DaveT

Why do this? Well, who knows what we may find? We can adjust and modify pretty much every other part, why not this one? Part of me always reads "no user serviceable parts inside" as a challenge, not a warning...

Wow! I'll download and check out those programs tomorrow. I don't see any connections on the ECU other than the external harness connectors, no secret ports. I can also read & burn & erase these EPROMS. When it gets far enough, I'll buy some. I'll install a socket in this ECU for the EPROM. I'll post pictures of the PCB tomorrow. [technically later today] I can trace out where at least some of the external sensor pins are wired, I have generated schematics from a number of circuit boards. The Big IC next to the CPU - I would not be surprised if it was a A to D / D to A converter or Analog I/O of some sort. There needs to be one, and there are a lot of analog circuity near it. The PCB looks like its only 2 layer. I still have the first computer I ever put together, an Apple II+ Actually ran it a couple years ago. I also have a Pentium that runs DOS and Win3.1 I've designed a few embedded controller systems, written a little code, but I'm not good enough at assembler to decipher this on my own.

Other ICs - Hitachi HD46520P 40pin DIP, right alongside of the processor. NEC D449C-1 24pin DIP along side of the EPROM. So far, I haven't been able to find any information on these 2. The 6301 history ideas above make sense to me. In the text HEX file, The leading :20 is ignored. using the first line as reference, the address is the next group of numbers, the 00 [first data byte] is 7F. Looks like 32 bytes per line.

I was hoping someone would have that sort of experience. I've written a tiny amount of assember code, some BASIC. I'm more of a hardware guy.

I was hoping someone would have that sort of experience. I've written a tiny amount of assember code, some BASIC. I'm more of a hardware guy.

The processor is 40 pin dip. I'll try looking up the other 2 good sized chips near the processor and EPROM. I'll have some time later today.

There is only 1 wire, because the normal situation is either pressure gauge OR oil light, not both. There is no reason to drain the oil pan, the sender is in the output pressure side of the pump. The oil in the pan cannot go uphill through a positive displacement pump to get out. Some oil in the channel will come out, but it's not a lot, and pretty much no way to avoid that.

Subaru GL Loyale ROM.txt This is a text file [hex] of the ROM I can send a .bin file of it, but apparently, not through the message board.

The sensors are easier to see from underneath. May have to take the skid plate off. I've left mine off for years now, as I don't do crazy off road stuff. If your instrument cluster has a gauge, it should just work.

The oil pressure sending unit is bigger than a typical oil light pressure switch. There are ports for both on the oil pump housing. There is 1 wire that comes out of the engine harness kind of behind the power steering pump. Goes past the dipstick, then strait down to the sensor.

You can rule out exhaust by getting rolling at a speed that makes the noise, then slip into neutral, Rev the engine a little. Never had a bad mount make that sort of noise.

That is not normal. My first GL did that. Someone had hacked into the wiring and wired it always on. The compressor was worn out and I had to replace it. The compressor should only be on for ac and defrost. It should cycle on and off when the thermal load is light.

Factory Service Manual. So much more detail than the generic ones. There may be sections uploaded. eBay.

I took a 1" square steel tube, and cut notches in one end that fit the piston depression. The other end, I slide a big bolt in, to make a crude pivot bearing. With the caliper flipped to the open position, apply pressure to the tube [about 12 " long] and turn with a wrench. Sometimes I've held the bolt end with one hand, or get in a position to lean on my hand with my chest. It's not about forcing it to compress, it's to keep the tool engaged. The piston turns in pretty slow, so bracing takes less effort.

Did you change the belt type also? These are normally a V belt. V belts for the alternator - not all your might. Moderate. On a stock alternator, after setting, try to turn the alternator by the pulley fan. If it slips on the belt, it's too loose. If it won't turn, or turns it a little, ok. [it won't deal with turning through compression, but if the engine is not on that stroke, I've had it move sometimes.] I don't have a trick for too tight, the idea is to work up from slip to just enough to not slip. Iirc, the swap you did doesn't have an external fan? Maybe a wrench on the pulley nut? Too tight will shorten the belt and bearing life.

There are a few different transmission end spline counts, depending on Auto, standard, Turbo, 4WD 2WD, etc. A FSM has a table of which is which, and how to identify OEM axles.

The front caliper pistons DO NOT compress. They must be "screwed" in. Hopefully, the tool took the damage. The rears, you have to push the pistons back in, make sure they didn't pop all the way out. Re install the dust caps. They should push in by hand or with only a little help.

HD6301V1P processor Data Sheet.pdf Here is the data sheet. It mentions compatibility with the HMCS6800 family.

It sounds like the old electro mechanical pumps I had on my 86 and 87 wagons. A spring pushes the fuel out. A contact makes, and energizes a solenoid. This pulls fuel into the pump body. Contact opens. The spring pushes fuel out. 2 check valves direct the flow in and out. Reducing the output flow increases the time before the contact makes again. Blocking the output stops the fuel from exiting, so the cycle speed drops to zero. Blocking the intake will make it speed up.

I started a new thread for the ECU investigation.

This is a thread to track whatever we discover regarding ECU internal wiring / code / experimenting. Dark color coating the external metal box. From an EA82 4x4 Wagon. ECU is labeled: 22611 AA100 MECF-001 5Y14 The UV erasable EPROM is a Hitachi HN482764G. 8K x 8 28pin Ceramic DIP The CPU is a Hitachi HD6301V1P 1MHz 8 bit 5V CPU I have the data sheet. Includes the Op codes. Object code compatible with 6801 family.

Maybe a cap from a spfi? Or investigate what is in one, and modify? Did you swap the evaporate system?

There are a couple of numbers in the FSM. I have a few more recorded at home.

The bearings are just normal ball bearings. I might have one with a readable number on it. Any decent industrial bearing supply house should have them.

I'll dig one out and get the numbers, pull the chip tonight. I just get in aND go. Having that big of a power drop seems unusual to me. I have 3AT s. I tend to delay up shifting a bit longer when cold. These engines are made for high rpms, not low rpm high tourque. The CTS can cause weird issues. MAF, check exhaust for no restrictions. Check for air leaks into intake.