tpm55 Posted March 30 Author Share Posted March 30 On the timing, long story short is that after installing the 10mm oil pump and retiming I felt that the crank sprocket was always off a half a tooth, all other cam marks lined up when the crank sprocket was turned just a bit past its own mark. No matter how many times I redid it the same result happened. Once back in the car and attempted start, my first logical thought was that it was the timing being off causing the no run issue. I took everything off and retimed it and I know at that point the driver's AVCS cam was off one tooth, so I did it one more time counting the teeth and I know its in time now. I would always do 2 full rotations to confirm every time things lined up and that no valves hit each other. I even ran it with the two side covers off and confirmed things still lined up after running for a bit. I think I can confidently say that timing should not be an issue at this time. If a new LH cam sensor does not fix the erratic idle, misfire codes, cam sensor code and then the eventual no start/hard start once hot, I will probably look into other solutions including the possibly the gears may not have been put on correctly. As you said I feel pretty confident that this is not the issue as it started great cold and ran strong with a good steady idle until it started to warm and that is when trouble set in. Hopefully its a simple fix but if not I am open to any ideas. Thanks! Link to comment Share on other sites More sharing options...
Infosecdad Posted March 30 Share Posted March 30 (edited) Running fine cold, but freaking out when warm usually points to a sensor. The ECU will run open loop largely ignoring most of the sensors until the coolant reaches a certain temp, then will switch to closed loop and pay attention to the sensors. If one is flaking out, that would help explain the behavior you are seeing. Edited March 31 by Infosecdad Had switched open/closed loop 1 Link to comment Share on other sites More sharing options...
rhino6303 Posted March 30 Share Posted March 30 5 hours ago, Infosecdad said: Running fine cold, but freaking out when warm usually points to a sensor. The ECU will run closed loop largely ignoring most of the sensors until the coolant reaches a certain temp, then will switch to open loop and pay attention to the sensors. If one is flaking out, that would help explain the behavior you are seeing. This is partially correct/incorrect. Open loop (uses maps and minimal sensors for fueling) is used at cold start and under any "hard" acceleration (several factors met in ecu). Closed loop is alway on once engine is warm (uses oxygen sensors, etc for fueling). This quote is from a thread on the outback forums to be a little more specific: Fueling on these cars starts with the ECM knowing where TDC is. Then it relies on the cam position to manage injector timing. The injector pulse is determined by TDC, Cam position and the AF sensor feedback at any rpm. The cam sensor is affective from start up. Higher RPM utilizes the AVCS system to help the car breath better and in conjunction the spark and fuel injector timing is altered based on feedback from several sensors listed below. CKP CMP MAF IAT MAP ECT AF Sensor(s) Rear O2 Sensor(s) Knock Sensor(s) 2 Link to comment Share on other sites More sharing options...
tpm55 Posted March 30 Author Share Posted March 30 So I had an hour today so I ran over and switched out the cam sensor on the driver's side (Left Hand). For anyone's benefit if they ever need to remove it, I had to loosen the entire intake manifold with the TGVs as the sensor can't clear the back of the TGV where the injector protector mounts, I pulled the entire manifold assembly up maybe a half inch and was able to slide the sensor out and same thing to put the new one in. I did read somewhere people had used a dremel to take off the edge of the mounting tab, I could see this working. Car started right up and seemed to idle fine. I warmed it right up and the radiator fans kicked on. Being winter still in Maine, idling it doesn't seem to get it hot enough to open the thermostat so ill have to wait for a drive for that. The idle once warm still doesn't seem super stable, still seems a hair rough. Revving it and letting it get back to idle speed causes the idle to drop low to the point I think it might stall and then speeds up a bit, but still seems a bit rough. No check engine lights which is good tho, and no codes. Tomorrow I am going to drop the oil and filter and put in motul break in and a new filter and then hopefully take it on its maiden voyage on the new rebuild, see what happens then, lots of engine braking and stopping and going. I am hoping the idle will even out over time, but Ill at least data log and see whats going on and maybe fine tune from there checking for possible vacuum leaks or more bad sensors. I do need to replace the electrical connectors on the coolant temp sensor and the alternator as they are both broken, maybe that is causing a mildly rough idle? I am doubtful but you never know, from all the reading I have done on these different forums, these cars/engines can be a bit fickle at times. But its running and revs fine so maybe it just needs to be driven. Link to comment Share on other sites More sharing options...
