Engine cutting out while driving

[D21_666]

Hey guys,

I have a 93 d21 with the KA24E. Have a 240 ecu, maf, intake manifold, etc. At full throttle in 3rd gear, at 4k rpm, it acts like it gets shut off.

If you slow down a tad, or let out of the throttle and accelerate slowly, your can go past 4k. The same issue happens in 4th but at 3600, and 5th at 3100. Roughly 68 mph, 75 mph, and 85 mph. Any ideas? It runs awesome otherwise

[OnTheChip]

Sounds like a fuel supply issue, maybe the fuel filter.

[D21_666]

It's fairly new, and when it happens Is likeyou turned the key off for a few seconds. There's no response from the engine. It feels like fuel cut in my old dsm.

[OnTheChip]

What ECU are you using? What's the 23710-xxxxx part number?

[D21_666]

Not seeing that prefix. Found a11-b13-g58 and then a big 14 on top of that

[D21_666]

Forgot to add, if you accelerate at only part throttle, you can take each gear to redline easily. So, I'm convinced this is a load threshold type issue. Be it, maf cutting out, ecu freaking out, coil breaking down, or fuel pump or similar. But, ive tried 3 or 4 different pumps and several fuel filters do to a fuel sediment issue.

[D21_666]

Bump. Really hoping to get this fixed and hate to start throwing parts at it

[OnTheChip]

Could it be a wire grounding somewhere, under acceleration or engine torque motion?

[D21_666]

Possible, but I can duplicate this issue every time in 3rd, 4th, and 5th gear, at the same rpm, as long as I'm at full throttle. I'm tempted to go buy a cheap replacement coil and start there. Maybe get a good aftermarket upgrade, just because my coil is the stock one. After that, the only thing I can thing of is load relative devices, like MAF, ecu, ect.

[OnTheChip]

The coil was going to be my next guess. Do you have a wide-band O2? If it's showing very rich, it could be hitting the high load rev limiter, which would indicate a MAF issue.

[D21_666]

My mileage has been dropping. Was at 24+ on the highway, now I'm down to 19 or so. So it's definitely a possibility. I had read about weak coils having spark basically blow out at certain loads, so both are definitely possible in my eyes. Don't have a wide band, need to get one. Didnt know it had a high load Rev limit. I guess that's the equivalent of mass airflow over run?

[D21_666]

I assume on a factory ecu, there's no way to get any form of actual live data stream is there?. Hoping to watch MAF signal, o2 signal, etc when it happens

[FaLKoN240]

When was the last time you changed the fuel pump and fuel filter?

[D21_666]

Couple of months ago. Maybe 5k miles tops.

[D21_666]

Fuel pressure and such checks out.

[OnTheChip]

Originally Posted by D21_666

I assume on a factory ecu, there's no way to get any form of actual live data stream is there?. Hoping to watch MAF signal, o2 signal, etc when it happens

Unfortunately, the S13 KA24E ECUs do not support Nissan Consult. A number of people have used a Stanza ECU in their 240sx (Google) which does support Consult data logging (Nissan Datascan). You will also need a special Consult cable to interface to your laptop/PC.

You can check for DTCs using the built-in LEDs. Check the appropriate Service Manual for instructions.

[D21_666]

Ok. I know about the leds. I have no codes, yet no code 55 either.....

[OnTheChip]

Make sure the diagnostic screw (for checking DTCs) is fully counter-clockwise before driving.

[D21_666]

I've heard that before. It is, just curious what happens if you don't. Lol.

[D21_666]

Gonna replace coil and maf with spares I'm picking up today. Hoping to find a stanza ecu as well. If I get the stanza ecu, other than the consult cable, what is needed for data stream?

[anti tyler]

Originally Posted by D21_666

Gonna replace coil and maf with spares I'm picking up today. Hoping to find a stanza ecu as well. If I get the stanza ecu, other than the consult cable, what is needed for data stream?

Start with the coil. I had this exact issue and that's what it was.


Of course yours may be different, that would be my first suggestion in your specific case.


I would fix the problem before you start jumping to any different ECU's

[D21_666]

Excellent. That's my plan too. I've been racking my brain like crazy on this. All my sensors pass every test, because you really can't test them while driving them at highway speeds. Lol. Thanks a bunch

[D21_666]

Replaced the coil. Didnt fix it. Was unable to score a maf at the pull yard. So, I'll keep looking

[OnTheChip]

What air filter and intake plumbing are you using?

[D21_666]

Cone filter from pepboys-maf housing-metal 3" 90° bend-throttle body-240 sohc intake manifold

[OnTheChip]

I know of cases where some filters have collapsed on the dyno at high load, cutting off the air flow. Can you try another filter, or no filter as a test?

[D21_666]

I'll definitely give it a shot

[D21_666]

Is there anyway I can trouble shoot the maf under load without data logging?

[OnTheChip]

You can watch the MAF voltage on ECU pin 16 with a volt meter.

[D21_666]

I solved it. It was the ecu the whole time. Thanks for your help guys! Much appreciated