jlander82

Hi, I'm new to this forum, though I've read through many of the threads here and can't find exactly what's going on with my car. Sorry for the length of this post, but I suppose one can't be too specific when describing what your car is doing.

I have a 95 w/ OBD1 that started shaking at lower RPMs (feels just like it's running on 5 cylinders), and would behave fine above 2000 or so. Specifically, I could notice it was worst at 1500 rpm while in overdrive. The check engine light came on and after pulling the code, and I found out that it was a 0304 knock sensor. I replaced the knock sensor and cleaned the ground contacts (old one did have a crack in it), and the car appeared to be fine. I drove the car about 50 miles during which time it behaved pretty well and seemed to have enough power.

When I got where I was going, I turned the car off for 10 minutes or so, and when I went to start it again, it died (it would not idle... feels like only running on 5 cylinders). This could be overcome by giving it gas when starting. So now I have to stay on the gas in neutral at stoplights so the engine won't die. Also, when it dies and the key is still in the "on" position, you can hear a clicking in the engine bay... I traced this down and I believe it's the IAC valve or solenoid or whatever it is called. I did the tests Chilton's recommends, the resistances are fine, though I suppose that doesn't necessarily mean it's totally ok. I ran it for awhile longer (I have to prop open the butterfly valve and run the engine at around 1000 rpm to keep it from dying) and when I turned off the car and removed the keys from the ignition, the previously mentioned IAC valve continued its clicking (it had been continuously clicking while the engine was running at 1000 rpm as well).

I have pulled off all the coilpacks and tested for their resistance and cylinder number 5 seemed to be off. I also checked all the plugs, which seemed to be ok (they are fairly new). Since cylinder 5 seemed a little off in its ohm reading, I left it disconnected and ran the car that way. It runs exactly as crappy as it did before, so I am assuming that cylinder 5 is still not getting combustion. I got a new coilpack and put it in cylinder 5, but it still didn't fix anything, so I put the old one back on. I listened to the front fuel injectors with a screwdriver and compared it to cylinder 5's fuel injector, and they all sound the same (all are clicking proportionally to the rpms).

I have checked for the infamous intake gasket problem, and I don't beleive it to be that either... I don't hear sucking anywhere, or see visual evidence of it once I hit it with WD40. I have also replaced the PCV valve and am running fuel injector cleaner in the gas (I did get new gas in case the old gas was bad).

Also, this is probably unrelated, but after having run it for 5 minutes at high idle (1000 rpm) trying to diagnose the problem, I looked down and noticed a big puddle of gas in front of the rear drivers side tire, but couldn't tell what the source was. I thought maybe it was originating from whichever cylinder might not be firing, but the leak did not appear to be anywhere near the exhaust system, plus I think the cat would have caught that anyway.

Any suggestions would be very helpful because I'm at my wits end after having searched through the chilton's manual and most of the threads of this forum and yet I still am having these problems. Thank you all!

mikem29ss

I would start with a compression check to verify the integrity of the engine, do a non- running and running. A running check will tell you if yo have a valvae hanging up in the guide. As for the gas leak, if memory serves me right, the evap canister is in that area, check that out. Just a few thoughts before I go to bed. I'll get some more thoughts in the morning.

bkea

IIRC the knock snesor will not trigger the CEL, it gives a silent code. So you need to recheck for codes. It sounds kinda like you may have a leaking injector.

jlander82

Sorry... fairly new here, but what does IIRC mean? Also, keep in my 95 has the OBD1, so the codes I pull will tell me very little compared to an OBD2.

pmohr

iTrader: (26)

Where were you told it's OBD-I? It's OBD-II, as are ALL A32s... IIRC==If I Recall Correctly.

jlander82

Oh you're right... my confusion was in that Autozone couldn't hook up an obd2 reader, so I mistakenly assumed it was an obd1.

