Recently picked up this 1988 TCD 535i with some problems

[M30turbodude]

Hello all, my name is Roman and I work at a euro classic shop in Seattle. I'm a long time e28 enthusiast and I recently traded my 535IS for a complete basket case of a 535i. The car has what I believe to be a TCD stage 2 kit on it, the water to air intercooler is present on the cold side of the turbo but none of the plumbing or tank for it are installed. From what I can see underneath I believe the turbo is TCDs T04e 60, says COMP TURBO on the housing. Pretty much all of the gaskets are slowly leaking and the passenger side 533i engine mount is broken in half at the engine flange among other little problems. When I bought the car none of the silicone couplers for the turbo were tight and therefor the car made no boost, since then I've fixed a bunch of small things and got the car running much better. I've been driving it a good amount recently and been keeping a good eye on the AFR gauge and I'm pretty concerned I'm running pretty lean. During part throttle the BEGI FMU doesn't seem to be richening the mixture, or perhaps something with the stock ecu is pulling fuel. The AFR doesn't drop like it should as it comes on boost. If I stab the gas and the TPS sees WOT it will go to about 10:1 and slowly creep up to about 12.5:1 which is about right. I've pulled the vacuum line off of the FMU and confirmed it is raising fuel pressure at atmosphere. I set the fuel pressure to about 60psi and also tried higher but it just wont richen up on part throttle. Normal vacuum cruising the AFR is 14.5 - 15 and stays there even if it starts dipping into boost, which is pretty scary in my experience. I have a good understanding of how everything works but this is my first M30 turbo car so i'm just looking for some advice on where to start from someone who's more knowledgeable on motronic with a rrfpr than me. Thanks in advance, Cheers.

[George]

Sounds like the car was pretty neglected prior to picking it up...

I would first check what e-prom chip is in the ECU. Based on markings/part # Todd might be able to chime in if its a "turbo" chip that pulls timing. I wouldn't assume anything based on your description.

I would also do a thorough check for vacuum leaks. Stoich for a little bit of boost shouldn't detonate and damage the motor.

How much boost are you running?
How are you "setting" fuel pressure?
At what PSI does the AFR begin to drop?



BTW, if interested, I'm local and have the following parts available to get your w/a intercooler working: Bosch Cobra pump, stock TCD reservoir and heat exchanger.

[marc79euro645]

Maybe try loosening the spring on the afm to allow richer/sooner.

[TheGraye28]

Not to be a twat, but:

Step 1. Ditch Motronic

Step 2. Get Megasquirt

Step 3. Profit.

No matter what you do, partial throttle will never be "ideal". It will be alright, but still room to improve and still a less than desirable AFR. For what it is, the begi unit and Todd's tuning works well. But if it is going to bother you, don't spend any sweat equity trying to tune the thing within an inch of its life. It will never be "right" and will never adjust for altitude, among other things.

[M30turbodude]

Thanks for the replies guys!

Sounds like the car was pretty neglected prior to picking it up...

I would first check what e-prom chip is in the ECU. Based on markings/part # Todd might be able to chime in if its a "turbo" chip that pulls timing. I wouldn't assume anything based on your description.

I would also do a thorough check for vacuum leaks. Stoich for a little bit of boost shouldn't detonate and damage the motor.

How much boost are you running?
How are you "setting" fuel pressure?
At what PSI does the AFR begin to drop?



BTW, if interested, I'm local and have the following parts available to get your w/a intercooler working: Bosch Cobra pump, stock TCD reservoir and heat exchanger.

The car definitely was VERY neglected but I'm hoping to give it a new lease on life. I was indeed assuming the TCD chip is installed but that is something i'll be checking ASAP. My friend recently gave me a Miller WAR chip and MAF conversion that I could potentially use if for some reason the TCD chip didn't make it into the ECU along with the rest of the kit. I went over the engine with a fine tooth comb searching for vacuum and any misc leaks, even did a smoke test and she's sealed up pretty good surprisingly. To answer your 3 questions:
Shes pushing 10psi on what I'm assuming is wastegate spring.
I'm setting fuel pressure baseline at idle with the vacuum line disconnected at the FMU to simulate atmosphere and am monitoring changes with a fuel pressure gauge.
Not sure what you mean by drop, the mixture will only richen under WOT, it stays stoich at any other throttle input no matter how much boost.
Id love to pick those parts up from you, care to PM me?

Maybe try loosening the spring on the afm to allow richer/sooner.

