disgruntled

iTrader: (7)

90 SE 5speed, just yesterday out of the blue, the car would have surging idle, then would return to normal for a couple of minutes, then does the whole thing again. This happens with clutch engage/disengaged, in gear/not in gear, and while parked on neutral also, so I think the tranny can be ruled out for now. So far, I have only been able to test one fuel injector, ring up 13.4 ohm, the rest is tucked away, so I will have to go get some gaskets so that I can take the upper intake manifold off to access the remaining injectors. BUT before I do that, can I simply take the spark plugs out and check its condition? Also, the car has had a nonstable idle ever since I got it, would idle between 500-700, but after a 20 miles drive, the idle is rock solid at 700. Exhaust pipe is doing a putt-putt, but I don't know if it's injectors related, or simply just the way its supposed to be like since out of the two 3rd gen that I have, they both do the same thing.

Also, when driving, the car would sound like it almost cut out, then I have to give it gas, which it will hesitate for a couple of seconds, then launch as normal.

MAF sensor had been rule out.
and I'm keeping an eye on my gas mileage.

Thanks in advance.

Greeny

iTrader: (43)

A strong smell of raw gas from the exhaust is also a good sign that a injector is going...

How long since your last full tune up??

internetautomar

iTrader: (30)

putt putt is a sure sign of a miss which your plugs should tell you which one it is

disgruntled

iTrader: (7)

I'm not so sure about the strong gas smell, but my tail pipe is quite sooty (black) and the exhaust gas do have some kind of raw gas smell to it, plus it makes my eyes water if I happen to walk into the "cloud". I just got done checking my 1,3,5 injectors, 1 and 5 ring up 12.2, number 3 ring up 13.5. I will check the front bank later and let you guys know my findings.

Internetautomart: I tried the unplugging method several times, each time, the report came back to all 6 cylinders firing correctly.

Last tune up was done about 6000 miles ago, cap was replaced, but rotor wasn't, seems to be in good condition though, sparkplugs were changed, timing belt, water pump, and thermostat was changed, along with a coolant flush. Sparkplug wires looks to be original OEM, but the conditions seems too good (the old owner did say that he only uses genuine nissan parts.)

I also did a little rewiring project (will tell you guys about it later) in the interior of the car, any chance that it might have caused interference with the ECU?

internetautomar

iTrader: (30)

you are probably running rich, which could be anything from an injector dumping gas because it's stuck open or a bad o2

disgruntled

iTrader: (7)

just an update: I checked 5 out of 6 injectors, and all rang up within range. I also cleaned the contacts and loaded them with dielectric grease since the corrosion on them is pretty bad, and for the test run, it only did the sputtering thing once, and that was when I was exiting a parking lot, but as soon as I gave it some gas, it runs like its supposed to. Keeping fingers crossed.

kblast523

Howdy,
1990 GXE here with 121K and had same thing happen. In a prevous life two rear injectors replaced along with one or two coolant hoses. Being a Texas car, the remaining rubber that had not been replaced was hard as rocks, so doing the entire underhood hose thing. Amazing this thing had not torched itself as #5 injector leaking, and both fuel rail crossover hoses leaking, as well as a couple of the cooling lines. Only started getting fuel smell about a month ago when cold, and shortly thereafter intermittent restart miss. Ran two tanks of 93 octane and Synpower fuel injector cleaner and improved, but not fixed. Last month it was timing belt, water pump and idler...
Decided to go ahead and replace all 6 injectors since 4 originals in 12.2 to 11.4 ohm range and one of the non-nissan injectors was at 9.9 ohms. Cleaning intake plenum of varnish, black marbly stuff in the corners, as well as in injector rail just below the injectors. PCV is dry, as well as hose into it, but looks to me like this thing missing maintainance...took the stock cap/rotor/wires off last winter and ran fine until it got cold...shoulda known.

internetautomar

iTrader: (30)

the car ran fine with no C/R/W??



j/p

dannydoo

maf/o2 sensors
vacume leak..

disgruntled

iTrader: (7)

more update: well, the cleaning didn't really fix, as the thing lost power when I was in the middle of a highway, so I gunned it, hoping the thing will make past the trouble spot rev. range which is 2~3k, while doing so, the car felt like it rocked back and forth for several times before accelerating. Pulled the ECU code, and it says 33 = O2 sensor, just disconnected this morning. Now the question is, can I safely drive without the O2 plugged in for a 20 miles trip for trouble shooting purposes? I know my cat will likely be harmed, but if the damage is marginal, I think I will try it.

Greeny

iTrader: (43)

20 miles shouldn't hurt the cat...I think the ecu will take over with a default setting for it while it is unplugged...