Pulled a code yesterday, and got the 0505, which if I'm not mistaken is the "everything's OK" code, so I'm not entirely sure what's going on here.

mikem29ss

There is an OBDII port on the passenger side of the ECU. Remove the panel near the floor board on the console and it is in there. You should remove the spakr plugs and compare them, look at the color on the porcelin. A bad injector would blacken the plugs pretty quick, and if it was bad enough, the plug would even be wet with gas. I would buy a generic scan tool that can provide you with a datastream. That will let you look at ECT, and fuel trims, along with other things. This info can provide you with a better idea of what is really going on. Plus it is a good tool to keep around. If you do go this route, pay attention to ECT (engine coolant temp), short term and long term fuel trims, mass airflow values, and IAC count. Plus you will probably pull a misfire code if it is running as bad as you say. HTH, good luck. Post any new findings and I'll try to help you the best I can.

jlander82

Well... here's the update. Me and the friend whose car this is decided to put it in the shop for the dianostics...

The mechanics are saying it's the number 5 fuel injector and they are saying that the "Idle air motor" is broken. I can only assume they mean the IAC solenoid. (I think that's what it's called... maybe AIC.)

Anyway, does this combo of problems sound feasible? Anyone ever had an "idle air motor" go out?

I'm also curious if the clicking of the IAC I mentioned in an earlier post is maybe a result of trying to adjust for the poor idle caused by a faulty injector, or instead if the clicking is actually a cause of the poor idle.

Also, thanks for the actual location of the OBDII port... I have a port in the inside fusebox, but it's not OBD2 compliant... It's weird they'd put both, and hide the most common one.

mikem29ss

That year was not OBDII required, which is why they can put it where ever they want. Nissan used those ports in the fuse panel area right up to around year 2000. A number 5 injector would def. cause a bad running problem. IAC's go bad fairly frequently, but usually result in a low idle and stalling, but usually no other running condition. If it were up to me, I would try cleaning the IAC, either removing it or decarbonizing the engine, and replace that injector, you may even want to put a new plug in that hole if it was running too rich. I don't think the guy is screwing you though. The clicking may have been the sign of the injector failing, and IAC will make some noise but usually isn't super loud. Good luck w/ the problem

super6

iTrader: (5)

well id say the iacv is likely shot from the sound u described and as ur mechanic confirmed. it is possible for them to go bad and a new iacv is about $205, the sound ur hearing is the iacv motor. i dont think that the injector problem would be connected to the iacv problem. did u notice any oil on the spark plugs when u took them out? and does there appear to be oil in ur antifreeze? maybe u have a busted head gasket, and that also cuasing a pressure problem in that cylinder or the whole rear bank?

the shaking at around 1500 is a symptom of the TPS going bad or set to an incorrect possition, but i dont think thats the problem in thsi case.

the gasoline problem is very strange, the compression check is defenatly recomended. id usually start by saying check ur MAF, injectors etc, unfortunately it seems like ur problem is much more invloved.

jlander82

Thanks for the feedback thus far... much appreciated. I will hear from the owner this week what she'd like to do.... and I will keep this updated. - Justin

stef_pen

i also had those problems, but eventually after changing a lot of parts, and still not able to remedy the problem. i accidentally found the culprit, its the hose from the maf to the throttle body, it should be inserted properly, you should apply a little wd-40 on the plastic surface, so that when you insert the tube, it will slide in . hope this helps

mikem29ss

Sometimes the inlet tube will crack and cause intermittent problems. I had one terd in that would run great in reverse but run horrible in drive, occasionally. that tube had a crack that would open up when the engine toqued a certain way

stef_pen

dis might sound strange, after regaining my idle from properly inserting all tubes from MAF to the throttle body. Another problem came up, the car's battery keeps discharging, i even bought a new one, but after it died again, i'm was pretty sure its not the battery. So i check the standby current draw, it was around 1.5 amps, so i checked my other cars standby current draw, it's only .15 amps, so i started pulling some fuses to isolate the problem, i came upon a fuse beside the battery thats labelled ECCS 7.5A, its been triggering a relay in front of the battery thats labelled EGI, so i tried starting the car without the ECCS 7.5A fuse, the engine started normally, so i took a test drive , the car seemed normal. After a few months , i returned the ECCS fuse, the engine started normally, but when i try to drive the car , the engine stalled, after i started it again, it stalled again, so i removed the ECCS fuse, the car became normal gain, any idea whats the ECCS fuse is? What the Relay EGI for?

super6

iTrader: (5)

not sure what it does, but id say thats ur problem, change that fuse i guess.