loyalist

If the booster is disconnected from the intake manifold how would the engine (or ECU)"notice" that the vehicle is slowing down? By the way if I use the brake just very carefully, the engine won't die. I mean rpm not dropping below idle. Went to Pep Boys to read a book about emission control stuff on cars and find a chapter about the Vehicle Speed Sensors. It said on some vehicles it affects idle, poweer steering etc.. don't remember what else. My power steering feels a little weaker lately too (reservoir is full, but have to top it off every two weeks or so, have a minor leak. The cruise control quit working some time ago (year or two). Hardly ever used it anyway. Today receved a new check valve for the brake booster vacuum line. THat damn little thing was $25.00 from Subaru. A new booster from them would be $200.00 - I ordered one for $169 plus shipping ($17.00), but since then saw it advertised for $149.00. Allegedly all genuine OEM pieces. Lewis

Yes, it starts right up with the "first kick", or if I still have momentum, just release the clutch in - say - second gear and the idle goes right back to 750. Or if I just lightly touch the accelerator pedal, it wouldn't die. I also operated the buttons on the heater control box watching the rpm, but no change due to that. You're talking about than black sphere, right? I grabbed all the vacuum hoses in the engine compartment I could find and moved them back and forth to see if the idle changes, but nothing. The only time the engine dies if I step on the brake very hard (don't forget the booster is still disconnected!), but what's strange, only going forward. Accelerate in reverse and do an emergency braking and the rpm goes up. Just beats me! (Did I say that before?) Lewis

Yes, it starts right up with the "first kick", or if I still have momentum, just release the clutch in - say - second gear and the idle goes right back to 750. Or if I just lightly touch the accelerator pedal, it wouldn't die. I also operated the buttons on the heater control box watching the rpm, but no change due to that. You're talking about than black sphere, right? I grabbed all the vacuum hoses in the engine compartment I could find and moved them back and forth to see if the idle changes, but nothing. The only time the engine dies if I step on the brake very hard (don't forget the booster is still disconnected!), but what's strange, only going forward. Accelerate in reverse and do an emergency braking and the rpm goes up. Just beats me! (Did I say that before?) Lewis

Just to keep you guys posted: One day I drove the vehicle around and when the engine backfired, I heard a loud popping sound from underneath the dashboard, where the pedals are and a burnt smell came into the cabin. This must be a cracked booster diaphram. Since the check valve from the vacuum line to the booster is missing - I've just noticed it - the backfire pressure damaged the booster - I think. I disconected the vacuum hose at the intake manifold and blew/suck into it and there is little resistance. My lungs is the limit. Found new booster on the net for $169 and ordered one. In the meantime removed the AIC valve and cleaned it. Checked resistance of the coil - 10.8 ohm and no short. Put it back and tested it. Running engine still cold, disconnected unit - high idle drops down significantly. So this thing is working I guess. Next step: capped off vacuum nipple for the booster at the intake manifold and drove the vehicle around the block (have to press the pedal harder, but the brake is still pretty good without the booster!) and when I put the tranny into neutral and applied the brake agressively (like in an emergency), the rpm drops down to Zero. (Can keep it from dieing by hitting the accelerator pedal. )Then tried the same in reverse and guess what? The engine not only did not die, but rpm increases! Bought two books: the Chilton and the Haynes manuals. Found a sensor it the Chilton's called Vehicle Speed Sensor. Could this be bad? It is located somewhere behind the speedometer. Noticed before, that - sometimes - on the highway when I slow down, the speedometer needle stays up (only at the higher regions - 70 mph and up) even though the rpm meter and the feeling in the car clearly indicate that the vehicle is slowing down. What's you guy's take on this? Lewis

Thanks, MilesFox! To remove the whole Throttle Budy, with all the vacuum, air intake, fuel line and accelerator cable seems to me more complicated that remove the PAS pump. I checked all the vacuum lines, hoses, electrical connectors, they are solidly in place. But now that you mentioned the heater control box behind the dashboard I remember that about 3 years ago we noticed that the air can not be directed against the windshield. That time I still had a Subaru trained mechanic (who was not only knowledgeable, but also thorough and pricewise reasonable) taking care of my problems when they occured - since then the place unfortunately went out of business and himself - while still in the phonebook, never answers my calls. So this guy said that the heater control box is bad and a new one would cost around $400. Buying a new one was out of question, so what I did was - after checking that all the vacuum hoses going to/from that box are connected, but they did not move the lever to direct the air upwards - I moved the lever halfway up and tied it there with a piece of wire to keep it in that position. Now the air is always coming out both at the dash vents and the defroster vents. There possibly could be a leak there too, inspite that all the hoses are in place. But this poses the same question like the brake power booster line/check valve. Why the ECU - and the engine - did not notice it for years? The car ran (when it ran) flawlessly until now. There were times when it did not run, but it it either ran well, or did not ran at all (due to broken timing belts or similar). Lewis

