So back in January I bought 2001 s40 for a pretty good price. For the first few months it worked great. I ended up losing my only key. I paid for a new one to be programmed 😪 a fat $380. I'm now like 4 or 5 months away from that happening and I'm already prepared to replace my fuel pressure regulator because I originally thought that was all my problem. Long time to start blah blah blah did my homework and found out my problem isnt only this FPR. My key sometimes doesnt work at all. It turns the battery and everything on but doesmt even attempt to turn the engine on it seems. I dunno if the heat has anything to do with it, but it seems like in the heat it takes longer of turning it on and off before it actually starts. I cant find anything on this but I was hoping some awesome possum on here could help!!! Thanks guys.

 

first on the FPR, did you replace or suspect its the problem? FPRs fail when the diaphram tears and allows fuel pressure to bleed out of the rail so you can long cranking on a cold start (until the pressure builds up). Quick test is to pull off the vacuum line on the bottom of the FPR - if fuel leaks out it needs to be replaced. As to the key, it unlocks the tumbler gets to position 1 but doesn't engage the starter? Any clicks etc? Any immobilizer warning message? Any change in behavior if you wiggle the key while turning to the start position? Keep in mind that the shifter also interplays with the start circuitry so you may have an issue with your PNP switch (park neutral position sensor will disable the starter if is senses the car is not in park). Try doing a shifter row to see if that cleans up the PNP contacts (Park to lo to park 20x fast).

 

So I'm able to turn the key all the way to where the ignition should start, but nothing. I haven't replaced the FPR as I'm waiting for my next decent check. But when I turn the key all the way to the definition there are no sounds just the battery turning on. I can hear something in the ignition starting to run but nothing else. No clicking or any turning at all. My roommates theory was something with the key. But I dont know. I know for sure the FPR needs to be changed though. Nothing on my dash other than the maintenance light and the check engine light now and occasionally the transmission light comes on but doesmt stay on long

 

Since it sounds like the key works some of the time, I'd suspect an ignition switch problem or possibly the PNP switch or shifter position. Try the shifter row and next time it fails, try wigglng the key while turning to the start position.

 

I do appreciate it a bunch. I will for sure try that. I know it's probably a silly question, but I'm not really obviously an enthusiast but would a diagnostic at oreilys show any of these possible problems? I known it only shows certain codes for things but i didn't know if doing that would give me any answers