Ok here's the thing it's not bad compression not hot start problem at all. As the title states my thinking is one of the three. Here's the problem got my new header gasket on (car sat for two weeks on 1/4 tank) started her up she started right away no trouble there let her idle for a bit because she sat there for so long. Took her out for a spin all was good through all RPM ranges. Went got fuel and noticed a hesitation or kick down in power at about 4500 RPM she's pretty limp till she hits about 7k then bam a blast of power she comes to life and goes. Now my thinking is bad gas because it happened right after fill up or condensation built up in the tank cause she sat so long with only 1/4 tank days have been hot and night cool. I also think perhaps fuel pump going bad but why would it spring back to life at 7k RPM. Or SSV seeing if I'm not miss taken is suppose to open at around 4500 and this is where you can feel a drop in power but again why the spring back to life at 7k. BHR coils plugs wires all done at the start of the year. No CAT. And one other thing makes me think fuel pump is if you let her climb slowly no drop in power it only dose this if you push the pedal and maker her go. Pumps never been replaced as far as I know and it never showed up on any service records so it has 140k miles on it. SSV has more than likely never been cleaned ether. Any thought on what I could be would be grate.

 

Little up date. Went out and moved the SSV with my finger. It moved quite easily I felt no stiking no choppy movement. I do have one other question would the SSV move with out being in gear or does the have to be a load on the engine for it to work?

 

"And one other thing makes me think fuel pump is if you let her climb slowly no drop in power it only dose this if you push the pedal and maker her go."

My fuel pump was acting like this when it was bad.

 

That's what I'm leening tword. Thanks for the input.

 

Going to order a fuel pump from BHR I have all but decided that's what it is. Just took it for a run after a long idle so every thing was hot. First take off was normal good power through the RPM range second take off it went limp at 4k and back to life at 7k but when I shifted out she almost acted like she wanted to die. It's only getting much wors now power is dropping out even when you ease the RPMs up she almost cut out at 5k but this seems to be only under load. Reving it sitting still has no affect runs through RPM range fast and with no hesitation. I did notice the tone of the pump when the car is turned on is realy low. No flashing CEL so no misfires and no hot start problems. Again any in put is welcome.

 

When my pump was really bad, it would cut out at high rpms even when it was in neutral under no load. There's a thread here somewhere on how to test the fuel pump. Mine past when first tested, but not when tested over a longer period of time.

 

Check your one way check valve right behind the upper intake tract and make sure it is intact. I left this unplugged and for a week it felt like I was spooling an enormous turbo and at 7000rpm it would just take off. The strangest thing really. Plugged it back onto the nipple and it was smooth though all rpms.

How many miles on the fuel pump?

 

If it's the chech valve I think your talking about I deleted it I have a CAI no need for it. The pump has 140+miles on it so way past failure time.

 

No he's talking about the back of the intake manifold by the oil filter.

 

The check valve he is talking about is farther back on the UIM. Kind of back and around the corner. The one you are referring to is for the intake thingy in the bumper (can't remeber the name right now). They look very similar, just reach farther back and you will find it.

 

Check valves in one peace and connected.

 

I think it's safe to say it's never been touched till me. 10 years of dust, dirt,and rocks.

 

Update got my DW200 in today but the locking nut is a %*&$@ going to fab a tool. I've opened lots of FI systems before and got sprayed lots of times by gas this is the first time I've seen no pressure in a FI fuel line is this normal or is this a good indication that the pump just isn't producing pressure?

 

Ok every things been fine till yesterday morning on the way to work I felt that power cut out at 5k rpm again. Gas hand was close to 1/4 figured with the DW200 I might just be sucking the bowl dry. So I filled up all good till this morning it cut power at 4750,6000 and 2750 rpm at first I thought perhaps the other solenoid I hooked the SSV to was going out till it cut out at 2750. Any thoughts or help would be grate.
When installing the DW200 I did melt the pop off but could it have broke free? The cut out only hapens under load ie exseleration no cut on cruse and it didn't have to be hard exseleration.

 

If the pop off came off your siphon wont work and you'll run dry at 1/4 tank. Depending on how the gas sloshes across that is.

 

I had a bad oem fuel pump around 54k miles and put in a DW200 with the pop off cap melted done. Everything was fine until I drove back from SC and had been driving at highway speeds for three hours straight in 95+ degree ambient temp weather when the pump cut out along I-95 in NC at just above 1/4 tank. Once i let the car sit for a few minutes and the pump seemed to cool down, it started up fine and ran fine. I just kept the fuel at half tank or above the rest of the 500+ miles home to NJ. It seems in my case to be a case of the pump overheating as the warm fuel in the tank could no longer carry the heat away from the pump when the fuel amount decreased to 1/4 tank. I don't think my pop-off came off as the car didn't run dry and was able to start and run fine ,including hard acceleration , after the pump was given a few minutes time to cool off. Don't know if any of this info helps you, but I thought I would relate a somewhat similar situation after changing to the DW200 pump which has a good rep for reliability.

 

That's what made me go get gas but as I said it's at 3/4 of a tank now and still doing it only now it's doing it all across the rpm range. It's not a slight hiccup it's a dramatic cut in power that lasts for a second or less

 

When you changed the pump did you clean out the flexible screen filter of the pump assembly. My screen had particles of crude and stuff from 54,000 miles of use and some questionable gas along the way. . My mechanic, Jim of JPR Imports in Blackwood, NJ (a well respected rotary wrench on the east coast) cleaned all this stuff out. I have a pic somewhere that he made with his cell phone of this crude while working on my pump. If I still have that I will post that to you. There is a photo of that flexible filter and the crude it can pick up , in the pump threads here on the forum. I read in the pump threads about this needing to be cleaned. Again your problem may not be pump related, but it also is probably not a coil issue as you have the BHR kit, which I also have. I think Mazdamaniac on the forum has the most experience with pump issues and replacement. It might be good to pm him, or pm RIWWP who have more experience with the entire RX8 fuel systems than I do. I have decades of experience with RX3,RX4 and RX7 fuel systems but not as much with the RX8. Also some people on the forum had real issues after getting cruddy gas.

 

Yea I beat her up, played nice with her and no more cutting out I think I still might have some water in it and the 1/4 tank thing might have forced it to pick it up. As for the sock filter yea I cleans it up it wasn't to dirty which was kind is a surprise to me as there is 145k miles on the car and the pump didn't seem to have ever been opened. But I did find one odd thing there was metal shavings in the bottom of the bowl and some shavings and flakes on the filter not shure where it came from.

 

Hopefully you have gotten through the bad stuff in your tank without any damage to your engine. Try a little drygas in the tank to help evaporate any water. That might help. Keep us informed how it goes.

 

Well drove to work just fine no cutting out no power loss every things smooth. Going to stop getting gas from that place and suck it up go back to shell for a extra .40 cent a gallon.

 

Sounds like a wise decision !

 

Up date think I found the culprit on my sudden cut outs. When I reattached the evap hose I notice it would slide up and down a little but didn't think much about it. I've got the day off today so I took the UIM off again and inspected what I did the last time and found that the little red clip under the blue one was under the ring on the conection point on the UMI. So I removed it and inspected farther and found I did indeed install incorrectly. As you can see from the pic. It no longer will slide or move at all now we will see if the vac leak I caused to the vap sys is my problem.

 

Just could be the culprit !

 

Seems that it was the miss when at idle is gone smooth run through all the RPM ranges. Took her out for a spin all seems well next step COBB ap and replacing all coolant system parts as they are all factory and aging at 10years and 145k miles. Hope she is good for another 60k miles with out any major issues. Thanks all who help with this string of problems I've had here of late