I recently purchased a '91 SE VG30E 5spd and having some problems. When I first got the car, it wouldn't start up. Process of elimination, bought rotor cap, button, and fuel filter. Now car starts a little more and have found a real problem thats worrying me.

On 4 seperate occasions, the car would only rev to 4000, 2500, 1500, and 1000. The car will repeat these rpm ranges everytime I start the car.

This is the only part I know of that does not work, speedo. Could this have something to do with my problem?

Also, when the car warms up, it doesn't like to start. I haven't figured out why or what is causing these problems and I checked the ECU in diagnostic mode and it said everything was running correctly.

Please help me with this car because I don't want to get rid of it.

 

with all the advice you gave in the other threads, you can't figure this one out yourself?

 

I can't seem to pinpoint what the problem is. I've been messing around with the car for the past week and I'm stumped. I know the 240SX's inside and out but this is my first Maxima and I'm dumbfounded

 

Maybe the clutch master cylinder fluid sensor is messing up....

 

it's a car, ALL cars are based on the same principal, once you figure out one car, the rest are easy.

 

I'll havta check that cuz I didnt think of this sensor would do that

 

True BUT Nissans have more sensors then most cars and I don't know that much about Nissans except the 240SX.

 

like which ones, specifically?

 

If you think that our maxes have a ton of sensor, you ought not to get a obd2 car.

 

ya

 

maf? sorry didnt get ur Q properly...

 

you are so full of it.
the amount of sensors vary very little between cars.
anything that applies to your 240 will apply to your max

 

could a bad cts cause this problem? ive never had a car do this and its the first one that i have come across to have this porblem.

 

when it goes to 4000, do you mean that it cuts off as soon as you hit 4000? or it holds dead-on at 4000? or flutters around somewhere close to 4000? does it struggle to reach 4000 or does it fly to 4000 and hold there? same for 2500, etc.

 

no struggle going to the 4000. doesnt cut off just stays dead on 4000. same for 2500, 1500, 1000

 

I've replaced the rear exhaust gasket because it was bad thinking it was the root of my problem. Still having the same problem as before and can't figure it out. Guess I'm gonna take it to Nissan and let them tell me what the hell is wrong with it.

 

i had the similar problem like wen my VE reaches to 4000 it cuts off like it doesn't wanna go that high then i changed my MAF and problem was gone....

EDIT: could be same wit urs? did u check ur Mass air flow sensor?

 

I'll have to check that. I was thinking something along those lines but like I said before, I'm not that familiar with the VG30 series motor.

 

Um, I have a completely obvious one for you.
throttle cable?
it STICKS at 4k rpm and other ranges??

Idle Air Control Valve? Clean it, or maybe yours only has a TB Idk, clean that.. i would just go crazy on a tune up, air filter, pvc valve, plugs and rotor, oil+filter, clean the throttle bottle, maf, check + replace vacuum lines.
thats all afforable common preventative maintenance anyways, so its no harm doing a very throurough tune-up.

check the compression? fuel injectors? TIMING? maybe its something with posistioning sensors, which would be serious eh? if your timing is say sticking/advancing to 4krpm
idk


sounds like your cars just running funky and needs some tlc, clean her and buy her some floor mats.. sometimes my car runs like junk, i clean it, and it purrs.. like it appriciates it. lmao..

 

the throttle cable is a good forethought... perhaps the TB itself is just getting stuck, and the spring in the pedal returns the pedal all the way but the TB is stuck open at a certain point.

but that would make more sense if it were HANGING at a certain RPM... he's indicated that the thing was being limited to these RPM levels somehow.

 

Update:

Found the original owner of the car when the problem first started. He said it was a bad fuel pump, so that has been replaced.

Unfortunately, there has been no change with the starting of the car, but now backfires between 4500 and 5000 rpms.

When the car was running a couple days ago, I checked the timing with my light and it was dead nuts accurate, according to the light. I haven't had time to check the belt tension nor if the cams are timed properly. Haven't had time because Dell has been in 'Mandatory Overtime' mode for the last couple weeks.

I'll keep you guys updated on my progress of this Max. If anyone can think of what could cause this problem without the Check engine light coming on, I would greatly appreciate the input.

 

You had this idea of checking CTS at the beginning, have you ever done it? This sensor can do backfiring according to FSM and can shut the engine down within 1 sec. When I disconnected mine on VE30DE and tried to start it would fire but die right after. CEL didn't come up too.