Thanks MilesFox for your thoughts! What is MAF? The vehicle accelerates pretty well and smooth and has no flat spots. Since the idle from star-up 1600 goes down gradually as the engine (coolant too) warms up to a fairly stabile 750 doesn't this indicate that the ECU senses the coolant temperature (and its changes) well? Or is there something else that still can be wrong? The "only" problem now I have with it is its tendency to stall when I let the rpm drop to idle while applying the brakes. As I mentioned in my first bringing this whole thing up - a week or two before it got that bad - was that I noticed the idle fluctuating. I don't know if it had anything to do with the problem later followed, but it never did that before throughout the 13 years of use. It dropped down from 750 to around 500 then went up over a 1000 then back to around 750 again. Maybe it had nothing to do with the rest, but sometimes there are "early warnings" before the real trouble comes, but one has to underdstand the signs. So, considering the depth of my understanding how a modern, ECU controlled, fuel injected engine works, for me this might have been an early "cry" for help from the car. Lewis

Hello, Skip: I've sent you an e-mail yesterday reporting my latest tests and findings. I wonder if you received it (or just got fed up with my problems...)? Tested the booster. With my right foot on the brake pedal I started up the engine and it sucked the pedal in about a half an inch or so. Found and connected the test code retrieving plugs (a white and a black or brown in this case) and the LED pulsed an 11, 13 and 14 stored trouble codes. Yesterday I purchased the Subaru Chilton's manual and found these areas in it. 11 and 13 means "Crank Angle Sensor" problems, while 14 is an "Abnormal Injector Output" signal. According to Chilton's the Crank Angle Sensor is part of the Distributor assembly. The Injector's abnormal output must be the consequence of the air leak that I have somewhere. Or it is more correct to say, that the injector output may be right, but the air is too much that goes with it? Test drived the vehicle around the bloc and had good power and acceleration, but still has the tendency to die upon slowing down the vehicle with the brake to a halt or near halt. I can keep it alive if I don't let the rpm drop down to idle. Meaning left foot on the clutch to put the tranny into neutral and the right foot on both other two pedals. After the tranny is in neutral, just one foot per pedal (brake and gas). Also found an illustration in Chilton's about the brake power booster - not a very good, detailed one - but it does not show a check valve. In the text it mentions it. I can't find one on my vehicle! Called the local Subaru dealer and they looked it up and it is supposed to have one in line between the intake manifold nipple and the booster drum. Ordered one (about $26.00), but a matching "Hose Kit" to install it would cost $99.00!). Will use generic. On a start-up from cold it runs at around 1600 rpm that then gradually decreases and finally goes down to around 750. Today I testdrived it again to check if it dies if I don't use the brake to slow it down. First three attempt NO, but the last one when I parked it, it died again. Who understands this? What I still can - and will - do (beside installing the one way valve in the brake vacuum line after the part arrives) is to remove and clean the Idle Air Control assembly. By the way: isn't the Power Steering Reservoir in the way, to access the two lower screws? But as the idle changes from 1600 down to 750 during warm-up suggests that the thing is working (maybe a little dirty after 180,000 miles). What still bothering a little is that it was the last time at least 4 years ago when someone worked on the brake master cylinder (got a new one). How could that check valve to be missing? And howcome its absence did not cause problem only now? Lewis

Thanks Skip for claifying the connectors for me which one is the diagnostic pair and which one is the stored code retrieveng pair. And also their location. That link has a drawing showing all of them under the dash. I received your e-mail, but I wanted to write you after I checked the booster as you suggested. This is the area that is the most suspicious ! The power booster must be working, because every time during this "ordeal" when the engine died I lost not only the power steering, but the vacuum assistance on the brake too. Actually the engine died every time when I used the brake to slow down the vehicle to full stop. But if the engine is just idling and I step on the brake, it doesn't make any difference. If I pay attention and don't let the rpm drop down to idle while stopping/slowing down the vehicle the engine keeps runnung. But back to what I did in that area: About 6 months ago I replaced the vacuum hose that goes from the intake manifold to the power booster. The old one was cracked. I did not even put clamps on it, just pushed it on at both ends. The manifold end went on completely, the other one only about a half an inch or so. It was a piece of 3/8 rubber hose, with realtively soft wall. But it worked even though I did not like the softness of it. A good month ago I replaced this one with a thicker wall hose and put calmps on both ends. After this stalling problem occured - being suspicious of evrything I've done on the car lately - I first disconnected the hose at the manifold nipple and taking the loose end in my mouth I blew air into it and applied vacuum alternately. Under vacuum I expected a certain amount of air coming out, then choking off, but I can suck air out of there indefinitely. Then I blew air into the hose and heard it coming out at the booster drum. Placing my fingers down there I could feel the air coming out. Isn't it supposed to be sealed? Like blowing into a bottle? There must be some flexibility felt because of the diaphram in the booster, but basically it is a closed space isn't it? So this is suspicious enough. Next thing to do was to disconnect the booster end of the hose, reconnect the intake manifold end of it (clamped tight) and then plug the loose end. If the booster has a leak that coused the problem (leaning out the mixture) this would have corrected it, right? Would loose vacuum assistence on the brake, but the engine should go back to normal. But it did not cure it. I plugged the hose with the tip of the rubber coated handle of a pair of pliers, so maybe I will have to place a rubber plug on the nipple on the intake manifold to make a positive seal there. What I'm going to do now is to go down to the vehicle (nice sunshine and hopefully not as cold as in the morning) and do the booster test as you suggested, after warming up the engine connect the code retrieving connectors and check the LED on the ECU. I'll send you an e-mail what I've found. Lewis

