Subarutex Posted September 27, 2005 Share Posted September 27, 2005 8 months and counting... car still runs like poo. Engine is a fresh rebuild with fresh pistons and rings. Copper head gaskets torqued to infinity, delta cams (mild grind) and tdo4 turbo, custom fuel system, wrx intercooler with stock bov to atmosphere. Cam timing is as on as its going to get, ignition is timed at 22 degrees. Fuel pressure is set at 20psi. Car usually starts, but really won't idle. Will hold 2000rpms steady all day long though. Trying to get it to idle on its own, it will occasionally backfire into the intake. Gas is new 92 octane (shell). If you try and hold it at 3000rpm it will suddenly fall out, and drop to factory idle even though you haven't changed throttle position. I just replaced the coolant thermo sensor as it was throwing a cell, now that is all clear. I haven't begun tweaking the SAFC, as I'm still unhappy with the performance without it. What could be wrong? Injectors? Plugs? Sensors? I really need to get this car running good so I can get it out of here. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted September 27, 2005 Author Share Posted September 27, 2005 One more thing... Car spent 10 days at a local Subaru Tech's house, he changed the following: Vaccuum hose routing, and fuel pressure and ign timing. He also diagnosed that it was my oil pump causing problems. Not pumping up the lifters and not allowing the valves to open all the way. So I replaced the oil pump, and still similar results... however I only have about an hour of run time on the motor since, and It hasn't been driven at all. I'm afraid to drive it (i've lost too many motors!) Quote Link to comment Share on other sites More sharing options...
Scoobywagon Posted September 27, 2005 Share Posted September 27, 2005 Inexperienced as I am with this sort of thing (performance building), I'll take a SWAG...Have you looked at your throttle position sensor? If the ECM is getting some whacky signal from the TPS, then it will do some whacky things. Have you ever had your injectors cleaned/tested? Frankly, I'm thinking I'd make the engine as basic as possible and build back up from there. Remove the IC and BOV, any boost controller you may have and anything else that isn't ABSOLUTELY NECESSARY to make the car run. Get it running, then add all that stuff back in one piece at a time. Add a piece, re-tune. Another piece, retune. Wash, rinse, repeat. I'm an inexperience performance builder, though, so don't take ANY of that as holy writ or anything. Cheer up, though. You'll get it running. I, and others, have faith in you. Quote Link to comment Share on other sites More sharing options...
Guest shadow Posted September 27, 2005 Share Posted September 27, 2005 I would (obviously) look to the fueling system in cases such as these. I know you have done extensive work in the rails and I guess something in the controls section now as well. For starters I would just take the time and go through and troubleshoot your sensors and wiring harness connections firsthand. A little time with a meter, a small wire brush, silicon grease can really do wonders for strange problems. You can use a small screwdriver to bend the female connectors to tighten them up a bit on the pins. Second, I'm not sure why your fuel pressure is so low? The specified pressure is 36 psig @ 1 atm manifold pressure. At say an average value of 24" of mercury at idle, the pressure should be around 24 psig. I hope you are not using a rising rate regulator, I'm sure you probably know how I feel about those, I can't remember if yours was a rising rate or just an adjustable constant rate. An adj. constant rate would seem to be the most beneficial to you w/ the SAFC. You can use the regulator to bump up the baseline PSI a few notches which in effect increases the 'size' (flowrate) of the injectors while maintaining a predictable fuel curve. Thus you can use the SAFC to pull nearly a set percentage of the incoming air value until you get to the point on the boost map where you actually need the extra fuel. This should get you to idle and cruise properly with minimal hassle IRT the safc and fpr combo. IF by chance you have a rising rate adjustable - I would set the base pressure at the factory stock pressure. This will keep you in range so that the factory ecu should idle properly without adjustment. Use the safc to pull fuel as necessary at higher rev ranges. One other note, make sure you check the MAF signal on the ecu side of the safc during troubleshooting to ensure the safc is not introducing some error of its own due in part to maybe a bad unit, etc. The MAF may read good but that signal might not reach the ECU in such good condition. I hope that is of some general help, I wish I was out there so I could help you with it in person. I would like to see your RX become a real force to be reckoned with on the west coast. P.S. the Delta grinds have been reported to wear fast and I suspect this is due in part to improper breakin. I personally have no experience with Delta, but other cam mfr's and engine builders/books recommend running in the cam right away at 2500-3000 RPM's right after install for 20 minutes. Idle is the worst condition for a reground cam - there is not enough oil and it causes faster wear than any other running state for regrinds. Idle as little as humanly possibly for the first 3-5000 miles. This could be your lifter problem if the procedure was not followed. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted September 27, 2005 Author Share Posted September 27, 2005 I plan to attack the sensors with a meter, see if anything is skewed. I'm debating getting the injectors cleaned/flowed. There is a place that will do all 4 for $60 or so. www.witchhunter.com My regulator is a rising rate (just like the stock) at 1:1. I would not be foolish and run one of these 4:1 or 7:1 regulators. I'm not sure whats up with the pressure either, I'll try upping it again. However, I had it at 36psi prior to having the tech look at it, and he lowered it cause he thought it was running to rich (lots of unburnt gas coming out the back) Perhaps this indicates an injector problem? The TPS might be the problem with the falling rpms with constant throttle... but i've already gone through that system once with a meter when I converted to a spider intake. I also realized that i have cheesy autolites still in it, I have a set of NGK's ready to go in, just forgot that I hadn't done it yet. That is a good idea to check the MAF voltage after the SAFC... Even though the SAFC doesn't have anything programmed in it, and it should just be passing the signal through, you never know. How would you go about testing that? It seems unplugging anything would make the car not run... Quote Link to comment Share on other sites More sharing options...
Guest shadow Posted September 27, 2005 Share Posted September 27, 2005 A "rising rate" fuel pressure regulator is one that has a constantly variable rate in relationship to the manifold pressure, i.e. it is not linear. It may start out at a 1:1 and then as manifold pressure rises the rate will change as it comes up. It is like setting the gain control on an audio amplifier, a input of 2db might yield 4db out, but an input of 3db could yield 10db out. Rising rate regulators usually have a base pressure adjustment and a "rate of gain" adjustment. If a FPR is 1:1 or can be set to other constant values, like 2:1, etc that is a constant rate fuel pressure regulator. The key thing here is the multiplier value or "rate" never changes during operation. You will see this concept butchered everywhere which can make it very confusing, car forums and even many online stores improperly list regulators with alarming frequency. Many people will refer to a non-1:1 regulator as 'rising rate', although the 'rate' is constant (linear). Of course I would say the best choice is a constant rate 1:1 ratio FPR with an adjustable baseline pressure. I use sewing pins to monitor wires, just stick 'em through the insulation anywhere, you can measure the voltage from the MAF on both sides of the safc with the car running this way. If the wires are under hood I usually dab a bit of silicone RTV or liquid electrical tape on there to prevent corrosion, inside the cab I don't worry about it. Injectors cleaned and balanced is always a good idea. It's possible you have a leaky injector which is never a good thing when your trying to sort out problems. Quote Link to comment Share on other sites More sharing options...
kingbobdole Posted September 27, 2005 Share Posted September 27, 2005 Sounds like a fueling issue... the tech thought it was too rich at 36 psi so he knocked it all the way down to 20? Try pumping it up 2-4 psi at a time and see if that helps... Quote Link to comment Share on other sites More sharing options...
tizzle Posted September 27, 2005 Share Posted September 27, 2005 My RX has been on my nerves too lately, and every time I try to fix, or tune something, it just drives worse. I just sent my injectors out to RC, so we will see what that does. Check your plugs to be sure. fuel filter? keep us updated. Quote Link to comment Share on other sites More sharing options...
4WDFrenzy Posted September 28, 2005 Share Posted September 28, 2005 Hey Tex, I am with Shadow on this one. It sounds like a fuelling problem. Factory pressure is 36psi. I have a sneaking suspicion that the low fuel pressure has alot to do with the problem. I do have a question for you concerning the ignition timing. Do you have it at 22 degrees above top dead center or 22 degrees below top dead center? Quote Link to comment Share on other sites More sharing options...
