power loss problems

[kapower240]

Hey guys i need some hep with some power loss i have been dealing with and its starting to get on my nerves. wel the power loss is from 2500-3000rpms and my tone from my exhaust goes from smooth to an erratic tone when i lose power. so i was thinking that it might be either the maf failing or the fuel pump not giving me enough fuel. and the other thing is that when i have gas pedal pressed lightly its hard to notice but when pedal is at least more that 1/4 the way down you can feel it. it also happens randomly so sometimes i dont have power loss and sometimes i do. by the way i have 1993 240sx HB w/ 97 KA24DE with 280k miles ond the body and 110k on the engine with few basic mods I/E. well hope you guys can help

[corn322]

Check the distributor cap & rotor. I had a similar issue, I couldn't go past 1/4 throttle or it would stumple all over itself.

The carbon contact button on the dizzy cap had disintegrated, and was making almost no contact.

[rsmithdrift]

Sounds like a Nissan to me.......

Also sounds EXACTLY like my car.

I wish I knew the answer...I'd be a much happier man.

So wierd when some days my car is peppy as hell and LOVES throttle and rpm......then other days it'll be bogging so bad you can't stand it and going over 1/2 throttle is pointless cause all you'll hear is a/f ratio going sour and you won't gain acceleration by it either......you can even smell that the car is running either lean or rich for a few minutes after a full throttle run when it's doing it. I can't tell which it is though...I'm thinking lean though cause it smell like catalytic converter and not unburnt fuel.......smells like that magnaflow hi flow cat I got is at 1,000* farenhieght....

[kapower240]

yea thats how mine is too. but yea am gonna get the distributor cap and rotor new tomorrow. probably have to wait a while for them to receive it but ill try that then wel see what happens

[rsmithdrift]

yea thats how mine is too. but yea am gonna get the distributor cap and rotor new tomorrow. probably have to wait a while for them to receive it but ill try that then wel see what happens

Erm.....I have a full tune up on my car.......

I think that'll make your car run better in general to give it a tune up.

But if a tune up issue was the problem it'd be consistent. And you already said that it's like mine and only does it when it feels like it. So the cap and rotor aren't your main issue here. I tried that. Along with NGK plugs and wires, and a new ignition coil, and a new O2 sensor and Coolant temp sensor and cleaned trottle body and MAF sensor and new fuel filter and new intake, new cat converter, checked vacumn lines, and removed AIV .........I don't know anymore.......I've just learned to accept it for what it is. I'd like to figure it out, but untill I get it figured out there's not much I can do but deal with it..... sucks......

[InsanityInc]

Make sure your TPS is in good adjustment.

[positron1]

Hey guys i need some hep with some power loss i have been dealing with and its starting to get on my nerves. wel the power loss is from 2500-3000rpms and my tone from my exhaust goes from smooth to an erratic tone when i lose power. so i was thinking that it might be either the maf failing or the fuel pump not giving me enough fuel. and the other thing is that when i have gas pedal pressed lightly its hard to notice but when pedal is at least more that 1/4 the way down you can feel it. it also happens randomly so sometimes i dont have power loss and sometimes i do. by the way i have 1993 240sx HB w/ 97 KA24DE with 280k miles ond the body and 110k on the engine with few basic mods I/E. well hope you guys can help

Exact same thing was happening to me so I got under the hood and checked and found a lot of little problems that I had been overlooking. I had replaced my radiator but forgot to tighten up the clamp where my intake piping connects to the engine. Had to take the intake off to get the radiator out. Found two vacuum hoses that were not capped off. I also checked under the car and found that the exhaust gasket and one bolt had completely come off where the catback and the test pipe connect. I replaced the gasket and bolts. Fixing these problems corrected my power loss, idling problems and noise reduction. My car would have erratic idle where it used to idle at 1000rpm always. After startup it would bog down and almost completely die when I would shift into gear and give it the gas. Between 2500-3000rpms it would lose power and bog down. I also noticed that my exhaust was louder than normal and the car did not accelerate the way it did before.

