fd3s7007

Hi All,

I've had this symptom for some time now. When i step on the throttle the rpm increase is slow and feels restricted. There is also a strange knock increase at 2500- 3400 rpm's which is not speed or gear dependant. I've checked every single place without any improvement. Among the items i've checked :

- ECU (PFC)
- Throttle Cable
- Fuel Filter (replaced)
- Fuel Pump (replaced with walbro gss342) Directly wired via relay and fuse
- High Flow Cat (removed alltogether)
- Tuning (Tuner says the engine seems very restrictive)
- Coils - Replaced coils,ignitor and fuel pump resistor with new units
- FPR - Replaced stock fpr with SARD

Items i am going to check this weekend. Hopefully some may chime in and tell me if its worthwhile or not.

- TPS (going to do this via PFC)
- Crank angle sensor
- Timing (any idea on a good writeup?)
- Fuel Lines

Anything else i should be looking at?
Car made the following power ;
RWHP - 344.6 @ 6751 RPM
Torque - 363nm @ 6441 RPM
Speed - 206kmh@ 6958 RPM
17 psi of Boost @ 5964 RPM

I appreciate any insight or advise. Thank you in advance.

Regards,

Dave

mirabile

Compression checked out fine?

GOOFYROTOR

check the muffler maybe plugged up.
check primary turbo maybe NOT spinning.

CantGoStraight

Have to ask since I didn't see any posting of your boost levels. ?other than your specs ofwhat it did make...is that the kind of boost your running now ?

pinkrx7

iTrader: (2)

dont think you can mess with your timing really buddy.

fd3s7007

My bad - I'm running a single gt35/40. Compression is fine with readings of 7 on all faces (mazda compression tester) This problem existed prior to going single and i've checked and rechecked everything above without much progress. Any kind of ideas however far fetched please throw them in the mix. It'll at least give me something to look for.

pinkrx7

iTrader: (2)

HOW TO PEP UP YOUR ELECTRICAL SYSTEM

A respected RX-7 mechanic says that no car leaves his shop without the following simple modifications done to the electrical system. All are done with 8 or 10 gauge wire. You can secure the wire to the battery terminals using the terminal clamps, or you can get clamps which have provisions for extra wiring--as you might find with a complex auto sound system.

Run two new ground wires. One goes from the engine to the negative battery terminal. The other goes from a bolt or bare-spot on the chassis to the negative battery terminal. The additional ground paths will provide a little cushion for the stock wiring which is marginal when new. This has been known to solve low voltage problems at the cigarette lighter--the kind that gives you low voltage warnings on cell phones or Valentine One radar detectors. The V-1 detectors will show a false "laser alert" if you try to power it with low voltage.

Run one new wire between the alternator output (the wire secured by a nut) and the positive terminal of the battery. This parallels the stock wire and makes it "easier" for the alternator to recharge the battery. With both these modifications, you should see at least 13.8 volts at on your dashboard volt meter when at idle (but without other electrical loads).

-fd3s.net

maybe its your grounds if you've checked everything else clean your terminals and grounding surfaces.

fd3s7007

thanks pinkrx7.

i had the chance to test the car at varying rpm's. i've noticed there is somewhat of vibration at 2500rpm and it picks up as gears move upwards around 3600-4000rpms. distinctively coming from the rear of the car. could this be something that would effect accelaration?

tiger18

iTrader: (1)

Have you got full boost (gauge)?
vibration at the back dont sound good,,have you checked the diff oil (maybe the LSD is knackered and holding back the engine in some way),,, also you sure the rear brakes arent binding does the car roll free when the handbrake is off?

dgeesaman

iTrader: (7)

Get your diff checked out. Drain the oil and see how it spins.

Out of the items you listed above, the TPS is the most important.

Have you ever had your injectors tested or cleaned?

Dave

fd3s7007

thanks guys for the input.

tiger18- yes i've got a boost gauge. like mentioned before its not specifically boost or speed dependant but only rpm dependant. thanks mate i'll check lsd and i'm sure rear brakes are not binding.

dgeesaman- will definitely get diff checked out. will also have a couple of days after monday to spend looking at things mentioned here.
injectors pri-550 and sec-1600 have been cleaned and flowed.
i'm pinning on tps and some drivetrain issue. i really miss how the car use to rev so freely.
Keep ideas flowing though.

dave