The semi-Comprehensive M60b40 into E30 swap Q&A

[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]

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.

[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

[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]

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

[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?

[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]

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]

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.

[LoneWolf]

I haven't found any specifics in swap guides about the oil housing. I would like to relocate the stock one or use an aftermarket one with screw on filter.

How are you guys modifying the stock ones to allow for the engine mounts? I see something about milling, but nothing in the way of directions.

Also what are you doing to get the oil lines hooked to where they came out of the block? Tapping and installing AN fittings? Welding something straight to the block?

Thanks again.

[JGood]

I haven't found any specifics in swap guides about the oil housing. I would like to relocate the stock one or use an aftermarket one with screw on filter.

How are you guys modifying the stock ones to allow for the engine mounts? I see something about milling, but nothing in the way of directions.

Also what are you doing to get the oil lines hooked to where they came out of the block? Tapping and installing AN fittings? Welding something straight to the block?

Thanks again.

http://www.r3vlimited.com/board/showthread.php?t=237743

http://www.r3vlimited.com/board/showpost.php?p=2999754&postcount=228

http://www.r3vlimited.com/board/showpost.php?p=3822917&postcount=781

http://www.r3vlimited.com/board/showpost.php?p=2486703&postcount=154

There's other options, just search. Some people just cut off the oil line part of the engine mount, and keep that bolted to the block.

[36brua]

Thanks JGood ^^^

[Vtec?lol]

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.

Thanks for your replies and taking the time.

I purchased a new DME temp sender for the m60. I don't remember the exact reading but it's in spec @cold and @normal operating temp. I made sure it's in the right plug as well.

I get the 1222 and 1221 codes even after clearing the codes and removing the ecu for 10min. I have 2 dmes, both 404 units. When it first started acting up I swapped DME's and it was much improved. The first one constantly fouled cylinder 8 plug. it no longer does this with the replacement dme so I'm guessing the first one has a frayed ignition driver.

Smoke test was done with a burnt rag mod and again with a fog machine. Both worked well and gave me one leak that was fixed which was a crack nipple on the back of the manifolds diaphragm/pcv plate.

Fuel pressure was checked and was in 28psi at idle and went up to a max 30psi. I swapped the filter, hoses, and pump with a 255lph. I've yet to test again. I'll need to go to my storage to get my gauge. I'll do a compression test as well.

MAF was swapped with a known working one. Same symptoms. I actually left mine in my friends 740i and he hasn't noticed.

I'm about 5ft away from tearing it all apart and re-doing the harness and adapter.

[JGood]

Fuel pressure should be 51psi, +/- .9

May want to try another gauge. If you're still getting 28psi, that's likely your problem. May have a bad FPR.

[The Dark Side of Will]

Fuel pressure should be 51psi, +/- .9

May want to try another gauge. If you're still getting 28psi, that's likely your problem. May have a bad FPR.

51 psi at idle or 51 psi with the pump primed but the engine not running?

M60 FPR is referenced to manifold pressure, right?

If the spec if 51 psi with engine off, then 28 psi with a strong vacuum in the manifold is a little low, but not grossly.