i'm getting bored with this lack of new threads so i'm going to go ahead and put this new problem on the table. if you recal a while back, my engine shook, and to fix this, and also because it was a new to me high mileage car, i had the heads rebuilt, put in new OEM fuel injectors, new timing belt, and the rest of the basic maintenance that would be expected with this job. i got it back together and it ran great for a few weeks, long enouph for me to get about 2k miles on it. then, the same problem came up again a week or so ago.
i have pulled coil packs and the removal of each one made the engine run worse. the cam timing did NOT slip. i thought that it had slipped but i turned the crank until all 5 marks lined up and there wasn't a single tooth off. so i'm looking for a problem that got temporarily fixed when i rebuilt the heads, and after a month of doing fine, it came back. the power is greatly reduced and it shakes a lot at idle and on acceleration. it runs steady, but shakes. ECU code is 34, but that has been there for a good while and i don't think that could cause it to run this rough, but please correct that statement if it's wrong. any advise will be greatly appreciated.

 

fuel filter?

 

It's normally a good idea to give us specs on your car .... I shouldn't have to dig through old posts to find out that your car is an NA and therefore a code 34 isn't the cause for a lack of power (on a TT, it would be). I think a good throttle body and electrical connection cleaning is due (and clean the MAS while you're at it - just remove it and spray brake cleaner through it). Let us know if that makes any difference. If this is the case, it's possible that disconnecting and reconnecting during all that work made a good difference, and then they corroded again over time.

You clearly have no serious mechanical reason for the shake, so it has to be electrical or simple (like a clogged fuel filter or a leaky vacuum hose or something along those lines).

 

ok sorry about the lack of back ground. it was late. i'll post back after i've done those things and see if the problem is gone. thanks for the feed back. as for the fuel filter idea, a fuel pressure test has been my next plan in mind, but i have to wait until work starts back so i can borrow the guage from work.

 

one possibilty that i thought of, which may not even be worth mentioning, so just tell me if i'm wrong, is that the cam journals (i think that's what they're called...) weren't tight enouph. the tech at the local Z shop said that the manual says 8-12 in/lbs. 8-12 in/lbs. is very loose. i could tighten that with my hand. so against my better gudgement, i left them like that. is it possible that there was error in this information and that some of them have backed out to cause this?

 

theyre supposed to be 6-9 ft/lb according to the FSM

 

owch! that might be a problem. that does sound more realistic. but why would the tech have told me something that's 8 ft/lbs. off? this is a good shop. he seriously does most of the z work in southern virginia

 

so now i've seen both numbers in two different service manuals for the same car. can anyone advise from experience? i know that if they are too tight then it will bind the motion of the cams. i'm not putting down advise b300z, but i see what's in the manual too but i still don't know what to put them at. this sucks pretty bad if i've been driving with my cam journals 8ft/lbs. too loose!

 

what other manual?

i havent seen any in inch/lbs. they show N-m, kg-m, ft/lb

 

i din't even know what manual it was. i didn't get to look at it. but it was an official onw. maybe for all z's or something. i guess it can't hurt to put that extra few pounds on there to get to the 6-9 ft./lbs. thanks. haha that sucks because i went out and bought a brand new super small torque wrench just for it!

 

so i finally got this thing put all back together with the new tensioner and a whole lot of cleaned connectors and it ran worse then it did when i took it apart. it took 10seconds to start (it's never EVER taken this long before) and it ran extremely rough this time. i don't know what i messed up. but i took the covers off to check the timing again and that all looks good. when i tried it again, it wouldn't start at all. i know it sounds like i just did something very stupid, but believe me, i have checked! there isn't ant knocking or anything like that. plenty of oil pressure. water in the radiator. (technically antifreeze in the radiator and the rest of the engine) I cleaned a lot of connectors like the MAF and coolant temp. sensor and Otiny2 sensors, but it still runs terribly. i did a spark check and found that while i'm turnign the car over, there is no spark, but for a second as soon as i let off the key, the plug sparks. i checked out the harness going to the ignition switch and this was pretty torn up from someone installing and then removing a remote start unit. i have a new harness on order so i shoiuld be able to try it again tuesday or wednesday. any other ideas or opinion on whether the ignition is a good bet?

 

Use MAS / MAF cleaner... little had to find but safe...

All you did is take the covers off, torqued the bolts and put it back together??? Check all the wire, see if you missed one...

 

I didn't even take the valve covers off, just the timing covers to replace the tensioner. (i said i had heard 1t/lbs. but i did do a bit more then that, and i think it would be making a lot of noise if they actually were loose.) so i didn't actually mess with many wires. here's another thing that makes me wonder about this problem: for a while i've had a code 34 and on-and-off a code for the coolent temp. sensor. yesterday,these suddenly dissappeared and i had a 55. no, i hadn't disconnected the battery since i last ran the diagnostic test. does this make it seem like a bad ECU is a possibility, or can these problems come and go?

 

so after replacing the ignition wiring harness with a brand new one, taking the front apart to re-time the cams(i didn't actually think that the timing was off(and it wasn't), but i did this to re-adjust the new tensioner. i got it too tight the first time), and even more contact cleaning, this POS still will not start. something has gotten worse and i don't know what to attribute it to. the car turns over and does so with a bit of a surging, sounding much like the starter is going out and has a flat spot, but it's still turning strong. i tried for about 1 min total on and off and it only sounded like it might want to fire a few times. the plugs are wet and i smell fuel from the tail pipes behind the car. the ECU still says everything is fine. PLEASE HELP!!!! this car sure makes me feel stupid but i've got to get it fixed before i can do anything

 

make sure your coils are all firing.

 

the coils are not firing. just a little bit of spark comes once in a while. but not enouph to make it run.

 

wow. just as i was about to give up i decided to test the PTU. it was good so i gave it an extra good cleaning and put it back in. after trying to start it again, it ran, but rough. so i decided this testing thing was cool. i tested the coil packs. all in the car. they were all good (0.7-0.9 ohms). i put all those connectors back on and the car started. beautifully (i had had the connectors off before, but it didn't fix it then). now it runs with great power and consistancy. thanks for all the help guys. but now i have a new question: the coil pack connectors are almost all broken in some way. to replace these, should i get a whole new harness or just crimp in new connectors?

 

http://boostpro.net/products.html

 

right on. thanks

 

I was about to post its the connectors cause i had the same problem a few months ago and my engine was shaking me while i was in the car like craz. I tried crimping the wires with new connectors and it worked but eventually it just messes up now im in the same spot with another connector ao im just buying a new harness you can get them for a lil over 300 on ebay and thats the cheapest i could fine.

 

Yeah that volt meter is your best friend with these cars. A worthy investment is either nissan datascan or conzult.

 

when i tested the coil packs, they were all 0.8-0.9 ohms. i don't know the accepted medium for these. does it sound like these are on thier way out or is that a fine reading? the FSM pretty much says that if it's not 0.7 then throw them out.