SR20DET - Dead stop? Will/Wont Start. Random?

[Nicelyphe]

1992 Nissan 240sx
SR20DET BLACKTOP STOCK

Strolling down the highway after work, going about 60 or so, and I just feel this loss of power. Well the cars in 5th gear, all electrical items are in working order, lights are all working, but the motors not running. Same feeling as when an alternator goes bad, just stops running while in motion. Pull over to the side of the highway, crank crank crank, about 10 revolutions and it doesn't wanna start. Get out, look at wires in the bay, and fuses and such, everything's good. Get back in, try to start it and it starts. Probably about 3 minutes later it does the same thing, motors not doing anything no matter how much I press the pedal.

Once again I pull over, crank it a couple revolutions, nothing. wait a little and try again, nothing. Now i try it once more and it starts again..Just enough to get off the highway ramp and around the corner to a side street, where yet again, it shut off..

I try to start it here on the side street and nothing..wait a little, and then it starts up again, I let it idle, which seems real off, floating around 500-700, bouncing up and down, sounds like its missing ina way. I pull injector plugs too see if it makes a diff, they all changed idle when pulled. A few mins after letting it idle a bit longer it shuts off yet again..attempt to start, and its a no go. So there she sits. Any ideas?

Last night during a crazy rainfall I had sputtering issues, and it didn't want to start. Now this morning it started fine, but my rpm gauge was working intermittently, jumping all over the place and such. Now after work I'm having this shut down while on for a few minutes issue.

Could this possibly be the ecu failing?

[silver350z05rb]

does it smell like anything , fuel? the stinky stench smell of a honda guy messing with your cars wiring?lol..................check timing, if you smell fuel, check injector/fuel releated items, also check your MAF clip or other clips, some swaps come without the retainer clips so for example, if your MAF is the syle where it doesnt "clip" on, but it requires you to have the little metal clip around the connector, it might rattle off or be loose causing similiar problems like you stated.so basically if you can just pull your MAF clip off the MAF with your fingers by just pulling it off then its not secured, you would need to press the clip to remove the MAF(i believe s14 s15 only) or remove the metal security clip with a flathead to remove the clip.(s13)

check for codes?bad fuel pump? loose grounds? try another ECU?bad coils?a really bad vaccum leak?

[Nicelyphe]

Well its late over here now, and freezing out sadly haha. Well, first things first, I got the car home from where it was sitting, about 15 minutes of sputtering home and not wanting to idle or anything of that sort. Is blowing smoke, grayish color. MAF connector does have the security clip, is secured. Did run through all grounds, fuses, connectors, ignitor. I do not have any smell of fuel, but as I was just looking through the bay, there is fuel scum all over the filter, and its wet. I am going to be changing the filter tomorrow and I will keep you updated. Also put in some dry gas just incase. I pinched the gas line from the filter to the rail and the motor idled fine, and stopped missing, but as soon as I let it be normal it starts its missing habit again, but I did pick up a new 300zx filter, so I will toss that on.

[silver350z05rb]

Well its late over here now, and freezing out sadly haha. Well, first things first, I got the car home from where it was sitting, about 15 minutes of sputtering home and not wanting to idle or anything of that sort. Is blowing smoke, grayish color. MAF connector does have the security clip, is secured. Did run through all grounds, fuses, connectors, ignitor. I do not have any smell of fuel, but as I was just looking through the bay, there is fuel scum all over the filter, and its wet. I am going to be changing the filter tomorrow and I will keep you updated. Also put in some dry gas just incase. I pinched the gas line from the filter to the rail and the motor idled fine, and stopped missing, but as soon as I let it be normal it starts its missing habit again, but I did pick up a new 300zx filter, so I will toss that on.
mhhh well hopefully the line has a crack on it thats near the clamp or the clamps are not on tight enough and you'll find the issue once you change the filter, maybe the filter clogged up

[Nicelyphe]

Put in the new fuel filter, still missing here and there, idle is bouncy. When i drive it, it builds no boost, earlier when I unplug MAFS it doesn't do a dam thing. Now when i just went out and checked it, I unplugged the MAFS and it almost died out, but keeps running. Thinking boost leak, or ECU being retarded..No idea on what to do next, checked all boost lines, inter cooler couplers and such. Any ideas?

