S13 hard to start problems

[Vitzio240sx]

Im having problems with my car. Car is a 91 twin cam s13. It will not start by just turning the key. The engine will turn and turn and it feels like it wants to start but it doesnt. Then after numerous times it starts and slowly creeps up to idle. The only way it started was with my foot on the gas, it feels as if it wasnt getting any fuel. Everything has been tested. It has a brand new walbro 255, z32 fuel filter, 3new injectors, new tps, timing is spot on 20deg btdc, egr and all the emissions has been deleted properly, cleaned maf, cleaned iacv, ecu shows code 55. Everything was perfect until it started doing this one day. It will do it in the morning when its cold or even when I just finished turning it off. I dont understand what it could be. I have already searched millions of threads and havent found nothing like this. I was thinking maybe another bad injector? The car also sputters and backfires if i hold it only and only at 2500rpm and the idle is not stable it will move up and down very slowly like it will not stay steady. This is my daily car and i really need it to get running right, any help is appreciated thank you!

The video below you can i see i turn the key and it cranks and cranks and finally after pumping the gas it slowly turns on and the rpms move up.

240sx s13 hard starting - YouTube

[godsmack]

i can think of 2 possibilities. either a vacuum leak or even a leaky injector. is it running rich? pull the plugs and see if one of them has the threads soaked with gas.

[Vitzio240sx]

Yes sir it runs rich, i will check injectors to see if any leak and i sealed the entire vacuum system. The only vacuum i have is for the brake booster, fpr, and the iacv. Im gonna pull the rail off and see if any leak

[godsmack]

another possibility is the coolant sensor. you have 2 of them. one for guage and one for the ecu. not 100% on your motor but usually one is a 2-wire and that's the one that you would need to check. the 1-wire goes to your temp guage in the dash.

[Vitzio240sx]

Although i doubt the coolant temp sensor is bad, i will check on it to make sure it's functioning properly

[Mishkin_707]

My DD SOHC coupe does something similar, I've had it since 2001 and it has never really started on the first try, every once in a while it will start up on the first try but since 2001 I have not figured it out, it doesn't matter if it is cold/hot/winter/fall/summer/spring I still use my car but it would be kind of nice to turn the key and it starts the first time with no hesitation, I'm leaning toward it just being a tired old motor it has 235,XXX miles on it so I'm just sure it's tired

[240meowth]

I'm paying attention to this thread, my car does the exact same thing and it seems to be worst when it's hot outside. I highly suspect it's a fuel problem because often time when I can't get it to start, i'll crank it once with the gas peddle all the way down then it usually starts the next time I crank it.

I also listen for the fuel pump when the key is switched to the ON position. The fuel pump primes itself I only try to start after I hear the fuel pump goes off.

[wangan_cruiser]

is your car turboed? why do you run walbro 255? wouldnt that flood your engine? thats what caught my eye on your first post

[wangan_cruiser]

Originally Posted by Mishkin_707

My DD SOHC coupe does something similar, I've had it since 2001 and it has never really started on the first try, every once in a while it will start up on the first try but since 2001 I have not figured it out, it doesn't matter if it is cold/hot/winter/fall/summer/spring I still use my car but it would be kind of nice to turn the key and it starts the first time with no hesitation, I'm leaning toward it just being a tired old motor it has 235,XXX miles on it so I'm just sure it's tired

my sohc does that too lol cheers you are not alone. mine has 198k miles

i already replaced fpr, serviced injectors, new fuel filter and still the same. haha

[nyka435]

Maybe clean the mafs sensor? Mine had an inconsistent idle and cleaning it did the trick.

[Mishkin_707]

Originally Posted by wangan_cruiser

my sohc does that too lol cheers you are not alone. mine has 198k miles

i already replaced fpr, serviced injectors, new fuel filter and still the same. haha

Nice, same here, all that stuff has been replaced and still the same problem too

[Vitzio240sx]

Originally Posted by wangan_cruiser

is your car turboed? why do you run walbro 255? wouldnt that flood your engine? thats what caught my eye on your first post

No the car is not turboed and i replaced it because my old one wasn't functioning properly. I fixed the problem turned out that to be a leaky injector o-rings. Now it fires right up in the first try.

