tahuyahick

Well, after a nice tall glass of home-made triple shot coffee & cocoa-mix... I decided to ignore the lack of sensor-safe sealer and electrical-taped the AFM cover back into place and just threw that back into the car. Ignored the lack of a clip to hold the harness connector to the AFM, more tape please! Funny, when I try turning the key on, I see a code 11, 12 & 14 on the first cycle, then it's just codes 11 & 12. Maybe I did something right inside of that AFM! I wasn't really sure about that part:grin:! And I decided to unplug a mysterious green connector next to the computer. Hey! With the key on but not started, the pump stays off. So I arrange the fuel pressure gauge where I can see it and try cranking the engine to see if the pump kicks on, oh and the cars starts! Woo-Hoo! And the pump does indeed kick on and stay running. And the engine is running kinda normal! So I drop some tools, run around up front and try bumping the gas by pushing on the throttle body end and the throttle immediately sticks wide open and whadda ya' know, it revs up all crazy-like, and it starts cutting of momentarily like there's some kind of rev limiter and something under the dash starts beeping. So I shut it off. With a quickness! Yeah, the throttle cable got mis-routed at the throttle body. A restart using the gas pedal this time, and it's almost normal. So I check the fuel pressure and it's back to 60 plus. Darn! Ok, one problem is I keep forgetting the vacuum hose to the regulator. That's one point for the leaks, home team still struggling. Pressure is holding at 60 with the engine off, so I remove the return line to check if it's a blockage on that. But nope, just a slow drip coming from the regulator. So I must've not quite fixed that thing, or maybe there's some debris in the lines that's sticking the regulator closed. Yeah, right. Debris sticking valve issues usually mean the valve is unable to close and the pressure would be too low. I probably need to re-think the regulator fix. Maybe an aftermarket unit is in the works. But I can drive the car as it is now. That's progress.!!!

Well if I have to shim the regulator again, it's not really that big a deal. At least it isn't 60 plus! Hey! I just thought of something, if the starting enrichment wasn't kicking-in but the pressure was at 60, then it would be enriched anyways, but would stay that way after cranking. Might be why it started to begin with. It's too bad I didn't look at the codes from the beginning. But I bet the code 12 was an issue before I got the car. Well, I haven't done a thing yet to the car. It was nice enough outside I had to take my dirtbike out in the woods. But the next two days are my weekend, so maybe I'll get something done around the house...

Uhm, fuel-pressure above manifold? Why did that give me a troubling feeling?:-\ I'm reading pressure from a standard 100 psi pressure gauge connected via a t-fitting inserted between the fuel filter and the engine. The book says 30 to 36 with the vacuum line disconnected & plugged, holding at 30 when the pump is off. The book also specifies that the regulator should be holding 30 psi after the engine is turned off for five minutes. According to the book I have, it should not be 36 above the manifold pressure level while running. But it will be that way when the engine is off! A lack of starting enrichment...darn pesky computer! Why can't it just understand what I'm thinking?

But after looking further into this, it's not actually a curve that's being outputted. If I go this route, I'd be using a hotwire sensor and it's a moving vane that creates the curve, but the resistor network is very carefully designed & laser-tuned to correct the value and output a linear signal. This era of computer is setup to expect a linear input to designate the volume of airflow, which is absolutely perfect! The newer computers had their software changed to use a cheaper AFM that outputs a log signal which the computer must then convert into the correct value. So, because the earlier AFM was designed to output an actual airflow value, it would be very easy to use a simple hotwire controller that calculates an airflow value and only make sure the voltage range is matched correctly. I'm supposed to sell this car, so I might not actually do this. But if anyone else would be interested in trying this out, I'd be very curious in what results!

Well, I just connected an ATX power supply across pins 4 & 5. The loaded supply voltage is 11.33 Setting my DMM to a manual range selection and connected to pin 2, I see 0.94 at the wipers rest position, moving the vane slowly results in a very smooth increase in output voltage ending in 7.23 volts at the highest travel. There were no reverses in voltage rise, or any kind of troublesome spots in the output signal, so I'm gluing this shut with some dessicant and move on to testing the harness wiring for the AFM.

http://the944.com/afm.htm Doh! - "You can not use an ohmmeter to test an AFM's potentiometer. It will jump about meaninglessly. You must test it as it is being used. You have to force a voltage UV and measure the output voltage UP. This can be done with the AFM in the car and the ignition on." Uh, you mean like what I've been seeing all this time?

