BMW 3 series E21 Turbo
2008.10.31
After blowing headgasket and radiator at extreme boost and advance (mean 50deg at 2+bars), the car has been rebuilt with normal (8-9:1) compression instead of ~6.5.
Now it's making power at normal advance values of 15-20degs.
It was working fine for a few months of normal usage, but a few weeks ago one of the injector drivers blown. (Always on)
I've checked wiring, found nothing strange and remapped this injector channel to a free output, now it's running fine again.
- Same thing happened on an Audi I was involved in, at the moment I blame it on a bad injector connector (really loose, cracked plastic) until someone says otherwise. (- Mattias)
- Interesting point, but hard to believe as a reason to kill an output after long normal operation, -will check connectors however.
2007.07.16
Car is started and barely tuned with firmware 1.1.18
Boost pressure is 1.2 bars.
The whole ignition table is strange, car NEEDS very large values, e.g. 40 degrees at boost.. I suspect that timing is incorrect. - I have the same things on some cars that i've made, did't know why. Although the cars works good. But strange.-FERO
(However I strobed it at idle and seemed correct to the mark)
- Use mda01 (0 degrees) and mda50 (20 degrees) or other values to verify the ECU calculated advance. Please explain exactly the procedure you used. Take care to realise that you are using WASTED SPARK which fires every revolution, if you use a strobe that can offset the spark this must be taken into account!! It's only true at 0 degrees advance, actually measured and calculated by ECU, actual is twice the offset. (- Mattias)
- It was last year, but we've utilized a load of methods to check, including strobing at 0 advance (every second flash was right on the mark), checked cylinder top in sparkplug bore and counting teeth, it was really on spot and running 50degs of advance. In the range of 15-25 degrees it was very weak with normal lambda and horrible EGT (measured and seen glowing exh. headers)
- note that this (unrealistic ignadv) can also happen with bad trigger settings. Like bad another_trigger_tooth or tooth_twidth1 or tooth_twidth2 variables. Obviously, IssueReports information (like config, preferrably mcd dump and setup description) is needed to check that config matches the real setup
- I'm using the very same trigger setup now (in 2008) with no problems after the compression has been raised significantly
- Please check it in MembersPage/GergelyLezsak/ETwentyOne/ConfigTables
- What kind of engine did you experience with? This is a really low compression one (8 bars measured peak press.) However I'll double check first cyl. TDC to the mark... -I experienced it with audi TT 1.8T 20 valve engine, the engine is slightly modifyed with compression ratio 9:1. But maybe the guys did't measured the right CR. So I'm not sure.
- You can't measure geometric compression ration by measuring the peak pressure while cranking. That's a completely different number and is a product of piston ring seal, engine temperature, oil film on cylinder walls, cam profile and valve seat condition, etc.. (- Mattias)
- 6.5:1 was a calculated ratio after disassembling. Pressure measurements was slightly higher like 8 bars, can't remember exactly. However, correlation between these values is interesting, especially why it's higher than calculated?
- You can't measure geometric compression ration by measuring the peak pressure while cranking. That's a completely different number and is a product of piston ring seal, engine temperature, oil film on cylinder walls, cam profile and valve seat condition, etc.. (- Mattias)
Questions:
- With 6+2, 2+6, 4+4 IGN hw config ordered, which outputs are power-outputs?
- IAC is one-coil PWM solenoid with preset spring but it seems that it CLOSES when IAC values raised. How to control this?
- Invert the output (i7 instead of 7), or change polarity of connector. (- Mattias)
- What can cause ignition advance over the table? I see 19 degrees when 14 is in the ign table (around idle).- It could caused by the ignition retard according to MAT.-FERO
- That's OK for retard. But it is advance over the table. Is it possible?
OLD STUFF
Project goals
- 300+ peak BHP
- reasonable daily driver
General hardware
- M10B20 (2000ccm) 4cyl 8v engine
- T3/T4 hybrid turbo, external wastegate
- big FMIC
ECU-related hardware
- custom 60-2 trigger wheel setup with VR sensor, missing tooth is 120 degrees BTDC (copied from M40 engine, the source of the wheel)
- 72lbs low imp injectors
- later motronic IAC valve instead of old mechanical one
- big throttle body with TPS potmeter. (from M50 2.5 24V)
- webshop IAT install with epoxy
- Ignition coil block from later M44 engines. see MembersPage/GergelyLezsak/MFortyFourIgnition
- EGT sensor bung in cyl4 exhaust runner
- WBO2 sensor bung in exhaust after turbo
Buylist
4 x Power-resistor (6R8,50W) = 5888HUF
1 x EconoSeal36-Wire side () = 4195HUF
2 x Sealed sensor connector () = 2984HUF
pincount 2
Sex pair
1 x K-thermocouple connector (K) = 3190HUF
mounting-style flying loom
Sex pair
1 x Wideband connector () = 2186HUF
With wire without wires
1 x Wideband O2 sensor (LSU4) = 19519HUF
1 x EGT sensor (K-type) (2x90mm) = 16249HUF
Size 6mm
1 x LCD4x20 (LCD4x20) = 5949HUF
Color green
1 x Econoseal18-Wire side () = 2487HUF
1 x Assembled v3.3 controller (v3.3) = 142353HUF
ignition driver 6+2
secondary_trigger HALL
primary_trigger VR
PowerFlyback no
mounting-style no-screws
MAP connection 400kPa onboard (6/4mm pneumatic)
Knock and EGT yes
LCD and PS2 yes
1-wire interface no