240 starts warms up then dies???

[RideNslidE]

i had an injector go out and replaced it. all of them look to have correct resistance, the grounding b/t the engine and chassis + chassis and battery is good. fuel filter good, spark is good ( timing not sure but when it starts it runs very smooth ). No trouble codes either. like it says i start it and runs good for 3-5 min but then sputters till it dies. I kept it running today as unstable as it was by giving it a little gas so it will keep running with the gas petal depressed a bit . seems to be rich but cant determine how.

anyone please.

[RideNslidE]

bumperoo any help for someone who serves you all everyday??

[christylyn]

Hello. New to the forum. Ummm the same thing is happening to my cousins car and someone told me it might be a vacuum leak. I havent had the time to take a look to see if that was true or not, but thought I could give you somewhere to look.

[RideNslidE]

maybe but i think it wouldn't run right at all if it was a vacuum leak. unless theres a heat activated valve related to the system.?

[RideNslidE]

bump

the problem still persists and no new ideas yet... anyone...

[Dattebayo]

5 possible things...

1. Bad injector o-ring(s)2. Bad fuel pressure regulator3. Bad idle sensor4. Bad idle switch5. Bad/dirty MAFS

How to decide: Answer these questions.

Does it idle rough when started up cold?When it dies, does it die suddenly or does it stumble downward until off?Will it re-start just fine after it dies?While it does idle, is there a limit to what RPM the car will rev to?

[RideNslidE]

1. Bad injector o-ring(s): replaced all o-rings with the injector installed with the vasoleen cleaned b4 putting them in.2. Bad fuel pressure regulator: not sure how to check but im sure i could find out how.3. Bad idle sensor: dido, but didn't know there was one.4. Bad idle switch: dido x25. Bad/dirty MAFS: hmm visually looks ok dido x3

Does it idle rough when started up cold? no. only starts when its cold tho.When it dies, does it die suddenly or does it stumble downward until off? it stumbles.Will it re-start just fine after it dies? no just turns over no go.While it does idle, is there a limit to what RPM the car will rev to? not sure what u mean it revs to about 1500 off the bat b/c of the cold but seems to run smooth above idle but it does get worse even at 2k or so and it will rev to red line.

BTW thanks for the reply.

[Dattebayo]

My money is on the fuel pressure regulator being bad. It's pretty easy to replace, kinda pricey tho for it's size.

DO you smell a strong fuel smell around the car after trying to crank it after it stumbles and dies?

[RideNslidE]

well seeing as how im all ready passed out from the gas smell when it runs i cant really tell but everything smells like gas. so yea and the plugs are coated in it.

[Dattebayo]

One final check, open the rear seat trunk access panel and turn the key to the position right before start. DO you hear the fuel pump work and then shut off?

[mychalous]

sounds a lot like your coolant temp sensor. i would get it replaced.

[RideNslidE]

yeah i could hear it when i relived the pressure by running it with the line disconnected after the filter.

[Dattebayo]

Coolant temp sensor wouldn't make the fuel system dump into the motor like that.

[Dattebayo]

yeah i could hear it when i relived the pressure by running it with the line disconnected after the filter.

SO, it stopped after it ran for a few seconds right? Make sure you pull the fuse when you disconnect any part of the fuel system, OK?

It's definitely a FPR. Classic symptoms.

[RideNslidE]

cool is it the same from a SOHC?? either way ill def give it a try. thanks for all the help

[Dattebayo]

cool is it the same from a SOHC?? either way ill def give it a try. thanks for all the help

Yep. Lemmie know how it goes, I'll watch this thread in the mean time.

[RideNslidE]

worked out and i appreciate all the help... unfortunately im might be pulling it out. today im going to look at a 2k6 350z eng trans and ecu for 1500 bucks wish me luck

[del82]

G'luck, and have the old engine checked out by a tech in your area. Your problem is too broad for any kind of definite answer. If I were throwing guesses out there, I'd say the MAF, based on the richness and the fact that it still runs while cold. Truth is, though, it could be anything from a stuck cold start injector to a faulty ECU. That kind of diagnosis needs a hands-on look.

If you're serious about scoring that Z drivetrain, call the dealer first and ask the parts guy if there's a PCM (powertrain control module) or TCM (trans control module) that comes with the car. If there is, make sure that, and the harness also comes with the deal, otherwise you may have to do a lot of hacking on the harness to make the ECU work without transmission signals. OBDII is a bear like that, but once its working, its a wonderful diagnostic tool.