Ok, I understand the intent. I'll have to ponder the ramifications of this circuit, it looks very useful for other applications. So if I understand that correctly, pin 4 is getting the regulated 5-volt supply positive. Pins 3 & 2 will show as a ratio of each other which will stay the same ( for a particular vane position) no matter what happens to the voltage level at pin 4. I haven't checked the links yet. I'll do that when I re-arrange my note taking. Thanks! I've got a lot of testing to do before I try cranking the engine over again. ps - did that formula give the definition on those variables? U-Fix, U-S & U-B are in volts, right? What's Q? CFM? And A? Is that a conversion factor?

I've got one of those simplified diagrams that tend to really annoy me. But if I think of it as a stand-alone harness, then everything is shown. Just not in the locations. And a real miracle - my diagram has numbers on the EGI pins! More notes to write-up here, thanks again. You really get the homework done! Awesome! I should've tried this already, I can connect a testlight to pins 3 & 4 and then use my DMM to measure voltages. This is showing what I measured on my AFM circuit board: It sure doesn't look very complicated when you see it like this.

Ahhh! My head thinks on it's own! - ok seeing as I measured the resistance between each point on the circuit board to find combined values for the resistor network, and having noted that the values are in a staggered decreasing value starting at 69.2 ohms/network section at zero airflow and ending with 1 ohm at the last network section. Well it's likely a series of straight lines, that when connected together form that curve. I'm actually just learning to program these controllers so I think I would prefer to just step through a series of linear stages to map an output signal. Maybe with that approach I could use a rotary encoder, or better yet switch to a hot-wire sensor and gain back that 7.3% torque loss from the vane! Of course I would rather do this with a car that runs perfect.:-\

Darn, it's on a curve! That might mean programming a $20 logic controller for a sensor interface. I'll just shelve that idea for a more desperate rainy day!

I'm just being funny. Makes sense that Bosch is involved. That's just Subaru making a sensible design decision to get their fuel injection up to speed. Nice techie page, thanks. I have some questions on the EGI pinout, it's a lot of answering. Is there a link to a description for each pin? For example, what's a Ti monitor?, what's the D-check jumper?, is throttle switch idle/full/ground at the gas pedal or on the throttle-body?, what's the pressure switch monitoring?, why is there an altitude signal when clearly there's a barometric sensor inside the EGI as a daughterboard?, is the power source on a key-switched circuit?, what's the F/ICCD?, is the line end code output going to a test connector? what does the 'distinction between california and 49 states' pin do? And many thanks so far! If you were ever to scan that FSM to a CD or DVD - I've got cold hard cash I could Paypal you!

I just remembered, what's the purpose of pins 3 & 4? One should be a voltage supply. I don't understand the function of having another pin with a resistor between 3 & 4. It's like a ballast getting bypassed during starting. Anything like that going on?

On a BMW? Did somebody 'borrow' somebodys design? I thought you meant he went at the carbon track with a chunk of 220 or something. I used a paper towel soaked in Deoxit D5 for the track, rubbing carefully. Then a piece of wetted 3M 600 to clean the contact surface on the wipers. I also shifted the board to get into a new swipe-zone. Didn't make enough of a change on the ohm meter, and I think I did about the same as the bimmer guy. But I hadn't thought of the dessicant yet, or the sensor-safe RTV silicone sealer. Good points there. So, does the voltage on the signal output ramp-up in a linear mode? I could get really serious and convert the whole deal over to a different kind of sensor. I'd like to see a chart on vane position/voltage output.

Awesome! Thanks!

Golly, I need to write-up a check-list! I can try the eraser trick, but I wouldn't want to really create some more dead-spots! I still don't know exactly what the test connectors look like, there's a bunch of stuff under the dash. Maybe there's a reson I don't see two sets of unplugged connectors? I only see one pair that look like the thing. Ok, I'll check on that Coolant temp sensor, and if it wasn't just that wire I had disconnected on the starter, another check there.. I took out the board in the ECU and looked it over. No visible signs of solder-joint breaks. Looks very clean too. I like that live voltage check idea on the MAF. I was just thinking about hooking power up to it on the bench and wiring the signal to an experimental analog gauge I built. It reads from 2 volts up to 6 volts in it's current configuration. I don't trust my digital meter to correctly show a live variable, always a nice thing about an analog meter. My analog can go from zero to full scale in just over a second, which is a sweep of 270 degrees. I'm trying to get it to move faster but that stuff is 'top secret squirrel' only!

