low power
 

1990 miata - loss of power when hit the throttle - comes up on rpm curve but takes forever when tb is blipped.
Where do yu check fuel pressure -- any test to rule out FP regulator - possible dirty filter
any experienced help would be grateful
figured check fuel out first prior to comp check

Thanks

RE: low power
 

Check fuel pressure under hood passenger side, two fuel lines pressure & return. Follow the hose from front of the fuel rail back to fender.
To release fuel pressure before disconnecting hose, disconnect the circuit opening relay. Located under dash above pedals, have engine running, pull relay, engine stall, then attempt to start several time. Reinstall relay, install fuel pressure gauge. Idling you should have 28-32 psi, disconnect vac hose to fuel pressure regulator, should raise to 38-46 psi. To test max pessure clamp off the return fuel hose should be 64-85 psi. The fuel filter is locate under the vehicle, on passenger side in front of right rear wheel, has black metal cover 10mm nuts & bolts.

RE: low power
 

After throught! Early Miata's can have a problem with the valve cover gaskets, leaking oil into the spark plug wells. This usually results in a misfire condition, sometimes it may jerk, hesitate or feel like nothing is happening when your accelerate. Might be worth checking before you mess the fuel system.

RE: low power
 

Was thinking the same gtxtreme. Fuel pressure would not really cause a problem unless was either really badly clogged or engine was loaded up. Thinking more along lines of missfire from bad wires or exhaust restriction. Have not run across exhaust restriction to any degree but plug wires and oil contamination from valve cover leaking way more common. What happens if you shift into 4th at 10 mph and try to accel? Do you get engine cutting out and missing or does engine accell slowly with no missfire felt

RE: low power
 

Does it stall completely? Do you smell gas when it starts to lose power? Babyhuey is on to something. If the thermosensor is going out, it can cause the engine to run rich. The first priority for the ECU on a cold car is to add fuel to the mixture to get the engine to operating temerature as soon as possible. The thermosensor is what reports the temperature to the ECU. If it is going bad and reading low, it is causing the engine at normal operating temperature to run much more rich than needed. I think the part is like $40-$60. Check the plugs first for good measure :D They're like $1.59 each for the stock NGK V-Powers at O'Rielly's.