RotaryEvolution

iTrader: (30)

that would be a problem if you're reading the correct wire. try moving the harness around while watching the DVOM and see if the voltage drops.

t2ae

iTrader: (5)

will post up more this evening once im off work. glad i finally found something though lol. looks like its a short to power

t2ae

iTrader: (5)

ok so i am not getting 4.99v on the green and white wire coming out of the ecu with the car cold

t2ae

iTrader: (5)

sorry that was suppose to say i AM getting 4.99v. now this is with the car bone cold. is this right?

Mahjik

iTrader: (1)

Typically, 4.99 indicates an error in that circuit. Whether that's an issue with the sensor or with the wiring is the question. Considering your other issues, I'm still betting on the wiring.

t2ae

iTrader: (5)

ok im sure its wiring as well. more checking when i get home. im going to warm the car up and see if the voltage changes

t2ae

iTrader: (5)

still trying to find out though if anyone has ever had this issue and the cause being a leaking
injector

Mahjik

iTrader: (1)

Easy enough to check. Extend your fuel lines and do the normal fuel system pressure testing like in my photo:

https://www.rx7club.com/3rd-generati.../#post11326413

If your injectors are leaking without being flipped on, then you'll see it. Now whether the spray pattern is correct and/or if the injectors are supplying the correct amount of fuel you cannot tell unless you have them benched by an injector servicing company.

t2ae

iTrader: (5)

ok thanks, i will try and do a setup like you pictured. i will connect it prime and and just let it sit while checking for leaks

RotaryEvolution

iTrader: (30)

a 5 volt signal from the coolant thermosensor indicates a short to the 5v reference wire. the car will always try to start as if it is extremely hot and lean out your fuel mixtures.

check your thermosensor wiring and see if the wires from the pigtail are touching/exposed. if not do a resistance test of the sensor itself.

t2ae

iTrader: (5)

it is a new sensor so hopefully thats good. i double checked the volts and even warmed up its showing 4.63v. ill check the wiring hopefully tomorrow

t2ae

iTrader: (5)

what do you mean a 5 volt signal from the sensor? i thought that the ecu is sending the signal as i can always see 5v on the green/white wire going to the sensor from pin 3E

RotaryEvolution

iTrader: (30)

don't have the schematics in front of me but the signal wire going back to the ECU is the one you want to check voltage on now, to see whether the signal is accurate.

hotter temps = less resistance through the sensor and closer to 5v signal, colder engine temps = more resistance and less voltage through the sensor.

t2ae

iTrader: (5)

according to the fsm the cooler temps= closer to a 5v signal-if i remember correctly it says around 68degrees is approx 2.5v
warmer temps= cless voltage-if i remember correctly fsm says after warm up below 0.5v

t2ae

iTrader: (5)

t2ae

iTrader: (5)

t2ae

iTrader: (5)

if you look at the pic above at the coolant temp sensor, i am getting the 4.62v on the g/w wire going to the ecu. the br/b...now is that considered the groud wire?? isnt that the ground?

ArmyOfOne

iTrader: (12)

I don't think that is the ground. If you look at the bottom, the (B) wire color goes to ground.

The way it reads there is that the (BR/B) wire is the 5v Signal. Since the sensor is a resistor, the ecu sees the result of that interaction.

t2ae

iTrader: (5)

but why would the g/w wire always have 4.62v??? even cut?

t2ae

iTrader: (5)

ok 4D where the br/b wire goes into the ecu is a constant ground. so 3E is the 5v signal coming from the ecu. hopefully tonight i will get around to checking the sensor resistance itself and then continuity on the br/b wire to see if its not grounding

t2ae

iTrader: (5)

So tonight I found that the ground at 4d is not making good contact to the pin on the ecu therefore not completing the ground. Haven't decided if I'm going to just buy all new connectors or just buy a new rywire harness but glad I finally found a problem. Thanks for all the help guys, I'll post up when i fix this

t2ae

iTrader: (5)

yup so thats no it either....jeez when does this end. another bit of info is you can cold start it by removing the intercooler pipe off the throttle body side and blocking it with your hand

t2ae

iTrader: (5)

with this being said it seems that it isnt getting enough fuel as "choking" it with my hand it will fire up. tonight ill be double checking fuel pressure. any other ideas guys?

t2ae

iTrader: (5)

About to test the fuel pressure next. So discard what I said about choking to start it as I just tried that again and it did not work......god this is driving me crazy

t2ae

iTrader: (5)

OK fuel pressure results....key on 45psi....while starting it drops but nothing odd....aftering turning key back off and letting it sit it doesnt really drop below 31psi after say an hour or so....i left the gauge on it through the night and it did drop to 6psi.. is this something i should look into??? please someone respond as i would like some help