PLEASE PLEASE help!

[demonZ73]

i have a 1990 none turbo 300zx i have been working on this thing for 4 years now and cannot...........CAN NOT for the lif of me figure it out why the 300 is not running right. someone please help. heres the situtaion i rebuilt the engine from top to bottom myself i am good with motors and had the manual on hand...... i have
1. replaced all gaskets and seals
2. bord cylenders .020 over with stock but over sized pistons
3. shaved heads (only enough to clean them up)
4. full stainless sleel exhaust from front to back
5. jim wolf technology stage 3 500 cams from import parts pro
6. egr delete
7.AIG delete
8.throttle body water coolant delete.
9. brand new injectors and connecters (cleaned fuel rail)
10. brand new water temp sensor and connecter
11. brand new fuel temp sensor
12. AAC unit has been completly removed, disassebled, checked and tested cleaned set and put back together and reatached, same with air regulator
13. brand new pcv valves
14. i have 3 groud wires attached to the plenum in the back.
15. did compression test and is good
16. is deff. getting good fuel pressure
17. removed both throttle chambers cleaned very well re-assembled with new gaskets and yes even put both back in sycronization.
18. brand new stock ngk plugs.

theres not really any point in doing the test of unplugging the coil packs while ruinning simply because the idle is that bad, i have to hold the throttle about a 1/4 way to stay running and even then its very unstabl, this is what confuses me the car right now is not throwing any codes (55) however the car will always start but will not idle not even close. and when i hit the throtle it hesitates bad i can hear a slight back fire throu the intak it sounds like. (like underneath the injectors) the cars timing seems to be ok however this is i think what my problem might be i have check the timing belt literally 3 times always thinking it was my timing but the white dots line up on the cam gears and i just checked my timing with a light and the white line seems to be on 15 deg. but a little shakey. another thing is i think i just blew another brand new TPS because now its not giving me my .04 reading and the computer threw code 21 but then went away and now i checked it many times and still get code 55. i curently have 93 octane in the tank now. and another this is when i unplug the AAC and try to adjust my idle with the screw almost aboslutly nothing changes it wont idle up or down. another thing that confuses me is that the problem the car is having as not changed a bit after adding alot of new parts and adjusting parts, so someting like even tho i think my tps is bad even when i put a new one on it made no differance, thank you so much for reading this and please help if u can

[A Paratroopers 300zx]

Have you made sure your timing is correct with an inductive timing light? If not, it can be rented at any auto parts store. Also, double check all electrical & vacuum connections. May want to check that your CAS (Crank Angle Sensor) is adjusted properly as well. Ohm test your injectors and pull your spark plugs to see if any fouling is present.

Remember, engines need fuel, air and spark to run... after you have the basics ruled out... start looking for timing issues and more complicated possibilities. Z32's are notorious for vac. leaks!

[nissanfreak12]

Im gonna throw this out there, are you absolutely sure you put the correct cam in the correct location? Stage 3 is pretty high without the higher rated springs on the valves. I am not doubting your ability to build engines, but we all make mistakes and sometimes its best to walk away and have someone else poke around.

Here is another list to think about:
ECU-even with 55, still could be giving a bad signal. Is it tuned to your mods?
TPS
Injectors-What brand do you have? What CC are you running? Higher CC will flood your engine with poor idle and hesitation.
New injectors are also very notorious for not spraying properly, due to sitting, until three or starts and maybe a few
runs.
Wiring harness
Timing belt-Did you rely on the markings or did you count the cogs?

[demonZ73]

thanks so much for the response i am checking w a timing light that connects to my battery and then a clip on the thick black wire in the ignition coil conncter number one cylender i thought this was an inductive timing light is it not ?? and i have checked my crank angle sensor connecter and it looks clean and is a little wiggly on the CAS but not bad its not falling off or anything.............and when i turn the crank angle sensor while running it doesant do anything once again the idle is so bad i cant really tell if it really changes anything but i really dont think it does, the injectors i bought were actually reconditioned however i have ohmed all them and applied battery voltage to all BEFORE i installed all them in the engine and they are stock ones CC should not be differant........my ECU is not tuned to my mods i was told from kyle puckette i should not have to do anyting with the ecu for the cams, when setting my timing i went by the manual and i did go by the timing marks and did not count the cogs.......ooohhh and what do you mean are the cams in the correct location like intake cam on the intake side and exhaust cam exhaust side ???.....and ur absolulty right ppl do make mistakes and i deff. could have......thank you

[nissanfreak12]

Yes, counting the cogs is really the only way to be sure your timing is good. The marks on the gears and the rear plate are for reference. It is very easy to have the crank pulley off and not even know it. Make sure the crank is TDC and lined up with the white line on the Belt. Then all the cam gears are lined up, it will be normal if the markings are not lined up perfectly. They will be close, but not on.

Yes, intake cam on the intake and exhaust on the exhaust. I know driver and passenger sides are different, but think, not 100% sure, the intake and exhaust you can mix up. They should have some kind of markings, call Kyle at IPP, he should be able to tell you.

I know when I hd stage 3 cams in my 240, the idle and drive up 1500 rpm sucked, after that it was a rabid bat from hell. Check the timing before driving, I am with paratrooper, something is wrong with timing. Do not use the loop on the PTU, use cylinder 1.

