MickyG's MX-73 to 7M-GE Swap

[mickyg]

Cool. I'll have to do the same thing with the air conditioning. As Mik pointed out somewhere near page 2 I think, the compressor on the 7M uses totally different hose connectors compared tot he 5M. So I'll need to pay the cooling man a visit in the next few months, as well as getting new hoses.

 

[JustAnotherVictim]

These cars have a/c??

 

[mickyg]

Just a quick update.

Drove the car to/from work today and no real dramas to speak of! I have an oil leak from the sump drain plug but that's easily fixed. Other than that, no other leaks that I've been able to see (oil or coolant) so I'm very happy with that!

Problems so far:

• Oil leak from drain plug
• Code 27 because I'm not running a second 02 sensor
• Slightly rough idle (vacuum leak somewhere?)
• almost a miss/stumble when going from high RPM back to idle (slow reacting ISC/IAC or possibly dashpot issue)
• Metallic buzzing sound on very rare occasions at about 2-3k RPMs (sounds like the exhaust shield vibrating - very "tinny" sounding)
• Air in the coolant (nothing the front being on ramps won't solve this weekend).
• Oil pressure light comes on when pressure goes high. I'm suspecting this is due to the change from an oil pressure switch on the 5M to a true pressure sensor on the 7M.

So far I'm very impressed with how things are running. The transmission is working perfectly, and all indicator lights work. No problems with overdrive, reverse lights, etc so that part went perfectly, even though I had no "how to guide" to refer back to.

In regards to the Oil pressure indicator, I think the sensor wire going to the dash needs to be divorced from the loom and perhaps wired up to the low oil pressure light integrated into my aftermarket sender unit. Only problem with that is that it's meant to come on at 10PSI, if memory serves.

Speaking of oil pressure - I'm at about 15PSI at 1000 RPM and 35 at 3000 so making very good pressure!

More to come this weekend when I finalise a few things and give a full report (as if I haven't just done that...)!

 

[mickyg]

Not a whole lot to report after 10 days!

Been driving on the new motor every day and the only nagging bit that's a constant is the oil leak from the drain plug. There's a slight groove in the drain on the pan that I think is designed to direct the oil out in an organised fashion during oil changes. Sounds like a rubber washer would do the trick. My existing 5M pan does not have this "feature" and I'm wondering if I should have used that one instead.

On to the real problems though. There's a ticking sound that's most noticeable between 2 and 3 thousand RPM. I haven't spent any time listening closely to it yet so it's unclear if it's valve noise or something more sinister. The more worrying thing is on cold startups though. There's a scuffing/thumping sound for about 3 seconds after startup and ZERO oil pressure during those 3 seconds. After that, the oil pressure shoots up to about 30psi and the sound stops. I'm thinking this isn't quite normal and am a bit worried.

I might start a new thread if I my searching doesn't turn anything up.

 

[Tire Shredder]

Micky,

what kind of oil filter are you using?

A low quality filter such as a fram have low quality drain-back valves and will not hold oil pressures. Essentially every start up will be a dry start up.

try switching to a quality filter such as toyota, K&N, mobil 1, wix etc. stay away from fram, quaker state and penzoil filters. it might help the problem!

 

[mickyg]

I'm using a cheap and nasty one for the first few oil changes and have some better ones on the shelf for when I go back to "real" oil. That's been on my mind though - could be bypassing during startup. My oil pressure jumps to about 55PSI at 1500RPMs and backs off to 30 when the idle drops down. After 10 minutes or so of driving, it falls back to the 10psi or so that you'd normally see at idle. So I'm guessing the oil is pretty thick when it's cold, thus the high pressures and possibly the filter bypassing.

Thanks for the tip! By the way, I don't think we have Fram, Quaker State or Penzoil filter products down here. At least I've never seen them.


[EDIT]
I just realised my understanding of "bypass" was a bit flawed. If it bypasses, it's bypassing the filter element. Would not explain the problem I'm seeing.

Your mentioning anti drainback however, does! So the better filters prevent oil from draining back via the filter. So on startup, the filter's already holding oil - makes perfect sense!

 

[Tire Shredder]

updates? how are the issues working out? oh...and driving impressions! how does the rebuilt 7m-ge compare to the tired 5m?

 

[mickyg]

Sorry man - been meaning to do a proper update and just haven't had a whole lot of time behind the computer in the last few weeks. Given my day job is IT Admin, I guess that's to be expected! So here's my observations so far:

• The 7M is noteably smoother than the 5M, especially after about 2000 RPMs
• WAY more torque from standing to 3000RPM
• Very tricky to drive in the wet without breaking traction - even in a straight line.
• The stock A43 transmissions appears to be keeping up with the extra power just fine. For how long is anyone's guess!

