Guest bastaad525 Posted September 8, 2003 Share Posted September 8, 2003 I really need some input here... anything, something... been having a hard time getting replies lately, but now I'm completely stuck and f**ked. Got the head completely back on today, everything put back together, and fired up the car. First thing I notice, and I expected this fully, is that the motor still runs very erratically with a bad miss, when it's revved above 1000rpm. Below 1000 it seemed to be fine. It's not a gradual thing, at exactly 1000rpm, the TPS goes open, the timing retards, and the car very suddenly goes from running fine to running like crap. This is the same problem I've been having for like 1 1/2 mos now, and before I had the head rebuilt. I did a little test today though. I disconnected the TPS, and immediately the idle got bad, lumpy, the same way the car runs above 1000. Then I took a jumper wire and stuck it into the two contacts on the wire that goes to the TPS, immediately the car runs good again, and if I rev it above 1000, it seems fine. So something is happening when the TPS is going open to cause the car to run like crap. I've checked all the sensors and they are all working. I've changed the cap/rotor/coil/plugs/wires/02 sensor/head temp sensor/tps/ECU. So it's gotta be something in the harness, a bad ground or a bad harness altogether. Does anyone have any idea what else it could be? and someone PLEASE PLEASE PLEASE answer me this question, what will/should happen if I try to drive the car with the ECU tricked into thinking the TPS is always in the idle position (if I just leave that wire jumper in there)??? It seems to rev perfectly just sitting in neutral, but I would think that if the TPS were always closed the injector pulsewidth would never change nor would the ignition timing. OR, does it just cause the car to run in closed loop mode (or is it open loop? the mode it runs in when the car is cold). I would have just tried driving the car like this myself and see what happens, but then the 2nd problem happened. Smoke from the exhaust. LOTS of smoke. Oil smoke. Of course first thing I did was hook the TPS back up to see if that was it but nope. It doesn't smoke at idle, but as soon as you rev it a ton of oil smoke comes pouring out of the exhaust. But it gets more interesting.... First thing I think, is oh sh*t my rings are bad and now the block needs to be rebuilt too. BUT, asides from the electrical bug mentioned above, and how the valve mysteriously got stuck/bent, the car ran FINE before. NO smoke AT ALL from the exhaust. So I pull the spark plugs, thinking one of them will be covered in oil... if only I were so lucky. ALL SIX spark plugs were covered in oil!!! ALL F'ING SIX! So I'm thinking... there's like .000001% chance that the block would go to no smoking at all, and a good even compression test, to suddenly all six cylinders are burning oil??? So I think... Maybe the turbo oil seal? Oil coming in upstream would burn in all six cylinders. So I pulled the J pipe back off. Mind you, I had cleaned the Jpipe out before I put the BOV on it, so there was no oil residue inside of it. Well I pulled it off today, and it's still squeaky clean, not one sign of oil in the pipe, so the turbo seal must be good right? I was thinking that the PCV system can cause symptoms like this, but weve elimated the PCV from the loop altogether. The port where the PCV valve would attach to the intake manifold has been welded closed, the pipe coming out of the block has just been left open to atmosphere, the hose running from the valve cover to the AFM-to-turbo boot has been removed, the opening on the boot blocked, and the valve cover also vented to atmosphere. So theres no way for the engine to be sucking oil in from there. So what else could cause all six cylinders to suddenly start burning oil like this?? I am so pissed off right now and so sick of dumping money into this car to fix one thing just for something bigger to go wrong. I can't afford to rebuild the block if that's what it is, but again, it doesn't make sense that it would be all six sets of rings. The head shop that rebuilt the head has done two heads for me in the past and has always done good work. Even if they messed up somewhere, say the guides were bad or the valve seals it still doesn't make sense to be happening in all six cylinders. I pulled a couple of the valve seals and they were definatley new and definately installed right, and I also checked the valve stems for side to side play and the stems were definately tight in the guides. So I'm really at a loss here. Anyone with any ideas......please.... I will throw some "Restore" or "CD-2" into the engine oil. A couple guys I know who had tired engines that were burning a little oil and smoking a little, put this stuff in there and they say that it helped, I guess it helps the rings to seal. I'm not expecting any miracles though. I also thought to try putting some ATF in the engine oil, drive it for a while then do an oil change, see if it cleans it out and helps any, but again, I expect no miracles. Anything else I can try???? Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 9, 2003 Share Posted September 9, 2003 Update Threw some "Restore" oil in there, put the battery back in and went for a drive. I decided to just try my idea and put the jumper wire in the connector that goes to the TPS, to trick the ECU into thinking the TPS is always closed. As I expected, the car ran much better this way, idled better, no miss and stutter off idle, pulled really hard all the way up to 6k.... there'd have to be a downside though right? Yep... ping. When I'd get on it, and the boost would hit 9psi it would start pinging. Reconnected the TPS, and the car goes back to running like crap, but wont ping when I floor it all the way up to 6k revs at 9psi. So, I took the boost controller out completely , and tried the jumper in the TPS connection again, and the car ran perfectly and wouldn't ping any more. So I'll just leave it like this for now. Apparently my guess was pretty close... tricking the TPS like that seems to put it on a leaner, possibly fixed fuel curve, and cant compensate for any boost over stock levels. But it will definately run and run well this way.... but only at 7psi I guess it's better to remain at stock boost levels until I figure out if my engine is shot anyways, eh? At any rate it may still be a moot point, the motor is still smoking pretty bad, not all the time, not even all the time when I rev it, but every so often it will let out a big puff. A few people I know have used the Engine Restore stuff, and they say after a few days their cars stopped smoking and seemed to be running better, and one guy swears that it raised his compression way up when he retested it after testing and finding low compression on 3 out of 4 cylinders. So... I'm crossin my fingers that it will at least hold up til I can figure out and fix whatever the rest of the problem is... just enough to get me to work and back. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 9, 2003 Share Posted September 9, 2003 Hmm - Suddenly burning oil after head rebuild - did the guy forget to put the valve seals in? Take the valve cover off and check for the seals on the stems of the valves (inside the valve springs). Apart from that - nothing else I can think of that would cause all 6 to burn oil. As for the Bosch problems - I can't help - I throw the stock system in the trash when I do a conversion. Good luck - Doug Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted September 9, 2003 Share Posted September 9, 2003 Sorry - My bad - didn't read all the post. If I had, I would have noticed you already checked the valve seals. Now - I'm kind of stumped. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 9, 2003 Share Posted September 9, 2003 Heheh yeah I thought of that, the seals are all there from what I can see, and they're all brand new. When I bought the felpro gasket kit it came with a set of valve seals. The fact that the smoke seems to be lessening after I put that "Restore" in there tells me maybe it is indeed the rings... though it still makes no sense to me how they would all go bad at once like that. There's a little bit of happiness at least that the car seems to be running great now, as far as no stumble or miss, after putting the jumper on the TPS connection like that... too bad I can't go above 4k rpm w/o it pinging Quote Link to comment Share on other sites More sharing options...
Afshin Posted September 9, 2003 Share Posted September 9, 2003 Sorry to hear that you are having so many problems in a row. I'll try to think about the TPS problem later. Meanwhile did you check the compression in all cylinders. My guess is it is OK, but it would be nice to confirm. sometimes rings can collapse, but I can't see how all six would. The only thing I can think of for now is the valve stem seals as already mentioned by Doug. You need to make sure that they clip fully in place or they do pop up and leak. Let us know after you check. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 9, 2003 Share Posted September 9, 2003 We did pull the rockers/springs etc. off a couple of the valves to check the seals, and they were firmly in place, and also confirmed that they used the new seals I supplied them with. It woulda took a long time to do all of them but I guess I'll have to at some point to be sure. I'm gonna drive it for a couple days and then recheck the inside of the jpipe and see if there's any oil buildup in there. If it does end up being the turbo, how much am I looking at to get it rebuilt? How much would a hybrid T3/4 be? Quote Link to comment Share on other sites More sharing options...