[demonZ73]

ok thanks again so much the next step i take it to take the front end apart again and 110% check and re-do the timing if i have to, freak is there a write up on exaclty how to set the timing the way you are describing it to me if you can post it for me that would be great if not could you explain just a little better i understand setting the crank gear on the mark but that has to be on the compression stoke correct?? and what exaclty do you guys mean by counting the cogs?? i do know what the cogs are i just dont know what im counting them from or to....thanks

[demonZ73]

i just did some reading a read a post about a guys trying to help another guys get his timing belt right and he said about 3 differant times that the only thing that is important is that u line up all 5 white lines with the dots on the cam an crank gears (not the backing plate) and does not matter if it either intake or exhaust stroke ........does this sound right ????

[nissanfreak12]

All this is is the FSM including the number of cogs between the marks on the gears. No doesn't matter what stroke it is on as long as it is TDC on number 1 cylinder. If you look on the crank pulley there will be a dot on the front of that gear. On the oil pump at about 5 oclock there will a hash mark, kind of looks like it was gouged out. The dot needs to line up with this mark, that sets the engine at TDC.

All the can gears have a mark on the front, I think a dot and the backing plates have a bump, line all those up. Put the belt on, have all the white lines match those marks on all five pieces. Tighten up the tensioner, this is just so the belt doesn't slip off.

Now what it means by counting cogs, you need to count each individual cog on the belt in between each marking. Like mark on passenger exhaust to passenger intake cam gear, you should get 24 cogs. The mark on Passenger intake to diver intake came gear you should 45 cogs. Driver intake to exhaust cam gear 24. Finally driver exhaust to mark on crank gear mark, this one should have 59. This one is the toughest one to count, so the easiest way I could find to count was mark every tenth cog and triple count. This has to be exact, otherwise the timing will never be right.

After you get everything set as per the FSM, crank the engine BY HAND to check to see it turns freely. Any resistance do not push through, you might have the timing off and a valve is hitting the piston. Just double check the counting of the cogs before putting everything back together. After all is put back on and together, start the car let it warm to operating temp, then time the car. Do not time it when cold, will not get a good reading.

Let us know if you have any questions in this process, it is tricky and can get irritating.

[demonZ73]

thanks freak thats helps alot and makes sense im taking it apart tonight and going to check it before i take the timing belt off now when when u say counting ur talking about the belt? and am i counting the bumps or the negative parts on the belt itself??...........thanks

[demonZ73]

ok freak can u tell me if this is normal i have the belt off .......well this is what happened while trying to take the big fly wheel nut off i accidently jumped cogs ( the belt slipped) and i then couldant tell if i was out of time or not but anyways i have my crank gear dead nuts lined up with the cut out on the oil pump and i have both intake cam gears also lined up but when i turned the exhaust cam gears one way they STOPPED so i stopped turning and then went the other way and lined it up perfect were they supposed to stop like that ????.............thanks

[demonZ73]

ok heres the latest i just worked on it for like 3 hours and that counting thing is where i think i went wrong, the manual does not show how to do it what so ever just shows some numbers........you have to be a straight genius to figure that out, but from what you told me freak and the manual im very sure i have it right this time, however the crank gear dot deff. does not line up with the oil pump notch, but is close, but i wanna say it has to be this way beacuase the motor has to be 15 degeas BTDC anyways right?? and those 3 times i said i checked my timing of course it would look right if i didant know the counting thing but it wasant, anyways thanks alot and let me know if theres anything els i need to know

[nissanfreak12]

The crank dot MUST line up with the notch, close will make your car run like crap. The other marks on the cam pulleys and backing plate are for reference, those will be a little off, but the crank dot and the notch lined up is TDC.

Go under in this forum, "everything you need to know about the z32", go to where is the online service manual, click on the link. Go to page 18 and scroll down. It has a picture of the diagram of the numbers. They have to be exact, otherwise the car will run like crap.

[demonZ73]

ok freak i found page 18 so would you recomend starting at the crank gear and then counting up to the drivers side exhaust cam gear and so on.......?? or would i have to do all four cam gears and then rotate them to get the 59 cogs down at the crank gear?? other than that it doesant line up correctly ???

[nissanfreak12]

Not trying to sound like a jerk, maybe you need to get someone else to get the timing set for you. This is detrimental to the cars function and drive ability. If its not set right you will ruin the work you have put into and just frustrate yourself to no end. These cars are not the easiest to set timing properly, but if you followed the FSM and still have issues or don't understand, you need someone else that has done it to do it.

[demonZ73]

Well See what ur saying But having someone els do it is not really an option and seein how I'm this close I need to just finish it Myself like u said thoU I understand what ur Talking about keep cRank gear dot on mark And count, and Just the cam ones are for reFerance

[demonZ73]

well the good news is that i didant blow my PTU, my multimeter probe fell off lol but anyways after setting the timing the correct way this time and sure of it i checked it 3 times and stared at it before putting it back together it still runs like sh*#, so what im think now it could be is the fact that i have never set my PTU while the car is running, but once again i cant do it by myself cuz the car wont idle thats probly why, but does it make sense that i have to keep it running while adjusting it?? do you think this could be the reason??