 

I haven't had the time to check it throughly, but the pigtails look good and they've got voltage, I just dont remember how much. I'm going to the junkyard Saturday and I have a few parts i needa get so ill just add these sensors to the list. Btw, whats 'CEL'? never heard that before.

also my local maxima group said it could b the MAFS which im gonna try to find one at my jkyd this wkend.

 

CEL = check-engine light

 

not to hijack ur thread but im experiencing some similar issues, such as car warm=no start.. or hard to start..it started yesterday when i did a small tune up..changed out the pulgs, disconnected the MAF harness, sprayed some electical cleaner on, sprayed some TB cleaner. and BAM..car acts up...the funny thing is, once it catches, the car purrrrs. this morning while it was cold out, the car started RIGHT UP, no problem at all. so now im stummped.. any suggestinos or whether u fixed ur problem or not?

-vince

 

havent pinpointed my problem yet, but im waiting for my new mafs to come in. if that doesnt work, then im gonna find another computer and swap them out to c if that was the problem from the beginning. ill keep everyone posted with periodic updates

 

If fuel pressure keeps steady, NEW, working ign Wiring & Cap has been swapped in - then the culprits for the "only rev to 4000, 2500, 1500, and 1000" -problem is either in MAF -or- rpm sensor, (problem(s) in their wiring/connectors).

All troubleshooting starts from checking charge voltage, at batt, at ECU +12V/GND -pins.

My guess is that at least your distr cap is leaking.

 

Just can't stay away can you?

 

no - we cant

... 'my' 3gen fleet just keeps increasing.

 

problem solved.. i had a vac leak from the intake tube to the iavc.

-vince

 

Ok, now your question was solved = rpm jumps w/o pushing pedal

When extra air flows in and is burned, lean condition results. O2 detects this and ECU compensates by adding more juice into the process. Sometimes this happens in a rush [honda show mode], rubber starts burning, hondas vanish from the rear mirror.

Whatever reason for extra air, (controlled or noncontrolled) ECU will always try to compensate - thus an wobbly airleak via ruptured rubber hose simulates drunken car thief who cant reach gas pedal = "would only rev to 4000, 2500, 1500, and 1000..."

IACV is used to induce a ctroled 'leak' to adjust/keep idle rpm steady in varying conditions. If engine is misfiring, its stepper motor is 'running wildly' CW/CCW in the loop to optimize airflow = keep rpm steady.

 

lots of good info.. thanks

-vince

 

i kinda have the same problem but with a 92 se auto and on mine the car like jurks like its not getting gas then its ok. Then it does it more and sometimes shuts off i think its the fuel pump but i just replaced it a few months back

 

Years ago, I owned a 91 SE with a 5 speed. I still own a '90 GXE that I am about to sell.

I never experienced the multiple rpm bands. It sounds like a startup check-routine. Do you have the cruise control on during start up? Perhaps try and turn it off to see what happens.

The difficulty in starting up after been warmed is common and exists in my '90 GXE. It has to do with a temperature sensor (unknown to me) that does not reset correctly. So when you start a warm engine, it thinks the engine is cold and sets the fuel ratio incorrectly. The engine stumbles but eventually runs OK. This problem only occurs if you start up and shut down within a very short (30 seconds) span of time

 

you can't have cruise control on during startup... the ASCD hold relay drops current as soon as you shut the car off....... :crazy:

and yea, a bad CTS will cause improper AFR cuz it thinks it's cold, but the ECU won't even look at the o2 sensor if the CTS is bad, so it'll never actually fix the AFR... it'll just run rich all day.

 

i know im asking for alot but can someone describe where the iacv and cts and knock sensors are pics will really help i just wanna get this stupid rpm dropping to stop . going to get a maf sensor tomorrow hopefully it does it

 

IACV is here: http://www.cardomain.com/ride/748507/4 -->The sputtering is gone after suggestions on the adjacent 10pages have been addressed. First on the put put -todolist is cap/wires/plugs, then distr gnd, then whatnot...

The KS does NOT cause erratic idle, just poor accel etc.

 

I think i fixed my rpm dropping problem I took off the purple plug and checked it also messed with the screw on the iacv but i dont know if it needs to be tighter or looser does anyone know???

 

Purple?

I guess u mean IACV idle adj screw. That should be neither but carefully adjusted... Idle adjustment is done in concert with ECU self diag program III, check this http://www.cardomain.com/ride/748507/4

 

im still having the rpm dropping problem it happed between 1500 and 2000 ive already replaced the tps iavc and the o2 sensor the only thing i didnt try was the maf sensor but i heard that wouldnt even cause this problem idk what to do almost at the point of selling my car