pleas help, fuel cut of @4000 rev 1,2,3,4,5.

[allos14]

Hello guy I am new at the nico club. The 3 last months have bean hell for me and my 240sx. It seams like a fuel cut of . ore e brake is being applied. in first gear @ 3000 rev you feel it. In 2 shift its at 4000rpm,3, 4 and 5 it’s the same . but when this happens if you let go just a little the gas it will gain jut a little more speed. If you push the gas pedal all the way the motor sound good but like its missing gas ore its choking on the gas any help guys


Modified by allos14 at 7:23 AM 11/1/2006

[HOMEMADE240SXTURBO]

hi,i thought this thread may help u a little bit. save up money and read:http://www.ka-t.org/forums/vie...39027

[allos14]

Hey thanks dude .. I will try it when a get to my house …. Can it be so simple? On Monday I will post the result… and thanks again

[kapower240]

If all else fails check your fuel pump. That used to happen to my car a couple months back until the fuel pump completely died and would work randomly. Check aprk plugs and if they have white deposits then that could mean your running lean. Also check your fuel pressure. Should be around 40psi.

After i changed to a walbro 255 all the problems were gone.

[allos14]

thaks i will chek that too budy .... one time that i remember the plugs had withe deposits so again thanks brother i will post one monday...... to tell you that your help was acurate ok ...

[allos14]

hello guys i startesd to chek the grond to my car . replace de cable. and nothing hapend. stil a cut off... then the iaac valve . and nothing.... but on sunday a put on a air fuel meter.. and everiting is ok but when you hit the 35k it goes to len and you feel the cut of.....and the lean , is to the bottom , so what can it be... fuel pump. maf. pleas help guys

[DriftSpecial180]

could be the fact that i can't understand a word you're saying.

[allos14]

im having a fuel cut of @ 35k in every shift, and they told me to check the ground of my car and the iaac valve, so i did everything is ok..... now the other day, i put on a air fuel meter. and wen you hit the 35k the meter reads lean,and the car feels like the e-brake is applied.... if you release the gas pedal a Little bit y will goo to optimal, and the car gains fast speed! my question now is .... what can it be?

wend the car is coold the air fuel meter is in optimal...... but when it gets warm. its crazy it will jump to lean all the way down. then to optimal. and then to a Little rich and back again......

[centralcoaster33]

I have a similar situation and would like some direction. Here's the details. Perhaps we have some common issues.

ISSUES:First off I have an s14 5speed and I bet you do to. Sometimes I get a bad start and the engine starts, bogs, and dies quickly. Other times I get a rough start and the engine will idle rough with dips between 400-600 rpms. Other times it starts rough, then smothes out at the normal 800 rpms. A cold start in the morning may create the first or third scenario. A warm start or restart will result in the second or third scenario. Something to note is that sometimes my temp gauge will look real shaky. I've even had the car run almost cold after running okay for a couple of hours. Okay, so the idle is a ***** and there may be a temp problem. Another issue which is scary and sucks is the cut out. I can't tell if it's fuel, air or spark, but something is missing. Taking off from a stop light I've had the car start to accelerate, then engine cuts on and off and shakes car violently. Will die if I step off of the gas, but sputters back up if I stay on it. Same happened in second and third. Wait, there's more... Other times it will cruise through town fine and I'll end up on the freeway. Car will run fine for a while, then almost out of nowhere, engine will start cutting (makes a loud buzz type noise). If I persist to drive the same, the cut outs increase until it kills my car. If I pull over, shut down, cool, restart, and go again. I can drive a while until the cut outs start to occur again.

HISTORY:There issome additional history I should mention. I have recently replaced my transmission. I couldn't get and s14 transmission so I put in an s13. My speed sensor on the output shaft does nothing that I know of. I get a working tach, but no speedometer. There was no sensor on the bellhousing at the flywheel so that sensor is just plain missing. The s13 transmission had an extra sensor on the side. Before these cut outs began, I was able to rev the engine up to 5,200 rpms before a cut out would occur in any gear. I also pulled, cleaned, and replaced seals and gaskets on the enginer (front and rear covers and oil pan). I put in new stiff mounts. My whole engine vibrates a ton! My AC was removed when I pulled the engine.