[240'sGoneWild]

Nice!!! Everybody check your injector o-rings

[spiderdida]

Well thats good news mine does the same things i always have to give it a little gas to start and always start in the 2-3 try. also did it hesitate or kinda loose a bit of power when you would step on it???

[Vitzio240sx]

No hesitations at all, it runs good. I beat on it all weekend at the track and ran perfect.

[spiderdida]

oh but before you fixed it??.. because mine fills like it runs in 3 cylinder lol i unpluged my third spark plug today and it didn't make a difference on how the motor idled or when plugged back... i barely bought some new spark plugs,wires and my dizzy is making sparks..... so i really don't know whats wrong with mine oh and also i checked my injector from the third spark plug and the O-rings do look in a bit of bad shape think that could be the cause ???

[Vitzio240sx]

yes dude thats your problem. If you removed the spark plug wire and there was no rpm drop thats your problem. Ok heres what you do, pull the fuel rail off the intake manifold and leave everything plugged do not remove the injectors the wires or anything else. Just remove the fuel rail from the manifold and then put the car key on the ON position, DO NOT attempt to turn on the the car just put it on the ON position where all your dashlights light up. With the fuel rail out observe it and it should not leak any fuel at all, it has to be dry no leaks from the injector tips at all. If you see any small leakage, drops, or any fuel escaping from the inector nozzles you have found your problem.

[spiderdida]

oh ok ill do that tomorrow then oh here is how that injector looked ...

[Vitzio240sx]

Yes i can see your lower o-ring is damaged, you can see the rubber has deteriorated and has ruptured. But do what i told you and if thats the problem, replace the lower o-ring and check again. Remember to lube up the new o-rings before installation or you might risk cutting them or rolling the new o-rings. But other than that it should fix your problem. Keep us posted

[spiderdida]

so basically yours did what mine did right and ill keep posting till i fix my problem..

[Vitzio240sx]

^^ yeah except mines was on cylinder #1

[spiderdida]

you were right the injector was liking like crazy after i took the fuel rail and when i turned the key. so i went and bought some O-rings and that fixed it now my engine sounds healthy and runs perfect thanks for the big help

[Vitzio240sx]

Yeah sure dude no problem.

[Mishkin_707]

Shit gotta try this, where should I get the o rings from

[Vitzio240sx]

^^ at any of your local auto parts store, (pepboys/autozone/advanceauto)

[Nikeboy355]

I've got the same problem with my 91 240SX... It will crank and eventually start with a big cloud of unburnt gas...

I replace the entire fuel system, battery, cleaned out the MAFS, and checked resistance and voltage on most of the sensors...

I was going to change the coolant temp sensor, make new ground cables, and check resistance on the sensor and ground wires and will let you know...

This problem is getting worse and sometimes the car dies out while at a stop and it takes me forever to get it started again...

[manofsteel]

nikle boy355 did u ever find ur problem?

[manofsteel]

Originally Posted by Nikeboy355

I've got the same problem with my 91 240SX... It will crank and eventually start with a big cloud of unburnt gas...

I replace the entire fuel system, battery, cleaned out the MAFS, and checked resistance and voltage on most of the sensors...

I was going to change the coolant temp sensor, make new ground cables, and check resistance on the sensor and ground wires and will let you know...

This problem is getting worse and sometimes the car dies out while at a stop and it takes me forever to get it started again...

did u ever find your problem?

[GrumpyS13]

So ive been reading this thread and I swear I have the absolute same issue with my DD s13 ka24de, so tomorrow morning first thing ima do is check my injector O-rings. If that fixes my problem I will let you guys know. Thanks a lot for all the help everyone!