# 87 NA model. odd ticking and idle issues...



## elvenson (Aug 20, 2009)

87 NA with about 105k, new catback with a glass pack

ok, a couple months ago my car was having some issues where it cut out while driving randomly.... then it one day just stopped starting... i figured while its dead, i should do some service and replaced the timing belt (with tensioner and rod) and the water pump. It didnt have a thermostat in the car, so i put one in while i was at it (nissan part matched to my vin by courtesy nissan). i also replaced the bit of hose going to the top of my fuel regulator (was leaky), the vaccuum hose that wraps around the intake hose by the throttle body, and the hose going from intake to idler. I snipped the worn tips from all other vacuum hoses and refit the hoses to eliminate the splits and leaks i had when the car died. I also replaced the secondary air unit because mine had some serious interior damage (looked like fire? was like that when i got it). and of course the drive belts got swapped out (except for the ac belt and tensioner which i left off since i dont use ac and plan to remove its components eventually).

now before doing this work, the car would not start... it tried, but wouldnt go more than about 2 seconds.... after completing the work, i can start the car no problem every try. the problem is that the engine immediately drops rpms to 0 unless my foot is on the gas a little, and there is now a light ticking noise that is consistent with rpms. I have also seen some plumes of white smoke escaping the exaust tip after turning the car off as well as a little bit of i believe gas if i run the car for less than 30 seconds... (smoke is there at any time period though.... ive only gone about 5 minutes so far...)

i just tore down the front of my engine again to double check timing and it looks spot on. both cam marks are slightly to the outside of the backplate marks (less than a tooth total) and crank mark is right on with the oil housing... there seems to be the proper number of teeth between cam markings and from drivers cam mark to crank mark... tension is also correct. 

this car was in need of an oil change before it took a crap on me, and i have heard that residue from the oil will foul up the lifters movement in these VG engines pretty fast and create that tick noise... i would simply flush my system right now, but money is a big deal at the moment and spending $50 to flush and do an oil change is not easy to afford unless i know it will do the trick. the fact that the car will not idle is whats screwing this up really, so im curious if anyone has any knowledge of this issue that can help... this is my daily driver and i need it going again before september school semester when i lose access to the car i have been borrowing to get to work...

this detail may be important:

the car took 2.5 months between when it died and when i finished fixing it and noticed the new problems it has... so thats 2.5 months it was sitting with old gas (91 octane with probly a bit of injector cleaner additive left in it) and crappy oil.

any help is greatly appreciated! (oh, and i have access to some 86 turbos in the local junkyards, but only 2 NA and no 87-89 models...)

i can post pictures of anything you want to see....


----------



## elvenson (Aug 20, 2009)

oh, and this is my first crack at acting like a mechanic, as well as my first zcar...


----------



## nkdmolerat16 (Mar 10, 2009)

if you know how to change your own oil (im assuming you do) go to your auto store and get a oil additive replace a quart of oil with the additive, if its lifter tick that'll fix it.


----------



## elvenson (Aug 20, 2009)

nkdmolerat16 said:


> if you know how to change your own oil (im assuming you do) go to your auto store and get a oil additive replace a quart of oil with the additive, if its lifter tick that'll fix it.


do you think this would be enough to cause my car to not idle without the slight pressure on the gas pedal though? 

i have read other places to flush the whole oil system out with some cleaners then run a heavy oil like 20-50 for a week or 2...


----------



## nkdmolerat16 (Mar 10, 2009)

no that wouldnt stop it from the idle. that would just fix the lifer tick. have you ran ecu codes?


----------



## elvenson (Aug 20, 2009)

No, not yet... i need a second person to keep it idling...


----------



## nkdmolerat16 (Mar 10, 2009)

the car doesnt have to be running to check codes. its really easy. 

check this out
XenonZ31 ECU Diagnostics


----------



## elvenson (Aug 20, 2009)

It says to get the engine to operating temp then select diagnostic mode...


----------



## nkdmolerat16 (Mar 10, 2009)

you dont have to. just run the codes. if it gives you a ton of codes, unhook the battery for like 20 min and try again. if the car isnt warm dont worry about it.


----------



## elvenson (Aug 20, 2009)

I put in a quart of gunk engine restore and ran it for 5 minutes as the label said, tick went away... put in fresh castrol gtx 20-50 and fram tough guard filter with half pint of seafoam.... battery was 100% dead, swapped it with a 800 cold cranking amp unit... fired it up and the idle is VERY eratic... it drops off even with my foot on the gas at 2k rpm, then frees back up after a moment... my buddy thinks i have a clogged screen in the oil pan that needs cleaning... would that be feasable?

havnt ran codes yet, just got the fresh battery... ill do it in the morning if i can...