Subarutex Posted October 3, 2005 Author Share Posted October 3, 2005 Ok, new update. Cleaned and flowed injectors in (240cc @ 43.5 psi). Fuel pressure adjusted back up to 35-36psi. Tweaking the SAFC, I was able to get it to idle at 800rpm. However, it was only the sub 1000rpm field I altered. Idling and offboost driving is acceptable. However, boost starts to come on at 50-60% throttle about 2500rpm. This bogs and chokes the motor. My narrowband says its 12.3-11.1 rich. However, if I feather the throttle and keep it out of boost till 3500rpm or 4000rpm it will really pick up (well as good as 5psi goes). Little narrowband shows 13's. I'm going to re-time it tonight. Probally going for 22-24 degrees. Ideas? Thoughts? Quote Link to comment Share on other sites More sharing options...
Cougar Posted October 3, 2005 Share Posted October 3, 2005 The problem sounds like valve timing to me sorry to say. Quote Link to comment Share on other sites More sharing options...
bulwnkl Posted October 3, 2005 Share Posted October 3, 2005 How were the injectors? Did witchhunter do a good job? Okay, my thought (worth slightly less than you're paying for it;) ) is this: You altered the SAFC's below-1,000-rpm programming and it fixed the idle, so that sounds to me like the underlying problem is the SAFC. How about fiddling with things above 1,000-rpm? I don't know much about these things, but that would to make sense to me. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted October 3, 2005 Author Share Posted October 3, 2005 How were the injectors? Did witchhunter do a good job? Okay, my thought (worth slightly less than you're paying for it;) ) is this: You altered the SAFC's below-1,000-rpm programming and it fixed the idle, so that sounds to me like the underlying problem is the SAFC. How about fiddling with things above 1,000-rpm? I don't know much about these things, but that would to make sense to me. The injectors turned out great. Unfortunately, I had a set other than the ones in the car cleaned... So i don't know if any of the old ones were leaky or bad. But the new ones are clean, and flow all within 1 cc of eachother, thats pretty darn good! I have thought about tuning the SAFC to try and correct the problem... but it doesn't seem like it is a too much/or too little fuel problem... could be though... Quote Link to comment Share on other sites More sharing options...
JWX Posted October 4, 2005 Share Posted October 4, 2005 I hate to ask agian, but are you sure the timing belts are dead on? it does kinda sound like vavle timing. or some sensor(s) somewhere is messed up, but not bad enough to throw a code. Quote Link to comment Share on other sites More sharing options...
bulwnkl Posted October 4, 2005 Share Posted October 4, 2005 I have thought about tuning the SAFC to try and correct the problem... but it doesn't seem like it is a too much/or too little fuel problem... could be though... You're probably right. Like I said I don't really know about that stuff. This was the post that really makes me think this is a fuel problem: My narrowband says its 12.3-11.1 rich. However, if I feather the throttle and keep it out of boost till 3500rpm or 4000rpm it will really pick up (well as good as 5psi goes). Little narrowband shows 13's. If the A/F ratio in the exhaust is wrong, there are a couple of likely reasons. 1) The intake is blocked/plugged/stuffed up somehow. 2) Dripping/leaking/etc injectors 3) Bad info at the ECU causing it to create a too-rich condition. I believe that #1 should NOT mess up the mixture because the computer will "see" how much air is actually coming in... unless the SAFC is throwing things off or the FPR is causing so much of an increase in fuel delivery that it is beyond the ECU's ability to trim back far enough. I think you took care of #2. #3 could be from various sensor sources, I suppose, though just off-hand I'd suspect the SAFC given your success under 1,000 rpm with a little reprogramming. The fact that the rich condition only shows up under higher boost appears to me to argue very strongly in favor of the source of the problem being the SAFC or the FPR (or both in combination?). I hope my comments are taken ONLY for what they're worth; I've never messed with some of that stuff myself (SAFC). I'm thinking more along general troubleshooting lines than programming lines. Quote Link to comment Share on other sites More sharing options...
oddcomp Posted October 4, 2005 Share Posted October 4, 2005 unplug your coolant temp sensor the one with 2 wires if your temp sensor is either bad or has a bad connection the ecu will think the car is dead cold and will add more fuel than needed to help it "warm up" i made a mistake like that with my megasquirt install .. shorted out the temp sensor wire to ground the megasquirt thought it was -40 degf and was just pretty much dumping fuel into it btw how far away is where you at from where i am at? Quote Link to comment Share on other sites More sharing options...