SUSPECTS:When all was working and rev limiter came on at 5,200 rpm, there may be a chance my fifth gear posistion sensor is stuck on, but I don't know. Do I do a continuity test?When idle problems exist I think I may need to test the IACV and IACV-AACV, the solenoid, and the wires. I have a manual, but the stuff seems rather inaccessable and I don't have a tool to do some of the tests mentioned in the FSM, any tips?When the fuel cuts out I read on this website that I may have issues with the fuel pump or my ground wires. I doubt it's either, but have checked my grounds and all are fine. Where do these fuel pressure measure devices come from? Where can I find out about my air/ fuel ratio?When I look in the FSM I found a page describing engine reving at no load being dangerous. So if the engine detects rpms in excess of 3,000 for a period of time (length unknown) it will automatically cut fuel until rpms drop back to 1500 or so then turn them back on. Does that clue help anyone to help me?

STAB IN THE DARK:So could my lack of speedometer create a no load situation and cause all of this? Do I have multiple issues? Where should I start checking stuff? Do I have to replace my speed sensor or can I test it or is it the one on the bellhousing that I'm not going to be able to get? Can any of these issues begin from getting water in a bad part of the engine while cleaning up old oil leak messes? My first fix, when it idled poor was to check my throttle position wires and to add a little air. That worked for a while until the cut outs began, then it went back to rough idle. What about removing my AC system? Could that cause issues with the IACV for the AC part? Does anybody live on the central coast with a consult and some free time this weekend?

[centralcoaster33]

Damn, that's a long post! I hope it get's read.

[centralcoaster33]

I can't figure out how to subscribe to this thread without posting again. If there's a way to do this I want to know. If there isn't, the website should be changed. We shouldn't have to post to subscribe, that's lame.

[allos14]

hey dude. nice info . my car some times when its warm , and you start the engine . it Will goo crazy , the Idell its @ 400 ore 500, and if you pres the gas it will goo down and die. put if you insist it will start normally lol..... ... :Weird

if your car its shaking violently it can be the maf sensor . its not reading the input of the air....... i had that problem . goo and check the wires. on my maf. the in-said connector's where broken, the welding broke......

its hard man hard.

[centralcoaster33]

Well, I tried a neat little thing last night to see what's up with my IACV. I turned on my AC (well, really I just pushed the button since I've already pulled my AC). That I guess opens up yet another little air valve which is more of an open close valve than a variable one. The idle rev'd up to about 1100 rpm for a while, so I drove a block then idled at the stop sign and it settled to a smooth 800 rpms. After driving a little with the AC button on and off I think I am able to recognize the fluctations in the main IACV and to an inexperienced guy like me, it seems to be fine. So I bet I have another air problem elsewhere.

So, I bet your onto something with the MAF. I guess I'll look closer at the MAF inside the intake. I checked the wires at the plugs and all is well, but never really scoped the wire inside.

For your cut out issues, if you have an FSM I would look at the troubleshooting. There was something in there somewhere about no load situations causing injector cut out after prolonged revs at no load... Does your speedometer work? I think there's other things that help the ECM determine load, but I don't know what they are without looking it up. I guess I'll be in your shoes when I fix my air problem.

[Logan76]

Clean your MAF's or check your MAF's wire's and such, I didnt even read your thread im just taking a stab at your problem.

[allos14]

its weird. and the thing is that the clutch was replace and that happened, but its gating worse. i will replace the maf ..... and tel my Friend to lend me his fuel pump he has one extra. and if that doesn't work y will jump off a Cliff guys lol ................. if you can fix my car ., i will send you 50 dlls guys....... tel me what to do and if it works i will send you a 50 dll money order

hey guys look @ my friends car page http://www.turboinnovation.com/

[centralcoaster33]

Logan76 - Thanks for not reading, you may have strayed from your original good advice. I cleaned the MAF like crazy last night. If it was a glass pipe, it'd would be as legal as the day was sold at the head shop. Engine cut out bs seems to have stopped. So I'm a little happier. I'm still getting some funky idles and they don't seem to be consistant with anything. I've also noticed that things like turning on the heater or the headlights cuases quite a jump in rpms, then settles down. If rough idle gets too low I can still turn on ac for more idle air, but I don't think that's a good work around. I guess I gotta go around and check ground spots, maybe cleanup and add some dilectric grease stuff. Ughh, still have some heavy vibration from all over and don't know what from yet. Maybe my new underdrive pulley or the clutch and flywheel stuff I put on.

strategically placed unnecessary smiley

[centralcoaster33]

Well, I spoke too soon. After running with the clean MAF for a while, the engine cut out problem returned. So I cleaned the MAF again and ran a tank of gas with injector cleaner in it. The problem persists. It seems to be a cut out while decellerating after the car is all warmed up. Once the cut outs start, the progressively get stroner and more frequent until the engine will even cut out during acceleration. What's going on?