Sent.

Two votes for the temp sensor. Can it go bad without showing a code? And if so, will that keep a car from starting? I'll check on those solder joints in the ECU. I seem to enjoy tearing this stuff apart a wee bit too much...

Well I already tore into the MAF, and I think I went a bit further than needed. So for those who are as morbidly curious as me, but don't want to risk their own parts - here you are! The top removed and the circuit board taken out, along with the harness connector. I recommend not doing that, but it wasn't too hard to solder back together. I would guess that the bolt right next to the gear will really mess things up royal if loosened! That appears to be how you adjust the spring tension so the flap opens the correct distance for a given amount of force acting on it from airflow. The gear is likely driven with a special tool inserted into one of two holes next to the teeth. The contact sweep arms are mounted on a black plastic hub that can be rotated to adjust the contact position so as to line up with the beginning of the resistance patch. I wouldn't mess with that either! The screw with the gunk on it's head, you might be tempted to think thats an adjustment sort of thing, but after looking at it I think it's just a clamping screw and while it might need to have it's position set correctly, I doubt it's something that would ever be 'adjusted'. The spring tension however, that's something that can change with age. But I'm not going to worry about it now. Oh yeah, the two black wires are for the temp sensor, which extends through into the passage beneath. This is the circuit board, which probably does not need to be removed, shown here removed. And underneath the circuit board, which has nothing much to look at, except for one detail - notice the hooks on each of those three connector tabs? That's why you can forget about unsoldering the three bus connections connecting the harness socket to the circuit board. Those hooks will probably mess the board up if you try pulling that out. Under the harness socket, you can see where they welded the three bus bars to the circuit board. But also a nice view of the contact pad that connects to the center of the vane. I polished this pad before re-assembly. And back together & the three bus bars soldered. Temp sensor still not hooked-up, but good enough to test. Now I'm thinking all this mechanical stuff is cool in a way, but I think I would prefer a hot-wire sensor. Just a little less moving parts to wear-out, is all! And there's a side passage that goes around the air-vane. Like the computer needs to not measure some of the airflow? Or maybe it helps the vane respond correctly? It sure isn't the idle-air bypass circuit, which is what I keep wanting to think it is! I'll just try not to think about it too much...:-\ So I guess I should see if this is another hard to find part! But I'm thinking what if I could get one of those defrost repair kits that let you paint the resistance lines back onto the glass. Then re-paint the circuit board so it has a fresh coat that responds like it ought to. Or I could just go to bed as it's like well after 4 in the morning and only think crazy thoughts in my dreams.

I'll have to look into that starter connection, but I think it might have been from the remote start I connected. I pulled a small wire off of the starter so as to connect the hand-held push-button and I noticed the fuel pump started running full-on. It's always been cycling on/off which I don't care for. But why would it change from pulling that wire? Very tricky... I get 185 for Ufix & 282 for Ub. Do you have Us correct? I got 42 with the flap closed and the higher readings with it open, but in a very flakey kind of way. The values go up & down as I sweep the range. Fully open is 275, with slightly less around 350 and somewhere in the range I think there's 400. I don't like these results!

I would think so too. No problems with supply, but a bit of resistance in the return. Not enough to affect the pressure though.

- X-Ray eyes! I myself would never have known that as I got the rims from a friend who had them in a pile, intended for an extremely lifted Luv. But when I got them home and ripped the tires off, I found paint-marked inside 'Dodge D-50' That particular rim happens to be the one I messed-up on while drilling the new holes. Thus the 'extras'! Oh, and the tires are 195/50-15. Which are good enough to really show how crappy the Brats suspension can be! I think it needs some swaybars...

Aw darnit, I keep forgetting again to mention the part where I tested the return line. I ran an extra hose to a catch can so there was zero back pressure for the return path coming off of the regulator. There does happen to be some resistance to the line going back to the tank, but it doesn't seem to affect the pressure. I found some cracked vacuum lines and replaced those. I still have not started testing all the other sensors, but at the moment I'm looking at a shot MAF. It's the vane type and has dead spots in it's range of movement.