birkhoff Posted March 31 Share Posted March 31 Why would the rad fans come on when the engine/rad is still cold? If the T'stat isn't open yet, the rad should be cold/ Is it possible that you are not getting a correct coolant temperature to the ECM? Maybe it thinks the engine is really hot when in fact it is cold. Or the other way around. There must be a few parameters in timing and fuel that are modified by the ECM based on engine temp. I suppose you could log that and see what the ECM sees for engine temp in the first few minutes of running. Link to comment Share on other sites More sharing options...
tpm55 Posted March 31 Author Share Posted March 31 I had the car idling for about 10-15 minutes so it should have been basically up to temp, or as much as I could get it up to temp with it idling in 30 degree weather. Tomorrow I’ll have to go for a drive and data log, but it’s also possible the electrical connector for the coolant sensor is spoty as it is pretty badly broken. I have a new one to replace it so hopefully things will be okay. The temp gauge read about 1/3 of the way up, I didn’t have my accessport with me to actually see exact values. I believe he t’stat normally opens around 205? The fans were def on but the bottom coolant hose was cold still. Link to comment Share on other sites More sharing options...
Infosecdad Posted March 31 Share Posted March 31 I think the thermostat opens at 180 or 190, the fans should kick on at 205 unless the A/C is on. (If I remember right) A bad signal from a coolant temp sensor will cause all sorts of issues. 1 Link to comment Share on other sites More sharing options...
xt2005bonbon Posted March 31 Share Posted March 31 If you just reset the ecu, then it is normal for the idle to be a bit rough when you apply some throttle and then let it go back to idle. The ecu is learning. But it does not take very long to learn especially if it idled for a while. At least, my cars behave like that. 1 Link to comment Share on other sites More sharing options...
kzr750r1 Posted April 4 Share Posted April 4 Needs that coolant reference. Should look at Throttle Body calibration. Pretty much letting the ECU get itself settled. Sounds like your chipping away at it. Link to comment Share on other sites More sharing options...
birkhoff Posted April 16 Share Posted April 16 If you don't fix this via electrical gremlins, another cause for rough idle at temp is valve adjustments out of spec. That would be kind of ironic given where you started this project but did you happen to check the valve clearances after mounting the heads and cams? It is not unheard of for machine shops to get this wrong and it is a quick check on their work before you pack things up. I have a car that suffered from this. Not a fun prospect to do this with the engine in the car. 1 Link to comment Share on other sites More sharing options...
tpm55 Posted April 16 Author Share Posted April 16 I did check before putting everything fully back together, the machine shop I used even had their values written down that I could verify with. Sorry for the slow progress and no updates. Busy between school, work, and wedding planning. Should have some time this weekend to tackle the oil leak from the banjo, drain the trans fluid (well whats left, I had to reboot both front axles so some fluid came out and I figured I'd switch it out with motul while I am at it). Also replacing the trans mount with a group-n 5 speed one. Then an oil change to motul break in and see what happens on the first drive around town, get some data logging in and go from there. My assumption is that Ill end up replacing most of the electrical parts as I believe most are original and after 15+ years of heat and abuse they are on their way out, seeing as one cam sensor was already bad. Either that or I have a small vacuum leak somewhere, I believe the only 2 vacuum lines I haven't replaced are the BPV to manifold and the brake booster to manifold. Maybe the data logging will reveal something as well. But the idling problem when warm points more to something electrical to me, but we shall see in due time. Link to comment Share on other sites More sharing options...