[allos14]

hey dude when my car is cold, yo press the gas , and it goes like a new car. and feel like a turbo is in there , but it gets warm an the fuel cut of starts, so can it be the Temp sensor in the water? can some one Tell's what sensor make the fuel cut off?

[centralcoaster33]

Yeah, mine too, at least kind of. My temperature gauge would start at the bottom, then as car warms up, go to about mid way (normal operating temp), then it would shake up and down. However, that problem seemed to go away when I cleaned the wire plugs near the thermostat and the engine is still cutting out. So I think I may have similar cut outs, but no more issues with temp gauge. My tach get's real bouncy around 3000 rpms, does yours bounce around allos14? I guess I'm gonna check fuel pressure tonight or tomorrow, but there are other posts where guys replace their ground, spark plugs, the wires, and the fuel pump and never solved their problem or maybe they solved it and never posted the solution. Thats a problem with searching forums, lots of questions and try this try that advice, little or no solutions. You know what else is interesting is that you say your issues started after a new clutch. Well, mine started after a new clutch also. Except that I also got a new shifter, mounts, transmission, flywheel, crank pulley, and replaced front and rear main seals and liquid gasket on oil pan and front and rear covers. Did you have any other work done? Does your speedometer work?

[allos14]

hello dude, on the temp sensor well there are 2 kinds the one for the gauge and the other is for the ecm , its a red harness. and as you told me wen you turn the heater your rpm goes down , well mine go down with the Head lights. and with my power window may be there is a connection. its power. the ground connector on my car is ok , i am gonna replace the power cable !!!!!! and you know what . lets make another post , but make it whit a catch Fraze so they will be interested in going in the forum hows that.!!!!!!

[centralcoaster33]

Yeah, the next question I have will be posted in technical but will have a title like "Hot Female Drifts at Night in the Nude". Maybe then I'll get more responses. Anyway, I get the same stuff with the headlights. Only, it's like the engine will rev up and then settle with the lights, or will rev down then catch up with the windows, especially if I hold the button after the window moves all the way. I don't even run my stereo any more because it seems to trigger the cut outs sooner. Hopefully in the next couple of days I'll be able to trace some wires and maybe do some continuity tests. I still haven't gotten around to checking voltage on sensors and I have to admit, I don't really know how to do it. I was reading the FSM and it seemed confusing.

[allos14]

i think that power is the issue then !!!!! some sensor is not getting the correct power ore the bat cable is busted !!! so man lets prey .... i wanna race, so dude lets do something!!!!!!! " put the drift girl in the nude" that will make me look lol but then i will be

[centralcoaster33]

Well, I ripped out all the wires around my battery and relay box. I thought it may be related to these wires because the issue of cut out occured more frequently when I had headlights and wipers on. They were the power and ground for the battery to the starter and alternator and some wires that go back to my transmission sensors. I seperated the systems, cleaned the connectors and rewrapped the lines and put it all back. This fixed none of the cut out problems but did fix my speed sensor. However it did allow me to narrow down my options. Since then I've been able to figure out that my TPS throttle position sensor is what went bad. I finally figured out how to cram some pins into the back of the plug to "backprobe" the sensor and found that none of the voltages or resistances were in spec. At least I think I did it right. So I decided to just unplug the sensor. Now I can drive around without the fuel cut out at all. The car runs poor though, I guess because it can't guesstimate the air coming in very well. So I need a TPS. Also, I see mine is the type with the throttle posistion switch as well as the sensor (two plugs, three pins each, only five wires). This is starting to make me wonder whether or not my car was a stock five speed or not. Did the OBDII 1997 240sx se come with the automatic style sensor or was my car a conversion? I'm concerned because even if I get a tps and the car runs fine again, I might not be able to pass smog in March. I wonder what the identifying characteristics of the Auto VS Manual ECU are. Anyway, try unplugging the TPS and driving around and let me know what happens. Oh, and do you know where to get a TPS? I can't find one anywhere on the internet and I have searched. I don't want to ask Nissan for fear of OEM prices.