This is all about a car that I got from a friend who is downsizing his projects. The deal is, I fix it and sell it, then I pay him the money he had into it. I think that's $200. I had always tried talking him into learning the computer thing and just start diagnosing this thing, now it looks like I get to put action to words because it's in my yard now! The grill is on the backseat, along with a pair of hood latches and one broken hood latch cable minus it's inner steel core. Original hood latch missing and that's how my friend got the car. Also 'as is' stuff: right tail-light assembly missing with a complete pair of tail-lights in the trunk. Original tail-light has black trim and the pair in the trunk are chromed. Extra instrument cluster - the all digital type. Extra turbo-charger looking very much like the original, in a box with some extra bits & pieces. No keys, but some oddball key that's from a different make or model that works the ignition if you pull it out slightly while wiggling it like a lockpicking genius on crack! So the whole time my friend has this car, it refused to start normally. The people before him had about the same situation, only they were pouring gasoline down the throttle-body and it would fire off & run for a few seconds. So all parties keep mentioning 'but it's got spark!' & 'da block's good...' which is the reason this car didn't get stripped for all it's parts and turned into a meth lab or something. Somewhere in the dim past the ignition coil was swapped several times, the fuel-pump was replaced and the cap to the radiator & oil filler were swiped. I think another project was parked near this car at one point because there's some parts in the trunk that are not Subaru. So what gets really annoying (among other things) is the first time I try turning the car over after it gets here, the engine starts! But it runs really rough and dies as soon as I touch the gas. But it'll restart and it'll keep idling, so I check the fuel-pressure and it's 60 plus. Then I pull the spark-plugs and they're caked & fuel-soaked. So after a little sand-blasting I put the plugs back in and it starts easier but the same idle issues. So, I decide to attack the fuel-pressure problem. Ok, the book says 30 to 36. Holds when off at 30. I phone Westbay/Napa and they can't find a regulator. I try the Cut Rate Auto Parts in Shelton, and they don't have it either. And they always have obscure stuff for Subaru's. So I call the dealer in Gorst and first off they can't find the part number. They get their 22-year experienced mechanic and he tells me he never seen one of these. Finally they find a phot of the engine compartment with part numbers drawn all over it but with no part descriptions and I tell them very carefully where the regulator is and what it looks like. Finally, a part number! #429517010, but they don't have it anywhere on this planet.... Ok, so I guess I have nothing to lose by cutting this regulator apart. A little bit of work with a dremel sized fiber-disk on my variable-speed scroll saw and the bottom is off of the regulator along with the spring that sets the pressure and a really flat sealing ring to keep the vacuum signal contained inside there. So there's a lot of dusty red sediment coating everything in there. I clean all that and decide to see if just putting back together cleaned makes any difference. Ok, a little time goes by here because I decide to build a clamping device to put the bottom back onto the regulator. Below is the upper & lower rings I cut, that go around the rim of the regulator. Which rim can be imaginatively pictured sandwiched between those inner steps: And the rings assembled on a centering jig so I can drill the bolt holes: The whole deal, before drilling: Yeah, this pic was photo-shopped. It was late and I was just taking a break. So after drilling, almost cutting the wrong ring in half, then some last minute adjustments to get the screws to go past the bottom half's rim - assembled for fit: A problem with installing this, my nice fancy clamping device is interfering with the power steering reservoir! Oh, do I hit the reservoir with a really big hammer to clearance it? Or do I forget about bolting the regulator in all factory-like?: I decide to take the safer option and opt for a power-steering reservoir that doesn't leak. The pressure didn't come down enough just cleaning the spring, so I cut one turn off the spring and the pressure went to 23. Whoopsy! Thought that was a cautious cut... So I cut a fender washer down to use as a spacer under the spring, now the pressures 29 to 35ish, holding at 28 & half. I think I'll live with that for the time being, but... Now the car wont start! I never did figure out why it started in the first place. So then I get the super bright idea to actually look at the codes being flashed from the ECU. I'm getting 11, 12, 14. I think the 11 I can ignore, I haven't looked into the 12 yet. I think it has to do with a signal coming from a starter circuit somewhere. So code 14, MAF sensor or wiring. Cool. First thing I notice is that the spring-clip that holds the harness plug onto the MAF is missing. But that's not what threw the code, darn! I got a pinout from a very helpful member here so I could chase after harness breaks, but after a simple ohms check on the MAF I think that the harness may not be the problem. Pin two on the MAF is the only one that shows a change while moving the vane by hand. And I get a resistance reading that jumps all over the scale from 100 to 400 ohms when the vane is moved. I think it ought to change smoothly and only rise or fall if it's a potentiometer inside. So that's where I'm at. The MAF is about to get cracked open and I'm going to look in there to see if I can persuade the circuit to work better using a big hammer or something!!!