Now, for a list of things that still need to be done:

• Ticking sound that sounds like valve noise at this point. I've pulled plug leads one by one and the noise doesn't change. It could also be a cracked transmission pump, given the problems I had putting the tranny back on the engine. We'll see...
• Still need to tap a feed in the accordian pipe for the power steering idle up line. No obvious problems without it as-is though.
• Almost 1000kms on the new engine so oil/filter change due very soon.
• Still need to mount the remote filter. All the parts have been obtained, just need to get it done!
• Need to test a camry VSV I picked up from the salvage yard today to see if it will work for my missing fuel pressure up VSV.
• Slightly annoying rough running from idle to about 2000RPM that needs to be identified and fixed.
• Fan shroud needs to be refitted.
• Engine under tray needs to be refitted.
• Picked up some new cosmetic parts from the salvage yard that need to be fitted. Trunk trim, rear tail light, etc...
• Need to trick the second O2 sensor input so I can get rid of my CEL/MIL code.
• Need to sort out wiring to the dash for a proper low oil pressure warning light.
• Need to get proper power steering lines made up. The current ones are routed pretty badly because they're too long.
• Need to get A/C refitted/recharged due to different compressor design.

So there's a lot to do but nothing that prevents me from driving it as-is! All an all, I'm very happy with things.

I could not have done any of this without some very appreciated help! So here goes one more list!

• Massive thanks to Ian for the Engine, loads of parts, the patience in answering my constant string of questions, your experience, the list goes on and on... Your friendship and time have meant heaps to me man!
• An equally big thanks to Allan for all of the above, plus the late night parts dropoffs!
• Cedric - Thanks for the encouragement, the "brain" you provided was absoposolutely required and I'm very appreciative for that, as well as your continued encouragement. You're also always good for at least a few laughs in pretty much everything you do. :biglaugh: Thanks man!
• To another Ian on the Cressida forums who provided me with quite a few transitional MX-83 parts and renewed passion for all things Toyota.
• To Boltz on the Cressida forums, your wiring/swap guides were invaluable!
• To Kamesama980 - those MX73 transmission electrical diagrams made my job a million times easier!
• To Peewee (on various forums) - you're a swap legend! Massive thanks for all your hard work and the amount of info you shared with me!
• To JetJock - you are the single most respected source for anything TCCS or electronics related on this and many other sites - If I wore a hat, it'd be continuously off to you!
• The many other people on these forums who took the time to follow this build and offer their opinions and encouragement. You guys all make this worth it!
• Last but not least, to my dad Glenn and my brother Jake, who were the original inspiration not only for the engine swap but buying the Cressida in the fist place! You're both original pioneers on Supras in my book! Keep at it!

There will be a few more updates in this space as I resolve those last few issues. I'll also be posting up some of my own swap guides as soon as they're polished enough.

 

[Tire Shredder]

what was the final word on the wiring situation? did that write up for a supra help you out at all?

I need to collect the connectors for my swap now and have found a 7m cressida in a junkyard. will the connectors from under the dash (the three listed in the write up) from a cressida work for my supra?

Thanks,
Steve

 

[JustAnotherVictim]

You'll figure out those bugs soon enough.

 

[mickyg]

TS - The writeup you linked me to helped me to realise I already was on the right track so thanks for that! It didn't have a whole lot there that was any specific help, simply because they were making a plug and play loom adapter. Since mine was a rewire of the existing stuff, it was pretty different. Like I said though, was good to use that as a secondary proof of concept. There was some stuff about in cabin wiring and stuff in the doors that had me totally confused though - if you decide to use any of the tips there, they may apply more to you than they did me. I didn't use any of that stuff at all though.

As for the whole wiring process, it went really well! I still need to put my glove box back in but it all seems to fit and is reasonably tidy (need to post some pics). No real dramas, even though I was prepared for the worst!

I'd be careful with a cressida 7M. The two engines/ECUs are VERY different. I didn't find much on the cressida loom that could be used on the supra engine. If you're going cressida engine/ECU you'll have a much better time of it. There are a few gotchas though. From memory:

• cressida ECU has a built in ECT for the auto. If you go manual, not such a problem.
• No ACIS on the cressy motor
• The coil/igniter is on the other side on the cressy motor/loom
• Not sure if this is a generational thing or cressy/supra thing but the MX83 loom I had did not fit the MA70 injectors. The clip was upside down between the two. Could be another difference between low and high impedance injectors though.

Basically, if you're trying to put a supra motor with cressy wiring, it's not going to be as straight forward as keeping the motor/wiring from the same car. As for using pieces from the cressy loom - look at what you've got and compare. There were very few differences between what was on my cressy and the supra stuff on the cabin side. The B1 connector and the ECU connectors were exactly the same. The wires weren't of course!

Hope that helps. I'll formulate all of this a bit more logically in a few days. Brain's a bit drained today I'm afraid!

 

[Tire Shredder]

TS - The writeup you linked me to helped me to realise I already was on the right track so thanks for that! It didn't have a whole lot there that was any specific help, simply because they were making a plug and play loom adapter. Since mine was a rewire of the existing stuff, it was pretty different. Like I said though, was good to use that as a secondary proof of concept. There was some stuff about in cabin wiring and stuff in the doors that had me totally confused though - if you decide to use any of the tips there, they may apply more to you than they did me. I didn't use any of that stuff at all though.

