SteveJ

The weekend after that is over at Jai's place near Chatsworth. I'm betting on the electrical connection. A multimeter is your bestest friend. If you're in town over Labor Day, you could bring the car over on Monday, and we can put it on the lift.

Joe, Drive down to Tim McGovern's house this Saturday. I'm already going to look at his car and maybe Pat Carr's car. We might as well make it a full day.

Even more reason for me to think that Philip is on the right track. When you start, stop, turn or change elevation, you stir up the tank.

When measuring the voltage on the ground side of the injectors, you will see 12 VDC with the key in the START or ON position until the ECU gives the command to fire. At that point, the ECU is grounded, and the circuit goes from the injector, through the dropping resistor and on to ground. When I measured voltage on a 280ZX one time, the voltage would drop to about 10VDC when the injectors were firing. If you want to "test fire" your injectors, I would ground the circuit downstream of the dropping resistors.

WIth the way it was running most of the time, I'm suspecting that it's picking up debris from the tank when it's crapping out. The next planned visit is the 29th. I guess we'll be focusing on the tank again.

My LEDs blink fast. I have some adjustable flashers on order. I'll report the results.

I have some you can modify.

Exact fit for the 1157 sockets in the Z: http://www.amazon.com/gp/product/B00K833BS2?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00 It turned and locked just like the stock socket.

Philip, I guess I can't rule that out, either. That would explain the rapid loss in pressure the first time the car died in my testing. That could also explain the problems Jai had today. I could drain the tank again. I also did put a small fuel filter in before the fuel pump. I didn't put the car up on ramps, so I didn't inspect the fuel filter yesterday. I'm trying to be methodical and focus on addressing and eliminating each issue I find. I am beginning to think some of the issues confound one another. It's also a challenge to make sure I have everything to test loaded up in the car to take over to Jai's place. I also have to admit that I'm hoping the problems found have easy solutions since Jai does not have the funds to purchase a lot of parts.

I have some in my garage. I can add that to the list for the next trip.

I ordered a 5K pot earlier today based on other threads. I'll bring a vacuum gauge, too. I'm hoping the remaining problems are electrical in nature and not clogged injectors. Of course, I didn't see much in the way of vacuum lines on the intake. I'll have to do some studying in the FSM.

Thanks, Greg. The next targeted date is August 29th. Is that good for you, Jai?

There are some older fuel lines that will eventually need to be replaced. I could use some help on my next trip, as seeing I have limited experience working on the Bosch style fuel injection. Including this car, I have worked on only 1. The fuel pressure gauge helped a lot, as did Tim's advice. However, as described by Jai, there is something happening down the line that is adversely affecting the car. With the fuel pressure leaking down, I am thinking a good FPR may be needed. The fuel pressure does seem a little low. Having an experienced opinion would probably go far in getting a more accurate diagnosis and fix. At least the car is marginally better than when I left the first time. I wish I could have seen into the tank better with the borescope when I visited the first time.

Unfortunately she did not. She was more concerned with getting the car off the road. I can't say as I blame her.

