mikeamondo Posted February 6, 2007 Share Posted February 6, 2007 Hello again... I'm still dealing with my old '90 Legacy, "Blubaru". He's blue. Anyway.... there are two issues and I think they are unrelated, but I'm curious to see what you guys think.... Here's the story. Problem 1: When the fuel tank gets below 1/4 tank, the car starts to run rough. It will also stall at intersections, with the miss becoming worse and worse as the tank empties. If you fill up the tank, the car runs fine... doesn't miss a beat... until the tank gets low again. This sequence is well established, and is not intermittant. It does this on every tank full. My guess on this one is...... Weak Fuel Pump. Less gas = less pressure pushing gas out of the bottom of the tank, leaving the system to rely more on the pump, which being weak, fails to provide enough fuel..... What do you guys think? Problem 2: Drove the car into town in the morning. Let it sit most of the day and started home. About 5 miles into the drive home, the car lost power at all throttle settings except for the first few inches of pedal travel. From standstill, the car can accelerate slowly, with very little pedal... but if you push the pedal further down, the engine "Bogs down" and sputters.... even backfires through the carb. Let off again and it will catch and run... very slowly speeding up. If you're on level ground, you can get her up to 40 or so... uphill only about 20.... Anyway, we limped the car home like this and then let it sit for a day. Today I went out and checked the codes. The CEL has been coming on now and then for a while. Codes came up as 32, 33 and 35. Then I connected the green connectors, followed the instructions and drove the car. Ran perfectly. Never missed a beat. Drove for over 10 miles. Nada. Codes are O2 Sensor, VSS and Canister Purge Solenoid. The canister purge thing has been coding for a long time.... hasn't seemed to mess up anything before. The O2 sensor was changed only a couple thousand miles back. So... whatcha' all think? Since it seems to be running okay now, we're going to take the car into work tomorrow, so maybe it will repeat the issue and I can reconnect the greens and see what it codes whilst messing up. Thanks! Mike Quote Link to comment Share on other sites More sharing options...
Manarius Posted February 6, 2007 Share Posted February 6, 2007 1. Car doesn't have a carb so... 2. I think fuel pump as well. Is this 1/4 tank by gauge standards or when it does this, can you actually put 12 gallons in the tank? The gas gauge in these cars usually starts to lie by this point in time. 3. The fact that the ECU is throwing a code for the VSS means that you need to fix that. The VSS is probably causing the ECU to go into limp mode which is why the car would drive so slowly. Quote Link to comment Share on other sites More sharing options...
nipper Posted February 6, 2007 Share Posted February 6, 2007 Is this 2wd or AWD ? nipper Quote Link to comment Share on other sites More sharing options...
mikeamondo Posted February 7, 2007 Author Share Posted February 7, 2007 The fuel guage in the car is a liar. Works about half the time, so we reset the odometer. Not sure if it's exactly at 1/4 tank, but certainly close. The fill up the other day that fixed the problem was maybe 11 gallons? The car is AWD... sorry I left that out. So.. the VSS. How hard is it to change that? Arn't those mounted in the tranny somewhere? Wait a minute.... I think I changed a VSS on this car. I'll need to check my records, but doesn't it mount low on the tranny, right at the fire wall, with one bolt into the housing.... I might be thinking about my Bonneville. Are there one or two VSS's? The one I changed was a VSS1.. so if the Sub only has 1, I prob. changed the Bonnie's. Too many old, decrepit cars. Thanks! Mike Quote Link to comment Share on other sites More sharing options...
OB99W Posted February 7, 2007 Share Posted February 7, 2007 Hello again... I'm still dealing with my old '90 Legacy, "Blubaru". He's blue. Anyway.... there are two issues and I think they are unrelated, but I'm curious to see what you guys think.... Here's the story. [...] What maintenance has been done recently? Specifically, when was the fuel filter last changed? Was the replacement O2 sensor an OEM unit? The trouble code may be misleading, anyway, because a sufficiently badly-running engine due to other problems can confuse things. By the way, have you looked at the fuel tank filler neck? They tend to rust out, and Evap system trouble codes don't always point to the actual cause. Check for bad lines while you're at it. Quote Link to comment Share on other sites More sharing options...
mikeamondo Posted February 7, 2007 Author Share Posted February 7, 2007 Fuel filter was replaced not to long ago.... 8 months or so? The fuel filler neck did in fact rust out and was replaced a month ago..... an odd side note, however... a week or so ago we started having a problem filling up the car.... the gas has to be trickled in slowly or else it backs up and shuts off the pump... I've filled the tank several times with gas cans (a free gas program through Giant Eagle stores gives you "up to 30 gals" at a big discount or free... so I fill the car and three gas cans to get all 30 gals.....) and my fear is, perhaps I let a cap or something fall down in there partially blocking the filler tube.... I can't think of anything else that could be down there. Would that play into these issues at all? The O2 sensor, I believe, was a Bosch... but I can't remember for certain. The problems are certainly intermittant... we drove the car about 12 miles this morning and the old boy ran great! Didn't miss a beat and threw no CEL codes at all....... Mike Quote Link to comment Share on other sites More sharing options...