[codyace]

I'd check MAF realted wiring (or the MAF itself) and or vacuum leaks.

When it is running, will it free rev to the rev limit? Can you drive it and put any load on it?

For it to just randomly quit going down the freeway, and then have issues after that crazy rainstorm we had the other night, I'd venture to say it's something in the engine bay (bad connection, shoddy splice/solder someplace) but it's hard to say without following the FSM test procedures for the individual parts.

[Nicelyphe]

Yea I'm going to run through everything tomorrow once its light out. I can put load on it, but it has the same feeling as a fuel cut, or a speed limiter. Boost gauge will not go over 0 as well. Idle is bouncy. Don't have a boost leak tester, wish I did actually..

[codyace]

What sort of vacuum is the car pulling at idle?

You can spray starting fluid/brake cleaner around all vacuum connections to diagnose vacuumleaks, ad it will cause for idle fluctuation. If the car can't generate any boost, it's got to be a pretty decent sized leak. Check all couplers for rips and or any that have popped off.

[Nicelyphe]

At idle my gauge sits at 20. Yea must be a decent leak for sure, Ive checked for popped off ones just from feel, once the morning comes I'm going to look for any rips and such. Possible bad turbo in anyway?

[Mishkin_707]

Unplug your CTS and run the car see what happens

[ultimateirving]

you said idle didnt change when you unplugged the maf, get a known good maf and test.

then also test continuity from maf sensor clip to ecu.

[Nicelyphe]

Yesterday, started the car, It smoked and missed a bit, after about 15 mins of idling it settled out and stopped smoking and only misses here and there, I'm thinking of going out there today and pulling the plugs and clean them up a little bit and see if it helps anything. When MAFS is unplugged, it now changes idle. CTS I'll have to check up on, I do have a new one of those laying around as well.

[Nicelyphe]

Beginning to rain around here and such, on the next nice day I'm going to go around and clean all grounds, clean the plugs. Also yesterday I found a vacuum leak (thank you carb cleaner) in the hose for the IACV, got that all fixed up.

[Nicelyphe]

Was working great for about a week, now today it starts acting up again, twice.

[Nicelyphe]

Several hours of hands in the bay I cleaned grounds, pulled and cleaned plugs, checked all over and can't find a thing. Only next thing I can think of is possible ECU, CTS, or something along the lines of a sensor that has to deal with fuel delivery.

[Nicelyphe]

I don't know if anyone is following this thread but here's something for everyone!

http://imageshack.us/g/836/4c2b11eb.jpg/

[Nicelyphe]

Replaced with another ECU, and it started right up!

[silver350z05rb]

Yay I win I said try another ecu.........but yea,good research and trial,

[Nicelyphe]

Yay I win I said try another ecu.........but yea,good research and trial,

Haha, yes and thank you.

I'm currently using a 63 ECU rather than a 62 which came with my blacktop sr. For some reason my 62 felt better before it took a shit rather than this 63.

I've done some searching and have seen some people say that the fuel map is a little different on the 63, could this be causing my kind of power hold back feeling every once in awhile. Usually notice It idles great with no misfire now or anything of that sort, just feels a little diff under load than my 62 did. Usually when at a steady speed on the highway under constant load in 5th.

Also when downshifting it has that srt4/subaru low rumble/consistant pop exhaust noise which I've never came to notice with my 62 as well. Could that relate to any differences in ECU's?

[Nicelyphe]

All in all I am getting laggy when boosting, split second cut out when under steady throttle, running a bit rich, cars hitting 9lbs[never has done that], believe I'm having wastegate issues. Going to pressure test the intercooler system tonight to see if anything may pop up. We'll see.

[Nicelyphe]

Took notice that my nipple in my intercooler coupler was being blocked off a bit by the piping, re adjusted the coupler and I now boost 7lbs as normal. ECU throws a 55, never got to pressure test my system but it boosts straight as of now. Only thing I dislike since all this started is that the car shows perfect idle, but in the shifter and steering wheel I can feel a little bit of a shake/stumble here and there. I guess that would just be a 20 yr old motor..Haha