Round two for the 280Z. I filled up the back of my wife's station wagon and drove over to Jai's house. I put in the battery hold down bracket I fabricated (and my wonderful wife painted). No more twine holding the battery in place. Those are M6 wing nuts holding the two parts of the bracket together. I figure that if a wrench is needed to get it apart, make it a 10mm. Then I put fuel pressure gauge in downstream of the fuel filter. (Thanks Cliff!) There was no pressure in the line when I removed it to splice in the pressure gauge. The car started up and idled fine. The pressure was around 30 PSI. Around the time the thermostat should open, the pressure went up to around 34 to 36 PSI, and it ran rough. I checked the block temperature with an infrared thermometer, and it was around 180 to 190. After a few minutes, the engine smoothed out again, and the pressure was back to 30. It went through this cycle a couple of more times. During the last time, we tried to give the car some gas, and the engine stalled. The fuel pressure dropped rapidly. We tried to restart the car. The fuel pressure went back up, but it didn't fire. I put an inline spark checker on #2, but it looked a little weak. The fuel pressure dropped slowly after cranking, taking about a minute to drop to 0. Thanks to Jonathan Russell, we had a set of plugs, plug wires and a cap. I pulled #2 first. It was black and looked a little wet. It was a couple of minutes before I pulled the other plugs, and with the hot engine, I am thinking they might have had time to allow gas to evaporate. Number 6 is the rusty plug. I talked to a friend and all-around Mensch, Tim McGovern, who advised me on how to adjust the AFM. I first thought the spring needed more tension. I adjusted it, and didn't like the results. I adjusted the spring to have less tension, but the screw that holds the cog in place would not tighten sufficiently. I took the screw out a couple of times, trying to get it to seat, and then it happened. The rectangular piece that locks into the cog's teeth fell off...into the gravel below. I uttered the appropriate cuss words and felt about two inches tall. Jai tried to search for the proverbial needle in the haystack, but she wasn't having much luck. We pushed the car back and searched some more. I thought I'd give my hand at fabricating a replacement, so Jai produced an old colander. I used my wire cutters and snipped off one of the feet. Zing! It also disappeared into the gravel. I managed to catch the second one I snipped off. I grabbed my metric bits and drill and drilled the correct sized holes. I trimmed off the excess material, using my memory to guesstimate. At that time, Jai managed to find the original part. Luck was on our side. For grins, we compared my fabrication to the original. It was almost spot on. I do think it would have worked. I took a stab at the spring tension and got the holding screw securely in place (after scraping off the silicone around the mount). I adjusted it counter clockwise a couple of more times to lean it out enough. I would give it some gas, and there was some lean backfire. However, it kept running. It even did well on a short drive down to the paved road and back. Out of curiosity I did experiment with clamping down the return line. The pressure went up to around 60 PSI, and the engine was humming. It responded to the throttle nicely, too. One thing I did not touch was the sensor at the thermostat. It is brittle where the wires come out, and the ground wire look pretty much like toast. I am pretty sure that it's not sending the signal to the ECU that the car is up to temp, causing it to run rich. (I also unplugged the connector for the cold start valve.) Tim said he may have one. I am thinking it needs the parts linked here: http://www.rockauto.com/catalog/moreinfo.php?pk=951105&cc=1209226&jnid=428&jpid=11 and http://www.rockauto.com/catalog/moreinfo.php?pk=4673250&cc=1209226&jnid=450&jpid=1 Anyway, I sealed up the AFM with a little bit of clear RTV. The pressure seemed to be dropping VERY slowly. Jai let me know that she checked the pressure about 3 hours after I left, and it was at zero. I'm going to look back at the thread created about a week or so ago where someone was asked about pressure leak down to see what else I can check for. I did not replace the FPR at this time. The next couple of pictures were taken a few minutes apart. I am hoping to go back in a couple of weeks to replace the sensor and implement any other prudent suggestions.

Frankly, after finding that some of the less expensive LEDs were wired in reverse, I bought wedge sockets and swapped those in. That way if I had the bulb in backwards, I knew that I could get it correct by flipping it around.

Well, that 1157 socket won't work without modifications. I'll need to take some measurements to say how much. I found some 1156 sockets that went in but did not lock. http://www.amazon.com/gp/product/B00AKX8MSO?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00 Then I found this one: http://www.amazon.com/gp/product/B00K833BS2?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00 I will get those on Tuesday.

Look at the EF section in the FSM. I believe it will have a diagram of the vent hoses. It's likely that either the filler hose or a vent hose is leaking.

Ha. I already ordered a set and should get them Friday. Being 3 time zones ahead of you, I have the advantage. I shall have my results FIRST! Maybe my wife is right about cutting back on caffeine...

The ones I found in my garage don't fit, but they are different. The one in the original post looks like it will fit. I bought a couple of sets to confirm. Here are photos of the ones I have and the 240Z taillight sockets.

If there are some big rust flakes, they could get caught against the fuel pickup, blocking it. The car stalls and the fuel pump stops. The rust flakes fall off the pickup tube because the pump isn't drawing, and the car will start right back up.

About half an hour after I get disgusted from working too much.

Well, I have some of those in my garage...somewhere...The rear panel in the 240Z is off, and I have some 280Z lights taken apart in the garage... Oh, hell. I'll probably forget about this thread by the time I get home tonight.

Check for rust in your fuel tank. Install an inline fuel pressure gauge under the hood and check the pressure when it's acting normal and when it's acting up. Clamp off the return on the fuel pressure regulator and see if it maintains pressure. The symptoms sound like not enough fuel from the pick-up or pump getting clogged, though.

Send a PM to Dave Irwin, aka Zs-ondabrain.