Car is hard to start

[LIBRILZ]

Ever since the window on my car was busted, the car has been hard to start. I think it might be charging related. I went to Advance auto to get both the battery and alt tested, both of which are brand new (batt 1 year old, car did sit up for a year) and the test showed them both to be fine. Thing is after it ran the test my car started just fine, ususally it takes many slow cranks for it to finally turn on. When the problem first occured the car would crank fine right after starting but now it's slow to crank all the time, And when the car is at low idle such as around 650rpms or so, the lights are significantly dimmer than at say 1000 rpms, and the blower fan blows alot slower and the radio cuts in and out, leading me to believe the car is not getting enough power. Maybe the batt is not getting charged enough for the next time the car has to be started?


Somthing to note is that when they do the altenator and battery test, they ask for you to rev the car to 1500-2000 rpms with all accessories on.

Thanks for the help in advance.

[evildky]

check the battery cables at the battery as well as the starter, sorrosion at either end could be preventing the starter form getting the full cranking amps

also the starter could simply be aging

also advanced ignition timing can cause hard starts, have you berified your ignition timing is still correct?

[LIBRILZ]

My timing is indeed advanced but I have always had it like that and never had this problem. I'm going to think about the starter and all that then. The terminals on the battery are clean but I will clean them again.


I just don't understand how at low idle such as 700, all the lights in the car are so dim.

[evildky]

how much advance are you running?

before you clean the battery terminals for a second time how abotu you clean the cables at the starter end for a first time;)

as for the idle, have you adjusted the iacv?

[LIBRILZ]

I'm running full advance. The car doesn't run very good since I did the engine rebuild. I think it has somthing to do with the wiring of the PTU to the new engine harness. The shop that did the wiring of the ptu to the new harness didnt do a very good job. But the starting problem wasn't always present until like a week ago. I will try cleaning the starter cables. As for the idle, I think 650-700 is fine, right? When the A/C is turned on the idle actually drops, and the idle becomes more sluggish. Maybe a sign of a vacuum leak? I have OHMed my injectors and they are within specs, ran codes and got 34 (detonation),and an intermitant 02 sensor code 33.





I dunno, don't wanna get into asking too many questions. Im starting to take your stance on hating these cars. Problems just never end.

[evildky]

address the codes before doing anything else! also "full advance" could possibly cause knock

"full advance" isn't the answer I was looking for, the actual answer should have been that you have no idea what your timing is set at. the standard as I'm sure you know is 15 btdc +-2 degrees, the more advance you dial in the better the top end power but the harder it is to start, you should set your timing with a timing light period, simply turning it to where you think it should be is simply not good enough

standard idle is 750 +-200 rpm IIRC, when the a/c comes on the idle should dip before raising to a high idle, the iacv handles this function

if the car starts and runs on all 6 cylinders then your ptu and wiring are fine, it's just a 6 channel transistor it's not as complicated as most people think it is

[LIBRILZ]

It runs on all 6 but the idle has a shake and occasional miss to it. Then when I start driving the car it likes to sputter above 3k rpms sometimes all rpms it will sputter, then it will seem to hit a point where it knows what it needs to do and it runs alot better. It's very intermitant. As for the timing I was told on an N/A that it wouldn't really lead to any ill affects, but I know I should get it timed.


If the A/C does not have the idle raised, does that mean the IACV isn't doing it's job?

[evildky]

if I were you:
first thing I'd do ss bypass or replace the knock sensor
second thing I'd do is ballance O2 test and replace the bad one (s)
third thing I'd do is set the idle to 750 rpm (adjust thsi at the iacv)

[LIBRILZ]

Alright man, thanks. I was hoping you would be the one to respond to this thread, you are usually one of the most helpful people. This car can make you crazy .

[evildky]

happy to help, hopefully we can get all the bugs worked otu before you pull all your hair out

[LIBRILZ]

Ok so I unravelled all the wiring to the PTU and I found out that it looks to be wired fine, only thing is, is there looks to be two ground wires for it, one coming from the harness and, one main one on the PTU itself, going into the harness. I think it's fine though. I'll have to snap a pic. So now I'm gonna change the 02 and see what's up after that. I'm still wondering though, if the idle doesn't raise when the A/C is turned on, what should I be looking at? I mean cause the idle sucks when the A/C is turned on, if I blip the throttle the Revs will drop to like 200 and sometimes they won't even catch themself. W/O the A/C on though it's fine, still sputters but the car won't die.

[LIBRILZ]

Okay, I decided to u-plug the bad 02 sensor to see what would happen. The car idles a little smoother and 95% of the hesitation is gone. Guess that was my problem. The idle still bounces around with the A/C on but the hesitation was my main concern. I just don't know whether or not to buy a Nissan 02 or a bosch. I think a Bosch one is fine, they invented the 02 after all.

[bartZ32tt]

Bosch is fine. Actually they are the same iirc. As for the ptu having two grounds, does one loop? If so, that's the wire for your ignition timing.

[LIBRILZ]

Yeah one of them do loop. Thanks.