Afshin Posted September 9, 2003 Share Posted September 9, 2003 hey, I think your last post came up while I was replying to the previous one. If valve seals seem to be in place, you should definitely check compression. I agree if the problem is getting better maybe it is the rings, did you use any cleaners or solvent in the cylinders when the head was off? I wonder if something like that could cause the rings to collapse ( I heard that it can, but I don't know for sure if it's true). Also try not to push the engine rpm or boost until every thing is fully ironed out, you change the oil and re-torque the head. it's also not bad to give the head rebuit a little break in time, specially if each lifter is not in the same location as prior to the head rebuilt, since the wear pattern on the cam lobes and lifters can be slightly off from one location to another. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 I'll do a compression test asap, I need an extra set of hands so I'll have to borrow a friend to do it. And/or, I'll just go get a leakdown test as soon as I get paid. I will say this, the smoking has definately gotten less since putting the Restore in last night, compared to when I first drove the car after installing the head. Maybe a coincidence, I dont know. BUT, it is still smoking so I'm not out of the fire yet. We didn't use any cleaner inside the cylinders when the head was off, however, we did use some carb cleaner around the top of the block to clean the gasket surface, and some of that did get into the cylinders... I dont think it was enough to damage anything but I really dont know. About retorquing the head, I thought I read somewhere that you're not supposed to retorque it when you use a felpro gasket? As a matter of fact, it even said on the gasket itself in orange letters "DO NOT RETORQUE". Or am I misunderstanding that? I know last time we did a head rebuilt on my 2.9 N/A motor, we never retorqued the head, and it was fine for the year that I drove it (and I was very hard on that motor believe me). Why did you also specify to change the oil before revving too high or boosting? Thanks for the tip on letting the head break in I had never even considered that... the rockers are in different positions if only because we didn't end up using the same cam! The other cam was shot. One cool thing that went right (for once!!!!!!) happened today though. I have been driving around since last night with the TPS disconnected and a jumper wire on the connection that goes to it, to make it stay in the closed position. The car was actually running VERY well like this, much better than with the TPS connected, which causes the car to run horribly and misfire like crazy. I've been doing everything I can to solve this problem, today I went and checked all the grounds on the wiring harness and made sure they were grounded really well, but still no luck. Anyways, as I said the car would run fantastic with the TPS disconnected and the jumper in place, however it wouldn't supply enough fuel on the top end and would ping (which it would NOT do with the TPS connected). So today I decided what the hell, took some of Yo2001's advice and reinstalled my MSD 6A, and hooked the TPS back up properly. To my amazement, the MSD really smooths out the stutter and miss that happens with the TPS connected, it STILL isnt running as well as if I left it unplugged and used the jumper, but it's much more drivable still. It seems to help the car start better too. And now I can rev w/o any ping again... so that has brought some happiness back to driving my car. Oh by the way Yo2001 if you're reading this, you dont need the tach adapter to hook up the 6A in the 240 turbo. Decided to try w/o it and it fired right up. For some odd reason the autometer tach stopped working though but I just wired the 12v on to something else and it works fine again. Okay guys, one thing I'm really trying to do still is figure out, w/o taking the engine apart if possible, just get an idea if it's the rings or the valves that are causing me to burn oil. I have some better details now if it helps. For one, I have, a couple times now, noticed smoking coming out from the vent off the valve cover (it's open to atmosphere now with a little K&N there). However, at those times I also looked at the vent coming out of the block (one that used to go to the PCV valve, also now open to atmosphere) but never saw any smoke coming from there. Smoke really only seems to come from the exhaust now sometimes when I first start the car, otherwise I only ever see it smoke if I get on it when the boost comes on, a big puff of bluish smoke blows out the back. Otherwise during normal driving as far as I can tell it does not smoke at all, even if I let it rev higher, up to like 4k, but not flooring it and no boost. Also if this makes any sense, adding the MSD seems to have cut down on the smoke even more. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted September 10, 2003 Share Posted September 10, 2003 I just thought of something. If your mechanic didn't use a "sleeve" to put the valve stem seals on he may have ripped them. This sleeve I'm referring to is like a drinking straw that is tapered at one end, and you just slide it over the valve spring retainer groove. If you don't use one, then the seal gets caught in the groove, and it is very easy to cut the seal. If you do a normal compression test, you can tell if you've got bad rings or bad valves. Just check the compression then squirt a little oil in the cylinder and do the check again. If the compression jumps up, then you've got bad rings. Jon Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 I dont know if the machine shop used a sleeve... this guy does a lot of Z heads, so I'm assuming he's using whatever tools he's supposed to be doing. The thing that gets me the most is the guy has done heads for me before, two other N42 heads, and they have always been flawless. The couple valve seals I pulled off were in perfect condition. Quote Link to comment Share on other sites More sharing options...
