Engine swap 1.6L 4A-FE to 1.8L 7A-FE, Anyone done it? Options

[Bikeman982]

I have swapped engines and transmissions and am running into some questions for someone that has done it. Please let me know if you have.

[Dr_Tweak]

What questions do you have? I'd be happy to help you out.

-Doc

[Bikeman982]

I have an engine, transmission, wiring harness, and ECU/ECM all from different sources. They don't seem to be as compatible as I originally thought.
The engine has a crankcase position sensor connection that has no corresponding connection on the wiring harness. Do I need it?
The wiring harness does not connect to the ECM/ECU - is there an adapter harness?
CA specs seem different and I am on my fourth harness without having one that has every connection for the engine/tranny combo and the ECM/ECU.
The car is not starting and I think I need another harness?

This post has been edited by Bikeman982: Aug 1, 2006 - 1:22 AM

[Dr_Tweak]

I have an engine, transmission, wiring harness, and ECU/ECM all from different sources. They don't seem to be as compatible as I originally thought.
The engine has a crankcase position sensor connection that has no corresponding connection on the wiring harness. Do I need it?
The wiring harness does not connect to the ECM/ECU - is there an adapter harness?
CA specs seem different and I am on my fourth harness without having one that hass every connection for the engine/tranny combo and the ECM/ECU.
The car is not starting and I think I need another harness?

Just use your stock 4AFE harness and distributor with the 7AFE engine and injectors.

-Doc

[Bikeman982]

The stock harness does not have the correct connections for the engine or transmission either.
It also did not have a connector for the engine's crankshaft position sensor.
It would fit the ECM/ECU, but that is supposed to be different for 1.8L 7A-FE.
The distributor part number is also different for the 7A-FE engine.
I have a distributor and that does not seem to be a problem, except maybe that it needs to be set for correct timing.
Do you know the stock number for the ECM/ECU for CA 7A-FE specs?? - should be 89661- something.
It is 89661 -02140 for the 1.6L 4A-FE engine.

This post has been edited by Bikeman982: Aug 1, 2006 - 4:25 PM

[Bikeman982]

Upon further examination I have discovered that the engine wiring harness does connect to the ECU/ECM, however the connector that comes from under the dash (part of the cars internal wiring) has the wrong connector and does not fit the ECM/ECU. It is similar to what goes into the ECM/ECU for the 4A-FE. I don't know what all the wires go to, or how to change the connector/wiring to fit the 7A-FE ECM/ECU.

[Bitter]

hey bike, it sounds like you have an ob2 harness maybe.

[Dr_Tweak]

The stock harness does not have the correct connections for the engine or transmission either.
It also did not have a connector for the engine's crankshaft position sensor.
It would fit the ECM/ECU, but that is supposed to be different for 1.8L 7A-FE.
The distributor part number is also different for the 7A-FE engine.
I have a distributor and that does not seem to be a problem, except maybe that it needs to be set for correct timing.
Do you know the stock number for the ECM/ECU for CA 7A-FE specs?? - should be 89661- something.
It is 89661 -02140 for the 1.6L 4A-FE engine.

The simplest thing for you to do is use the 4AFE harness and just swap over the 7A connectors where you need to. And use your 4AFE distributor. Basically use all the 4A parts you can.

What car is the 7A from, and do you have the whole harness and ECU?

-Doc

[Bikeman982]

The engine/tranny and wiring harness - ECM/ECU came off a 1995 and the car is a 1994. The reason I changed the harness was due to the transmission having a different park/neutral connector on it and the harness for the 4A-FE was different. There may have been other connectors that were different as well. Since the majority of changed parts were 7A-FE from a 1995 I was trying to keep it all 1995 compatible.
The ECM/ECU has three connectors on it and on the 4A-FE there is a 12 Pin connector whereas on the 7A-FE there is a 22 Pin connector.
As Bitter has said - I may have a harness that is for an OBD2 car and not from a OBD1, but the harness is the same and it is the cars connection to the ECM/ECU that appears to be different.
I don't know if the donor car is still at the junkyard, but I can check the connector on that car. It was a 1995. I took both the ECM/ECU and the wiring harness from the same car - but the cars internal wires must be different. I will have to check it out.

This post has been edited by Bikeman982: Aug 3, 2006 - 7:03 PM

[Kwanza26]

The engine/tranny and wiring harness - ECM/ECU came off a 1995 and the car is a 1994. The reason I changed the harness was due to the transmission having a different park/neutral connector on it and the harness for the 4A-FE was different. There may have been other connectors that were different as well. Since the majority of changed parts were 7A-FE from a 1995 I was trying to keep it all 1995 compatible.
The ECM/ECU has three connectors on it and on the 4A-FE there is a 12 Pin connector whereas on the 7A-FE there is a 22 Pin connector.
As Bitter has said - I may have a harness that is for an OBD2 car and not from a OBD1, but the harness is the same and it is the cars connection to the ECM/ECU that appears to be different.
I don't know if the donor car is still at the junkyard, but I can check the connector on that car. It was a 1995. I took both the ECM/ECU and the wiring harness from the same car - but the cars internal wires must be different. I will have to check it out.

