240 idle is getting worse. NOT distributor as dealer service tech claims.......

[bgoodwill]

Me again. I'm the greenhorn with the '92 240 that was idling rough 2 weeks ago - thought cylinder #4 might be bad. Well, I've checked out and changed out lots of things and it's just getting worse. Doesn't want to idle at all now, but runs okay when on the open road. Finally took it to Nissan dealer and they diagnosed bad distributor. WRONG! (I'll be taking that up with the dealer on Monday). Not the coil, either. Anybody know what else would be causing it to act/test like it's got a bad distributor?

[Silvia007]

bad idle but runs ok on open road, sounds like a vac leak. Oh, and what do you mean by ok?

[bgoodwill]

Runs as usual except at idle. No performance problems, no gas or oil consumption. It is all stock and does have 222,000 miles on the car (only about 50,000 on engine block that was replaced last winter), so not a rocket, but I've been driving this car daily for 12 years and there is no appreciable change in performance now, just won't idle. Dealer tech said it was "all over the place" during testing, but I don't feel that when driving, only at idle. Even very slow speeds are okay, as long as my foot's on the accelerator. Starting coasting or idling and it acts like it "loads up" and then stalls.

Many people seem to think it's a vacuum thing, but haven't been able to find it yet. I'll keep at it, but any other suggestions?

[nissanfreak8]

Its a long shot but it might be a weak fuel pump. It sounds silly but its worth a shot.

[bgoodwill]

Have been working on this thing all day and am still frustrated. I have discovered that the rpms are not holding steady - are running up, as well as down. When I prop something on the accelerator w/ rpms at about 1600 to get out to listen to the engine up close, the rpms run up as high as 3000, then back down to 1600, then down as low as 300, then back up to 1600 (if it doesn't stall at low rpms) and so forth. Sometimes does it 2 or 3 three times before it stalls. I'm beginning to think fuel regulator, or as you say, maybe fuel pump.

Thanks for your help and any other thoughts will be appreciated.

[Acecool]

Post a picture of your engine bay, and a closeup of the fuel rail, and the vacuum lines coming and going from that general area.

[180fan]

you're getting a bouncing idle? is this always there or does it go away when the engine is warm or cold?

[bgoodwill]

I have owned this car for 11 years and never had idle problems before. A couple of weeks ago it started to idle really rough and after a few days started to stall when idling. Now it is doing this bouncing idle all the time. time. Engine revs higher than usual the minute you turn the key (up to about 2200 rpms vs the usual 1500 or so), then the bouncing starts. I don't feel any problem with fuel delivery when the car is out on the road.

I can try to post pictures in the nextcouple of days.

Thanks guys!

[Acecool]

Vacuum lines, I had same jumpy idle... Vacuum lines were all chewed through.

[bgoodwill]

Here's the latest. Just came from talking to the Nissan tech (who was trying to sell me a new distributor last week, so I AM skeptical.....), but he insists the computer was throwing bad distributor/crankcase readings only. No vacuum codes at all. He suggested changing out air meter and taking in-line fuel pressure readings and, if neither of those are the issue, changing out ecu. (Luckily I have a running parts car, so I can do these things without extra expense.) Does this make sense?

[bgoodwill]

Oh, by the way, any suggestions which vacuum lines to check? I think we've looked at them all, but anything hidden we might have overlooked?

[Acecool]

Near the end of the fuel rail... There is a small round thing with about 3 or so hoses coming from it.. Take the 2 bolts off it and lift it up.. Check the bottom hose for cracks, as well as the other ones.

[C3Sar4U]

hey man im having the same problem with my 93 240 hatch...i took it to my mechanic and he looked at it...he said that my engine was mis firing, that one of my cylinders wasnt firing.... and so in essence i am running on three cylinders

he tested it by turning on the car and popping out the thing that connects to the spark plugs...each time he popped one out halfway the engine would slow down but on the last one the engine ran as if he hadnt done anything...

he said that i had probably bent a few valves or something along those lines through exessive high reving...

his solution was to repolish the head of the cylinder and have some work done on tha valves....im not quite sure he is right so i will b taking my 240 out to the dealership to see if they give me a diff diagnosis...

any of you have the same prob?

[bgoodwill]

Yes, my origin complaint was that mine seemed not to be firing on #4, at least at low rpms, but I'm not noticing any problems with it at road speeds, and no change in gas or oil consumption. Since we checked/changed injectors, plugs, wires, etc. 2 weeks ago and that didn't fix the problem, I haven't really checked cyl #4 again since. Guess I bet check again.

[nissanfreak8]

hey man im having the same problem with my 93 240 hatch...i took it to my mechanic and he looked at it...he said that my engine was mis firing, that one of my cylinders wasnt firing.... and so in essence i am running on three cylinders

he tested it by turning on the car and popping out the thing that connects to the spark plugs...each time he popped one out halfway the engine would slow down but on the last one the engine ran as if he hadnt done anything...

he said that i had probably bent a few valves or something along those lines through exessive high reving...

his solution was to repolish the head of the cylinder and have some work done on tha valves....im not quite sure he is right so i will b taking my 240 out to the dealership to see if they give me a diff diagnosis...

any of you have the same prob?

Do u know if ur getting spark to the down cylinder?

[bige240]

This may sound weird but it could be your coolant temp sensor. If it is not reading right the volumetric efficiency is off and could make your car knock or misfire...its only a 20 dollar part. It is on the upper coolant output near the intake manifold....There are two of them the one that gives the ecu the reading is the one with 2 wires coming out...other than vaccum leak that's all I can think of

[Silvia2b]

If he is getting idle problems and it bounces and sometimes dies it could also be the IACV, located on the firewall side of the intake manifold under the EGR. It may need to be cleaned up so the valves in it stop sticking and adjust the right vacuum levels in the lines. Here is a picture of a dirty one I removed from my 95.