tpm55 Posted April 26 Author Share Posted April 26 So I was able to go for a first drive this morning, did about 30 miles, lots of slow pulls from 2k-4k and then slowly let the engine slow itself down, also a lot of coasting down hills to really get those rings seated/grind into the crosshatching. I know a lot more is still to go but I would say it was a success, no issues of note, low idle seemed totally fine, clutch felt good, I seemed to have fixed my oil leak. I also reworked the IAG turbo/AVCS feed line kit that I bought. The way it was set up it was next to impossible to disassemble, I ended up buying a short 9" section with a 90 that I placed at the banjo running it to the T-fitting that came with the kit which splits to the turbo and AVCS respectively. The other issue with their kit I found, and maybe my head was just weird, but it never seemed to clear the head so I could properly torque the banjo down, which is why they give you a thicker crush washer to begin with. I ended up reversing my 90 so it runs down and then turns directly to the fender where it tees out. I don't see how this could be a problem and it is super easy to get to now, out of the way of the turbo coolant line too. The only thing I noticed is that my oil pressure is generally always around 80-90 while cruising even at low RPMs. Idle its around 35-40 which from reading seemed okay (this is fully warm obviously), but any RPMs at all and it runs higher than what I have read, most say 10 psi for every 1000 rpms. It is 10w40 Motul break in oil in the car now, so it is thicker than what it calls for but that is what is labeled for use for break in on most sites, I doubt the little extra AN line would cause the oil pressure to be that much higher, especially since the banjos control oil flow to begin with, at least the turbo one does. Should I be concerned and look into that more? Or it should improve over time with lower weight oil eventually? My only concern would be the oil bypass always being open. I attached a somewhat crappy photo of my current oiling setup. I have seen similar ones posted on here and people report no issues, but maybe I should replace the other longer lines with shorter ones to reduce resistance a bit? I am also going to examine the datalog I took from the drive and see if everything appears to be working okay. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted April 26 Share Posted April 26 Not answering your question, but what was the problem in the end? Link to comment Share on other sites More sharing options...
tpm55 Posted April 26 Author Share Posted April 26 With the idling? Not really sure. I didn't do anything in an attempt to directly fix it. I did replace the broken alternator connector and broken coolant sensor connector, but other than that I just fixed the oil leak as described above and replaced the trans mount and trans fluid and took a long drive. Idle remained stable. Ill keep updating as I go along and any issues I may have, but so far so good. My assumption is that over time ill have to replace coils and other sensors like the crank and O2, not sure how new/old any of them are other than obviously the crank. Looking at the datalog everything seems okay? I am far from an expert and will be doing a lot of reading on datalogs and proper values. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted April 26 Share Posted April 26 (edited) I'd check the following: -long term fuel trims (should be within +/-5%) -making sure both OCV angles are in sync and the same, whenever the angle is non zero. Usually happens under load. -keep an eye on misfire count per cylinder -knock obviously Both of my cars are still rocking original crank, 02, maf, etc... sensors . I did change one coil pack on each car, but that's it I think. Both 180K+. Edited April 26 by xt2005bonbon 1 Link to comment Share on other sites More sharing options...
birkhoff Posted April 26 Share Posted April 26 Quote 3 hours ago, tpm55 said: With the idling? Not really sure. I didn't do anything in an attempt to directly fix it. I did replace the broken alternator connector and broken coolant sensor connector, but other than that I just fixed the oil leak as described above and replaced the trans mount and trans fluid and took a long drive. Idle remained stable. Ill keep updating as I go along and any issues I may have, but so far so good. My assumption is that over time ill have to replace coils and other sensors like the crank and O2, not sure how new/old any of them are other than obviously the crank. Looking at the datalog everything seems okay? I am far from an expert and will be doing a lot of reading on datalogs and proper values. .... and broken coolant sensor connector . . . my guess is that was a big problem, given the behaviour of the fans you reported and if the ECU thinks the engine is full hot, when it is not, that will mess up all sorts of things. Plus probably intermittent. I wouldn't worry about the oil pressure you are reporting. In my experience it is highly non-linear and should pop up to max with a modest amount of throttle. There is an active relief valve in there. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted April 26 Share Posted April 26 (edited) That's a good point. I know that past a certain coolant temperature, the ECU adjusts a bunch of things such as AFR, timing and probably a bunch of other things. Edited April 26 by xt2005bonbon Link to comment Share on other sites More sharing options...