You're doing it the hard way. You don't need to swap harnesses or ECUs or anything like that... the 7AFE can run alright on the 4AFE ecu and wiring. All you need to do is to swap over the sensors from the 4AFE to the 7AFE... and ignore the sensors on the 7AFE that the 4AFE doesn't have. That way you can just plug in your old 4AFE harness and not have to worry about anything else. There shouldn't be too big of differences between the two... at the most you might need to splice injector plugs and swap distributors. It should be a very straight foreward swap... cause I'm pretty sure the 4AFE uses about 90% the same sensors as the 7AFE... except for a few different plugs here and there.

[Bikeman982]

What about something similar - I swapped the engine/tranny and wiring harness - can I use the old 1.6L 4A-FE ECM/ECU, since it plugs right in?
What about the wires that are not on the 12 pin connector from the car that are used on the 22 pin on the 7A-FE ECM/ECU?
What about the engines crankcase position sensor - just ignore it?
Someone has told me that the 1.6L 4A-FE engine uses a hydraulic shift transmission, while the 1.8L 7A-FE engine uses a computer controlled electronic shift transmission - is this true? What does that mean as far as the swap? Don't both use the ECM/ECU to electrically control shifting??

This post has been edited by Bikeman982: Aug 3, 2006 - 7:53 PM

[Kwanza26]

What about something similar - I swapped the engine/tranny and wiring harness - can I use the old 1.6L 4A-FE ECM/ECU, since it plugs right in?

Use your old 4AFE engine harness and ecu... and primary sensors that have different plugs. Avoid using the 7AFE harness and ecu.

What about the wires that are not on the 12 pin connector from the car that are used on the 22 pin on the 7A-FE ECM/ECU?

Refer to above. Don't change the engine harness... use your exsisting 4AFE harness.

What about the engines crankcase position sensor - just ignore it?
Someone has told me that the 1.6L 4A-FE engine uses a hydraulic shift transmission, while the 1.8L 7A-FE engine uses a computer controlled electronic shift transmission - is this true? What does that mean as far as the swap? Don't both use the ECM/ECU to electrically control shifting??

Is it automatic? All autos are computer controlled mostly for speed inputs and stuff... manuals are either hydro or cable... but toyota did away with cable trannies in the mid 80's... so this should not be a factor. The 5 speeds are the same. Ignore the crank sensor.

[Bitter]

wouldnt the 4afe ecm make the 7afe run lean since its got .2L more displacement that the PCM doesnt know about?

[Dr_Tweak]

wouldnt the 4afe ecm make the 7afe run lean since its got .2L more displacement that the PCM doesnt know about?

No, because the 7A injectors are a little bigger.

-Doc

[Bikeman982]

What about the problem with the connector and transmission wires - totally different on the 7A-FE? - hence the reason I changed the wiring harness.

[Kwanza26]

What about the problem with the connector and transmission wires - totally different on the 7A-FE? - hence the reason I changed the wiring harness.

What wires and what do you mean? The only wires attached to the trannies are the reverse light, neutral safety switch (I'm not even sure if toyota intergrates this into the tranny), and speedo sensor. At the worse... you do some splicing.

Why not use your old tranny?

This post has been edited by Kwanza26: Aug 3, 2006 - 11:52 PM

[Bikeman982]

The wires I am referring to connect to the Park/Neutral switch on the tranny.
The old tranny had a smaller connector and different switch.
I tried to use the old tranny from the car, but it was incompatible with the 1.8L 7A-FE engine, therefore I changed transmissions.
I think the 1.6L 4A-FE engine uses the A131L tranny and the 1.8L 7A-FE engine uses the A245E tranny. They are not interchangeable (both are automatic).

This post has been edited by Bikeman982: Aug 4, 2006 - 1:46 AM

[Bitter]

http://www.corolland.com/forums/index.php?...30&#entry131312

bike, based on that i dont think the 4afe pcm will contol the a245e trans at all. it'll goto its defaults if not plugged in, which is to sit in 4th gear with a unlocked torque converter. it'll move but you have to floor the pedal and wait about 20 miles to get to 10mph.

[Bikeman982]

http://www.corolland.com/forums/index.php?...30&#entry131312

bike, based on that i dont think the 4afe pcm will contol the a245e trans at all. it'll goto its defaults if not plugged in, which is to sit in 4th gear with a unlocked torque converter. it'll move but you have to floor the pedal and wait about 20 miles to get to 10mph.