----------



## elvenson (Aug 20, 2009)

Also, after oil change i had alot of sweet smelling white smoke from the tail pipe... dunno if thats normal...


----------



## nkdmolerat16 (Mar 10, 2009)

the smell and smoke it from the seafoam probably, and a clogged screan woulnt make it idle like that. its something else.


----------



## elvenson (Aug 20, 2009)

Just ran the codes... heres what im getting:

13 - cylander head temp sensor

23 - idle switch (mine has a cracked case, i grabbed one from an 86 turbo model that looks good, but it has a wire harness hookup on the bottom, mine didnt... not sure if it will swap, though i do have a matching connection on my main harness that looks like the one that was on tne turbo model i disconnected... not sure of its function or the units differences between years and na to turbo model change...)

31 - air conditioner (dont see how this would effect things...)

41 - fuel temp sensor

would the temp sensors be the issue here if not the idle control? not sure how bad they play into things...


----------



## elvenson (Aug 20, 2009)

Oh, and thank you VERY much for the fast replys you have been giving me.... my deadline is only a couple days away, so im busting my but to get this thing running right... your help is very much appreciated. thank you 

and if you ever need any computer help, just shoot me a message.... i code custom scripts and small applications on windows and linux/unix, web design, graphics (2d and 3d, also animated), and some some security related stuff if you need advice on hacker prevention...


----------



## nkdmolerat16 (Mar 10, 2009)

so what i would do, if you can afford it of course (i know i couldnt lol) i would replace all of them and fix the codes. and if it doesnt fix it download the factory service manual and take multimeter tester and test all your sensors. the manual will show you how. if you cant afford it, test them all first. if you dont have a fsm you can download it here


XenonZ31 Reference


----------



## elvenson (Aug 20, 2009)

I have the fsm... and im pretty low on funds... i was going to try to check some things tomorrow, but if i need the car running them im screwed... nobody here to help...

as for the parts, as stated, i have an idle control switch, just not sure if its fully compatable or not.... the fuel temp sensor is part of tne fuel regulator assembly, i can find them in the junkyard, but they dont mount exactly the same... and a new one will take too long to ship here... as for the cylinder head temp senson, i need to see if i can even find it lol...

so yes, ill be testing parts before i buy any more... gonna bolt on that idle switch first thoigh... they dont show the test procedure for that one in the fsm...


----------



## elvenson (Aug 20, 2009)

this post helped me alot.... i didnt find it on these boards, but got it through google.... funny how that works... lol

http://www.nissanforums.com/z31-300zx-t/90872-trouble-code-help-nissan-300zx-z31.html

anyway, status report:

i swapped my throttle control switch that was cracked and bent (and rattled when shaken) with a unit from an 86 turbo 300... guess what? now my car holds an idle.... its idling with slight variance between 275-350 rpm.... i tried adjusting the switch with no effect... im not sure why its idling so low, my car used to idle around 1000 rpm, but i swapped my secondary air unit (EAI valve assembly) durring the time i did the timing system... the old one was VERY shot and had the vacuum hose on the top of the air control piece glued half on, so it basically was non functioning and was being bypassed.... im not sure if that would have effected idle before, if so then maybe the previous owner had used the idle adjustment screw to turn the idle down, which might explain why its so low now that those problems have been fixed... i dunno, im going to bed now though, so let me know what you think.... im not sure if the secondary air unit would effect idle that much, that system is a mystery to me still... im planning to adjust idle when i wake up (too early in the morning to play too much with it now or ill have some unhappy neighbors)

also, if i put hit the throttle, i can get a steady purr out of my engine if i get it over 600rpm.... so im thinking that the idle SETTING may just be off at this point... im going to clear my codes when i wake up too and see if that 23 comes up again with the new switch in place...


----------



## elvenson (Aug 20, 2009)

148 Secondary Air System :: Engine Mechanical :: Genuine Nissan Parts :: 300ZX Parts (Z31) 1984-1989 :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

thats the secondary air unit im refferring to in the right side illustrations.... my car was an 09/86 manufacture...


