K-Tune

iTrader: (26)

so i swapped my motor out..just unplugged the harnesses and laid them to the side.

however now that everything is back in it's like the computer isn't telling the plugs or injectors to fire.

when i mess around with the harness ground that bolts to the top of the engine i can get it to spark and eventually spark the plug wire.

does this sound like a short? ground issue? something unplugged?

tried a spare computer, spare CAS, computer is getting power, coils are getting power, injectors are getting power, engine block is grounded to chassis and negative terminal.

this sucks :[

Icemark

Sounds like you have a bad ground connection on the block.

Your bump has been deleted. Bumps are forbidden here in the 2nd gen RX-7 technical section, and frankly bumping in less than an hour just makes you look like an impatient child.

theGhost

my buddy had a similar problem and it was the injector plugs were mixed up an easy way to check this is pour some gas thru the air filter if it starts for a sec the pugs are mixed up and if that doesnt work get a spark checker and put it on the spark plug side of the plug wires, you probaly already have but check the compression even tho it cant be started and warmed up itll still give you an idea if its in ok condition

K-Tune

iTrader: (26)

ill check the injector plugs, are they like christmas lights where a break in the connection causes problems?

my block grounds are setup as ground straps bolted to the tops of the rotor housings. one 4ga wire that goes directly to the negative side of the battery, the other bolts to the chassis, then goes to the negative side of the battery.

the thing that makes this so bizarre is that it worked great before i unplugged everything and swapped motors.

dave007

iTrader: (1)

No the injectors are not 'like christmas lights' They all have they're own ground and power. What ground are you 'wiggling.' The only ground that really affects the ECU is the ground that bolts to the top of the rear rotor housing, and you can't get to that one when everything is together. Make sure you got all of the connectors plugged in under the dash by the computer. If this is a TII, make sure the knock box is plugged in by the computer. And how are you checking power? Are you measuring from a power source to the chassis, or from a computer power source to a computer ground. In other words, make sure the computer is grounded.

K-Tune

iTrader: (26)

measuring power im using a volt meter and test light to be sure im getting 12 volts to where it needs to go. as well as using the volt meter to try to pick up on the signals to the coils.

the ground is indeed the one on the rear rotor housing, i've got the UIM off to see if i could visually see something wrong as well as checking injector plugs and such.

K-Tune

iTrader: (26)

back from the garage after more fiddling.


the 4 ecu grounds are proper, power is being provided throughout the harness and injectors.

turning the CAS by hand gives me NOTHING though. no injector click, and no fire. its as if the ecu doesn't think im turning the CAS.

the engine itself is grounded throughout, as anywhere i poke it with a test light from the + i get current flow.

i lost an apex seal on the last motor, however the electrical parts were still good and proper, the motor would run(poorly) so its making me think i snatched a wire somewhere, but i can't seem to figure out what it could have been.

dave007

iTrader: (1)

I have had a car that had a bad wire from the CAS. An easy way to get that off your list is a continuity test from the CAS connector to the wires at the ECU. Are you using the harness that was originally on the car?

K-Tune

iTrader: (26)

this is in a 1st generation rx-7, i had to run new wires for the CAS. ill trace them from the ecu to the CAS to ensure none of them are damaged...

K-Tune

iTrader: (26)

CAS wires look good, no marks in the sheathing and good connections from cas to ECU...

this is so confusing :[

T2GTUS

cas shielded wire has a good ground as well?

K-Tune

iTrader: (26)

i dont have a CAS shielded wire. i know the factory setup used one..however i ran the car for many miles without problems sans a shielded CAS wire.

its basically 4 wires inside of wire loom running across the engine and into the engine bay

K-Tune

iTrader: (26)

excellent..ive either just screwed myself or found the problem. while cleaning plugs and connections i pulled on the cas plug and 2 wires fell out :|

i had printed out my diagrams and i've lost the papers and cant find an online FSM :[ any help in that department? tried searching, most links went to what used to be on fc3s.org