[mmm240]

nice color choice! sorry i can't help with your problem, but you should join the chuki crew anyways!zerothread?id=186859

and welcome to NICO!

[240fstbak]

i had a very similar problem and i found that it was fixed by replacing the fuel filter and never using phillips 66 gas again!

[kapower240]

i just changed my fuel filter today but i still get that same hesitation around the same rpm. am moving on to checking my TPS and probably change my cap and rotor (since its pretty old). but thanks for all help and suggestions everybody

[positron1]

i had a very similar problem and i found that it was fixed by replacing the fuel filter and never using phillips 66 gas again!

Anybody know how often you should change your fuel filter? I changed mine after I bought the car about a year and a half ago.

[oki-drifter]

50k miles, and you can use a 300z fuel filter btw, bigger, more flow

[kapower240]

:::::::UPDATE:::::::

hey guys my car is still running ****ty. but today i was checking my sensors and injectors with my voltage meter and when i got to the fuel pump it read around 1.5 ohms and according to the FSM it should read a resistance of 0.5 ohms so i was wondering if that could be a problem. i also checked my NGK iridiums and they were getting kind of white so i might be running lean. and another thing is when i lose power the engine gets shaky specialy with throttle fully open as if i was running on 3 cylinders but it happens randomly. so far i did replace the cap and rotor although the old ones seemed fine. as far as the things i checked is the resistance on the CTS, TPS, and injectors, and voltage on my MAF and they read good. but am open to more suggestions and please help my 240

[rsmithdrift]

:::::::UPDATE:::::::

and another thing is when i lose power the engine gets shaky specialy with throttle fully open as if i was running on 3 cylinders but it happens randomly.

Uh oh.....sounds like somebodies got the EXACT same problem my car has.......sticking valve........:/

Sucks don't it??

If that's not it then please, please somebody find something to prove me wrong. I had two mechanics and a bunch of car guys tell me it was my sticking valve. And I never mentioned valves to them at all, i just described the problem and that's what they all pretty much told me.

God I hope they're wrong though.

[kapower240]

Damn i had the sticky vavle theory in the back of my mind, dreading it and it could be possible. If it is then am f"ckd. Is it possible that it could be the vavle spring or something? i guess am gonna end up opening my vakve cover to see if i see anything out of the ordinary.

[kapower240]

what might cause the valves to stick? amm about to search

[rsmithdrift]

Heh, just to keep this thread up to date with a solution........

My cars problem was a bad fuel injector. Fixed all kinds of problems my car had......all better now.

Also kapower240 said his problem turned out to be the fuel pump in another thread.....

[seanman]

how badly would putting that 300z fuel filter drop your gas mileage alot?

[KaPoweredHatch]

Wow I love how much this thread exactly explains my cars same problem!

It had the power loss/cut out since I bought it so heres what I replaced in the past two weeks

Distributor capRotary button10mm hot ignition spark plug wiresNGK True Iridium spark plugsWIX late model 300zx fuel filter

None of that helped the problem go away.I seafoamed my car though (recommend to everyone!) and it did run a lot better for about 2 days.My power loss is just killing me though. I also noticed that when in 4-5th gears when im doing 50-75 or so that the power loss is not there as hard but very often and its so slight you can barely tell but it feels like a miss or a bad fuel injector.

I need a good site to buy a nice walbro fuel pump (mainly inexpensive sites) and maybe some inexpensive new nismo fuel injectors. Let me know.

[mmm240]

zerothread/193130

here ya go bud!

[KaPoweredHatch]

Hey thanks for the link!

But do you know where I might find some oem sized nismo injectors for a fair price???

[ubrbilly]

i had the same problem as you and i wasted alot of money on changing dist cap, spark plugs etc, what the problem was my manifold gasket, take to a garage and have them to check it out or do a diagnostic test and if u get po304 then you defo need the manifold sorting out

goof luck, let me no ur out [email protected]

[Sonikfuri]

I'm havin this same problem, so I'm gonna try getting some fuel injector cleaner and try that.

