mhisstc

What diameter exhaust tubing are you using?

Thanks for the tip on the windshield rubber. I'll keep that in mind if we have difficulty finding one. Several years ago I put a new windshield and rear sliding window in a '79 Chevy pickup with a similar style rubber surround. I was super paranoid about breaking the windshield, but I got fresh rubber and sealants from LMC Truck, looked over several tutorials, took things slowly, and it worked out great. I was hoping that by having someone else who was supposed to be more practiced at replacing windshields than I am, the windshield in the BRAT would have been a simpler affair. That hasn't been the case.

With as much time as I've put into this vehicle over the last several months, I don't even want to look at it. And I still need to get it to a local shop to replace the front half shafts (a project that snowballed from a single torn front CV boot), the poorly constructed replacement exhaust probably needs to be completely redone, and the replacement windshield I had a body shop install is leaking and has cracked following the recent temperature fluctuations. The same shop broke the first replacement windshield trying to install it. The windshield rubber is very had to find, and any replacement chrome trim in the rubber is impossible to find. I may end up taking it to another place if they want to charge me for another windshield. At least my daughter is happy being able to drive it as-is for a few days before it heads to the shop again.

Yup. Took me a while. We'll see how long it stays running. Hopefully a long time.

IT RUNS! Absolutely correct the new FPCU made no difference. But, I did want to have a new one to verify functionality. I also got *another* new distributor. So what's different? Absolutely nothing. Every circut, wire, component, etc. tested out exactly as before. I have no idea why it is running now, and why it wasn't running before. Here's how it happened. I tried the new FPCU. Nothing. I put the old one back. I put in the new distrubutor with new ignition module. Nothing. I was ready to tow it to the dealership, open up my credit card, and give them instructions to "make it run". That's when my wife forced my daughter to come out and help me with her car. I proceded to show her everything I tested and did to her car to make it run without success. She was bummed. As I was cleaing up, the only thing I hadn't tried was to run a wire directly from the batter to the (+) side of the coil to bypass all of the other wiring through the car. So I pulled the (+) lead off the coil and replaced it with the wire directly to the battery. I did that and it immediately started. So then I went back through the circuits thinking the ignition switch was at fault and maybe I hadn't tested to make sure the coil was receiving power when the strater was cranking. I verified that. So I still had no idea why it wasn't running. previously, but I went ahead and set the timing again as it got dark. This morning I went through everything again to verify I was getting power to everything I was supposed to get power to when I was supposed to get it. It *should* run with the (+) ignition wire attached to the coil without the jumper. I put the (+) ignition wire back on the coil as I had done innumeral times before. Nothing initially, then it fired after I pumped the throttle once. That's where things are now that I've put evetyting back together. It runs great and starts with no issue. And I have no idea what the difference is.

In post #5 above, I did a little ASCI schematic of the plug with the colors and purposes listed. It will be a couple more days before I get to plug that black box into the car and actually test it out with fingers crossed this was actually the issue. At that time I'll try and get a couple more actual pictures and provide labels of everything now that I have more practice loading and linking pictures to my Gallery.

This evening I picked up a brand new FPCU for my '85 BRAT. As you can tell, it doesn't look exactly the same, but the parts person who found it for me has over 17 years experience at the dealership. The person I talk to when I picked up the part assured me if he was the one who found it for me, it's the right part. Apparently, if what I was told is correct, this was also the ONLY brand new part in the entire U.S.A. That's right. There was only one of these in the whole country, and now I have it. With tax, it was just shy of $190. Ouch. I sure hope it works. If not, I will be totally stumped with this issue. I didn't take a picture of it, but right outside the front door on display at the dealership was a very nice light metallic blue '85 BRAT. The only wear I could see on it was where a shell had been on the bed.

I'm definitely interested in what you find out. What I mean by jumpering the FPCU is that I'm essentially bypassing what's in the black box and I'm able to get the fuel pump to run continuously when power is applied. So, the pump works and I know I'm getting power to the black box. I've still never been able to get it to start in that condition, which should mean that I'm still not getting any spark. Everything I've read, also seems to indicate that if you have spark, the fuel pump will run. But what I'm wondering is if there is some feedback circuit in the module that says everything is OK or not OK and then send a spark signal back to the ignition system. What exactly happens in the black box has never been clear and there is no schematic for that. That said, a mere one hour ago, I picked up my brand new rev sensor at the Subaru dealership. Pics to follow.

