Ive got an 09 rx8 that im having issues with. I ran pretty low on gas in a hurry one day, the next day the car was hard to start and misfired heavily under load. It gets better as it warms up but under hard load it still has trouble and wont rev past 7k, at that point it sounds really flaccid and wont pull.

Sound like fuel? The car recently had the whole ignition redone and carbon treatment and ran great until this.

How can I test this? Ive got fuel pressure gauge but I found no fitting. I havent checked with my snapon solus to see if it reads anything that specific, only code Is p0301

If it is the issue, what are my options for replacement? The car will be boosted or ls swapped someday so a stronger pump would be something im interested in.

Ill take a video of it later if possible.

Thanks for any help

 

If you are considering a stronger flow pump, I suggest the DW200 or DW300. Especially important if you will be boosting the engine. Can be easily had from BHR. As you have an 09 RX8 you already have the better Series 2 fuel pump.

Important question , were your issues only when the fuel level was low, or did you experience the same problem with a full tank ?

 

aeromotive 15120

 

It started on an irresponsibly low tank and got maybe a bit better on a full one

 

Yes the low tank scenario points to a failing fuel pump which gets overheated when the fuel level is too low to cover and help cool the failing pump.

 

If I go to a dw300 will I have to use a connector from an s1 or is there a drop in for s2s?

 

First a DW300 is a little overkill unless your RX8 is boosted. If you are going boosted then the Dw300 is a good choice. The DW200 is more appropriate for NA application. . Hey drop Charles of BHR an email, he may be able to answer your question about your dropping a DW200 into a Series 2. It is a straight drop in for a Series 1.

 

There are no drop in fuel pumps for the S2 unit, it was redesigned and uses a Denso pump motor that is much more reliable than the S1. It sounds more like a clog than a bad pump, fuel sludge sits on top of the fuel and if you go super low then you can suck a bunch of sludge and clog the sock and/or the injectors. I went through a similar situation a few months ago, it was sludge. There was another guy on this forum that also went through a similar problem, it was sludge.

You may be able to make a DW200 pump work, it will be a custom job though. I spoke with a tech at Deatschwerks ( I was entertaining the thought of making it work) and he said he doubted it would be easy to do.

Theres a thread on testing the voltage across the pump, but you'll need to buy the fuel pump removal tool to get past the ring of death. BHR offers one now. Good luck whichever route you go.

 

Whenever I have had a fuel pump fail it usually starts with slight hesitation under load. As it heats up the pump will stop working all together.

I can restart after a break however, it will play up again as it heats up. After several stops I will finally make it home.

This has happened to me twice once with an Aeromotive pump and the second with Walbro. Now back to stock.

 

skc is your car a Series 1 or Series 2 ? Your scenario is the classic failing and overheating pump scenario. It happened with my stock oem Series 1 pump with 52,000 miles on long extended highway driving in hot weather. switched out the pump for a DW 200 which is running much better. But the OP has a Series 2, which as "no redline" correctly points out has a much more reliable pump.

 

So ive pulled then pump out and checked the filter inside and it looks fine. The pump doesnt make any odd noises but there seems to be a lot of turbulence in the actual sending unit where the pump is. Just a lot of moving fuel, could be normal from all the fuel that moves through it or the feed tube could have a small hole. What's weird is the car has started running better. If you drive it like an old lady and stay below 6k rpm or so you wouldn't know anything is wrong other than how hard it is to start. The ignition system is literally brand new but its the second time I've done it because the napa coils seem to be junk.it really doesn't seem to be ignition though because when I got the car only two plugs were firing (stock at 55k miles) and it ran way better.

 

I think it might be your cat. Can't pull, misfire under load.. yep.

 

Have you tried actually trouble shooting?

http://www.normalexception.net/docum...p%20Manual.pdf

 

Cat is gutted. Only troubleshooting I havent done is a compression and fuel pressure test.