Pick-up coil replaced, no help

Action taken

Replaced the pick-up coil inside the distributor

Results

No changes; symptoms remain.

Other

Since changing the coil involves taking most of the distributor apart, I got a chance to clean it more thoroughly. Looks like the magnet has fractured in  at least three locations. 

Also, this clip was quite helpful - http://www.youtube.com/watch?v=K5QRK9VZwcM

Spare part lottery II

Action taken (Apr 12 - 20, 2013)

• Distributor cleaned, pulled out and cleaned some more
• A lot of dust, rust etc under the distributor cap
• Also, there were some mysterious black flakes on the distributor shaft, but they didn't seem metallic. They don't react to a magnet, and break when you crush them with your fingernail.
• Ignition Control Module (ICM) in the distributor replaced (Standard Motor Products LX340)
• Ignition Coil replaced (Standard Motor Products DR37)
• ECM & its PROM chip replaced (original part, ordered from an eBay merchant in California, pulled from a 1992 Camaro, )
• PROM version is "AXKT", while the original was ANTT. As far as I know, AXKT is just a compatible upgrade.
• Battery negative terminal connector replaced
• The threads attaching the cables to the old connector were gone, so this might have caused some contact issues
• Grounding cable between battery and chassis replaced, contact point in chassis cleaned
• Grounding cable between battery and engine block was left in place, looks "ok"
• Battery terminals and connectors cleaned
• Wires to the Heater / AC blower motor disconnected
• Wires to the AC compressor disconnected
• I don't know what condition the AC is in, at best it's very low on refridgerant

Results
I had hoped that blindly replacing most of the ignition-related parts would take care of this problem, but the same symptoms that I had last fall are still there. I think things got a bit more reliable after I fixed the battery contacts and disconnected the heater/AC blower motor, so bad grounding and that worn-out motor were probably at least part of the problem. Still, this only lowered the frequency at which the symptoms occur.

I made a test drive of about 9 km today (5.5 miles), and the car died / SES'd maybe half a dozen times.

Other
Next up, I'm looking at

• Replacing the distributor Pick-up Coil (since I already have a new spare part)
• Replacing vacuum hoses
• Replacing the whole distributor (at about the same cost as all those distributor parts above....)
• Replacing the grounding cable between battery and engine block
• Checking / replacing the cable for the VSS (Vehicle Speed Sensor) 
• Replacing that 8th plug...

And possibly

• Checking the fuel pump wiring
• Replacing the TBI injectors

If none of this helps, it looks like I'll have to switch my brain on, do a bit of homework and actually try to diagnose the problem in a structured way.

Running trouble, Spare part lottery

[backdated for chronological order]

Recoup of the mysterious running issues that started last fall.

Symptoms

• "Service Engine Soon" light flashes randomly when driving
• This happens very often when you hit a bump, but it also does it randomly on an even road
• "Security" light flashes less randomly when driving 
• (referring to the VATS chip in the ignition key)
• Tachometer jerks up and down randomly, maybe +/- 500-1000 RPMs
• Speedometer jerks less randomly
• Engine dies semi-randomly when driving or taking off
• After the engine has died, the SES light sometimes stays lit, other times it's off
• No error codes given by the ECM, ever, despite the SES light

Steps taken last autumn (Oct 2012):

• Switched from E85 (Ethanol) back to E95 (Regular Gasoline)
• Injector cleaner stuff added to gasoline
• PCV Vent replaced (Standard Motor V178)
• old one was making a rattling noise, although it was less than 6 months old
• TBI injectors and their filters taken out and cleaned with a carburetor cleaning spray 
• Stream from the injectors looks clean, stable and has a conical shape like it's supposed to.
• Spark Plugs 1-7 replaced (AC Delco R45TS) 
• Plug no. 8 was impossible to reach in the freezing weather....
• Spark Plug Wires replaced (Standard Motor Products 7850)
• Distributor Cap replaced (Standard Motor Products DR468)
• Distributor Rotor replaced (Standard Motor Products DR326)
• Battery replaced (62 Ah)

Some late updates

I realized I haven't updated this blog since last summer.

I did finish replacing the fuel lines in August 2012. This was a much bigger undertaking than I had imagined, not least due to crappy (or nonexistent) tools and having to do all the work on an open parking lot. Having finally gotten all the pipes bent correctly, hydraulic hose fittings, fasteners, etc. installed etc, I didn't have much motivation left to document the whole process. Pictures and details will be coming soon-ish, though.

In August-September 2012, I also acquired a chip, calibrated for E85 Ethanol fuel, from a friendly hobbyist who has invested his time in getting TBI engines running on this stuff (amongst other things). To our mutual surprise, the car started immediately after filling 30l of E85 and replacing the chip. A couple of calibration runs were made using WinALDL, and new chips burned based on the results.

In civilized temperatures (15+ C) the car started and ran normally on E85, the only difference being a slight vinegary odor in the exhaust - and of course slightly higher fuel consumption per volume. When the temperatures started to drop below that 15 C mark, a lot of problems starting and running on a cold engine appeared, though. The chip needs some further calibration to deal with cold temperatures that we weren't able to finish.

Finally, in September-October 2012, some weird running problem appeared where the tachometer would suddenly jerk up or down about 500-1000 RPMs. This was sporadic at first, but rendered the car undriveable within a couple of weeks. It started after the spark advance was adjusted, and since the ECM had been lying in the passenger side footwell for about a month, my main suspects have been ignition and the ECM. It could just be incidental, of course. I tried changing the spark plugs, spark plug wires, distributor cover and rotor in the autumn, but none of this helped.