Hi, there
First post here.
Let me introduce myself - my name is Anton.
I've installed 3sge into the e30 BMW, and everything is awesome - it pulls, revs, and on top of that gives about 35-40 uk mpg.
The engine is a blacktop 3sge (yellow label says G1), coupled to J160 box. Harness connectors are standard for A and B, and custom made for D and E. O2 sensor wire is shielded. Outside temp sensor and oil pressure sensor are disconnected.
The problem is the following:
very rough idle. Rough as engine vibrates like mad. It gets better when its revving, motorway cruise is also good - pulls strong and gives good fuel consumption.
The following things have been checked:
1. Air
All the vacuum lines have been checked (including brake servo), every single doubtful joint resealed and then put together. Vacuum gauge shows no evidence of severe vacuum leaks (that may cause such a horrible vibration).
Engine also uses shed made intake system (cannot fit altezza box in the engine bay). Thought that silly cone filter may cause this, removed filter - no result. AFM has been replaced with a brand new one - no effect. shows very steady 1.2V (checked with a scope) with fluctuations of 0.005V. Toyota manuals specify 1-1.5V AFAIK.
Drive by wire throttle body has been replaced with a second hand unit - no effect
2. Spark
I had leaking head cover gasket and initially thought that this might be it - a dead coil causing misfire and vibration, but no - replaced gasket and coil packs with second hand units (revised thinner COPs) - no effect. Spark plugs have been replaced - no effect. IGT and ION signals are verified.
3. Compression
14 bar at closed throttle cranking - super even and steady
4. Fuel
Fuel pressure is at 60psi all the time. Increasing FP gives no effect. decreasing makes things worse. Injectors are cleaned and verified not to be sticking. Scope shows almost ideal injector voltage pattern (well "ideal" according to tech guys and ScannerDanner from youtube ;)).
5. Timing
This was the last thing i thought about. I got a second hand Power FC controller and hooked it up. I "initialized" it before start, and previous owner kindly shared based map unit came with. I verified that "init" map and provided map are identical and fired up the engine. Exactly same symptoms. I then played with injector timing - and oh god, changing injector firing delay to +0.5ms smoothens out engine by a great deal. It still idles like a dead Lada, but nothing as horrible as before. That got me thinking that timing was off. Cam pulleys were aligned properly (to my understanding) - when crank is at 0 mark, cam notches must align with extrusions on timing case - they did. I pulled the valve cover to see if cams align to their internal marks - they did.
Can somebody point me in the right direction, since money's running out and im tired of replacing parts?
Thanks,
Anton