Ok so I own a '84 GSLSE and I pulled my stock GSLSE engine out and threw in a custom 2nd gen one. (S5 rotors, S4 cast irons and housings, S6 eshaft, ported exhaust, pineapple racing sleeve inserts, S4 intake, K&N air filter, and efan) Anyways got everything hooked back up and no vrroom vrroomm. Ignition is great, and I have fuel to the rail. Checked power to the injectors and they have a ground. The ECU is recieving a signal from the trailing coil telling it that the engine is trying to run. Checked the wires going ?into? the ECU from the injectors with a test probe. When the test probe is grounded on the chassis and I check the connection, I can manually turn on an injector and run it on that one inejector for about 3 seconds until there's a click inside the computer and the engine shuts off. Weird thing is I parked it and the ECU was fine. WHAT AM I MISSING? I've been ruling out all the possibilities and it has to be the ECU.

What do you think? Please help.

 

I gather you are running a second gen ECU, what about the AFM? May want to jumper the flow switch on the AFM. Also, check your circuit opening relay is staying closed to activate your fuel pump.

Let us know.

Scott

 

Using the S3 wiring harness. Yes its been done successfully. You just have to plug up the injectors on the intake and modify your intake tube from your AFM to the plenum. Yes the pump is working. Already tried jumping it to activate. It comes on I found out anyways when the engine sucks the AFM door open...

 

if you're running s3 ecu, make sure you're running s3 afm. 2nd gen will plug up i believe but voltages are different. Make sure your timing is set correctly. that prevented my swap from starting.. got timing right and it crunk right up.

 

Yep.^ S3 AFM. Connected the dot on the distributor drive gear with the indicator on the distributor housing itself. Like I said, it will run if I manually turn on each injector, then a click inside the computer shuts it off...

And if it were timing I would hear a sputter once in a while but I get nothin

 

Have you confirmed fuel delivery?Not to the rails,but that the injectors themselves are firing?Pull the plugs and take a whiff......
Did you change out injectors?,because there are 2 types,low and high impedence.The break was about mid 87 and the S3 ECU needs low impedence.

 

like steve said. what injectors are you using.
84-87 ish use differnt injectors than 88.5 and later rx7's...meaning some ecu's are not compatible with the some fuel injectors

 

try testing your fuel pressure. are you using a GSL-SE pump? if so your pressure needs to be at least 35psi for the injectors to fire. if using an FC pump try to find out at what fuel pressure the FC pump pushes. you may need to do that as well as find out your injector impedance.

 

Put a Weber on it.

 

F*ck the carb. Yes same injector setup that I had before. No the injectors are NOT firing. This is my problemYes I have the GSLSE fuel pump pumping out 62psi when shorted at the connector, 42 w/o vaccuum and 37psi with (last time it ran). . My ECU is not letting them work. My question is why?

The fuseable link is good, main relay works, power from the trailing coil to the ECU. Power and ground to injectors.....

 

 

still nothing. I have ruled out the injectors themselves, all other relays, ECU, TPS, fuel pump and pressure, afm, timing. I disconnected the wiring harness at the ECU and tested from ground to all other connections for open leads or something that has lots of Ohms..nothing. My engine builder can only suggest a wiring harness.......I'm at the end of my rope.

My thinking is if it were a bad connection it would at least sputter. But i get nothing unless i let it sit for a bit and the injectors drip and i get a drop of fuel. WHY WONT MY INJECTORS FIRE??????

 

sorry i dont know anything about FI but maybe they are clogged? idk. i might be saying what you already stated but thats what it sounds like. sorfry i cant really help

 

if all else fails go to a stand alone like a haltech or microtech...

 

$1200.........anyone got one for less?

 

Megasquit.

 

BTW-a few days ago for some reason I noticed the ignitors are on the "same" circuit as the "ground" side of the injectors. I swapped the trailing with the leading and it started but died a second later. Does this everytime. yesterday I went through some more diagnosis and found a 1.5 inch gap after the AFM was causing the non starting issue. Piece of duct tape and SHE RUNS!!!!!! YAY!

 

KICK ***!!! I will be there in about 7months buddy!!! POST SOME PIX LIKE A *****!