WoodsWagon Posted February 7, 2007 Share Posted February 7, 2007 If the problem goes away when you hook up the green connectors, it's not the fuel pump. Having a bad VSS will cause it to accelerate OK if you lead it up to speed with the accelerator, but fall on it's face if you floor it. If it's a manual tranny, the VSS is in the spedometer head in the dash. If it's an auto, it has another one in the tranny. The car drives like the suck when the VSS is broken. When the green connectors are together, the CEL will flash codes as you drive, but the problem with the acceleration will be mostly gone. Quote Link to comment Share on other sites More sharing options...
OB99W Posted February 7, 2007 Share Posted February 7, 2007 Fuel filter was replaced not to long ago.... 8 months or so? The fuel filler neck did in fact rust out and was replaced a month ago..... an odd side note, however... a week or so ago we started having a problem filling up the car.... the gas has to be trickled in slowly or else it backs up and shuts off the pump... I've filled the tank several times with gas cans (a free gas program through Giant Eagle stores gives you "up to 30 gals" at a big discount or free... so I fill the car and three gas cans to get all 30 gals.....) and my fear is, perhaps I let a cap or something fall down in there partially blocking the filler tube.... I can't think of anything else that could be down there. Would that play into these issues at all?[...] Gas and water don't mix... ...okay, I'll elaborate . I'm not sure exactly what's going on with your car, but here's some food for thought: Fuel tank filling problems are (of course) usually due to obstructions; that can be at the filler, or tank vent. Rust from the filler could have found itself a home in the tank, etc. Water tends to condense in fuel tanks, especially with the temps we've been having in the eastern US lately. If I'm understanding your fueling habits, you're letting the tank get pretty low before refueling; that makes the condensation problem worse. Water in isolated pockets can freeze. A few cans of "dry gas" (anhydrous alcohol) might help if water is a problem, assuming you're not already using gasohol (E10, etc.). Quote Link to comment Share on other sites More sharing options...
mikeamondo Posted February 7, 2007 Author Share Posted February 7, 2007 Thanks for the input! We'll be checking the filler tube and vents to see if they're blocked... we normally don't let this car run nearly dry, due to the sputtering at low tank problem..... I normally fill the other car and three cans and then pour the cans into this car. As far as the VSS.... the descriptions here of the VSS fail mode seem to match what we've seen.... but to clarify... hooking the green connectors didn't neccessarily make the problem go away..... the problem simply did not repeat itself while they were connected. After I unconnected them, we drove the car 12+ miles (so far) with no further problem. Which leads to the next question: Can the VSS fail intermittantly, or is it a die suddenly kind of part? AND.... Where can I get instructions on how to replace it. Is it a fairly easy job? The car is an automatic... so does that mean there are two VSS's and if so... which one is bad? These questions and more will be answered in our next exciting episode of "Blubaru - King of the Soobs!" Thanks guys! --Mike Quote Link to comment Share on other sites More sharing options...
newsance Posted February 8, 2007 Share Posted February 8, 2007 This could also be a failing fuel pump on both issues. The rough running at 1/4 tank could be because the fuel pump starts to overheat when it doesn't have a full tank of fuel to cool it. The issue of it falling on its face past part throttle can easily be a fuel delivery problem, where the car is only getting adequate fuel under light loads, which could be a deteriorating pump as well. Quote Link to comment Share on other sites More sharing options...
johnceggleston Posted February 8, 2007 Share Posted February 8, 2007 the 90 legacy A/T has 2 speed sensors. VSS#2 (for the speedometer) is on the front right of the trans visible from the passenger side rear of the engine compartment. it's abpout 1 - 1.25 inches in diameter, and threads in the trans housing. there is a cable (stiff black thing) comming off of it which finds it's way to the speedometer. possible problems are broken cable, gummed up cable, frozen cable... etc. or there is the possiblity that it is the speedometer, bad unit , bad connection, bad.... it's electric. (in 95 - 99 the VSS#2 is only a sending unit sending electric info to ther speedo. in 90 the cable relayed mechancial turns to the speedo and the electric work was done there.) there is a second one, VSS#1, on the AWD unit in the rear of the trans, very different. rumor has it that when the front one dies the second one takes over, but i thaink this may be for later models only. this is just foe the AWD unit. you should be able to get one used or certainly new online, and not too expensive. easy to replace, i think. but you need to determine if it's the VSS#2, cable or speedo. try: posting a wanted ad here or http://www.carpart.com and search. Quote Link to comment Share on other sites More sharing options...
nipper Posted February 8, 2007 Share Posted February 8, 2007 The reason i asked FWD vs AWD is because a AWD soobie has a split tank, and uses a "jet pump" (siphon) to move fuel from one side of the tank to the other. The 1/4 tank sympton is telling me that the fuel pump is not strong enough to make the siphon action work. Thats why your running out of fuel when you (knowing suabru fuel senders) have 1/4 tank or more left. about 1/4 tank is where the seperation is for the two parts of the tank. nipper Quote Link to comment Share on other sites More sharing options...
mikeamondo Posted February 8, 2007 Author Share Posted February 8, 2007 Well, it seems to me that the best plan of action would be 1) replace the fuel pump first and see if that fixes the low fuel problem. Then replace the VSS if it is cheap and easy to do so and maybe wait to see if the problem reappears if it isn't cheap and easy.... How hard is it go change the fuel pump? Where can I get instructions on the how to do it? How do I determine what part of the VSS system failed to throw the 35 code for VSS? How do I know whether it's VSS1 or VSS2? --Mike Quote Link to comment Share on other sites More sharing options...
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