SR Idles rough, then dies

[ProjNightshade]

Both my dad and I have searched the forums trying to find someone who ius having a problem like ours.

Here goes:
I have a 1995 240sx, and we swapped what we believe to be a kouki motor into it. Everything is hooked up correctly, and the motor starts.

However, when it starts, it starts idling high about 2000 rpm, then slowly drops down until eventually it dies on its own about 3-8 min later. In order to rev the motor, you have to very very slowly open the throttle plate, or else the engine dies. If you so much as brush the accelerator, the motor dies immediately.

We took it to a local shop to have them look at it, and they told me that the fuel pressure starts off in the mid 30 psi area, then drops off. This is with a walbro 255 hiflo, so I'm confused. I know it can't be the afm b/c the engine rev's past 2500. No one I have talked to has ever heard of a problem like this. It was explained to me that it is possibly the knock sensor, but I'm not sure. Has anyone ever encountered a problem like this one? I'm going crazy, and if I cant get it running I may have to part out. This problem makes me feel like this --> :madfawk:

Any help or guidance is more than appreciated. Help a guy not part out! Thanks.

[vutony]

get a fuel gauge and regulater to check and adjust pressure, did u do timing yet, follow fsm if u havent

[ProjNightshade]

I'm sorry I wasnt clear. that pressure check was taken before the filter. Basically, thats what was coming out of the lines right before it reached the filter. The shop checked this with a different pump and got the same figures.

I'm not sure if they did timing, but would that really make a huge difference since the car idles well even though it dies? i mean, timing cant be that far off for it to crank right up and idle, right?

[koukimonster139]

would that really make a huge difference since the car idles well even though it dies? i mean, timing cant be that far off for it to crank right up and idle, right?

YES.^


u need an adjustable fuel pressure regulator with a gauge.


also
Stock injectors?

[ProjNightshade]

u need an adjustable fuel pressure regulator with a gauge.


also
Stock injectors?

Everything is stock except for intake filter and exhaust pretty much. The shop that played around with my car fitted a different stock FPR and said that made no difference. would a nismo FPR make a difference?

does the timing issue address why the engine dies immediately when the accelerator is pushed? this problem has me totally stumped, so i guess I'll try to find a way to reset the timing according to the FSM (in miami now, car is in tampa)

Im guessing the timing is the same b/w a Zenki and Kouki sr20? I only have the zenki FSM. Also, where should I look if timing doesnt fix it?

Thanks

[HalveBlue]

Might be a timing issue, although I don't think it is. Only one way to find out for sure though; check it. If it's not, reset your timing to stock spec and see if that helps.

From (unfortunate) personal experience I can tell you that even the slightest bit of offset in timing can make a huge difference in the way the engine runs.

Just be 100% that your timing is correct before you start the egine. Pistons hitting valves is not fun.

[RedtopTech]

i believe they were refering to the ignition timing. Incorrect VALVE timing would cause interference b/w the pistons and valves. Adavanced ignition timing would explain the high idle but it wouldnt cause the engine to shut off with applied throttle. I think you have an intake leak. that explains the high idle and the car shutting off due to un-metered air flowing through the engine.

[ProjNightshade]

ok, I can check, but any other thoughts? I'm pretty sure its not an intake leak.

[ladiesman8527]

does the car smoke at all while its running?

[donkayroo]

Timing is a huge possibility. But if that checks out OK and you haven't already done so, run the TROUBLE CODES. I didn't see this step mentioned in any of the posts.

I had to diagnose and repair three SRs that have had the same exact problem but the timing was fine. The aaicv was either improperly wired, faulty or not wired at all because the wiring harness was hacked half-ass.

Hopefully it's just the timing.

Are you running the OEM style BOV or aftermarket?

There are a few other possibilities but those mentioned have been the main problems so far in my experiences.

BTW, the shop who diagnosed your car, are they the same shop who did the swap? If so I smell a scam around the corner..."Hmm, you need this, this and this to make it run normal again...". If not they're either incompetent or...trying to sucker you to buy more goodies.

[the head]

Do you have an atmoshpered BOV? Could also be that your IAC is sitcking or shot DL the FSM to get instructions on how to test the IAC...also you can disconnect the IAC and use the set screw on the TB to level out your idle

[Markovich]

nobody said anything about the tps wouldnt that put into play that if that is faulty or not hooked up that the throttle would mess up and choke its self.

just my 2 cents
peace

[ProjNightshade]

does the car smoke at all while its running?

No smoke.

Are you running the OEM style BOV or aftermarket?

There are a few other possibilities but those mentioned have been the main problems so far in my experiences.

BTW, the shop who diagnosed your car, are they the same shop who did the swap? If so I smell a scam around the corner..."Hmm, you need this, this and this to make it run normal again...". If not they're either incompetent or...trying to sucker you to buy more goodies.

I have an OEM bov/recirculation valve. I did all the swap work myself. Before you go out saying that its noob screwups, I know that everything I did was installed correctly.

I'll check the ECU trouble codes and diagnose the IAC. It really seems like something is cutting the fuel, b/c now it won't idle for more than a few minutes, and then dies. We're also gonna check the fuel relay to see if that may be faulty.

Thanks for the help guys. If anything else I'll come back for more help.

P.S. My Work VS-XX's are on their way UPS. Cross your fingers I'll have them by Friday.