craiglew Posted May 8, 2009 Share Posted May 8, 2009 Ok so Ive been reading for days along with doing most of recomended things for my problems.....Not to mention read FSM for both years since I was told the head may have been swaped but learned that the n47 was also used in my year. engine runs good horrible knock and runs rich and richer than Ive ever seen car run.... Compression test canme in low but have been told I didnt let it cycle enough times and they still came in pretty even @ 130. Just bought the car and these are the problems that came with it... told me it needed a fuel pump? also said it has newman sharp cam? head shaved? currently the valve cover is off to check valve lash... which came out good cold adjust for now. here is her vid: http://s657.photobucket.com/albums/uu296/craiglew/?action=view¤t=CAR.flv So she is a California car in Buffalo NY with no rust and I dont intent to just dump her but cash isnt a huge option... should I think swap out from the get go or start tearing her down? Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 10, 2009 Author Share Posted May 10, 2009 Really No help for a noob? Quote Link to comment Share on other sites More sharing options...
smoorhs02 Posted May 10, 2009 Share Posted May 10, 2009 For starters...you need to be more specific with your post. What year car? Be more detailed overall...even if it is not completely relevant for your post. People around here LOVE details...My point is if you ask a really vague question...youre probably going to recieve a very vague answer! And being a newb is no excuse...Ill be nice(trust me...others wont be) and say...Will you please search before posting...Not tryin to be an a$$hole, just tryin to give you some advice. Jeremy Maybe broken ring, causing the piston to slap around inside the cylinder?? Quote Link to comment Share on other sites More sharing options...
Daeron Posted May 10, 2009 Share Posted May 10, 2009 Could be a dropped valve, pull the valve cover and check things out. honestly, it could be VERY poorly asjuted valves. Get a big screwdriver, stick the handle against your ear, and put the tip against various parts of the motor, at each cylinder at various heights, head, block, etc, and try to localize the noise. That will help you rule things out. It COULD be: crankshaft bearing (main or rod); rod problem; piston problem; valve/valvetrain problem; other (sorry, I am no Encyclopedia Brown, i just have some ideas to help you) Try to rule out certain regions by localizing the sound. Try disabling each cylinder one at a time while it is running. If you pull plugwire on say, cyl 3 and the knock goes away, chances are its a rod bearing on that cylinder. If you hear loud noise at that point also, then bingo. More data is required to help diagnose. Check the Similar Threads feature at the bottom of the page, and then do the same on any you click to, and read what other people have had happen and what theyve been told to do. The more you can tell us the better. Quote Link to comment Share on other sites More sharing options...
seabee280z Posted May 10, 2009 Share Posted May 10, 2009 sounds like head to me. Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 10, 2009 Author Share Posted May 10, 2009 1980 280zx high miles. Bought it for next to nothing 900.00 came as you see it... all the info I really have other than what the post states. Car can drive, obvious loud though... and is running the richest Ive ever seen a motor run. Pretty even compression accross the board within 2-3 psi I have checked motor with steathascope def top half sounds like alomst every exhaust valve... cover is off and checked valves cold only, seem a bit tight. hope because its cold. My overall concern is if the head was shaved as I was told on a little paper with the bill of sale. and what looks like a regrind if not stock cam. Could this just be a simple timing issue? I have never worked on any real nissans This is my first and I thought was a great choice as a 1st project. And due to the current info or lack of history Im puzzled and cautious of ripping into a motor I know little about even after reading the fsm. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 11, 2009 Share Posted May 11, 2009 Put a timing light on it and see if the knock sound happens at the same speed as the flashes or twice that. If same speed, then it's top end. If twice that, it's bottom end. If it idles slow enough and is bottom end noise, sometimes you can use the light to determine which cylinder it is....sometimes. Quote Link to comment Share on other sites More sharing options...
josh817 Posted May 14, 2009 Share Posted May 14, 2009 http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=41966 Works like a charm. Quote Link to comment Share on other sites More sharing options...
kinknoppix Posted May 14, 2009 Share Posted May 14, 2009 Ohh...sounds like my old one. I just swap motors.. Quote Link to comment Share on other sites More sharing options...