----------



## elvenson (Aug 20, 2009)

Ok, played with it today... the car idles a bit, then boggs down, if it doesnt die, it will come back up (with foot on the gas at any rpm, adjusting idle screw did nothing for me). its definately shooting gas out the tail pipe which is obvious since the ground was wet from rain so you could see the rainbow color of the gas on the ground.... my thought is its too damn rich and maybe fkooding itself out as it revs till it boggs down.... 

after further inspection, the contact for the fuel temp sensor is broken off in the harness boot (which is very dried and bad conditioned rubber). will this be the cause? i dont know how much it would play in, but if that thing is tied into the fuel pressure regulator then maybe im getting too much gas because the ecu is acting blindly... any ideas? the parts about $65 and i need the harness connector too, so i cant afford to screw around here...


----------



## nkdmolerat16 (Mar 10, 2009)

no the temp sensor wouldnt make that happen. check your maf. you can adjust the lean/righ mixture with the twist of a screw


----------



## elvenson (Aug 20, 2009)

nkdmolerat16 said:


> no the temp sensor wouldnt make that happen. check your maf. you can adjust the lean/righ mixture with the twist of a screw


Where exactly is the screw?

also, i have a couple buddies telling me its the o2 sensor, and another telling me ut has to be a cylander not firing because of the gas comming from my exaust... i have 2 days and $150 to fix it or i lose my job since i wont be able to get there anymore...


----------



## nkdmolerat16 (Mar 10, 2009)

do you have a compression tester?


----------



## elvenson (Aug 20, 2009)

No i do not... 

another buddy thinks i just need to replace the fuel pressure regulator and fuel temp guage assembly and that if i dump my gas and put in fresh gas i should be ok.... any merit to that? its a half tank of gas thats been in there about 3 months or so... it was 91 octane...

that regulator is about $65 on courtesyparts.com, but i dont have much time to wait for it to get shipped out... will an aftermarket from a local parts shop work? or should i call a dealer?


----------



## nkdmolerat16 (Mar 10, 2009)

before you do that check your regulator. with the engine running pull off the top vacuum hose and if fuel doesnt spirt out you fpr is fine. and the temp sensor wouldnt make your car run like that but i you said you have access to a couple other cars? take the temp sensor out of it. i know the fsm says to change the whole unit but its no big deal. if you can get ahold of a compression tester i would recommend doing that. i dont remember if you have checked your plugs or not, im assuming you did, but if not do that. the gas is possible. mine sat for a while too and wouldnt even start till i got new gas. so try that, the only way to really drain the gas is to pull off the fuel line and just keep priming the fuel pump over and over. if you have any questions ill pretty much be on my computer all day tomorrow so ill check up every hour or so.


----------



## elvenson (Aug 20, 2009)

regulator was checked earlier today.... no fuel leakage at 4k rpm.... so it seems ok.... ill try to get a unit from a fresh arrival at the yard though (1986 na auto which has sat there less than 3 months)

ill see if autozone has a tester as a loaner tool (buy the tool, bring it back for full refund... best program ever made, and how i got a puller for crank pulley)

i checked plugs 1 and 4 since they are easy to get at.... they seemed pretty damn new... no real wear... ill pull and test all in the morning though...

i have a secondary pump rigged to a toggle switch in the cab in place of a fuel filter (came that way from previous owner, was going to replace the in tank unit and pull this one out in favor of a filter when the car originally broke down on me... on my todo list still). so draining the tank is not an issue, i just run the line to my 5 gallon jugs and hit a switch... 

i get my email alerts from this site on my phone and reply from the mobile browser, so i can keep you updated as i work...

as a curiosity question, how long did your car sit with that gas? mine is around 3-3.5 months at this point.... it was 91 octane...


----------



## nkdmolerat16 (Mar 10, 2009)

8 months and 13 days. it broke down the day after my birthdat, thats how i know lol it was also 91 octane.


----------



## elvenson (Aug 20, 2009)

lol, mine went down the day after i put new tires on... there went my repair costs...


----------



## nkdmolerat16 (Mar 10, 2009)

ya mine died after a sensor went out, but u have no idea which one because i didnt replace the gas until i replaced like evert sensor. just keep testing man. you'll find it.


----------



## elvenson (Aug 20, 2009)

lol, sounds familiar!


----------



## elvenson (Aug 20, 2009)

ok, i just got some more gas cans, new multimeter, and a compression tester... time to do this...


----------



## elvenson (Aug 20, 2009)

so far i did plug #1.... it was heavily covered with black residue (wasnt when i was still doing the timing work), and had no spark in that state.... cylinder 1 had compression at 195 and 170 (tested twice). im waiting for my buddy to get here to do the rest of the cylinders and check that plug after the cleaning...


