Okay, i am just getting into this whole rx7 bit. I own a 1991 RX7 GTU N/A. I did a transmission swap from auto to manual, and I am now just trying to finish up a few things. However, I have run into a huge roadblock. When ever I put a load on the engine, it hesitates really bad. If I go up hill, or put the pedal to the floor, it jerks and hesitates like someone who is learning to drvie stick. I have checked and changed all the obvious things
intake
cats
spark plugs
wires
o2 sensor
fuel filter
but i still can't figure it out. I think it might be something electrical, but im not sure. Is there anyone out there with any advice for me?? Thanks a lot!

 

Check all your grounds, and make sure there good wires and grounded correctly.

 

Another common issue - The short range TPS will wear out after ~100,000 miles or so.
The ohms (warm engine) value starts at 1k at idle and goes up to ~5k as you open the throttle.
If there is a worn spot that drops below 1K just above idle, the ECU will give fuel cut hesatations.

 

Grounds? One on drivers side, that bolts to the tranny, one on slave, that has a plastic end with it, and one on top of bell housing that has a small bolt and washer with it( this one is actually critical to fuel management).

Also maybe the fifth gear, nuatral switch. Not sure about that one tho, maybe it helps control fuel under a load? Maybe some one can help here. I havent done this swapp.

 

Double post....wont let me delete.

 

For grounds, what size wire should I use, 4 gauge, 8 gauge...?

 

You can also have your fuel pump going on you or it has a dirty sock.

 

I don't understand what you said Hollywood

 

I grounded the battery to the frame, the leading coil, the trailing coil, the ecu, the pressure sensor, the transmission, and the intake. It helped out a good bit, but my car still does the same thing. Whenever a load is placed on it, it hesitates really bad as if it isn't getting any fuel or something. But if no load is being placed on the engine, it revs up reallly high and sounds great. Any help here is much appreciated!! Thanks

 

Fuel filters have a "Sock", it's a tube of metal mesh, that surrounds the intake, so that rust flakes and larger particles don't get injected into the engine. They're a common place of blockage, as a good number of them have never been cleaned/replaced, and then all the rust and dirt at the bottom of your tank gets kicked around if your tank is either too low, or the car is being raised and lowered a lot (you're working on it).

Check the FSM for more specific details.

 

check your secondary injectors or primary injectors, sounds like they might be the cause

 

When taking the fuel pump out to check/replace the "sock", will I NEED to replace the gasket between the fuel pump and the gas tank????