Fuel rail instal, thermostat issues.

[robftw]

I'm making a new thread because this is a separate question, on my 78 280z i have removed the old fuel rail and replaced it with a much nicer one.

The current fuel line setup is this,

Tank -> Filter -> FPR in-> FPR out-> FUEL RAIL -> block off plate

I have the return line routed with the vacuum line intact. Cold start removed

Problem 1 of 2

When driving the car takes off very sluggish now, i don't think i have any vacuum leaks and the EGR system has been completely blocked off. I have one line going to the TB and one line going to the FPR, and finally brake booster.

As for the emissions stuff on top of the manifold i have retained the idle air flow regulator valve so i don't have to drive with three feet. However i have removed the bypass plate and ran a new hose going from the passenger side of the engine block into the thermostat housing.

Problem 2 of 2

For whatever reason the car nolonger has any type of temp reading for the gauge.. when i turn the car on it slowly raises all the way to one side and stays.

[Zed Head]

It should be tank>filter>rail>FPR IN>FPR OUT>return line>tank. The FPR is at the end of the system that you want pressurized. Fuel will flow continuously through the lines, rail, and FPR. You have what's called a dead-head system now which is not desirable, especially considering the fuel heating/poor starting discussion in your thread. The only fuel flowing through your rail with your current setup is what goes through the injectors.

The vacuum line (small one) from the throttle body is probably ported vacuum and is meant to go to the vacuum can on the distributor. The vacuum line to the FPR (another small one) should come directly from the main body of the intake manifold. The brake booster has its own large vacuum hose.

The "bypass plate", if you mean the water line that goes under the AAR, is designed to keep the AAR at engine temperature so that it doesn't reopen prematurely. Best to leave that there is you're keeping the AAR.

You probably shorted your temperature sensor wire to ground somewhere. I believe that that is the test for gauge operation. Check the wire that runs to the sensor.

[robftw]

It should be tank>filter>rail>FPR IN>FPR OUT>return line>tank. The FPR is at the end of the system that you want pressurized. Fuel will flow continuously through the lines, rail, and FPR. You have what's called a dead-head system now which is not desirable, especially considering the fuel heating/poor starting discussion in your thread. The only fuel flowing through your rail with your current setup is what goes through the injectors.

The vacuum line (small one) from the throttle body is probably ported vacuum and is meant to go to the vacuum can on the distributor. The vacuum line to the FPR (another small one) should come directly from the main body of the intake manifold. The brake booster has its own large vacuum hose.

The "bypass plate", if you mean the water line that goes under the AAR, is designed to keep the AAR at engine temperature so that it doesn't reopen prematurely. Best to leave that there is you're keeping the AAR.

You probably shorted your temperature sensor wire to ground somewhere. I believe that that is the test for gauge operation. Check the wire that runs to the sensor.

I just looked it over again and again... i found a big vac leak between my AFM and TB, i guess i shifted a connector hose the wrong way when i removed the manifold. The car runs good now.

I'm going to take your advice and change the FPR around tomorrow and see how it goes.

I took a small peak around the water temp wires and couldn't find any loose connections or shorts, this was giving me problems a while back i think one of the wires is just broken inside its plastic shielding, i'll take two wires tomorrow and bridge the gap and see if i can get it to work. if so i'll just replace the connector + wires after the bullets

Also i will probably be removing the AAR when i shave the intake manifold completely. I'm just trying to keep the street driveability there for a little while longer.

[Zed Head]

There are many hoses to be concerned about on the EFI Z engines...

The AAR should only be active for about 5 minutes right after you start the engine. It has a heater inside that gets 12 volts when the engine is running, so it closes pretty quickly, if everything is working right.

It might be possible that your temperature sender is internally shorted. Did you try unplugging it to see if the gauge drops?

Made a mistake in my earlier post, I was thinking about 5thhoresman's thread. Still better off with a flow-through rail and FPR system.

especially considering the fuel heating/poor starting discussion in your thread.

.

[robftw]

There are many hoses to be concerned about on the EFI Z engines...

The AAR should only be active for about 5 minutes right after you start the engine. It has a heater inside that gets 12 volts when the engine is running, so it closes pretty quickly, if everything is working right.

It might be possible that your temperature sender is internally shorted. Did you try unplugging it to see if the gauge drops?

Made a mistake in my earlier post, I was thinking about 5thhoresman's thread. Still better off with a flow-through rail and FPR system.

When i unplug the temp sender it raises the RPM, when i apply throttle the car stalls out

[grantf]

when you unplug the "temp sender" (water temp sensor?), the ECU will get an infinite resistance reading causing way to much fuel delivery this will stall the engine. Did you get a wiff of gas?

[robftw]

No i don't smell any gas at all, it just stalls out

[Zed Head]

You unplugged the water temperature sensor that the ECU reads, the one with the same connector as a fuel injector.

The water temperature gauge sender (sender is just another word used, the FSM calls it a thermal transmitter) that connects to the temperature gauge only has one wire connected it. The FSM also says that if the temperature and oil pressure gauge act up at the same time, it might be the voltage regulator (the one internal to the oil pressure gauge). How is your oil pressure gauge doing?

[robftw]

You unplugged the water temperature sensor that the ECU reads, the one with the same connector as a fuel injector.

The water temperature gauge sender (sender is just another word used, the FSM calls it a thermal transmitter) that connects to the temperature gauge only has one wire connected it. The FSM also says that if the temperature and oil pressure gauge act up at the same time, it might be the voltage regulator (the one internal to the oil pressure gauge). How is your oil pressure gauge doing?

Oil pressure gauge works fine too, i'm thinking its just a wire short somewhere

[grantf]

sorry I did not mean to confuse the issue. I was thinking he disconnected the water temp sensor instead of the sender

ujjjjjjjjh (cat walked on keyboard)

Edited August 2, 2011 by grantf

[robftw]

This car is making me want to pull my hair out, i removed the IAC and put the fuel rail back on. Re-routed the fuel so it goes tank->filter->rail->FPR IN -> ->FPR out return (plugged one inlet)

Now i got the thermostat working again, however the car is running hot now, about 25% hotter than usual and my oil pressure is running 80lbs @ 2000 rpm, is this normal?

it also feels sluggish on acceleration again, this time with no vacuum leaks.

This has been hell week, and finally the one thing that made me extremely worried is my blow by is still there, even after adjusting the valves.. i found a trace of oil/water mix in one of the hoses leading back to the intake manifold. I'm hoping its just condensation. I'll find out more when i change the oil.

Edited August 3, 2011 by robftw

[Zed Head]

Page BE-42 has a pretty good clue (hint - already mentioned once) about the oil pressure and temperature gauges getting weird at the same time. Get a separate pressure gauge or thermometer and verify that what the dash gauge reads is true.

Does your PCV system still function? If not, have you vented the crankcase? You need one or the other, blowby gases need a place to go. Most blowby blows by the rings. Blowby is the gas from combustion and it contains moisture. Those gases need to get out of the crankcase.