[dkdeleon68]

check your injectors. also check your oil to see if it smells like gas.

[nelson8708]

Check the rubber tube between the intake pipe and the throttle body. Mine had a tear at the bottom and it caused a bad idle. Also to clean the iacv just loosen the large hose on the intake tube just enough to get one of those small red tubes off a can of carb cleaner and squirt some in their while it is running. Not to much though because you will hydro lock the engine. Give it a small squirt every 7 seconds. Maybe 7-8 squirts total. If that doesnt work i would also sea foam the car. Hope this helps

[C3Sar4U]

ill soon b checking the injector on my #4 cylinder, i noticed that there was a wire that went from my remote starter control box to one fo the electrical wires that connected into the #4 injector...i was pretty pissed when i found out it led to the remote starter of my car

anywho i removed the wire...who ever installed the remote starter for the previous owner connected that wire onto one of the injector wires, they stripped one of the wire, connected the remote starter wire to it then taped over it with electrical tape, im not sure whether it required them to do that but ya suffice it to say that remote starter is gonna b trashed soon as i get some time...

ill try and check the injector tomorrow, see if it primes when i set the key to on or wuteva..i saw some instructions around the forums a while ago...

hey question...is it potentially fatal to the engine to run on 3 cylinders??i mean ive been driving mine like that since its my daily driver and all...just dont want it to go to ****s

i asked my mechanic and he said as long as i aint pushing it too hard i should b fine...but i just wanna make sure

[nissanfreak8]

ill soon b checking the injector on my #4 cylinder, i noticed that there was a wire that went from my remote starter control box to one fo the electrical wires that connected into the #4 injector...i was pretty pissed when i found out it led to the remote starter of my car

anywho i removed the wire...who ever installed the remote starter for the previous owner connected that wire onto one of the injector wires, they stripped one of the wire, connected the remote starter wire to it then taped over it with electrical tape, im not sure whether it required them to do that but ya suffice it to say that remote starter is gonna b trashed soon as i get some time...

ill try and check the injector tomorrow, see if it primes when i set the key to on or wuteva..i saw some instructions around the forums a while ago...

hey question...is it potentially fatal to the engine to run on 3 cylinders??i mean ive been driving mine like that since its my daily driver and all...just dont want it to go to ****s

i asked my mechanic and he said as long as i aint pushing it too hard i should b fine...but i just wanna make sure

I don't see why it would cuz i just replaced two plug wires so im back on all 8 cylinders and i drove like that for about 5000 miles.

[C3Sar4U]

aight so i tried taking off the injector today and failed..haha

i got the metal cover off the injector which was a ***** since one of the two screws was badly worn...i used some WD40 on it and i managed to pop it our after an hour or so...

now as for my actual injector i just couldnt get it to come out... i tried and i tried to no avail.... i tried using a flathead but i couldnt get a good enough wedge to pull it out from, i used vice grips but nope nada...

any ideas as to wut i should do besides going to a mechanic and having them do it?

[wzntha]

.

[nelson8708]

I am having similar problems with my 93 240SX. When I step on the clutch to coast to a stop sign or stop light, the engine will die. It would usually drop to about 500 rpm when it idles, but recently the engine will stall when it step on the clutch. I've tried coasting from different rpms and found out that the engine will die when I step on the clutch will its at 3000 rpm, but if i do it lower than 2500 rpm, it won't stall. I really do not know what's going on. The car worked perfectly before and after about an hour in between, i drove it again and this started happening. Is there anything I can check that doesn't require more than a screwdriver because I'm dorming at my school and I don't have any tools with me other than a screwdriver. Also would it be safe to drive back home on the freeway with my car(about hour and a half drive)? Hopefully someone can help me fix this within two weeks because i have to go home in two weeks. Any help would be appreciated. Thanks.

My buddies ka24de was doing that also at the end of the last school year. It ended up being the o2 sensor. Try replacing it with another single wire o2 sensor since they are only 15$ or so.

[wzntha]

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[Ramius83]

Ok guys. Here you go.....

KA24DE engines have a bad tendency to start a bad idle and stumbling over time. In most cases that come into our dealership, it is the intake manifold gasket. What happens is the intake manifold gasket gets a break or crack in it. As the engine is sitting at idle is when vacuum is at its greatest. This high vacuum will suck air in through those breaks or cracks in the intake manifold, and cause a lean/detonation condition in 1, 2, 3, or all four cylinders, depending on the crack and condition of the intake manifold gasket. This will cause the engine to run extremely bad at idle, but run "ok" when driving.

Now, how to check your intake manfold gasket. Get yourself some carburator cleaner. Start your engine and let it idle. Spray the intake manifold gasket down as best you can with the carb cleaner. The idle should fluctuate each and every time you spray the carb cleaner and it finds the crack. Keep spraying the intake manifold gasket on the top as much as you can. Let us know how this goes.

[el-biejon]

yo Ramius83 im trying to get a hold of you this is jessis friend with the rb26 member me? email me at [email protected]

[bgoodwill]

Many thanks to everybody who offered a suggestion. Believe me, I tried them all! After three weekends of checking, cleaning, and changing parts, as well as two visits to the dealer service department out of desperation, the carb cleaner around the manifold trick gave me the answer. It IS my manifold intake gasket, even though it was replaced with the new engine install just 9 months ago. I'm not happy to think that I'm going to have to replace that puppy, but at least I know what I'm up against. Yeah, NICO club!!

[sedoken]

how do u know it's not the distributor?

pull off the cap and look at the rotor and where it connects to the spark plug wires. mine were all galvanized to hell. too a bit of sand paper and got the **** off and my car ran fine after that. sounds like what i had as well by the way