Which leads me back to why I need to get the 7A-FE ECM wired in. It would seem compatible with the engine and transmission, but needs whatever the wiring (and connector) is inside the body of the car.

[Kwanza26]

Which leads me back to why I need to get the 7A-FE ECM wired in. It would seem compatible with the engine and transmission, but needs whatever the wiring (and connector) is inside the body of the car.

But what's wrong with your 4AFE tranny? If there's nothing wrong with it... there is no problem. The 4AF trans does fit on the 7AFE if you swap flexplates. It's not all that complicated... and I think that's where your fitment issues are. The whole ordeal of messing with wiring isn't worth something mechanical.

[Bitter]

i think he wants the 4spd auto with the 7afe for fuel economy reasons, but im not sure.

[Bikeman982]

Which leads me back to why I need to get the 7A-FE ECM wired in. It would seem compatible with the engine and transmission, but needs whatever the wiring (and connector) is inside the body of the car.

But what's wrong with your 4AFE tranny? If there's nothing wrong with it... there is no problem. The 4AF trans does fit on the 7AFE if you swap flexplates. It's not all that complicated... and I think that's where your fitment issues are. The whole ordeal of messing with wiring isn't worth something mechanical.

I tried using the old transmission (from the 1.6L 4A-FE engine) and it did not fit. The problem was too much gap between engine and tranny so the bolts did not connect. The torque converter seemed to be too thick, but they were the same for both tranny's. There was no flex plate difference - that I could tell.
The transmissions are different and have different housings and transaxles. Definitely not a match for me, so I changed it to a newer tranny. Now engine and tranny match up and are installed in the car (I did change the mount that held the tranny to the body - (new part from AutoZone).
The problem now is the car's wiring is different and the connector does not plug into the ECM.
The wiring harness has been changed and seems to be suitable (no connection for crankshaft position sensor, but I won't use it?).
I did not want to change to manual transmission because I am not prepared to do all the modifications required.
I thought a straight swap from automatic to automatic would be easier than automatic to standard.
I did not realize that there was such a big difference between electrical systems on the 1994 and 1995.
I thought they were the same with the exception of individual car options (that may still be the case - I am seeking answers to the differences).

[Bikeman982]

After careful examination of the cars wiring and also the connections to both 4A-FE and 7A-FE ECM/ECU's, I have come to the conclusion that I need to abandon the project.
Althought it is physically and mechanically possible to swap a 1.6L 4A-FE engine and A131L transmission with a 1.8 L 7A-FE engine and A245E transmission, it is electrically unfeasible (within my capabilities) to convert.
My next step I believe will be to locate a working 1.6L 4A-FE engine and purchase it for replacing the 7A-FE engine that I have installed in the car.
I will re-use the old transmission (which is still good) and also the old wiring harness and ECM/ECU (will match up with no complications).
Thank you all for the helpful advice and encouragements.
Unfortunately the operation was a failure and my only recourse is to return it (as much as possible) to stock condition.
At this point my son will settle for any operating vehicle and this decision seems to lead to that desired outcome.

[Kwanza26]

I still say the tranny issue can be dealt with pretty easily outside wiring. Toyota trannies and bellhousings simply do not have much variation to them
(Still using the same old C series trans as they did in the mid 80's). I also don't see there being too much difference between the bellhousings, considering the manual trannies interchange freely between the 7A and 4A blocks. Oh well... sorry.

[Bikeman982]

Transmissions are not the same.
The main problem now is that the cars wiring does not connect to the ECM/ECU. That connects to the wiring harness and that connects to the tranny and engine.
Other than a complete rewire, I see no solution to doing a successful swap. Back to original stock engine/tranny.

[Bikeman982]

I have abandoned the larger engine/tranny and pulled it out of the car.
I have pulled a used 1.6L 4A-FE engine from a local junkyard and will be putting that in.
I hope that will solve all my compatability problems, by returning everything to stock.

This post has been edited by Bikeman982: Aug 19, 2006 - 9:00 PM

[Bikeman982]

I had trouble (once again) when matching the transmission up with the engine. I ended up changing the flywheel and using a different torque converter. Even now it seems like the bolts don't go in easily and I may have stripped one of them. I am pretty sure I cross-threaded one of the bolts that holds the flywheel to the torque converter. One problem is that I never identified which bolts went where and as a result, I have various bolts that I don't know their exact place. I may have to go back to the junkyard, find a similar transmission, then get the bolts and label them. That would work (I hope).

This post has been edited by Bikeman982: Aug 22, 2006 - 2:41 AM

[Bikeman982]

Tomorrow I start connecting everything back up and installing everything that was removed for the engine change.
The hard part will be saved for last - re-installing both half shafts.
The starter is a little difficult to get installed as well. I can put on the A/C pump and the alternator pretty easily now. I have had lots of practice.
I can also put the main engine electrical wiring harness and connect everything to that (as well as the ECM/ECU thru the firewall).
The gear shifter is tricky since it uses a different mounting bracket on the old engine. I also have to replace some of the fluid lines that I bent switching to the other transmission. I may need to go back to a junkyard to get other ones.
I will keep you posted on the progress.