z-ya Posted May 14, 2009 Share Posted May 14, 2009 Definitely not in the bottom end. Check the valve lash on all cylinders. Make they all have a lash pad. Sounds like it is running OK (on all cylinders). Something is loose in the valve train. Pete Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 15, 2009 Author Share Posted May 15, 2009 Ok so I went to double check all the valves and long behold a few way out there I also found some of the locking nuts loose. went and adjusted them all over again.... Car Runs good no knocks but still blck plugs and white smoke on revs? Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 16, 2009 Author Share Posted May 16, 2009 Update: went out today let it run finally.... mixed reviews. smokes bad at times...let her run for 1/2 hour here is a video http://s657.photobucket.com/albums/uu296/craiglew/?action=view¤t=richorheadgasket.flv you can see to black soot I have seems to have dropped off a little I still think she is running horribly rich. did time it better minutes after the video but same results. Also smoke was usually thicker same color most of the time Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 16, 2009 Author Share Posted May 16, 2009 Im going to get temp sensor at parts store this afternoon have new one already but was for the diffrent na head and also fuel pressure tool at harbor. will update soon. anyone know why I have 3 sensors on the thermostat houseing? I have already replaced the big thermotime sensor... 80 bucks. bought temp sensor but had 2 wire hook ups I have one. Quote Link to comment Share on other sites More sharing options...
Daeron Posted May 16, 2009 Share Posted May 16, 2009 before you go throwing money at parts, do some electrical testing. http://forums.hybridz.org/showthread.php?t=135748&highlight=efi+bible+step There are three temperature-related sensors on the car. The thermotime sensor is one; the CTS is another, and there is a sending unit for the gauge. The CTS is the two wire sensor, and it is used for the ECU to change the mixture. The one wire sensor is the gauge sender unit. The reason I suggest doing testing before buying parts is, the system is verrrry simple. It can either run right, run rich, or run lean. Sounds to me like you are running rich. CTS and thermotime sensor are good starting points, but TPS adjustment is a freebie and the AFM setting needs to be right. Both of these are higher-priority inputs than the coolant temp, so with bad TPS setting and a good CTS, you would run crappier than you would with proper TPS setting and a horrible CTS. Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 16, 2009 Author Share Posted May 16, 2009 Well I have already replaced thermotime switch 2 wire sensor... can you tell me what sensors are what? the parts store only gave option for temp switch? will be there at 4 pm Quote Link to comment Share on other sites More sharing options...
greghassen Posted May 16, 2009 Share Posted May 16, 2009 duct tape on the afm boot in the video is screaming "REPLACE ME" . Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 17, 2009 Author Share Posted May 17, 2009 duct tape on the afm boot in the video is screaming "REPLACE ME" . first things first.... im sure thats not the cause of the richness... I had no luck at parts store kept trying to give me a 2 wire sensor? you can clearly see..... ^ one wire Ive Found this and seems to be my sensor on the left at about 9 oclock in my pictures. the other single wire sensor is I belive the temp signal for the dash. "dash is out cant check" Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted May 18, 2009 Share Posted May 18, 2009 The important sensor is the one who's harness gets in your way when replacing spark plugs. It's the one that tells the engine management system the coolant/head temperature. The connectors on these are similar to the injector connectors and are known to corrode (turn blue/green) very badly. If it's disconnected, you will get unbelievably rich running but corrosion can add to resistance which could cause the ecu to think the car is colder than it is and add fuel accordingly. Quote Link to comment Share on other sites More sharing options...
craiglew Posted May 19, 2009 Author Share Posted May 19, 2009 The important sensor is the one who's harness gets in your way when replacing spark plugs. It's the one that tells the engine management system the coolant/head temperature. The connectors on these are similar to the injector connectors and are known to corrode (turn blue/green) very badly. If it's disconnected, you will get unbelievably rich running but corrosion can add to resistance which could cause the ecu to think the car is colder than it is and add fuel accordingly. That sensor isnt there on the n47 head its in the picture above they are all in the thermostat houseing ... I have already replaced the thermotime switch and the temp switch is falling into parts trying to get it out... collet came out but sensor lodged in there adn the othe one with the green wire is on the way from ebay. I'm starting to think its te fuel pump or pressure regulator. bought fuel pressure gauge at harbor last night hope to try it today. after I finish the sensor. Quote Link to comment Share on other sites More sharing options...
craiglew Posted June 29, 2009 Author Share Posted June 29, 2009 replaced all the sensors in thermostat houseing and the puel pressure regulator and still runs rich? can a bad valve adjustment cause it to still run rich, and or timing being way off? dnt have timing light I mean the plugs foul out black soot aftr about 1/2 hr Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.