[Sonikfuri]

**UPDATE**

I tried putting in the fuel injector cleaner, and so far it's helped out drastically. I can still feel the power cut out during hard turns, but I also didn't follow the directions perfectly (I couldn't just "waste" 1/2 tank of gas). So I'm going to run my (now) full tank down and pour another bottle in...now i just gotta change my ignition coil.

[KaPoweredHatch]

**UPDATE**

I tried putting in the fuel injector cleaner, and so far it's helped out drastically. I can still feel the power cut out during hard turns, but I also didn't follow the directions perfectly (I couldn't just "waste" 1/2 tank of gas). So I'm going to run my (now) full tank down and pour another bottle in...now i just gotta change my ignition coil.

I did the same thing as well as sea foamed my car 2 times and yes it does help the problem for a little while but does not fix it permanently.

I just got some MAS cleaner today and Im going to clean my MAF and air temp sensor but I know that wont help out all that much.

As for it being a manifold gasket I highly doubt that would cause such cutting out. The rough idles, Cutting out around 3 grand and when just cruising in low revs simply just sounds like a bad injector. In fact When I recently polished my valve cover My number 2 spark plug seemed to be where the misfire was...Im going to fork out the 220 dollars for new injectors and update.

goodluck

[240_ESEX]

KaPoweredHatch did you switch out those injectors. I've got this problem just like everyone else, only I pulled out my plugs to look at the wear on them and 2 and 4 have unburned fuel on them, still wet. 1 and 3 are fine they burn like they're supposed to. Also there is litterally fuel coming out of my exhaust along with white smoke. Not like pouring out or anything, but spiting it out, and the longer or harder the car's running the more that comes out. Anyone able to solve this problem, or other idea's of what it might be?

[KaPoweredHatch]

KaPoweredHatch did you switch out those injectors. I've got this problem just like everyone else, only I pulled out my plugs to look at the wear on them and 2 and 4 have unburned fuel on them, still wet. 1 and 3 are fine they burn like they're supposed to. Also there is litterally fuel coming out of my exhaust along with white smoke. Not like pouring out or anything, but spiting it out, and the longer or harder the car's running the more that comes out. Anyone able to solve this problem, or other idea's of what it might be?

Sorry its takin me so long to reply.

No I have not changed my injectors although I did purchase them Im just waiting for a dry day to go out and do the work. I purchased mine for around 230 dollars shipped. Im hoping that it fixes my problem so I can address everyone elses problems. Until then I guess goodluck to everyone!

Try and keep this thread updated for any future 240 owners looking for help.

[KaPoweredHatch]

KaPoweredHatch did you switch out those injectors. I've got this problem just like everyone else, only I pulled out my plugs to look at the wear on them and 2 and 4 have unburned fuel on them, still wet. 1 and 3 are fine they burn like they're supposed to. Also there is litterally fuel coming out of my exhaust along with white smoke. Not like pouring out or anything, but spiting it out, and the longer or harder the car's running the more that comes out. Anyone able to solve this problem, or other idea's of what it might be?

UPDATE:

OKAY after a REALLY long time of having my new injectors I finally swapped them out. As soon as I put the new injectors in and started my car up it Idled really low around 500rpms but I let it idle for a good 10 minutes before I took it for a test drive.

The test drive went excellent!!! There was no cut out, power loss, hesitation, or anything. Ran really smooth. I drove probably 35 miles already and its idling perfect and smooth at 900-1000rpms.

Sooooo to say the least to anyone who has had this problem. If you change out all the cheap ignition parts as everyone tells you thats the problem but it doesnt fix it. Buy new INJECTORS!

Im sooooo happy! Now I can pull my motor out of my car and rebuild it, then throw it in my newer shell Im going to be getting.

Good luck to anyone with this same problem!

[mmm240]

^ a man of his word!

[KaPoweredHatch]

^ a man of his word!

Yea it may have taken me a long while but at least I kept everyone udated.

The hardest thing about changing the injectors hadto be actually seating the new ones.

I would do a write up since I took pictures but I think its too simple.