so my car started to have the 3800 hesitation, then it just started running flat ( no power at all) so i did some searching and redid the grounds on the batt terminals, eyelet, boost sensor, still had both issues, then i changed and adjusted my tps, that took away my flatness but i still had the 3800 stall, so reground the ecu at the ecu per the pinout in the fsm, not once it gets warm i can't apply any power in any gear above 2nd ( no power, backfires, drinks gas) . so i removed the ground wires, still have the problem, anyone know what i have missed?

 

ECU ground under the intake.
http://www.aaroncake.net/RX-7/grounding.htm

 

fixed already as stated in my first post

 

tried my spare ecu and a new 02 sensor and it gets worse anyone have any ideas?

 

injectors? AFM? fuel pump? plugs? cracked distributor?

 

um...clogged catalytic converter could be the culprit of the lack of power.

The hesitation can be fixed with the addition of 8gauge ground wires....ground the manifold to the chassis and such...also, check and make sure your transmission ground is still connected to the firewall...

 

car had rb true dual (no cats) already has extra grounds from engine to chassis, engine to battery, and the top engine ground eyelet to battery, and not sure about the tranny groud but ill check

thanks
Dennis

 

update, the car now instead of richening out leans out but about at the same time, 1/2 throttle. any ideas as to why it might be doing this?

 

did you tap a new ground wire into the ECU grounds and bolt them to the ECU bracket? worked ok for me.

 

tried that and thats when this problem occured

 

update: car still richens or leans out after it gets warm and sputters, since last post i have

cleaned the injectors
changed all engine sensors but the afm and ecu
fixed and added a ground at the starter: (my alternator voltage is now 13-14 volts or so, b4 it was barely 12)
changed the spark plugs
re-wired the fuel pump

not sure if i said this but the engine is a rebuild with 1300 miles on it and streetported, did a compression test to see how much compression i had built so far
90 psi front
70 psi rear

and just for giggles and advice from a riend of mine that is a mechanic i unplugged my 02 sensor, it ran exactly the way it had been with it plugged in and didn't throw and codes either, maybe the wire to the ecu needs to be replaced?

thanks for any help
Dennis

 

02 has no relation to your problem at all. None.

It sounds like you grounded the wrong wires on the ECU imho.

Post a jpg of the ECU plugs and point to the wires you added a gnd to. By jpg, I mean a page out of the FSM showing the pinout of the ECU plugs.

 

the car is at home and im at school so i can't double check which wires i regrounded. but by the pinout im pretty sure 2r 3g and 3a

Dennis

 

isn't that low compression for 1300 miles?

 

yes it is, out of spec.

Check your injector resistance
check to make sure all injectors are getting power when the key is on(check continuity between the positive lead on the harness and a chassis ground)

check your pressure sensor on the passenger shock tower, injectors switching on is also dependant of inputs from that sensor, check it out according to the fsm and check the continuity of the wiring.

have the injectors been serviced?

 

That's a good idea. Why not get a meter out and go the the ECU plugs and compare the readings on each pin with that given in the FUEL AND EMISSONS pages of the Control Unit section. That should give a clue.

 

so my rear rotor is low?
and the injectors were cleaned by whitchhunter when the engine was rebuilt

 

You stated that you re-wired the fuel pump, but have you checked the fuel pressure with a gauge? and how about the fuel filter and sock filter?

 

fuel filter was replaced this weekend, sock filter is new cuase i got a new walbro when it was rebuilt

 

If you rewired the pump and are using a walbro 255 on an NA, you're way rich. I know this personally. My '90 NA hesitated after I replaced my stock pump with the walbro. Rich mixtures can cause lack of power just like it did on mine. I had 44 PSI fuel pressure at idle with the walbro and the resistor pack. Without the resistor, you are probably approaching 50 PSI at idle. Even higher under accel due to the FPR. This is way way way too rich. As soon as I went to a stock pump my pressure came down to about 29 where it should be and my power and mileage went back up to normal. Do what I did and save your walbro for a TII or sell it to someone that owns one. It's a good idea to invest in a good quality fuel pressure gauge and tee fitting. This applies to anyone with hesitation or low power symptoms. There are several possible causes for this, and low or high fuel pressure is just one.

 

Yeah you need to tap the rail for an aftermarket FPR.

 

so my problem is my fuel pump?

 

It takes but a half hour to put the old pump back in and find out.

 

i'd have to buy another stock one, i bought a walbro cause my old one failed, but i will do that

 

i may be interested in your walboro. i have intermittent hesitation issues/lack of power on my TII