I've found the codes for my vehicle, but the connectors' location and color in the article are different from mine. The link says: "Retrieving Trouble Codes 96 & Later ... " Mine is a '90. As you - and others - suggested I have a pair of connectable green plugs at the firewall (engine side) that I used for checking/adjusting the ign. timing. Are these the ones that I have to use to read stored codes too? I don't want to make such foolish mistake like shorting out something that will make finding the cause of the problem harder. Yes I sprayed starter fluid around the intake manifold/head flanges too. Almost used up a whole can to make sure I don't miss any connection, or location for possible air leaks. No change in rpm. Aren't there supposed to be separate pairs of connectors for retrieving stored codes and for diagnostic testing? Lewis

I've re-read the whole thread and couldn't find where you mentioned the location of those plugs. I forgot to do the brake booster test you suggested - it was not out of disrespect. But I sprayed the starter fluid in that area too and the rpm did not pick up. The cracked original vacuum hose I replaced did not have a check valve between the manifold nipple and the booster. The link you suggested is for model year '96 vehicles and the locations and colors of connectors on the drawing are different from mine. All the connectors I've found sofar under the dash are female. Or is my car a lesbian? I will check the ignition check connector area for another pair today - along with the booster test as you suggested. Never had the "Check Engine" light on with the engine running since I have the car. Someone told me that there are "Read Memory" and "Test Mode" connectors that need to be plugged together depending on what you want. Retreiving the stored codes, or do a test on the running engine. Looks like the problem is either the Idle Air Control valve - or the brake booster/vacuum line/check valve. All on the top of the engine fortunatelly, because I have no access to lift or pit to work on the underside. Will take it from here, but I applied the starter fluid very generously and the idle did not change a bit at all. Thanks for your patience and help Skip! Lewis

Thanks, MilesFox! But, please explain in this case what am I supposed to do with those green plugs that I plugged together for the ignition timing. And what to look for or check after I connected them together again? We are talking about that matching - maybe two-wire - green plugs hanging behind the brake fluid reservoir, right? Lewis

Thanks guys again for replying so quickly! Today I started the engine up. First it did not want to rev over a 1000, but then it changed its mind and actually became very responsive to throttle. Almost peppy. Then I sprayed starter fluid all over the hose and flange/seal connections and it did not make difference. I expected the idle to rise, but it did not happen. During initial startup it backfired once or twice into the air cleaner and as I'm writing this I remember that it happened earlier during these experiences. Once, when my right foot was on the brake pedal (left one of course on the clutch) I felt a strong kick on the brake pedal, when the engine backfired. Is that normal? Isn't that is supposed to be a one-way thing (vacuum only from booster to intake manifold)? My Land Rover's booster drum has a replaceable check valve, where the vacuum hose is attached to it. Also let me mention again that when I blow into the vacuum hose's intake manifold end, placing my fingers down at the hose/booster connection (clamp on this end of the hose is tight) I can feel - and hear - the air coming out. Is this normal? Today I also discovered the ECU. There is a LED on it, which is black until the engine warms up. Then it gives RED - not GREEN pulses. I've also found connectors hanging there: a brown one, with two female spade connectors in it (perpendicular to each other), a green one with four similar connectors in it, (parallel in pairs), then a blue one with three connectors (two parallel, one across), and two white/clear connectors - one of them has four round female thingis in it and the other one has five connectors with a sixth space left blank. I used once a pair of matching green connectors - plugged together for the test - to adjust ignition timing. But it was in the engine compartment. A friend suggested it, I did not just figured out it myself. This friend of mine unfortunately left town since then. The LED - after the engine warmed up - started pulsing. Those pulses were of different lenghts. Now I will look up the pages you suggested and take it from there - if I can. But I really appreciate the way you guys hold my hand and try to walk me trough all this! Thanks again! Lewis.

