injectors???

[Sdavne]

i have 1 90 300zx n/a 2+0 and i am woundering where the injectors are locakated?? do you have to take off the center cover on the enjine to get to them? where is says 3000 v6?.. please let me know and maybe pictures if possible thank you scott.

[evildky]

it's a lot more complicated than that, the throttle cable cover had s to come off the get the plenum off whihc means disconnecting all manor of things liek the pcv's, egr, throttle cables, air inlet piping, idle air piping etc, it's nto an easy job, you might be better off having someone else do the work if you aren't prepared to deal with such a pita

[Sdavne]

yeah that is what i was going to do i am still trying to pinpoint my misfire and have bin throughing money and parts at this and the two next things i was going to do is check timming and injectors, but i think i will have a garage do the injectors, after i compression test it, and if i do not find that i might dignose the wires, thank you

[evildky]

then before you go through the troubleand expence fo replacing the injector how about we help you narrow down the problem?

step 1. check the ecu for codes http://www.zmods.org/index.php?page=ecu_diag

step 2. verify that the car is idling on all 6 cylinders;

with the car idling unplug each cop one at a time, when a cop is disconnected the idle should drop or the car should die, if you unplug a cop and nothign changes you have a dead cylinder and next we figure out why

ohm the injectors: a bad injector should test bad, standard is 12-14 ohms, open or much higher is a bad injector

check the cop's and spark plugs, the easist way to do this is to simply swap the cop and spark plug from the troubled cylinder with a good cylinder, with the car at idle again unplug the cop's one at a time, if the problem moves then you have a bad cop ro plug, if the problem stays the same, it's a ptu, wiring or engine problem

ley us know what you find

[Sdavne]

i ran the ECU and ran code 55 so nithing nwrong with ecu... OBDI sucks haha and i pulled att the coils and wires and found witch one it is the first one on the left is the one that does not change. i changed the coil and nothing happend so i think that it is injector, hopefully not somthing internal. or maybe the wireing. im thinking its injector though or wires because it started out as intermitten misfire and now it is counstent, also i was talking to someone about timing and they said you can not adjust timing belt you have to replace it if it does not mesure to 15 degrees, is that true? timing belt was done only about 30k miles ago so i am not thinking its timing. this is very frustrating and i really am praying that it is not going to cost alot of money to fix' also could it be fuel pump? and if so how could i check to see if it is fuel pump? thanks scott

[evildky]

it's not the fuel pump

no you can't "adjust the timieng belt" cam timing and ignition timing are 2 different things, you adjust your ignition timing by rotatingthe ptu, but incorrect ignition timing won't cause 1 cylinder to miss and you've already stated that the timing belt is 30k old so the physical cam timing hasn't changed

at thsi point you need to ohm the injector

then you want to lay that cop and plug connected on top of the plenum and unplug the other cop's and crankt he engine and look for spark if you have no spark then it's most likely a bad ptu

[emt-z]

at least check the injector with the screwdriver test if you don't ohm it, taking an expensive gamble by not checking it somehow. at the very least if it is working you can cross it off the list. a lil bit of time to possibly save alot of money

[Sdavne]

Yes i am going to check the injgectors, it makes most sence i still just do not understand how injectors can go bad in 30k miles..

[evildky]

30k miles? you car has 30k miles? or the injectors were already replaced once 30k miles ago?

I had 3 rebuilt injectors fail within 3k miles so yeah it's possible, and it only takes a few minutes the ohm the injectors, well witht he old style injector cplis it might take a while to unplug them

have you verified spark on the cylinder in question?

[BigTDogg (MA)]

30k miles? you car has 30k miles? or the injectors were already replaced once 30k miles ago?

I had 3 rebuilt injectors fail within 3k miles so yeah it's possible, and it only takes a few minutes the ohm the injectors, well witht he old style injector cplis it might take a while to unplug them

have you verified spark on the cylinder in question?

Even brand new "old style" injectors can fail within 30k miles easy with 10% Ethanol gas and no switched injector power.

[DCaff300ZX]

Yep, our switched-on old-style injectors on pre-'93 cars are a PITA as they fail from the ethanol and factory wiring method.

One of the most common upgrades on the Z32 is the injectors/fuel rail/injector connectors...been there, doing that on my '90, and there have been quite a few others facing the same problem this year.