Time for a short update. Have been working on getting the engine, OEM CFI system and new ECU integrated. The issue with engine timing is at the crux of my slow progress.
Have had an issue with timing, engine tune for years with the OEM CFI system. There is no ability to adjust the various CFI system tune to address issues.
The CX500/650 forum that I frequent is having issues with the '82/83 FI turbo models and the ECUs. There is a company in the Netherlands, Carmo, was sent an ECU and it is not repairable. Back to my ECU project.
Have been setting the engine timing by locking the timing in the tuning software, and setting the trigger angle for the "T" and "F" crank markings. This has been moderately successful, but not exactly what is needed.
Connected vacuum gauges to the engine to supplement the indicators in the tuning software. As was usual, the vacuum gauges indicted that there is an issue with valve timing and/or vacuum leaks, came in around 8 in HG. This has been historic for the past 8 years. Have chased a fuel smell on start(s), and lack of a fast idle.
Used starting fuel to check for vacuum leak(s), and did notice a very small change in engine RPM where the injector holders connect to the heads, and the air chamber. Going to get some new o-rings and install. Have been using what is available from a local hydraulic shop. Going to request one size larger.
The vacuum gauges shown here:
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The vacuum gauges indicate that there is a vacuum leak and/or a valve timing issue. Not being able to change the engine tuning such as timing, makes this problematic. Have not seen other '85/'86 FI models with different results.
Making sure that I have not damaged the engine did a compression test 160 ish all round. Made sure the engine components were aligned properly. Then went back to engine timing.
Set engine timing for the crank "T" and "F" markings. Checked the timing using cylinders 3/4 as well as per the OEM service manual - pleasantly surprised it worked.
Started the engine with the various setting(s) and found that when I reduced the trigger angle (TA) from the base setting, and noticed the same annoying engine stumble. Increased the TA from the base TA and the engine started to come to life.
The vacuum gauges indicated a change as well. The vacuum reading(s) are now in the black area between the initial red warning of vacuum leaks and/or valve timing, and the red area for ignition timing - progress.
Check the spark plugs. Colour is brown to light brown. Once I get the engine timed as well as possible and address any vacuum leaks, can do further tuning.
Stumbled onto this scenario, but glad that I have. Thinking the better the engine vacuum at idle, the better the engine should operate on the road.
The 1200 engine with the CFI system is not intuitive, and is designed such that it is not to be played with.
More to follow.
