KaLiKoStreet

Still haven't gotten rid of the hesitation in rpms. This guy, https://www.rx8club.com/series-i-tro...rating-235596/ had the exact same problem but the thread died sometime ago with no resolution as a lot around here seem to do... After gutting the cat, cleaning the ssv maf sensor and filter, coils plugs and wires only had about 2000 miles on them when last engine died so I assume they're all still good. Running out of ideas...guess its time to look into the fuel system. Everything's fine and no hesitation until the car gets to a certain hot operating temperature. From cold to warm and about 7 miles later it runs great but from there on the hesitation comes back. I thought maybe the fuel pump was getting weak after it got hot like the guy in that previous thread said but even after he changed his pump it was still there. Someone said something about the fuel rail regulator. How does one go about checking it?

9krpmrx8

iTrader: (46)

There is no fuel rail regulator, just a fuel rail pulsation damper and that would not cause it. Did you reset the NVRAM after installing the new engine? Any codes? And by hesitation does it feel like fuel cut, like the RPM's just hit a wall?

KaLiKoStreet

Yes have reset the nvram a few times for other reasons. No cel no codes. Hesitation comes in after the car is at operating temperature at 5500ish rpms, revs up as fast as u want until then. After 5500 is starts acting like its not getting enough gas and will not increase up in rpms as fast as it should until around 6500 rpms then it gets like a sudden boost back to normal and the power returns and continues climbing through the rpms as fast as u want. Its like after 5500 rpms its not getting enough gas fast enough until you get up to where the secondary injectors kick in.

KaLiKoStreet

After changing the fuel pump and still not fixing the problem I went to advanced auto and used their code scanner, even though I do not have a check engine light on I still have 5 codes coming up. They are p2270, p2096, p0456, p0661, p1039. I'm searching them all now but if anyone wants to throw in some help feel free.

Edit: Update, Found these
P2270 - Rear HO2S signal stuck lean
P2096 - Target A/F feedback system too lean
P0456 - EVAP system leak detected (very small leak)
P0661 - SSV solenoid valve control circuit low
P0139 - Rear HO2S circuit slow response (couldn't find anything on p1039 so maybe i heard wrong or the guy read it wrong so the next closet code is this)

I know the o2 codes are from me gutting the cat (thought the nonfouler trick worked but i guess not) but it seems i have a vacuum leak and a power problem to the shutter valve solenoid


I found probably 50+ threads which sounded very similar to my issue and no one ever seemed to have found a fix or decided not to share with the forum how they fixed it. Just because you don't have a check engine light it doesn't mean that there might not be codes stored, goto advance auto, autozone, o'reilys, etc... and ask them to use their obd2 scanner to check your car computers codes. You may have a blown check engine light bulb or be like mine and just not come on at all for whatever reason...

Check engine light code descriptions can be found here: https://www.rx8club.com/new-member-f...4/#post4533723

9krpmrx8

iTrader: (46)

P2270 and P2096 are due to the rear O2, do you have a cat converter?


P0456 is likely due to a vacuum leak. P0661 is a problem with the SSV solenoid and would explain a lot of your issues.

P0139 doesn't come up in the FSM, have to Google that one.

KaLiKoStreet

I edited my last post to include some things be no to the cat question, I gutted it trying to fix this problem. I thought the non fouler trick worked but i guess it didnt so Ill try fixing that another way. I assume p2270, p2096, and p0139 all are because of the cat but the vacuum leak I will have to hunt down and the solenoid I will take off and try to clean it or just buy another one.

On another money wasting topic, I managed to put a hair line crack in the main fuel pump line of the plastic fuel pump housing while changing the fuel pump so its leaking gas everywhere but yay me theres another $200 for a new housing assembly.

I think all those mirrors I broke and ladders I walked under and black cats that ran out in front of me as a kid are finally catching up to me and taking the form of my car

9krpmrx8

iTrader: (46)

The spark fouler tricks don't work, the only way to get rid of it is to mask it with the Cobb AP.

You have three vacuum actuators/solenoids under the UIM. Since you gutted your cat, then you don't need the air pump so just get rid of it, cap it at the header with a air pump block off plate (make your own or buy the RB one), and the use that actuator in place of the SSV one (they are identical) and see if it works out. That is a fairly common problem.

KaLiKoStreet

After changing and cleaning everything I did, none of it was really necessary. I took the top of the engine apart and I changed the ssv solenoid, replaced every vacuum line and cleaned every grounding point and the problem is finally fixed. It was the ssv solenoid that was going bad, after it got so hot it would stop working and not let the ssv open when it was suppose to. I had a crack in a vacuum line so I went ahead and changed every vacuum line there is. I use to have problems with my power steering going off and on so I rerouted my coolant overflow hose to underneath the car and I cleaned and repositioned every ground point of the engine bay. Hopefully I can get to take a break from having to fix or change something every week now.