Car is down again

[Cornbreadxd]

ok, I just ran into another problem I used the fuel pressure gauge and it read about 32psi then to 35/36psi when cranked but still wouldn't start. I unplugged the various conectors and checked to see if they were damaged at all. when I plugged the harness in the altenator back in however the fuel pump wouldn't cut on, the gauge rose but I didn't hear it run nor did I see fuel move in my g3 filter.

When I unplugged the harness and turned the key I heard the fuel pump cycle and saw movement in the filter. is this supposed to be able to happen or is there an electrical problem that is keeping the car from running? I originally suspected something electrical because I think water got into the engine bay when snow melted on it while it was slanted open.

[Cornbreadxd]

[sorry I couldn't edit my post and the email was temp. unavailable]

I also noticed that the wire for spark plug #2 look bent and corroded, cause this be related to my starting issue?

[Rockr69]

upon further review of your video, I noticed one of your fusible links is gone. I'm no expert and maybe Sblake has more knowledge in this area, but I know before I updated mine if those were not just right the car would not run. You might PM Sblake and seeif he can suggest anything about that. Dan

Nevermind I looked again and indeed it is there. As for the water issue I powerwash mine all the time and I just have to pull off the TPS connector and blow out the harness and the sensor itself and no probs ever. I would say rusty plug wires are good place to start. Does your pump cycle every time you turn on the key? I believe, though again I'm probably wrong, it's supposed to do that. Pressurize and stop until the either the power is lost or the pressure drops. Also if your getting 36psi fuel pressure while cranking the engine, your ignition system, somewhere in it, is probably faulty.

Again, Sblake is very knowledgeable about these cars especially the 78's, cuz that's what year he owns. Listen to what he has to say.

[Cornbreadxd]

yeah it cycles everytime the key is turned but now it only does it with the harness out of the alternator, and i checked the guage again while trying to crank and it read lower this time 32psi, i don't know what the P/O did but the car is acting crazy now and I notice alot of stuff around the engine is butt spliced and taped together instead of solder and heatshrink (which I use for audio installs) and there are a few ground wires that are just hanging free, but I don't know if that had any affect on my problem because it ran well before.

[JimmyZ]

I own a 240 and know very little about Bosch injection but I'll take a swing.

First try spraying some starting fluid to see if it will run. Have someone crank while you spray since the path from the AFM is long. This will help you figure out whether it's ignition or fuel quickly. Use minimal amounts of starting fluid as it can cause a fire or backfire and cause a fire. I've been synged once by the stuff. Just go easy with it!

If starting fluid doesn't get it to run the there's an ignition problem. When you say you cleaned the plugs this should mean bead or sandblasted them? Simply sanding the faces doesn't count. Wire brushing them leaves metal tracks/conduction paths = no good. If you can't "properly" clean them then purchase at least three new plugs install and crank. I recently helped a 280Z owner whose plugs were fouled due to EFI probs. His new plugs had seen a few hours service and were fouled to the point that they wouldn't work. (Covered in black soot from rich mixture) He could not properly clean them but thought he had. :)The car wouldn't start until he replaced the plugs. Does the 280Z rotor have a resistor built in? If so I'd replace the rotor. Newer cars have resistors in the rotor for noise suppression. When the resistor goes bad they stop carrying the spark but will still pass a continuity check. (Go figure!) A bad pickup in the dizzy is also a possibility. I'm told that there are extra precautions to take when doing spark testing on 280's. (To avoid damaging electronics)

Check for vacuum leaks next. You're looking for a big one of course. It could be as simple as that.

Once you've completely ruled out the ignition aspect then I'd look at the fuel system. An excellent book is How to Tune and Modify Bosch Fuel injection by Ben Watson. It explains the system in very simple terms and has excellent fault diagnosis content.

Jim

[Cornbreadxd]

ok, so anyone have any ideas on why the fuel pump will only run when the harness is removed from the alternator? I read the thread started by shadesh but it doesn't really relate to this issue

[Cornbreadxd]

update-

The autoparts stores around me are pretty worthless so i had to order parts online and wait for them to come, i did get new sparkplug wires and am waiting for new plugs but i tried to start the car after i replaced the plug wires and it actually turned but it sputtered and I had to keep giving it gas to keep it from cutting off. I read the thread by johnnyddn but that didn't help much.

It sounded VERY ROUGH and I did see grayish (i think hard to tell in the mirror) smoke coming out of the tail that smelled pretty much like oil, when I tried to see if it would idle it didn't and it cut off on me and wouldn't start again. I checked the plugs and they look oily now. So does this rule out a fuel problem or ignition or what? Riding the bus to school is getting annoying.

[eddieeats]

I just bought a 77 280z and have been going through similar problems. I've found that if the fuel pressure is not correct the car won't run properly. I'm almost there and need to replace the fuel pump check valve. It's not holding the pressure needed and a new check valve should do it. Nissan can't get you one but Bosch has one part # 1583386011. Checker auto or most Bosch suppliers can get you one. I'm hoping when I get my new check valve on Wednesday all my problems will be solved. This part is less then $30.00 and could solve the problem. I hope this is your solve as well.

[JimmyZ]

If you smell the plugs and they smell like gas then something is wildly wrong with your fuel system.(Running rich) Normally a fuel fouled plug or it's neighbors will have fluffy black soot deposits before failing.

Oil fouling feels and smell like oil. Might be severe leakage from cracked rings??

Regardless if a plug gets fouled and the engine is allowed to run it will get wet with unburnt fuel.

Try using a new plug for a minute then remove it and see if it's powdery/fluffy (rich fuel) or slick (oil fouling).

2c

[Cornbreadxd]

Well, i received my plugs today in the mail and put them in but the car wouldn't hold an idle at all. They felt oily and didn't smell like gas though. I was able to record a video though. I was only able to keep it going by giving it gas and it wouldn't go above 2300rpm. I didn't replace the gas and its been in the tank for 2 weeks could it be old gas or is there a different problem here?

[Cornbreadxd]

update-

Ok I got it to run and drove it around the neighborhood, the elbow going to my intake was ripped open on the underside so I that it why the car wouldn't idle I guess, i'll be ordering a new one on ebay unless anyone knows the part # via Nissan.Its from the air filter pipe to the afm kinda like this.

I used tape for a temporary fix and it is now able to drive, thanks for everyones help.

Once the semester is over I will drop the gas tank and have it cleaned/rust proofed so everything will be ready.

[sblake01]

I don't know what that picture is. Are you talking about the rubber boot between the AFM and the throttle body? 16578-N4710 is the part number for a 78. Make sure you don't confuse it with the boot that goes between the throttle body and the air cleaner.