[lil_ben_2020]

i had an injector go out and replaced it. all of them look to have correct resistance, the grounding b/t the engine and chassis + chassis and battery is good. fuel filter good, spark is good ( timing not sure but when it starts it runs very smooth ). No trouble codes either. like it says i start it and runs good for 3-5 min but then sputters till it dies. I kept it running today as unstable as it was by giving it a little gas so it will keep running with the gas petal depressed a bit . seems to be rich but cant determine how.

anyone please.

check ur egr vaulve if that is colloged or vaccum leak on those hoses when the engine heats up and it opens it draws straight air makin it run like that

[RideNslidE]

wait what do you mean the 240sx 5spd doesnt work with it...jkjk. i meant the car is fixed now but thanks for the imput. it does come with a good harness ecu and bcm all that junk i just need to out what sensors i need besides the obvious ones and how the CAN lines are hoked up from the ecu to the bcm.

[lil_ben_2020]

is ur comment to me

[del82]

wait what do you mean the 240sx 5spd doesnt work with it...jkjk. i meant the car is fixed now but thanks for the imput. it does come with a good harness ecu and bcm all that junk i just need to out what sensors i need besides the obvious ones and how the CAN lines are hoked up from the ecu to the bcm.

Holy crap. Can you edit this so its in english? Maybe need to know what sensors, etc? Its so frickin hard to understand

[RideNslidE]

the car is fixed due to the new fpr. del182 as for the sensor stuff its in regards to my upcoming vq35de (350z) engine swap. the trouble i was having is finding information about the BCM AND ECM's integration into the 240sx. as for the trans controller it is integrated in the ecu on the manual cars it also has a complete harness. i just need the dash harness now, it contains the CAN lines necessary for the ECM and BCM to communicate. sorry about the bad engrish tho...

[RideNslidE]

check ur egr vaulve if that is colloged or vaccum leak on those hoses when the engine heats up and it opens it draws straight air makin it run like that

if it had unmetered air coming in the system (ie vaccum leak) it would be less rich not more. just to clarify it ran better with a vaccum hose disconnected.

[Dattebayo]

if it had unmetered air coming in the system (ie vaccum leak) it would be less rich not more. just to clarify it ran better with a vaccum hose disconnected.

It doesn't work that way... You're forgetting about the oxygen sensor on the exhaust. The computer will over compensate for the extra air in attempt to keep things favorable for the motor. Running lean is a danger to the system you know...

[RideNslidE]

yes i understand it is dangerous but it was at idle under no load and the o2 sensor could not compensate enough. the o2 sensor was not toggling at all it was in a completely rich situation and adding a little air was getting the mixture just a little closer to normal not not even close to lean plugs were still wet with gas. it was not ideal i understand but just something i checked. it was not intended to be a fix at all.

[hachiroku781]

Maybe There is a surge of fuel causing the engine to get "waterlogged" my supra was quite finicky like that. There was alot of pressure in my injectors caused by a build up in the fuel lines. im not sure thats whats causing your problems, but its worth a look.

[mteelucksingh]

I'm having the same problem RideNslidE was having with his 240! I was wondering if anyone can tell me how if it is the FPR why is it temperature related? How come it doesn't happen when the car is cold? If anyone can answer PLEASE PLEASE help!

[Dattebayo]

I was wondering if anyone can tell me how if it is the FPR why is it temperature related? How come it doesn't happen when the car is cold? If anyone can answer PLEASE PLEASE help!

Because all computer controlled cars have a warm-up mode in which the fuel ratio is made rich to warm the car up in the morning or whenever it is cold. This is matched by a "idle up" valve that lets more air in to offset the added fuel.

When a FPR is faulty, it basically gets stuck in the same mode as engine warm-up, but without the support of the "idle up" valve.

When the FPR is faulty and the engine is cold, the computer thinks everything is normal at the beginning since the FPR is supposed to let alot of fuel through, but later as the engine warms up, it becomes more and more difficult to keep the engine running. Idle would have to be maintained after this point by holding the accelerator down.

When the sensors show the motor is warm and the FPR is faulty, then the air/fuel ratio is incorrect to allow combustion to happen.

[RideNslidE]

well its not that anything on the FPR changes its just that on warm up the idle air control valve lets extra air in to help warm it up initially (just what i believe don't quote me on this). BTW the FPR is the same on all of the 240sx's (got mine off a SOHC motor) and probably the same for all KA24DE/E's good luck.