in fairly good shape. Here's the progress made:

Car runs great and is now timed correctly. Huge thanks to Preston for coming over for like an entire day to help me and then some. He was able to calibrate the CPS and get the ignition timing correct.

Got the exhaust put on. You all probably saw my post about the exhaust being too quiet. Still not 100% happy with it but just need to fine tune the look and sound.

Wired up fuel pump to turn on by the ECU. Previously I jumped the fuel pump test connector. Now, wired up the FC output from ECU to the fuel pump test connector. Basically the ECU grounds that wire which in turn allows the the circuit opening relay turns on the fuel pump. It's much safer this way and not have the fuel pump running all the time. Plus the ECU will be able to detect fuel cut conditions and save the motor if too much boost, lean, etc...It took me like 6 hours to figure out that only one wire was needed. Craziness but hey it works now. Wiring is pretty much complete now. There's still some intermittent issues that I can't seem to fully diagnose. I've found that a lot of the butt connectors I used didn't work or I didn't crimp them correctly. I only used a few of them where soldering wasn't easy or where I needed to splice three wires together.

There's a BAD oil leak coming from the remote oil filter sandwich plate. there are two ports blocked off with allen caps and I didn't put any Teflon tape on the threads so oil is pouring out. Fun part about fixing is going to be getting to it. I'm still running the stock oil filter bracket and oil cooler. The motor mount is in the way so i'll have to take it off and support the motor. There's also a small coolant leak coming from somewhere. I ended up buying pretty much all new coolant hoses for the entire motor from toyota. So one of these days I'm going to replace every damn hose. I should have done that when putting the motor back together.

Preston finished up my front end last night while i was messing up with some wiring gremlins. Put back on the turn signal/fog lights and the grille. WE noticed on the passenger side there is a gap between the turn signal and the bumper. The driver side has no gap and looks right. I don't know if it was like that before i pulled up the bumper. I also have like a bag of bolts left over from the front bumper too. So i'll need to figure out where they all go.

Need to put dash back together and the interior bits. Hook up boost gauge, EGT gauge, and turbo timer.

Install new rear hatch carpet and interior pieces in the trunk.

Install AGX kit and lower springs.

Preston and I swapped shifters temporarily. He has the S3 V2 Shifter. It's freaking awesome and I can't believe how much better it feels and shifts from the stock shifter. I am definitely going to buy one.

I'm sure there's more little bits here and there. Once I get this list knocked out, I am going to drive and enjoy the car for a while. I've been at this for over a year now and really just want to drive it!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top