[shpaintball]

is it a SOHC? ...if so ...i just may win 50$...here the issue....wiring....old motor like mine i rev out every so often...it hits 4 something kicks me back to 3 thousand...basically its the FKin speedlimiter feeling some sort of no load compasity and its screwy cuz it doesnt show up on the ecu code...try this maf ....this works proced to next and so on.....maf....fuel pump....wiring ....fpr and injectors....wiring...speedometer ( my problem plus some others) .......wirings ....maybe get a ground wiring kit?....lastly emissions and AC....check that stuff make sure it was unistalled properly otherwise your in trouble this doesnt fix it ....your pretty much outta luck : (

[shpaintball]

to figure that ^ out it took 2 nismo mechanics and me explaining everything.....should fix it make sure all that stuff works and i bet it works...

[centralcoaster33]

I dunno man, those are good guesses. But, you'll see I was already trying to get credit (and $50) for the no load rev limiter in previous posts. Also, we both have s14s with DOHC. For me, I'm 99.6% sure it's my TPS, since last night I finally figured out a way to back probe and measure voltage. The voltage confirmed my weird resistence measurements as they are kind of a mirror image of eachother. Finally, just running disconnected was the big clue as I don't get any cut outs. If it was another problem, I suspect with the TPS disconnected, the whole thing wouldn't work. Example: if MAF fails, TPS input is substituted, but if TPS and MAF were gone, nothing would work... Any thoughts? By the way, I never even started on getting into diagnosing the fuel system (pump, FPR, injectors...). I think that'll have to wait for me to install a working TPS.

[shpaintball]

good call i agree it seems like a very hard problem to trace... i think your headed in the right direction tell me how it works out...and for the record the FSM give the no load rev limter gets credited ...lol...lmk tho very interested you can have the 50 if your right...

[shpaintball]

have you looked at the o2 sensor? get a gauge and see what it reads out ....just a shot in the dark ...has been case before...

[allos14]

Its me guys

I still have the same problem, and dam the other day my car was out running mustangs again, and it went dull again guys, check your knock sensor, and your o2 sensor , that day I was messing around with the cables and boooooom my 240sx was a devil. So guys the 50 bills its still at your disposition if you give my the solution.

Go and check your timing, some thing is messing with the timing, my air fuel meter goes crazy it doesn’t stay more then 2 seconds in one place. So I think that my timing is constantly changing so check your knock sensor, ignition coil, iaavc,

Nice to read you guys

And the offer went up 60 dlls

Best regards

Alonso Urueta

[centralcoaster33]

Dang, we hadn't heard back for so long I thought you'd fixed yer sht. Does your car vibrate a lot, I mean a real lot, like you can never see out of your rear view mirror? Mine was like that when I put on the UR crank pulley, but it wasn't on straight so it buzzed the whole car and triggered my knock sensor. So straighten and that helped a lot. I first thought dirty or bad MAF, but cleaned and car was happier. For me, the true failure was TPS. After some tests, I realized it was fried and ordered a remanufactured one by Wells. I put it in and it was tough to tune and adjust my idle, but I finally got it. When the TPS was out of tune, the light pedal feel was super crappy. Like trying to cruise downtown slow and the engine would hiccup and stumble or try to idle when I ease off gas and then rumble and rev when I'd tap gas on. Tuning that helped me tons. Then I thought I had it and it suddenly went crappy again. This time my O2 sensor in the header failed. I had just put a new one in for gas mileage reasons. Cars seem to really like this sensor to be working, so I put back the old one and reordered another new one. Now car works great except for one big thing, I still get a limiter at 5200rpm. I checked my 5th position sensor for continuity and it works fine. I should trace wires and see if the previous owner was trying to bypass the top speed limiter somehow, but I don't really know what to look for yet. I still think I could gain some more realiability with a little professional tuning of my TPS, distributor and then ECU, but that'll wait for more funds. Maybe that helps? Dude, you really really need an OBD-II code reader thingy. Borrow, rent, buy, whatever, you can't just keep guessing at codes. Does your CEL stay on constantly or have you pulled that out already?