It doesn't richen up period unless at WOT so I don't think that will help.

Not to be a twat, but:

Step 1. Ditch Motronic

Step 2. Get Megasquirt

Step 3. Profit.

No matter what you do, partial throttle will never be "ideal". It will be alright, but still room to improve and still a less than desirable AFR. For what it is, the begi unit and Todd's tuning works well. But if it is going to bother you, don't spend any sweat equity trying to tune the thing within an inch of its life. It will never be "right" and will never adjust for altitude, among other things.

You're not being a twat, you're 100% right. Stock Motronic will never be ideal or the best engine management solution but for now id like to just get it running properly and maybe upgrade in the future. I already have a boosted m50 e30 so I'm trying to keep the e28 a little more tame, id like to just dial it in to what TCD intended with their kit.

Thank you all for the replies, greatly appreciated.

[M30turbodude]

Here's a picture of my car. The previous owner told me there is a build thread on the forum but through all my searching I haven't been able to find it. If any of you recognize it I'd like to find the thread.

[Kyle in NO]

Please tell me this is your car:

[T_C_D]

That car isn't 100% TCD parts.

[M30turbodude]

Please tell me this is your car:

Thats it! I recognize that stupid e brake handle. I already put in a replacement.

That car isn't 100% TCD parts.

If you know anything about it I'd love to hear from you.

[TheGraye28]

Maybe try loosening the spring on the afm to allow richer/sooner.

It doesn't richen up period unless at WOT so I don't think that will help.

Worth it to pry open the AFM and see if the sensor tracks are worn. Getting a refurbished AFM from Bavarian Restoration will solve this issue. I have one getting redone now.

[tschultz]

^^ IT could be that the wot signal from the TPS was cut. I did this when I was running RRFPR/motronic.

[M30turbodude]

Maybe try loosening the spring on the afm to allow richer/sooner.

It doesn't richen up period unless at WOT so I don't think that will help.

Worth it to pry open the AFM and see if the sensor tracks are worn. Getting a refurbished AFM from Bavarian Restoration will solve this issue. I have one getting redone now.

I'll pull off the cover to the AFM and see what the traces look like, good call.

^^ IT could be that the wot signal from the TPS was cut. I did this when I was running RRFPR/motronic.

What was the reasoning for that? I don't think it's cut but it's worth a look.

[TheGraye28]

Worth it to pry open the AFM and see if the sensor tracks are worn. Getting a refurbished AFM from Bavarian Restoration will solve this issue. I have one getting redone now.

I'll pull off the cover to the AFM and see what the traces look like, good call.

I had a stroker m20 that would continually lean out progressively at WOT. This ended up being the problem.

[M30turbodude]

Pulled apart the ecu today and discovered it is still rocking the TCD chip. I never noticed any detonation even while running a little lean so it would make sense its pulling a bunch of timing like it should.

[tig]

Tally-ho:

http://www.mye28.com/viewtopic.php?t=91346

http://www.mye28.com/viewtopic.php?f=2&t=134291

[tschultz]

I think this car has to be referred to as the Cupholder Turbo.

Maybe place a badge on the trunk that reads 535CTi or something similar!

[M30turbodude]

Yep, Its the cupholder turbo alright... now sans cupholder. I've done a whole bunch of work to it since I was on here last, rebuilt the driveshaft, put in a low mileage LSD, all of the front suspension and steering is now brand new, ripped out the old coffee stained tan interior and swapped to a complete black interior with cardinal sport seats with a nice map light rear view mirror. Now it looks like im going to be dealing with a blown headgasket because I found a good lil bit of milkshake on my oil cap and the top of the dipstick. This thing is just one problem after another but I think as soon as I get the motor rebuilt and freshened up I'll have a pretty nice e28.

[86GT635]

Man, you actually have a pretty nice car to start with. A lot of the forum members gave the PO a hard time because of his limp dick cupholder that looked 10x worse than my 3rd grade pencil holder for the art fair. But, to give him credit he did actually piece together a turbo kit that ran pretty hard at 12-15psi for several thousands of miles.

Freshen up the head gasket with stock head bolts/gasket and keep the boost lower than 12psi and you'll be able to have a good time for a while. The PO really lost his ass on selling the car.. He was selling for around $2k or something right?

Just keep what's there, go over everything with a fine tooth comb and enjoy a awesome deal. I would be completely stoked to have that set up for the price. It will take some homework and a lot of tinkering but that's the way it is for what you have.