----------



## elvenson (Aug 20, 2009)

ok... so today:

i set the throttle position switch at 1000rpm, sucked out a half gallon of gas (pump wouldnt give me more... just air...), checked and cleaned all spark plugs (details below), compression tested all cylinders, and now have a different run condition.....

passenger side plugs all covered in dried black residue, all spark with it, but then all got cleaned.... spark increased. plugs all in good condition, no real wear is visible after cleaning... wires all ok. compressions (averaged of 3 tests per cylinder) from front of car to rear of engine: 170, 200, 180.

driver side plugs all covered in darkish wet fluid (i think gas with a tiny bit of oil?). 1 sparked very strongly, one didnt spark at all, one was a bit weak, but sufficient... once again, no real wear... all got cleaned and produced good spark. compression was weak on this side: 135, 118, 140. there seams to be a slight bit of dampness around the valve cover edge all around on this side... bad gasket possibly?

all plugs are gapped at .039 as verified after each was cleaned... all wires are ok. cap is ok.

after all the plugs got put back, i had a buddy hold the rpms at 1000 while i set the throttle position switch. then we disconected the fuel line at the engine and ran it to a gallon jug. flipped on my auxillary fuel pump and got almost 1/2 gallon from it with a bit of sputtering here and there which became straight air.... kicking over the main fuel pump didnt help at all so we hooked it back up and started the engine.

the engine idled at 600, my friend got out and we went over the lines and wires again to see if we missed anything. when i looked again it was holding smoothly at 1000rpm and purring like a kitten. we got all my tools out from under the hood and in front of the car and double checked al lines and wires again, then i hopped in. i put it in first and started to touch the gas while easing on the clutch and the engine bogged down a bit... it would not rev higher... i put it in nuetral again and touched the gas and again the revs would not go up, instead it bogged a bit then idle dropped to 600, again and idle slowly dropped to 300... it held 300 for a few minutes as we inspected under the hood again.... after a minute we could here what sounded like a belt rubbing and also a light rythmic grinding noise both in rythem but at staggered times that overlapped a bit.... i shut it down at this point unsure of what it was.... i didnt see any belts rub... also, after rpm went down to 600 i started getting more light smoke from the tail pipe... a nice cloud that smelled sweat (must have been the seafoam). heres the aftermath of it on my street...


















my one friend is convinced its the gas thats making it run like crap and i should be fine when i swap it out (tomorrow i will), and i should switch the fuel regulator anyway.... but he also thinks i may have a bad seal somewhere in that low compression piston.... ideas?

and for sympathy sake... this is what it looked like the day it died...


----------



## nkdmolerat16 (Mar 10, 2009)

shit ma, my arsenal is running low. change out the fuel and let me know what happens. good luck man.


----------



## elvenson (Aug 20, 2009)

lol, ya.... this car is sweet, but it has already killed my summer by having these issues.... when i wake up im gonna go cash in $100 in change, get a gas siphon, check fhe plugs again after warm up to see if they fouled up again, use a stethescope on the cylinders to check if they all are firing, dump my gas, put in 3-4 gallons fresh 91, see if it gets better... if the issues resolve ill swap plugs, rotor, cap, and wires for some fresh bosche stuff and upgrade the plugs to a more intense spark if i can get anything i know will run. i heard only to use ngk plugs, but i dunno if i can get some good bosche platinum doubles in there... 

looking at picts from back in late february or march i saw that my fuel temp sensor has been busted even then when it ran better.... but ill be getting a new nissan regulator soon after i get this running smooth followed by the cylinder head temp sensor then the o2 sensor. after that im planning to redo the fuel pump, sending unit, filter and some lines as well as the oil sending unit... i hate having no or false guage readings...


----------



## elvenson (Aug 20, 2009)

Ok man.... i have a crank angle sensor code now.... and after hand cranking to tdc using the rotor as a guide, the crank pully reads a hair over 5 degrees advance when the rotor is aligned to fire position 1... what should that be at? seems pretty off to me...


----------



## nkdmolerat16 (Mar 10, 2009)

dude i honestly have no idea. timing is one thing i havnt quite researched too much. sorry. try posting everything on z31.com. theres alot more knowledgeable people there. they could help you with that.


----------



## Spongerider (Nov 18, 2002)

Second that, take care of the sensor issues.


----------



## elvenson (Aug 20, 2009)

http://z31.com/forum/viewtopic.php?t=10325

if you care to keep up on this, i posted it on z31...

im gonna go dig around under my hood some more... rotate the engine and see if my timing changes..... set to TDC on the crank and see what the rotor is at, and all that timing related stuff.... grr.....


----------

