Well, there have been a couple times when I go to start my car, and it won't start.

It turns over, and I can hear the compressions, but, it won't start.

Normally when I start my car or put the key in the ON position, I can hear the whine of my pump when it kicks on. Usually when it won't start, I don't hear that.

So, I am guessing either relay or pump? Where is the pump relay?

Anything else it could be? My pump is usually very loud, always has been.

Thanks!

 

I believe the pump relay is in front of the air box. Is on mine which is an s5 but I am not 100% sure that the s4 is the same although I believe it is.

 

If you swapped the manifolds make sure that the ground for the EFI harness is still there. There's a small hole to bolt it up by the oil filter pedestal and clutch slave. You would be getting fuel, but it would not the injectors would not be firing, as far as I can tell. Also, check to make sure the AFM plug is hooked up.I had the same issue after putting my emissions back on. The car had fuel and spark, but would not turn over.

 

Air flow meter unplugged on a S4 would prevent the fuel pump from activating too.

You could jumper the fuel pump diagnostic plug to make sure that you really are not getting fuel.

 

Well, after I jumped the fuel pump, it took a bit, but then started.

I am guessing it is flooding. And, it only does it after I drive the car really hard.

Checked fuel pressure, and it is at.... 28 psi.

Gotta check the FSM and see if that is right.

Fuel pump stopped making the whine sound when the key is in the ON position, but it still makes it once the car is started. Strange?

Thanks for your replies.

 

Probably leaking injectors... pretty common on a older rotary.

 

Fuel pressure isn't 28. haha, was off a bit. Can't read tick marks. haha. It's about 34 psi.

I sent the injectors to be cleaned and serviced about 5 months ago. They were completely cleaned out, and I was told they weren't leaking. Could they have gone bad in the 5 months?

Thanks for the quick reply!

 

Pretty rare to have fuel injectors bad in only 5 months, but I suppose it is possible if your fuel filters and or gas tank are really dirty.

The lower (28psi) and flooding is what suggests that, but if you are back up to 35 psi, then probably not, but if nothing else pops up, then I would pull then and check them.

 

Alright, thanks!