1977 280z fuel injection problems

[projectz1]

Hey everyone. just joined the site. have been talking to freaky510 told me to join. A lot of good information here. I have a 280z givin to me by a friend. Ok project car.

Im in Sandy Or. Heres the thing. I like my car needs work. not a whole lot. Im stumped. I have a fuel injection problem. in short the injectors are not getting pulse or signal. I can use an old bosh fuel injector checker to crack the injectors open or the cold start and the engine will run with someone turning the key. seems to be the only element i am missing.

I have gone over this checked components. maybe i havnt found it yet. or maybe i have overlooked the component but im stuck and need help. If anyone is interested in coming out to my place and lending a hand or just shooting me some info. that would be awesome. I really want to get this thing on the road and get to some rally's or events. thanks.

[freaky510]

come on guys let help him out.

 

bttt

[DanielC]

Even though you are pretty sure that there is a problem with the fuel injectors not firing, first step is to check get the fuel pressure. If your fuel pressure is low, the engine may want to fire, because a cold engine automatically enriches the mixture, and it might be getting a mixture that will almost start.

 

Next step, make sure the ignition is good.

 

Most fuel injectors use a system where they are always supplied with battery power, and the computer grounds them when it wants the injector to come on.

 

Backprobe the electrical connector in the injector, to make sure is is getting battery power, and then check the other wire to make sure the computer is switching it on, and off.

[hughdogz]

I suspect DanielC hit the nail on the head. Make sure the Fuel Pump and ECU are getting power. The FP should prime for ~2 seconds with "Key ON" and stay on during cranking.

 

There is a "main relay" located above the passenger kick-panel below the dash. This supplies power to the fuel pump relay (in the box near the passenger strut tower in the engine bay). Often times the main relay has a bad ground (make sure the mount has a good tight ground to the body at the mounting screw) or is just too old and worn out. Tap it to see if it is stuck.

 

Are you getting spark when cranking? The ECU will tell the injectors and coil to fire when it senses the engine rotating. It could also be the combination switch is only giving signal to the main relay when cranking and not while "ON".

 

Hope this helps...

[projectz1]

the fuel pump is working and there is pressure at the injectors. There is also spark. if i un plug a injector clip and ground out an ijector they will spray fuel. And If I do that to the cold start injector while someone cranks the engine over. It will run. as long as i manually ground the cold start injector.

[projectz1]

ok. i got a book. called, Bosch fuel injection and engine management. I went to troubleshooting. under no start I tested. the air flow meeter. removed it and according to the book. using a multimeeter. I touched each pin with one lead and the other to a good ground. no reading at any pin. according to book no reading or out of limit reading means bad air fow meeter. so at this point im guessing thats the problem. kinda spendy though. for a new one. is there anyone out ther that has one for testing perposes? or for sale. And does the part number have to be exact. none of the parts places didnt seem to know. thanks.

[Skib]

ok. i got a book. called, Bosch fuel injection and engine management. I went to troubleshooting. under no start I tested. the air flow meeter. removed it and according to the book. using a multimeeter. I touched each pin with one lead and the other to a good ground. no reading at any pin. according to book no reading or out of limit reading means bad air fow meeter. so at this point im guessing thats the problem. kinda spendy though. for a new one. is there anyone out ther that has one for testing perposes? or for sale. And does the part number have to be exact. none of the parts places didnt seem to know. thanks.

 

 

ya the numbers should be exact, there a bit different between the years.

 

Id throw a wanted add up on hybrid Z for a 77 AFM, youl be able to find a good used one

[projectz1]

thanks, will do. thats good to know. there are tons of part numbers aparently.

[Skib]

thanks, will do. thats good to know. there are tons of part numbers aparently.

 

 

ya they had fun changing up the ECU's (and the AFM's that go with them) up just a hair sporadically on the L28e :rolleyes:

[projectz1]

If i cant find one soon im thinking about going to the event in canby. swap meet i think. Thanks again.

 

 

[Skib]

If i cant find one soon im thinking about going to the event in canby. swap meet i think. Thanks again.

 

 

Canbys a week end long show with some swap meet action goin on

[projectz1]

im looking foward to it. i only will be able to go sunday. i work saturdays. but maybe there will be something there that i will need.

[510six]

They cold soldered most of the Nissan AFM's and they are infamous for failing. Try using a soldering iron on the solder connection to the pin that is not registering a signal. This solution worked on two of my Dads 280zx's over the years.

[projectz1]

none of the pins are reading anything. is that possable?

[510six]

Check the solder connections on the AFM's board and see if any look like they have lifted. The then very carefully use an iron to melt the solder.

[projectz1]

ok, sooo...afm is good. i messed up. its actually good. so back to squar one. kinda. now its ether coroded wiring or faulty ecu.

[datzenmike]

There are only 4 ECUs for the '77 280z (if you count California) The two that you might have are:

 

A11-60000 for 4 or 5 speed. The '76 280z (manual OR auto) uses the same ECU as this one.

 

A11-601000 automatic.

 

The '78 280z uses the same two ECUs as the '77 listed above.

[projectz1]

well thats good news. at least i wont have some huge search there. thanks.

[projectz1]

ya its A11-600 000 im trying to find one now. the sticker under the hood says non catalyst car so i believe its non calif.

[Skib]

ya its A11-600 000 im trying to find one now. the sticker under the hood says non catalyst car so i believe its non calif.

 

 

might have one Ill check, Iv got a few ECU's laying around.

[projectz1]

If you do that would be awesome!

[datzenmike]

might have one Ill check, Iv got a few ECU's laying around.

 

You know I believe you skib. If all of us rats got together we could build a car with the parts.

[Skib]

You know I believe you skib. If all of us rats got together we could build a car with the parts.

 

 

:rofl: we could build a few cars hahaha

[projectz1]

that woud be sweet.

[projectz1]

i have been loking on ebay.