There are three wires to each coil terminal. The black to the positive, yellow to the negative. All wires have been verified by tracing them back to the component they originate from and are labeled. All components of the ignition system have been tested and found good along with all wires and grounds properly attached and in good shape. The baseline timing has also been reset by indexing the #1 cylinder at TDC with 0 deg. on the flywheel. All components of the fuel system have also been tested and found good along with all wires properly attached and in good shape. The ignition switch has also been verified it is operating correctly. And yet I still have no spark when cranking the engine and the fuel pump refuses to operate. So what I am left with? The only thin I can think of is the black box shown below. The Fuel Pump Control Unit/revolution sensor. This is the only component common to both the fuel system and ignition system that no one has been able to tell me how to properly test, and for which my searches have found no test procedures to verify correct operation. So now I'm looking for one of these for an '85 BRAT with a manual transmission. Are these things still available through the Subaru dealership network, or are they going to be a junk yard/parts car only kind of find?

Excellent. I forgot about White Out.

They can be hard to see, but there should be an "A" and a "B" (meaning after and before) letters marked just above the timing scale to the left and right side of "0" when looking at the flywheel from the front of the car. Before TDC should be to the right of "0" (zero) and After TDC should be to the left of "0". You can also logically work this out by considering the engine's clockwise rotation as you stand in front of the engine bay looking at the engine. The end of the range of numbers seen first in the timing window (on the right side of 0) would all be on the Before TDC side of TDC. Then as the engine continues to rotate, you pass TDC and everything beyond that (on the left side of 0) would be After TDC. To make the timing scale show up better, I usually take a little solvent or mineral spirits on a rag or paper towel and wipe as much gunk off the marks as I can. Then I'll get a little dust or dirt on a finger and rub it once across the scale and numbers. That usually helps the numbers and scale show up better. I've also used a white grease pencil to fill in the marks followed by a paper towel to wipe off the excess. That makes a nice contrast that shows up nice with a timing light, but it isn't permanent. For the ultimate in visibility and durability, I'll take a white paint pen, or a little modeling paint on a brush and actually mark a line on the timing scale where I want to set the timing. The bright white timing mark I'm trying to match to the timing indicator is then completely obvious.

I have not. I wish I could find one.

I also went back and installed all of the original parts I had replaced (coil, cap, rotor, distributor) to go back and try and replicate a known running state. The only thing different this time around, is that it had a new ignition control module installed in the old distributor since the original was definitely bad. The results were the same as with all the new parts installed. The vehicle will not start. There is no spark. The fuel pump will not briefly run when turning the ignition switch from OFF to ON. I can still get the fuel pump to run continuously if it's jumpered at the FPCU to run when the key is ON. And if I pull the coil fuse when the key is ON, it will run briefly if I pull the coil fuse.

Test light on the (-) coil terminal = solid light when cranking, no pulses. Doing the diode function test of the known bad module, it tests open in both directions. Doing the diode function test on one of the modules that is supposed to be good, I get a reading of 913 in one direction, and open in the other direction. The other supposedly good module was a similar value. I also did a little searching online. What I found indicates you can test diodes in either diode or Ohmmeter modes. http://www.electronicshub.org/diode-testing/ In Ohmmeter mode, the known bad module tests as open in both directions, while the supposed good ones test as 820-830 Ohms in one direction, and open in the other direction. That corresponds to the Ohms value shown in the Subaru factory service manuals for a Hitachi distributor module. The instructions for my cheap little Leviton Multimeter say this about the diode mode: "The display will then show the approx. forward voltage of this diode. If the test leads are connected the other way round, the display will show an overrange status of 1" What it doesn't indicate is where the decimal place in that voltage should be. I'm pretty sure it's not actually 913 or 91.3 Volts, but I don't kn ow if I should assume a more realistic value of 9.13, or 0.913 Volts. Any idea what a good module should read in diode mode?

I'm new to the Subaru game as of this year, but yes, that's exactly what I've found out and should have known from previously using the Chilton's manuals with my Mustangs. I regularly use a combination of 4 different manuals with them including the Chiltons, Haynes, the OEM factory manuals. I pulled the distributor and double checked it was properly indexed, but then I also pulled it out again and re-indexed the distributor with the marks that place the rotor at the #1 cylinder terminal along with ensuring the cylinder #1 piston was at TDC on the compression stroke with the 0 deg mark on the flywheel in addition to checking the resistance of all the plug and distributor wires. Still no spark being produced. The basic ignition system really isn't that complicated, but being super paranoid about it all, I made sure I labeled all of the wires and verified the labels and connections against the wiring diagrams a minimum of three separate times. Black wires to the positive (+) coil terminal and the yellow wires to the (-) coil terminal was something new I had to get used to and was why I had to triple check it to convince myself it was correct. I still have the OEM distributor since I didn't have to turn it in as a core. So I think my next step will be to clean up that distributor as best I can, install the replacement module I have into it, and see if anything changes. It can't hurt, and there isn't any additional expense to do it at this point.