[Bikeman982]

UPDATE: Today I installed the starter, the charcoal cannister, all the vaccuum and fuel lines and some of the coolant lines. I also put in the airfilter box and cover as well as the battery. I put the distributor in but did not tighten it down as the timing has to be set. Next I need new transmission lines (I hope to get from the junkyard) and I need one of the fittings for the transmission. After that will be the radiator and the connecting lines. All that will be left is the ECM and the interior lower dash panels and then I need to add all the fluids, spark plugs, cap and rotor, and final adjustments. I am hoping it will crank right over when I try to start it. More to follow.

This post has been edited by Bikeman982: Sep 13, 2006 - 12:35 AM

[Bikeman982]

Everything but the drive shafts have been installed.
The car will not start - does not crank - tried different battery - no crank.
I had the solenoid/starter tested - it is good.
Checked all fuses - look good.
Anyone familiar with the starting system??

[Bikeman982]

I bought a new battery and the car cranked fine - just would not start.
More troubleshooting required - spark/fuel/timing checks.
Getting closer to actually running again!

[Bikeman982]

Here is an update.
Car would not start and did not have spark at the plugs. I used a T/S tree supplied by Bitter and found a malfunctioning, corroded relay (EFI-F HTR). I replaced the relay and car started right up and purrred like a kitten.
I drove the car around and it seems like the tranny is slipping.
I added some Slick 50 Automatic Transmission Treatment and that seems to have fixed the slipping problem.
The car is up for sale and my neighbor is very interested in it.

End result - seized engine has been changed, original transmission and wiring harness/ECM used and car is operational.

[normality78]

hm... weird. i personally had my 4afe engine changed to 7afe without any issue at all. same apply to the rest of my fren who done the samething except thiers was manual and mine was auto.

the only thing i swap over was the engine itself only. ecu, wiring, gearbox all was 4afe stuff. The whole job only took me 3 days to complete so i can safely assume that there is no compatibility issue here.

the only very small problem that i got is im using 4afe TB which now my throttle cable abit lose as the 7a tb position seems abit diff

[Bikeman982]

hm... weird. i personally had my 4afe engine changed to 7afe without any issue at all. same apply to the rest of my fren who done the samething except thiers was manual and mine was auto.

the only thing i swap over was the engine itself only. ecu, wiring, gearbox all was 4afe stuff. The whole job only took me 3 days to complete so i can safely assume that there is no compatibility issue here.

the only very small problem that i got is im using 4afe TB which now my throttle cable abit lose as the 7a tb position seems abit diff

Was everything from the same year?
Did the donor car have all the same connections?

[normality78]

hm... weird. i personally had my 4afe engine changed to 7afe without any issue at all. same apply to the rest of my fren who done the samething except thiers was manual and mine was auto.

the only thing i swap over was the engine itself only. ecu, wiring, gearbox all was 4afe stuff. The whole job only took me 3 days to complete so i can safely assume that there is no compatibility issue here.

the only very small problem that i got is im using 4afe TB which now my throttle cable abit lose as the 7a tb position seems abit diff

Was everything from the same year?
Did the donor car have all the same connections?

i just bought the complete engine itself. block, head and inlet manifold. thats all. i dun even know whr does the engine came frm. hehehhe

[Bikeman982]

Update:
The car has been sold to a man looking for something more gas efficient.
He has two trucks that get 12-15 MPG and needed something better.
His wife took a wrong turn and ended up going down my street.
She saw my car with a "For Sale" sign on it in front of my house and told her husband.
He came by and then arranged a full diagnostic for the car at a local shop.
He paid $37.50 for the diagnostic and they came up with a stripped transmission drain plug (I used the wrong sized allen wrench - 3/8 instead of 10MM). It was also leaking a little.
The right rear brake cyclinder was also leaking a little (they had to pull back the rubber to find a few drops outside the seal).
They also recommended a tune-up - points, wires and cap, rotor ( I had already put in new plugs - of course any car would be better with new ignition parts).
They found nothing else wrong with the car.
I think that is a fairly good testimony as to my ability to repair a car with a seized engine and have it running again.
I had changed the engine, radiator, battery, and put in several used parts from a junkyard.
I sold the car for $3500.00, which was far more than what I paid when I purchased the car from e-Bay.

I am looking for another 7th generation car needing repair, that I can get cheap, to fix.
I still have some left-over extra parts (including a 1.8L 7A-FE engine and A245L transmission).
Anyone have a need for 7th generation Corolla parts or have one they want to sell that needs work?