this is super helpful, i didn't know about JIS screws, explains all the challenges i've had with TPS screws, coil, etc. with various vehicles. usually end up putting hex-head screws back in!

i've been pretty busy, but getting back to the project now. i did check the timing with the ground-wire connected to turn off the ECU, and it was absolutely steady no matter how much i tried to revv it. revving is hard -- if i open too much, it gutters and drops lower, but if it feather it slowly and carefully i can get it to what sounds like 2500+, with no advance.

so that's definitely a problem, right?

i will say i liked xboxrox's idea of working on unsticking the advance before swapping dizzie's (with potential alignment problems, stripped screws, etc.). but my initial look at it doesn't make it obvious how to do this. any ideas? has anyone had an experience like this?

fwiw, it looks like the PO replaced the distributor recently, it's shiny-looking, and it could be a cheap-o part.

also still would love to rule out fuel pressure as a problem, anyone have a good way to test? (how *do* you attach a pressure gauge to these things? <shakes head>)

thanks again everyone!

Quote Originally Posted by SubGothius View Post
Get a JIS* screwdriver or bit set. Hozan or Vessel brands are good and widely available online. I like my ball-grip Vessel with swappable bits, even came with Pozidriv bits that came in handy for assembling Ikea stuff.

Philips screws/drivers are designed to cam-out as a torque limiter for ease of assembly without stripping threads, but this can lead to stripped heads with repeated dis/reassembly or trying to undo even a mildly-seized screw.

JIS screw heads look similar but differ, being designed for a more secure fit between the screw head and driver bit; these often (but not always) have a dimple on the head, so that's a dead giveaway you've got a JIS screw, which is pretty much all of them on these trucks. A Philips driver bit engages these even more loosely than a proper Philips screw head, further contributing to head strip-out.

Nearly anything assembled outside the US will be using JIS or equivalent screws, so having the proper driver/bit will help enormously. Better yet, a JIS driver bit also works better on actual Philips screw heads, and a JIS screw head stripped by a Philips driver/bit may still be recoverable with a JIS driver bit.

*Technically superseded by DIN 5260-PH/ISO 8764-1, but outside the industry ppl still call them JIS anyway as they're nearly-enough identical, and only these newer successor standards are readily available anymore anyway.