Afshin Posted September 10, 2003 Share Posted September 10, 2003 I have been trying to think a little more about the oil problem. As we all seem to agree It really doesn't make sense that all rings would collapse at once and I also thought about the solvent issue I brought up earlier (it makes no sense either) and that should not be able to do it. Rings collapse because of rapid temperature change (hot then cold). SO I keep getting back to the valve seals, which typically cause smoking when you start the car. the reason is that as the engine sits. oil on the valve stem leaks down into the cylinder, and when the car is started the excess oil burns and smokes. this is not the case with rings. faster RPM would not effect the amount of oil leaking in from the seals that much, however under boost the positive pressure would cause more oil to leak in and cause smoke. I know you said you checked the seals but are you able to tell if they are truly fully clipped in place and making a PROPER seal without taking the springs off ? I know this does not explain why the problem seemed to get better (off course the engine will smoke plenty when you start it right after a rebuild for the first few minutes). In the end only 2 things can soak all of your spark plugs with oil: 1)six simultaneous collapsed rings (for no apparent reason) or 2)leaking valve stem seals after a head rebuilt . It can be either wrong size such as wrong part put in and leaking from the valve stem or valve stem seals that are not properly in place and sealed over the guides. ALso why don't you recheck the spark plugs to see if there is still oil on all 6. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 yeah I know I keep coming back to the seals also. One thing though, I was under the impression that if it was valve seals, it would smoke LESS under boost as there's positive pressure in there that would push the oil out? I'm kinda confused on the whole thing. I doubt they would be the wrong part, the seals, as they came as a set with the felpro gasket set, eveyrthing was included. The couple that I took off to inspect definately were a tight fit and were definately clipped on, and seemed like they were designed for this head, as far as being the right diameter around the guide and the stem. I'll take a flashlight and take as good a look as I can w/o taking off the springs to see if indeed they are all clipped properly into place. I dont think I'll be able to really tell with the springs in place but maybe I can. I'll do as you suggest tommorow and pull all the plugs again too. One thing someone mentioned to me is that there are two different commonly used types of valve stem seals, the 'black' ones and the 'brown' ones. I guess the brown ones are a nissan dealership item, from what I can gather. The ones on there now are the black ones. One person at this Z-only shop I go to said that he's known the black ones to leak like that after a rebuild, and that they are crap, but then the other 'expert' at the same shop said no they wont, that they are just well known for not lasting as long as the brown ones. Anyone know anything about this? Quote Link to comment Share on other sites More sharing options...
Afshin Posted September 10, 2003 Share Posted September 10, 2003 Why did you also specify to change the oil before revving too high or boosting? because you oil is contaminated. after any rebuild and assembly there is always some fine metal and non metal particles that make there way into the engine. Also there is some potential slight grinding as the valves, valve reground seats... break in. Furthermore, you used some solvent to clean your piston and you where leaking plenty of oil in the chamber, which means that you also leaked fuel into the oil which thins out the oil. So as a easy protective measure just flush out the oil with clean oil and a new good quality filter. About retorquing the head, I thought I read somewhere that you're not supposed to retorque it when you use a felpro gasket? the reason for retorquing the head is that with the initial torquing of the head and the first few times that the head heat and cools (expands, constricts,expands...) the head bolts may losen. Retorquing has been recommended by many engine builders. However I don't know why felpro says not to do it (I was not awar of that). Perhaps out of concern for the metal rings/seals to fail/collapse if the retorquing causes the head to reseat slightly differently. Maybee someone else knows the answer. I guess you should hold off on the retorquing for now. Quote Link to comment Share on other sites More sharing options...
