The semi-Comprehensive M60b40 into E30 swap Q&A

[JGood]

Are you using the correct m60 DME temp sensor, plugged into the correct plug on the harness? Is it working properly? (ohm it out, temp-based specs are in the Bentley)

You get codes 1221 and 1222 with the old and new o2 sensors? You clear the DME codes and get them back each time, with both sensors? Those codes are only for the passenger side sensor, so something is going on with the AFR, or that o2 sensor.

I'd do a fuel pressure test and compression test as well.

How did you do a vacuum leak test? Smoke machine? If not, do that.

How did you test the MAF? Do you have a spare you can try?

You said new DME... does that mean you tried replacing it, or that you have a new one so you're assuming it's good?

Do you have the o2 connectors swapped? Probably not since you aren't throwing codes for the drivers side... but good to double check.



Regarding fuel cut under decel... Mine doesn't cut until about 2-3 seconds after lifting off the throttle. And after it does cut, when I get back on this gas, it backfires. Every time. I also get some rumbling/popping from the exhaust under decel. Apparently everyone has this problem... at least with m60's in e30's. I don't understand how/why this isn't an issue with e34's, but I gave up chasing it.

[Vtec?lol]

No chip. I totally forgot about the TPS. Thanks I'll get on that in the am.

Also, I get the 1222 code even with working o2 sensors. Not sure why.

[JGood]

What chip are you using?

Have you tested the throttle position sensor, per the Bentley's specs?

1221 and 1222 are because your oxygen sensors are unplugged.

[Vtec?lol]

Hey guys, in need of some opinions.

So My swap has been done for most of the summer and fall and I've been driving it at least twice a week. Short distances mainly and once I drove it for about 4hrs straight once. It did a decent job but I'm noticing a few things.

Check engine codes 1222 and 1221

1: I can't seem to figure out why the fuel isn't cutting off under decel. I'm getting loud cracks and gargles and an occasional backfire. I'm assuming my speedo wire isn't making it to the ECU so I'll crack into it. Any other reasons this could be?

2: At a cold start it drives phenomenally. It pulls hard as hell till redline. Smoothly and effortlessly. once it gets warm however it's terrible. Now this wasn't so noticeable at first but lately it's getting worse and worse. Once warm, the lower rpms are very spotty when I give it gad and load. It's like it wants to choke out. Even when cruising I have to drop a gear and give it gas and then it does so willingly until I get to about 4k rpm. Then the entire exhaust note changes and it feels as if all cylinders aren't firing. In fact I'm sure it's not because the spark plug on the drivers side closest to the firewall usually ends up fouled.

These symptoms usually require me to pull the ecu out and let it reset and then it's all back to normal.

Here's a list of things I've ohm-checked or replaced:
Maf -pass
knock sensors -new
Temp sensors- new
coils -pass
O2 sensors - bad so I left them unplugged. This however shouldn't cause the symptoms I'm experiencing. I've also swapped them temporarily with a pair of used but known working sensors. Same issues
ECU/DME- new
vac leaks-pass
oil press-pass

Not sure what else to check.
Again, the check engine codes are 1221 and 1222. Any ideas?

[LoneWolf]

Ya I have just done mine here is a pic. You wont need spacers going this way and fairly cheap didnt cost me much

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great! thanks for the quick reply

[hesham]

Ya I have just done mine here is a pic. You wont need spacers going this way and fairly cheap didnt cost me much

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[LoneWolf]

I have another question, this one is about the engine mounts.

So the alignment issue with the transmission at the guibo is what requires subframe spacers of some kind or oil pan modification, correct?

To get everything in line, the oil pan needs to be "flattened" at the spot behind the lower pan correct?

Thanks

[P Arkus]

Thanks JGood. Thats what I was hoping to confirm. I've read certain threads that mentioned bad idles using the auto harness, however some people had this and some didnt so i'm guessing it was a different issue causing the bad idle. Also read that the M60B30 harness works as long as the chip is properly programmed so I guess that would be another option.

[JGood]

I'm doing some research into this swap and have read majority of the build threads/DIY's for the swap, however certain things are still a bit unclear to me. Both at the beginning of this thread and on the RTS link posted, it states that to do an M60 with a 6 speed transmission, you need the engine, the engine harness from a manual, and the transmission.

Here is the issue i'm noticing though. The 6speed can be from any E34 or E39 540/M5, however the engine harness needs to be OBD1. Now there isnt all that many 6 speed M60's being parted or sold for cheap. What is the reason that a engine harness from an 540i Auto cannot be used? is there a TCU that i am unaware of? or is it ok to use an E34 harness from an auto 540?

The only difference is that it has a couple extra wires and the extra trans computer connector. I have no idea why everyone makes a huge deal about it. I swapped an auto harness onto my m60 e30 while troubleshooting an unrelated issue, without modifying it at all, and the car started up and ran perfect, with no DME codes or anything.

[P Arkus]

I'm doing some research into this swap and have read majority of the build threads/DIY's for the swap, however certain things are still a bit unclear to me. Both at the beginning of this thread and on the RTS link posted, it states that to do an M60 with a 6 speed transmission, you need the engine, the engine harness from a manual, and the transmission.

Here is the issue i'm noticing though. The 6speed can be from any E34 or E39 540/M5, however the engine harness needs to be OBD1. Now there isnt all that many 6 speed M60's being parted or sold for cheap. What is the reason that a engine harness from an 540i Auto cannot be used? is there a TCU that i am unaware of? or is it ok to use an E34 harness from an auto 540?

[LoneWolf]

The starter wheel is the same amongst all. I have a starter from an auto tu on my m60/6spd.

All accs will need to be from an m60 car. Find the latest AC compressor you can find. Chances are it'll be in far better condition and easier to rebuild.

Thanks, so the a/c compressor will have to come from the m60 as well?

[Vtec?lol]

The starter wheel is the same amongst all. I have a starter from an auto tu on my m60/6spd.

All accs will need to be from an m60 car. Find the latest AC compressor you can find. Chances are it'll be in far better condition and easier to rebuild.

[LoneWolf]

Alright so here is another question, let me know if this should just be a separate thread, but I felt it would go well with the general knowledge.

I have picked up an M60 from a 740i but need the accessories like starter, powersteering pump, alternator, and a/c compressor. Also picked up a 6-speed transmission from a 2002 540i.

Anyone point me in the right direction to find out which accessories will mount up? I know the newer m62 water cooled alternator is a no go. Anything else to look out for? Hoping to pick the parts up second hand.

Also wondering if the starter wheel changed between the m60 or m62.

[LoneWolf]

He reworked the pedal and pedal box to move the booster pattern over by its own width (IE, the original left holes become the right holes in the new pattern) and installed a an E32 hydroboost in that location. He picked a MC which put the connections at just the right locations to straddle the brace on the strut tower.

For my swap into a 325iX, I think that an E23 hydroboost, which sits deeper into the firewall, combined with the more forward location of the strut towers may allow the entire setup to nestle behind the strut tower.

Ah ok thank you. That makes sense.

[The Dark Side of Will]

He reworked the pedal and pedal box to move the booster pattern over by its own width (IE, the original left holes become the right holes in the new pattern) and installed a an E32 hydroboost in that location. He picked a MC which put the connections at just the right locations to straddle the brace on the strut tower.

For my swap into a 325iX, I think that an E23 hydroboost, which sits deeper into the firewall, combined with the more forward location of the strut towers may allow the entire setup to nestle behind the strut tower.