Jump to content
HybridZ

Hello and Please Help with my 280Z


Recommended Posts

Alright! Used a voltmeter and it shows the following when connected to the battery terminals:

 

Car off: 12.8 volts

Car at idle: 12.8 volts

Car under load: 14.8 volts (sometimes getting up to 14.9)

 

"Car under load" is the lights on, fan on high, and engine revving up to between 2000-3000 RPMs. As I release the gas pedal and the RPMs drop, the volt meter's reading drops. So, it looks to me like the alternator is doing it job.

Link to comment
Share on other sites

Alright! Used a voltmeter and it shows the following when connected to the battery terminals:

 

Car off: 12.8 volts

Car at idle: 12.8 volts

Car under load: 14.8 volts (sometimes getting up to 14.9)

 

"Car under load" is the lights on, fan on high, and engine revving up to between 2000-3000 RPMs. As I release the gas pedal and the RPMs drop, the volt meter's reading drops. So, it looks to me like the alternator is doing it job.

 

I agree, your alternator appears to be good.  But some auto parts stores do not know how to correctly test them either.  Before I learned much about auto electrics, I took an alternator in for testing, and it tested good.  But that was only because they did not load it, as soon as a load was presented to the alternator, the voltage collapsed.  It was due to worn brushes, not a bad internal regulator.

Link to comment
Share on other sites

Concerning the car stalling out issue:

The issue to me (and I don't know anything, really) does not seem to be temperature related (i.e. the car running too hot, vapor in the gas line, etc.). Not any more. I've run the car for an half hour, in city and on the highway, and had no issues ... and on a hot day (near 90 degrees outside). Then there are the times that the car is running for only a few minutes and she starts to stutter and stall.

 

If the car is running for a while (30 minutes, etc.) and then stutters and stalls, I only need to let it sit for about 5 minutes or less, and the car starts right back up again (in most cases). The way the car stutters, it is acting more like rust or other junk is clogging the filter from time to time.

Link to comment
Share on other sites

Alright! Back onto the electrical issue with limited time this week.

 

I took the back panel off (the plastic cover you need to remove to gain access to the back lights and all the wires there). I checked all the wires, the ground, the connectors and bulbs. Everything looks good. So, now it's on to other things.

 

As a reminder, the following is NOT working on the dash:

 

- Turn signals and hazards (neither are they working externally on the car)

- The oil pressure gauge

- The volt meter

- The clock (though I don't think that was working before the dash lights went out)

 

The following is what is working on the dash:

 

- The speedometer (of course)

- The tachometer

- The temp gauge

- The fuel gauge (though the float in the tank gets stuck at 1/3 tank even on full)

 

Other things work like:

 

- The fan for the vent

- The center dash light (the one you flip down to turn on)

- The fasten seat belt light and buzzer

- The bright, red brake light at the bottom of the speedometer (in fact, for some reason this is on continuously)

 

I don't know if any of this information helps to pinpoint what could be the issue, but I thought I would post what I know so far. Again, I am learning about electrical, so any help would be appreciated.

Link to comment
Share on other sites

Okay! As I am learning all of this, I went out and purchased a circuit checker (one of the ones that both lights up and beeps) and decided to do a test. I removed the covers to my fusible links, removed one of the links, turned the key to "ON" and used the circuit checker on it, connecting the one end to one 'peg' and touching the other. As expected, the light came on and it beeped. So far, so good. However, when I did the same to the second link, I got nothing.

 

Here is a photo to show you precisely which link (it is the red circled one):

 

fl_01.jpg

 

I know the set on the right has a ground (the big black link), but does the back one on the left also serve as a ground of some kind? Or should it also produce a light/beep on my checker?

Link to comment
Share on other sites

Found out that line apparently connects to the headlights and no current is going through it, even if the key is turned on, unless the headlights are turned on. ;)

 

On a side note, the car was still stuttering from time to time and it was not heat related. So, I installed a fuel filter between the tank and the fuel pump. I drove the Z hard today and had no issues, either on the highway or in the city. The filter seems to be helping.

Link to comment
Share on other sites

Some small progress on the electrical side of things.

 

A rechecked the fuses and two of them were no good. One was for the hazard. Now my hazards work (both on the dash and outside on the car) as do all of my gauges on the dash (voltage, etc.). However, the actual dash lights do not work nor do the turn signals (neither on the dash nor outside on the car). So, the only non-working things are all my dash lights and my turn signals (internally and externally). All other dash components appear to be working properly.

Link to comment
Share on other sites

  • 2 weeks later...

Good news! Internal and external turn signals are working! Bad news is I am not sure why, actually. After having the front end aligned, and the steering wheel adjusted (it was a custom wheel the previous owner had installed and was all crooked), the turn signals just started working again. The mechanic who had worked on the car previously (the one that did all the engine work) had also done something in that area because the horn had not been working. I am wondering if something, like a connector, had been lose (and maybe still is) and when they adjusted the steering wheel it knocked it back into place?

Dash lights still are not working, but I have not had sufficient time to work through the harnesses, etc.

Link to comment
Share on other sites

Well, I think we know what the stuttering/stalling issue is with the engine:

fuelfilter_01.jpg

 

fuelfilter_02.jpg

 

I replaced the inline fuel filter (between the tank and fuel pump) after only running about a half tank of gas. I definitely need to clean out the tank.

Link to comment
Share on other sites

Okay! Here is what I've noticed the past few times I've run the car. I don't know if this helps at all, but I thought I would add it into the mix.

 

When I first put on the inline filter, I had filled up the tank to full. The car ran great for about an hour (on the highway and off). Then, as gas was used over time, I started to run into more and more trouble with the engine starting to run rough ... not continuously, but periodically. The more gas I used, the more I hit these stuttering and stammering spots (including a few times when I stalled out). Since my gas gauge is not working, I am using the tripometer to estimate how much gas is being used. In each case, the troubles start to increase after about 70 miles of gas use. When I get up to 95 or more miles, the car starts to have frequent stutters, especially under load (i.e. on the highway going over 50 MPH). Now, just to be clear, these miles aren't all put on the car at once. I am not driving 100 miles at one time, the car doing great for the first 70 and then slowly degrading as I drive. I am driving a few miles here and there (going to the store, going to pick up a part, going to visit a friend, or just going to take the car out on the highway).

 

Judging by the fill-ups and how much gas I had to put in compared to the tripometer, I am averaging about 15 MPG. So, after using about 5 gallons of gas (from a full tank), I start to get stutters periodically. After using about 6-7 gallons, the stuttering becomes a lot more frequent, making it hard to take the car anywhere.

 

Does this provide any useful information?

 

Yes, I am planning to get a gauge to measure fuel pressure. I just am waiting for my next paycheck to do so. Then I should be able to provide some additional information.

Link to comment
Share on other sites

Easy. 

 

Two things

 

Broken/holey gas pickup or worn out fuel pump. 

 

If your pickup is broken/rusty/holey as is likely due to how much rust seems to be inside your tank, then once you expose the hole in your tank (probably about when 5 gallons is used) you start getting a fuel delivery problem like sucking through a straw with a hole in the middle.

 

Alternatively your fuel pump might be tired/worn/clogged/not getting enough voltage. Once the gas pickup level starts to dip and the pump has to actively pull up on the pickup tube then the pressure can drop.

 

Alternatively it could be a cracked/loose fuel line that without the additional pressure from the full tank is leaking more, but that seems unlikely.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...