Car:S13 Rb25 S1 with the j60 maf.
Problem: Car will hesitate, than backfire loud as s***, than stall. It happens at completely random times. Doesn't matter if it's warm/cold, boosting,idle or cruise.
Has anyone had symptoms like this? The car ran perfectly fine for months, than out of no where it started happening .. and now a week later it's constant. I couldn't even drive it today.
Anyone??

Try cleaning your MAF and checking your spark plugs. Then check back.

I already cleaned maf and filter, which didn't help.
The reason i think my maf is bad now is because when I first got the maf 4 months ago or so, I had to clean it because it would stall out randomly. Not like it stalls now though, it's worse now. It ran perfect up until a week ago, and now yesterday I couldn't drive it 5 miles without it badly stalling out three times.
I also have a s*** filter which I didn't oil. So you think it's possible that the combination between no oil on my filter, and the salt on the streets just made it fail?
Since it only does it under load, it's hard to test it while it's failing..
Any ideas or know where I can find another J60?

When a fuel pump starts going bad, it meets your symptoms.

I don't think it's that either.. A walbro pump failed on me already and I just replaced that around the same time as the maf. It primes, I don't have a gauge or anything but I can still feel gas pushing through the line.
I'll try putting my stock fuel pump off the ka and see if it does anything though.

Hard to diagnose a problem without being there...

I hear ya. It's hard to know without a wideband. I tried putting the stock ka fuel pump in hoping it would lean out but it actually made it worse so I didn't even drive it. I'm picking up a new maf tomorrow so hopefully it's that.

Okay, just picked up a new maf and it did not do anything. Car won't even start and stay running now. It turns over but will die instantly.

Will it run with the MAF unhooked?

nope won't even start with it unplugged.

Can you take a video clip of it trying?

i will tonight on my phone and see how it comes out

Have you checked for common problems like boost leaks, crankcase ventilation? Ohm out your injectors and make sure they're all good. Make sure you're getting spark at all cylinders and that the spark plugs aren't gummed up from running rich or anything.

Yup. I've had boost leaks. It won't run under load and idle might be rough, but it still runs..
I checked my plugs a couple of weeks ago and they were fine. Gonna check condition of plug and test spark once I get the car home though.
I'd like to know my air/fuel ratio and fuel pressure but don't have the gauges..
How can i test my relays?

just swap with one that you know is operational... for example, you said the fuel pump is priming, then the relay is good. should be the same relay as the efi relay for example. switch and see if the symptoms change, eg: no more priming.

The only other way i know to test a relay is to throw a signal on the two "switch" prongs and listen for it to click closed.

It could be only one problem causing this, but don't rule out the possibility in two different issues causing problems simultaneously. A boost leak could be present with an improperly shielded MAF signal wire. Which reminds me, is your MAF signal wire properly shielded?

All the wires are in good condition.. I'm taking the manifold off when I get it back though to double check all connectors/wires.

I'm not asking about the condition of the wires. One of the wires carries a signal (small voltage) to the ECU that changes with the velocity on incoming air. If that wire isn't extra-insulated, the MAF power source wire interferes with the signal. It is a common cause of MAF-esque issues. One wire should have the 12 volt battery source, one should have no voltage, and the other has a small voltage when running <--insulate that one. Just extra electrical tape back to where it was connected in should be sufficient.

Okay, I'll try it tomorrow when I go to check everything, and make a video clip.
I just don't understand why it would happen all of a sudden. Whatever the problem is, it took a total of one week ( about 4 days of driving) for it to completely take over.

I've seen stranger things. We just need to rule things out to narrow it down.

Had no 12v source going to CAS, changed EGI relay and power returned. Started car, actually idled for ten mins until i started giving it heavier gas and than it stalled. Just trying to narrow it down now.

Bad O2 sensor caused me all kinds of issues once. Lots of chugging and back firing depending on load. Any Bosch unit will work. Do you have all of the grounds grounded? My RB20 had a ground at the back of the valve cover for the coil that I left off one time, caused lots of trouble with stalling/stuttering.

WD

I'm hoping it's the o2 sensor, and I thought it was going to be that ground towards the rear of the valve cover too, but it was fine. Double checked all other grounds as well, and they're fine. It's just tough trying to trouble shoot this thing, because of the wires being routed differently from the FSM, due to the swap.

Yeah I bet, mine was in a GTS-t when I was oversea's.