marcus70ZT Posted September 10, 2003 Share Posted September 10, 2003 i didn't read your entire post, but did you make ABSOLUTELY sure the TPS wires are hooked up correctly? i'm sure you know that one contact is not used on the turbos. if you are getting it to run better with the wires jumped together, that must have something to do with it. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted September 10, 2003 Share Posted September 10, 2003 I think FelPro's reason for saying "no retorque" is just to sell the gasket as something you can throw in and go. Very attractive to a mechanic who wants to repair the car and be done. With a normal street car, you can undoubtedly get away with it, however retorquing will certainly help and not hurt. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 10, 2003 Share Posted September 10, 2003 Ok, I'm kinda new to this area of engine trouble, but I thought I would offer my two cents to try to at least help. Now, if your rings are bad then if you put something into the cylinders it would drain down into the case, right? If that is so, then could you squirt some oil into the cylinders with a little of that leak checking stuff that glows under a black light and wait for a while and drain some of the oil from the pan and check to see if it made it's way down into the case? (we should have an emoticon added with two little pennies for "two cents" ) Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 Nic-rebel that sounds like a great idea! I've never heard of that stuff... anyone know what it's called? Sounds like the cheapest way to find out for sure if it's the rings or not. Actually as of 5am this morning I'm not so sure it is the rings OR the valves anymore... now i'm leaning back toward a possible bad turbo seal. When we first started the car after putting the head back on and saw it smoking so bad, then pulled the spark plugs and saw them all with oil residue, the first thought for both of us was the turbo. So I pulled the J-pipe (which I had thoroughly cleaned about two weeks before the valve got stuck) and wiped the inside of it with a finger, then a paper towel, and it was nearly spotless, very very clean on the inside and definately no oil residue. Well this morning I was messing around with some hoses and had to take the J-pipe off for access, and decided to have another look. This time there was definately some light oily film and residue on the inside of the pipe at both ends as far down as I could see. Now, I know some light oil is usually considered normal after extended periods of time, on the turbos, but such a drastic change after only two days? It certainly would explain everything, but i must admit with the level of smoke that was coming out of the car (though it keeps getting less and less, today I only saw some when I first started the car) I would have expected much more buildup in the J-pipe... it was really only a light, thin film all along the inside of the pipe. Is there any 100% way to confirm if the seal in the turbo is bad or not? Sure would be good news for me as the cost wouldn't be so bad (I've been quoted $300 to rebuild the T3... though I'm thinking maybe it'd just be better to upgrade to a hybrid??? how much to T3/04's cost????) and the labor should be cake too... well compared to pulling the motor! I'm gonna drive another couple days and see if the film gets any worse in the j-pipe. About the TPS, I'm 100% sure it is wired and adjusted correctly, I had a Z-only place do it right in front of me. I did find all five ground wires on the wiring harness today, and cleaned them really well and also cleaned the areas the mount to. One of them was not even grounded to anything and I thought AH HAH!!! there is my problem... sadly it was not the case. One thing I noticed is that the thickest one, the one that comes out of the harness right next to the AFM wire, is very very corroded... thinking this may have something to do with it, and dreading changing it if it does! Anywho, cleaning all the ground contacts did not seem to have any effect at all. It is running much better now with the MSD 6A installed, so I'll not worry about it any more for now until I figure out what is causing all the smoke. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted September 10, 2003 Share Posted September 10, 2003 Nic-rebel that sounds like a great idea! I've never heard of that stuff... anyone know what it's called? I can check and see what it is called here, it might have a different name over in your neck of the woods. BTW, Nic is my name I just added that to my username of Rebel450CA Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted September 10, 2003 Share Posted September 10, 2003 Thanks man... I asked at the local auto zone and they had no idea what I'm talking about Quote Link to comment Share on other sites More sharing options...
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