As for the whole wiring process, it went really well! I still need to put my glove box back in but it all seems to fit and is reasonably tidy (need to post some pics). No real dramas, even though I was prepared for the worst!

I'd be careful with a cressida 7M. The two engines/ECUs are VERY different. I didn't find much on the cressida loom that could be used on the supra engine. If you're going cressida engine/ECU you'll have a much better time of it. There are a few gotchas though. From memory:

• cressida ECU has a built in ECT for the auto. If you go manual, not such a problem.
• No ACIS on the cressy motor
• The coil/igniter is on the other side on the cressy motor/loom
• Not sure if this is a generational thing or cressy/supra thing but the MX83 loom I had did not fit the MA70 injectors. The clip was upside down between the two. Could be another difference between low and high impedance injectors though.

Basically, if you're trying to put a supra motor with cressy wiring, it's not going to be as straight forward as keeping the motor/wiring from the same car. As for using pieces from the cressy loom - look at what you've got and compare. There were very few differences between what was on my cressy and the supra stuff on the cabin side. The B1 connector and the ECU connectors were exactly the same. The wires weren't of course!

Hope that helps. I'll formulate all of this a bit more logically in a few days. Brain's a bit drained today I'm afraid!

thanks micky! I'll keep watching this thread of updates on you working the bugs out...we need some pictures of this thing installed!

 

[mickyg]

Minor update:

First 1000km oil change is done. After switching to a better oil filter, it appears the anti-drainback valve still isn't doing its job. If I let the car sit for less than an hour, I've got almost immediate pressure after startup. If it's longer, it's obviously draining back as there's a longer interval between pressure rise after startup.

I have temporarily given up on fitting the remote filter mount - no good place to put it without drilling, no space, and most importantly (and frustrating) not enough room to get tools in to tighten the damned fittings!!! In hindsight, I guess attaching the fittings and pushing the hoses on after everything's mounted is the smartest thing to do. I'm not too fussed about it at the moment. It's a bit of extra oil capacity and filter location convenience, nothing more.

The ticking I noticed has become less obvious and quieter. Whether that's due to the multi-visc oil or something else, I'm not certain. I'm still thinking it's just valve noise though.

On a more annoying note, the rattling/buzzing I described a few weeks back is still there but only between a very narrow RPM. I haven't been able to pinpoint transmission or engine yet but it's very annoying. It's been happening right after a downshift at something between 2000 and like 2100 RPM. Faster or slower and the noise/vibration completely disappears. The noise is like a coke can rattling against the exhaust pipe or something. It's sounding very much like external in origin. Could be trans cooling lines, ex manifold shield, or something else that's sheet metal in composition.

Other than that, she's behaving very well. I'm hoping to get my code 27 eliminator made soon (second O2 sensor failure code) to see if it will help my fuel economy at all. Averaged about 20 miles per gallon on my last fill up, which was normal driving instead of break-in driving. I was expecting better but perhaps this is normal?

Pics and writeup are still coming. I'm just not as enthusiastic about it as I was a few weeks back (naturally)!

 

[JustAnotherVictim]

How are you planning on getting rid of the 2nd O2 sensor code?

 

[mickyg]

I'm going to make a dummy sensor. Just a 555 timer based signal generator. It sends out a just above zero to just below 1 volt slow pulse (every couple of seconds) to imitate the slower sub o2 sensor. I could feed it a constant voltage but it needs to be exactly right and I've already got the parts to do a "proper" one. So why not?

It's possible this code is for the missing heater element in the sensor as well. If that's the case, I'll need to figure something else out.

 

[mickyg]

Sub O2 Sensor Simulator (as I'll call it from here on) is done and works when tested. Just need to temporarily install it to see if it gets rid of the code 27. That's proving more difficult that previously though, as the wires are all very hard to get to on the ECU. More after it's tested...

 

[mickyg]

Well, that was a lot of effort for nothing!

Plugged the simulator in, checked for necessary voltages and everything was fine. Plugged the sensor into the necessary spot on the ECU but still got the CEL. Cleared the code, double checked the absense of a CEL before starting the car, then started, only to find the CEL came back after a second or two.

Based on the code 27 info from the TSRM, it looks like this could be the heater circuit as well. I'm not big on sending 12 volts through a resistive load for no reason so I'm thinking I might want to invest in a heated O2 sensor to replace the primary one. Then I can run the heater circuit to that and actually see some benefit!

Anyone know if the heater circuit in a primary O2 is always on? Ric, I'm still curious about whether the donor car this ECU came out of had some secondary sensor or at least a heater circuit to prevent this code?

 

[JustAnotherVictim]

I'll ask and see if my friend remembers.

 

[JustAnotherVictim]

He said he only had one o2 sensor and nothing else that he can recall.

 

[mickyg]

Thanks for checking! I don't see how he could have ran this ECU without a constant, annoying CEL. Very interesting.

I was talking to my bro this morning and he didn't think there'd be any issues running a heated O2 for the main sensor. Apparently the heater circuit is only on immediately after the car is started and only for a minute or so. I might need to see about getting a decent aftermarket heated sensor.