kzr750r1 Posted April 26 Share Posted April 26 Just take it easy on it for the first 500 miles. Keep out of da boost. Stay on top of the early oil changes. Found coolant sensors very important even on an old 89 CRX. It was running very rich for a long time. After changing was a different animal. Then a Prius blasted me in the rear on the freeway. Still kinda miss that little unit. 30MPG all day long no matter how hard you flogged it. Acura trans, CV and Hubs helped keep it solid till the end. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted April 26 Share Posted April 26 yeah, when the coolant temp goes above a certain threshold, the ECU commands a richer mixture, probably to help cool down the combustion chamber. Link to comment Share on other sites More sharing options...
MrEvanchi Posted April 26 Share Posted April 26 (edited) 31 minutes ago, xt2005bonbon said: yeah, when the coolant temp goes above a certain threshold, the ECU commands a richer mixture, probably to help cool down the combustion chamber. I haven't come across any AFR compensations in my 07 LGT's stock ROM, but it does at least pull timing with extreme coolant and IAT temps. -2.11* @ 212F, -3.87* @ 230F Coolant And -2.11* @104F-158F, -5.98* @176F+ IAT Edited April 26 by MrEvanchi Rephrase Link to comment Share on other sites More sharing options...
xt2005bonbon Posted April 26 Share Posted April 26 I have to check mine. Maybe I am wrong. But I do recall watching my real time AFR values while coolant temps were above 219F (with IAT>110F) and she was running rich. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted May 1 Share Posted May 1 This is what I found in my 05 ROM. Timing compensation when running real cold or real hot. And there is in fact a fuel compensation table based on coolant temp. However, as you can see, the current set up does not affect fuel enrichment if the coolant temp is real high. So me seeing rich situation when running hot was probably from some other reasons (e.g. high boost situation). 1 Link to comment Share on other sites More sharing options...
tpm55 Posted May 11 Author Share Posted May 11 Well I have 150 miles on the new shortblock and rebuild, knock on wood, so far so good. Only issue that has come up is I am getting the code p0420 regarding a malfunctioning cat. The car seems to run fine, looking at the datalogs I have been doing don't show any obvious issues, AF correction/learn is within normal limits, MAF sensor readings look okay. I did buy a new rear O2 sensor before putting the car back together as when I was trying to remove the downpipe from the turbo it slipped and was hanging off the O2 sensor wires for a bit. I am wondering if this is what is causing it? Seems like there are a lot of possible reasons this code gets thrown from my readings. There also appears to be a small bit of hesitation/stuttering from about 2.2-2.6k rpm, nothing real bad, but just noticeable enough. Possibly its a fuel quality related issue. I did fill the tank up with 93 and seafoam prior to even tearing the engine apart months back, I doubt that is the culprit but you never know I suppose. I did install a stock 2019 sti catback on the car as the old exhaust was rusted out, I can't imagine that is causing an issue either. Not looking forward to getting the O2 sensor out to replace. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted May 12 Share Posted May 12 Stock downpipe? Also, you are probably suffering from the famous stuttering almost everyone (including me) has been complaining about. Link to comment Share on other sites More sharing options...
tpm55 Posted May 12 Author Share Posted May 12 Yeah it is the stock downpipe. Always a chance it went bad, but hopefully not. I always wanted to eventually get a better downpipe for it and then have it tuned but I am already a bit over-budget at this point, but I may have to anyway. We will see after replacing the rear O2 sensor and go from there, seems like there are a lot of possible reasons for that code, so I guess ill continue to troubleshoot. As for the stumbling, I did read about the blue T causing issues with the FPR but I believe that is for the 05-06 cars, didn't really read much on the later years and what could cause the stuttering. Its not super noticeable, or not nearly as bad as my 99 Nissan Maxima back in the day. At WOT that car was stumble heavily with its bad coil packs. This is just perceptible enough. Link to comment Share on other sites More sharing options...
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