Sorry to be Redundent - Help

[Zed Head]

As Eurodat said, you'll rarely see the 36 psi unless you open the throttle wide.

The simplest check is to follow the FPR vacuum hose to where it attaches to the intake manifold and remove it from the vacuum nipple. Temporarily plug the hole in the manifold to avoid a high idle and start the engine. Then you should see 36-38 psi on the gauge.

25 psi at idle is very low, even with very good intake vacuum (implies 22 inches of vacuum) so you might have something weird going on. When you remove the vacuum hose check it for gasoline. If it smells like fuel or has liquid inside, that's a problem.

[bhermes]

Sorry to be ignorant but I am a little confused on which vacuum hose to remove to check the 36psi fuel pressure.

This thing is getting frustrating but having fun learning. The car seems to be really good in the driveway.

Thanks.

[Zed Head]

follow the FPR vacuum hose to where it attaches to the intake manifold and remove it from the vacuum nipple.

There's only one b. Look underneath the FPR.

[EuroDat]

There is a photo in the second post in this thread http://www.classiczcars.com/forums/fuel-injection-s30/18449-280z-fuel-pressure-regulator.html showing the FPR with the vacuum hose attached in the centre of the photo.

Chas

[bhermes]

Finally got back on the z today. I removed the FPR vacuum hose (just a side note my hose was only a few inches long) and the fuel pressure increased from 25-26 psi to around 36 psi. I am assuming that this is good.

I have the resistor pot soldered and hope to be installing soon.

I am considering moving somewhere warm. Getting sick of cold days. Any suggestions? Also, needing to find a z expert in the area just until I get a little more knowledgable.

Not sure what else to check at this time.

Thanks.

[siteunseen]

From "The Ballad of Jed Clampett"

....kinfolk said "Jed move away from there"

Said "Californy is the place you ought to be"....

[FastWoman]

Your fuel pressure is just where it should be. Your FPR seems to work fine. The $20 question is whether your fuel pump can maintain a healthy pressure and flow when it heats up.

That's how mine failed. Fuel pressure was fine when I started it, but after I took off down the road, the pressure and flow began to fade until the engine died. Then when the fuel pump cooled down, I could fire the engine up again, and after 10-15 min, the engine would die again.

[bhermes]

I know a drive is in my future. Just not looking forward to breaking down in zero degree weather. I will take a blanket. I am trying to install the resistant pot today or tomorrow.

FastWoman, I don't recall, did you end up replacing the fuel pump and fixing the problem?

Thanks.

[FastWoman]

Yes. I had two fuel pump problems. The first was a crusty/melty connector problem. I replaced the connector. Then my pump faded away, so I replaced it with a new, OEM pump (expensive, but worth it). In hindsight, the fading fuel pump problem might have aggravated the melty connector problem (excessive current draw). However, with both issues fixed, I have plenty of fuel now, and my engine runs great.

Edited January 20, 2014 by FastWoman

[bhermes]

I am going to try and install the resistant pot today but still having problems understanding exactly how to install. The schematic in the earlier attachment shows it going inline with one side of the temp sensor to the ECU. In other words; temp sensor to pot to ECU back from ECU to temp sensor. Does this make sense?

Thanks.

[FastWoman]

As I recall, it's ECU pin 13 to CTS to ground. The pot would be inserted between the ECU's pin 13 and the CTS. That said, don't ASSUME your fuel supply is good just because it checks out at 36psi in the driveway. If you find yourself in a barely-running, limp-home situation, it's not a CTS resistance issue. It's most likely fuel supply.

[siteunseen]

The pot goes inline where the bullet connectors are about 8" from the thermostat housing back towards the windshield. If you make it just like the picture with the male end off the shorted ends on the right and the female off the left side pin it'll only work 1 way. http://atlanticz.ca/zclub/techtips/tempsensorpot/index.html Think of putting 3 hose pipes together, the pot is the middle hose pipe. I hope I'm helping and not confusing you.

Cliff

I think Fastwoman has hers under the dash in the wiring harness to the ECU. I'm talking about plugging it in between the coolant sensor wire from the thermostat where the bullet connectors are.

Edited January 20, 2014 by siteunseen