Thanks GD and Skip! Yes, the vehicle is a SPFI. But now we are getting where I have no knowledge of - the electronics. I still have a healthy amount of common sense, so if someone would explain how those things work there is a fairly good chance I will understand. I understand this car has at least a half a dozen different sensors monitoring the operation of the engine and other circumstances. I have a list to tell what those code numbers mean, but have no code reader. I tried at Pep Boys but they don't have one that covers my car. Is there a sure place to find one or I have to call around all the different suppliers? How much is it roughly? In case that green LED on the ECU is blank, do I have to take out and dismantle the unit in order to replace the LED, or is it like replacing a lightbulb? Skip said that the O2 check/indicator LED is supposed to flash green if the sensor is still OK. No light means burnt out LED. What should I see if the LED is good, but the sensor is bad?In case the O2 sensor is bad, where is it? How can I access it? Do I have to rise the car up, or from a pit? I know where the idle control thing is. Is there anything that I need to know to avoid possibly ruining something in the process of taking it off for cleaning? A special gasket, seal, or similar to pay attention to? Lewis

I was not clear I believe. I transferred all the manifold/fuel injection stuff over from the trashed engine to the "new" used - originally carburetted - unit. I understand the cams of the fuel injected engine are slightly different, but that time (about 5-6 years ago) I was not aware of this. New fuel pump installed three years ago. Lewis.

Thanks guys! I hope it will be that simple. The fuel filter is about 8 months and maybe 6000 miles old. Since the vehicle comfortably cruises at 75 mph is it still possible that the fuel filter is - even partially - clogged? Definitely will try the brake cleaner - or starter fluid - sprayed around the top of the engine where it can be sucked in by the engine - if there is a leak there. I tried to shake every visible hose and cable connection on the top of the motor to see if the running would change. So you think it is not some electronic engine control, or sensor problem? Because those I don't know nothing about. Lewis

Hi, all: My name is Lewis and I'm new to this forum. I have a 90 Loyale that I've purchased new. It has 180,000 miles on it, but only about 100,000 on the engine. I've lost the original engine due to a broken waterpump bearing on a cold January night up in the mountains close to the Cal/NV border when I tried to get to a place to call for help. Purchased one of those "Low mileage used japanese engines" and installed it myself, relocating the intake manifold and up, because the replacement engine was a carburetted one, compared to the original SPFI. Anyway I've just done some work on this engine lately, namely: new belts, tensioners, idler, oil pump, hydraulic lash adjusters on the driver's side, waterpump, clutch, rear main seal, throwout bearing, alternator, a Bosch starter, clutch and accelerator cable. It ran like new again until about two week ago, when it started acting up like this: * the idle started fluctuating. Dropping down to around 500 and the rising to over 1000 rpm and back to normal. * the engine stalls after taking off, driving about 100-200 yards. Starts up okay, but it never did that before. And it did not do it all the time, only a couple of times a week. * after a 200 miles drive when I slowed down at a Hwy exit, the engine died. Started up easily. Gassed up the car and it was hard to restart. * another 150 miles okay on the highway, 75-80 mph, but arriving to destination the engine dies when lifting foot off the accelerator and applying brakes. Restart after every stop at a red light. * next day starts up right in the morning, dies at stops, running excellent on highway. Got back home safely. * started up next morning, but won't pick up rev over about 1000 rpm with the pedal floored. * next time it started up and ran "normal" - I mean it is driveable, but dies at stops. It actually can be kept running by paying attention to not to allow it to down to idle. But after that short critical seconds it is willing to idle normally again. I'm not a trained mechanic, but I'm attached to my vehicles, don't replace them every 5 years. Beside this Subaru we own - and drive daily - a '72 Land Rover and a '71 Citroen Mehari. I keep them running. I'm - as they say - mechanically inclined, most of the time even enjoy working on our cars, but this one beats me. Anyone can help me to solve this problem? As a possible clue another detail: I replaced a cracked vacuum line that goes to the brake booster. It is not original part, not even metric, but the closest SAE size (I believe 3/8") and I couldn't really push it on the little upward curved metal pipe that 's sticking out from the booster drum. It was also a soft-wall hose. Then I replaced this with a heavy-wall one and put clamps on both end. When I disconnect it at the manifold end, leaving the booster end attached and blow/suck into it, placing my fingers at the booster drum where the hose is attached, I can feel air coming out when I blow into the hose (clamp is tight). So I thought there is an air leak there. Then I disconnected the hose at the booster drum, leaving the manifold end attached and plugged the loose end of the hose. It did not make difference. Any ideas? Please Help! Lewis