[evildky]

standard idle is 750 +-200 rpm IIRC, when the a/c comes on the idle should dip before raising to a high idle, the iacv handles this function

and bosch makes the majority of OE O2 sensors, i would never considder buying the marked up nissna part when I can get the bosche for less

[LIBRILZ]

Ok explanation for this problem? I installed the new 02 and the car runs alot worse than it does with it unplugged, except for at WOT(IIRC, the ecu doesn't use them at WOT) the car is alot more hesistant. This is the Bosch 02 sensor. Should I try to get a Nissan 02 sensor?

[evildky]

then it's not the sensor, witht eh O2 unplugged the ecu should be running rich,. if it runs better this way the mas si suspect, or even the fuel pressure

with the new O2 does the O2 code clear?

[LIBRILZ]

When the MAS goes bad the car can usually only rev till like 2500 right? Mine goes all the way. And fuel pressure I don't understand why it would matter whether the 02 is plugged or not. When the o2 is unplugged it actually seems to run less rich and gas mileage is actually better, but with it plugged in the car runs pig rich, and unless I'am at WOT the car hesitates and sputters really bad. I have no cats, Just Headers, Test pipes, exhaust, so I know im gonna smell more exhaust than usual.




Time to start pulling hari out

[LIBRILZ]

Ahhh, double post.

[evildky]

do you have O2 codes with the new O2 sensor plugged in? I the function of the O2 sensor is to detect rich lean condition,, when unplugged the ecu should by default assume a lean condition and add fuel, same goes for the cts and the fuel temp, the mas is far more complicated and can have different results when it fail, the ecu could be an issue as well

[LIBRILZ]

Ok, still having this problem but now things are getting worse. On a cold start the car has a miss to it. It idles bumpy. As the car gets warmer it goes away, although you can still feel a little harshness in the idle but nothing crazy. I'm going to re-ohm the injectors and see what I get. Also while it has the miss i unplugged all the Coil pack wires and each one made the car drop idle and stuff.


After installing the new o2 the ECU is still telling me I have a problem. code 53 is the passenger side 02 right? Well I decided to see what would happen unplugging the driver side 02, and leaving the passenger(new one) plugged in and the car ran better. Funny thing is I drove it for about 15 min came home did codes, still got a code 53 but not a code for the driver side 02.

I have an automatic Z and I have been getting speed sensor code even before I rebuilt my engine. My speedo does not work. I'm just wondering if this could have anything to do with the hesisitation problem. It never hesistated before even when I had a speed sensor problem, just after I rebuilt my engine and put a new Harness on. I hate this car.

[evildky]

ohming the injectors si a waste fo time, if an injector had failed it woud be a constant miss and when you unplug the co for that cylinder there would be no idle drop

so you have a new passanger side O2 sensor and are still getting the O2 code? sounds like you might have a bad O ring on the passanger side, ro a weak cop or plug or somethign causing excessive unburnt fuel in the passanger side of the engine

[LIBRILZ]

I think what I really need to do is a compression test. This is a rebuilt motor but still the possiblity is there that something is messed up. Oh and now I got a oil leak from behind the timing covers but can't focus on that, gotta get the car running right.


I didn't reset the ecu after installing the new 02 sensor, should I do that and see if the code persists? Code 34 went away on it's own weirdly enough.

[LIBRILZ]

ok did a compression test on 4 cyls, didn't have time to do all 6 as doing 5 and 6 requires removal of the balance tube. Anyways this is what I found

1: 155
2:145
3:155
4:135


After I added some oil to number 4 the pressure jumped up to 210. There was also burnt smoke coming out of the exhaust, this has never happened before, and after driving around it went away. But now the hesistation is just completely awful. The car can not even really be driven unless I hit WOT. Misfire is still there like usual.

[evildky]

the car has 6 cylinders, while your numbers are good don't both doing the test if you aren't going to do it right, removing the ballance tube is 5 bolts, it's not brain surgery

back to the issue at hand,you have spark you have fuel, have you verified that the car idles on all 6? if not do that now!

if the car is idling on all 6, check the plugs, see if any of them come out wet (yes even the ones requiring you to remove the ballance tube)

[LIBRILZ]

When I take of the balance tube, do I have to cover the holes for the compression test? Also, I forgot when I did the test I ddint have the throttle wide open. Time to redo this

[evildky]

yes you leave the holes open for compression test and yes the tb should be wired wide open

[LIBRILZ]

Ok, I did check to see if it idles on all 6, pulling the coil packs. it does Idle on all 6 cylinders. Everytime I pulled a plug the idle would drop. If an injector was bad it would be a constant miss. So its safe to say coil packs and injectors are fine? Time for swapping parts I guess. I have a buddy with a 300zx that runs fine. I'll ask him to swap some parts from his car to mine like PTU, CAS and see if that does anything?

[evildky]

CAS and PTU are fine, if either were bad you'd have a misfiring injector or cop, since the injectors and cop's check otu we know the cas and ptu are working properly

just to be clear, idles fine, drives like poo poo right? mas, tps and ecu are the only electronic components that could cause seuch an issue

[LIBRILZ]

Well It's more along the lines of, it idles kinda bumpy when cold, once warmed up it idles a bit better, n o bumpyness or anytihng. When driving it just sucks though whether cold or warm. I will be taking a video of the problem soon. Man I just wanna drive my car