JWX Posted October 4, 2005 Share Posted October 4, 2005 wrx intercooler with stock bov to atmosphere. that could be the problem aswell. I've never had trouble with it but others have from what I've read. Quote Link to comment Share on other sites More sharing options...
ezapar Posted October 4, 2005 Share Posted October 4, 2005 8 months and counting... car still runs like poo. . . . I really need to get this car running good so I can get it out of here. I couldn't say it better myself. Except to say, "Impreza". Quote Link to comment Share on other sites More sharing options...
oddcomp Posted October 5, 2005 Share Posted October 5, 2005 eh a atmosphere bov on a maf system usually causes problems depending on the type of bov something like a hks ssqv were it stays closed until you let off the gas and the vacum + boost push it open on maf systems that wil usually cause a minor if any hiccup/backfire in the exhaust now like the kind on my turbo dodge minivan that one hangs open at idle and cruise and closes down once 0 manifold vacum is reached and the boosting begins those "hang open" style really play hell with a maf based injection system since the maf is metering fuel for air that passes thru it and then just gets dumped out of the system except under boost causeing a over rich idle and cruise and on catless cars is usually acompanied by the "fireball out the exhaust effect" when shifting under boost just for fun pull the bov so the bov is closed down plug the vacum line and then try and drive it Quote Link to comment Share on other sites More sharing options...
wes200x Posted October 5, 2005 Share Posted October 5, 2005 Have you degreed the cams to make sure they ground them right. Delta cams messed up another guys EA82 cams and they had to replace one. Your timing marks may be dead on but that doesn't mean the cams are. Put a degree wheel on the cams and check to see if the specs on the cams measure the specs on the sheet. The only thing that really sucks is that you would have to pull the motor to get a degree wheel on the motor. As for the super afc I would disconect it until I had the thing running good. I run a HKS super afr and I always put a jumper between the afr'ss maf signal wire when I am having problems to make it seem like it is not there. Also check the instructions on the super afc. My afr had to have a 5v digital square wave rpm signal like alot on new cars have. This involved buying a piece that converted the stock analog signal to a digital signal. Even if it doesn't say I would call Apexi and see if the super AFC will work off an analog rpm signal. On the stupid side since I did it once. Check to make sure the vacume lines are good. My car was doing the exact thing and it turned out the line from the manifold to the auxilary idle control valve had come off but it looked like it was still connected since it was just sitting on the end. It would rev up if you kept it off boost and after about 4 lbs. it would completely go back to idle. Also it idled like crap from the huge vacume leak. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted October 5, 2005 Author Share Posted October 5, 2005 Last night I checked for vac leaks again, and retimed it. Gave it another 3 degrees, so its at 23 degrees now. Seems a bit better. New plugs should go in the next time I have some spare time (this weekend) what should I gap them at? Quote Link to comment Share on other sites More sharing options...
NoahDL88 Posted October 5, 2005 Share Posted October 5, 2005 factory spec is .039-.043 if you have a good coil i'd gap them at .045, on that note, if you have an accel coil you might swap that out and see if that helps. Quote Link to comment Share on other sites More sharing options...
Subarutex Posted October 5, 2005 Author Share Posted October 5, 2005 factory spec is .039-.043 if you have a good coil i'd gap them at .045, on that note, if you have an accel coil you might swap that out and see if that helps. Stock Coil. Will be NGK's... so what should I go for? .039? or bigger .043? Quote Link to comment Share on other sites More sharing options...
bulwnkl Posted October 5, 2005 Share Posted October 5, 2005 More boost makes it more difficult for the coil to push the spark across the gap, so you might go to the narrow side of the gap range since you're having running troubles anyway. Just a thought. Quote Link to comment Share on other sites More sharing options...
WJM Posted October 6, 2005 Share Posted October 6, 2005 Ive had no problems with 0.050......and that was when i was runing 2 steps colder with 15 PSI on TW header/DP, STI TMIC+intake. sounds like a tuning issue with the SAFC, or definatly cam timing. I know that out of the 20+ cars I have installed SAFC's in...they seem to run fin with 'default' values...but are still funky until properly tuned. Keep playing...we are not allowed to have only 3~5 fuctioning RX's on USMB. We need WAY more. Quote Link to comment Share on other sites More sharing options...
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