Gas Tank?

[eightytwoturbo]

Every few days my car wants to run like pure crap, then it will all of the sudden clear up then pure crap again after the next day or 2, could this be something in my gas tank or old fuel lines?

[gjc5500]

Id try fuel lines, filter, and debris screen for a start.

[Pop N Wood]

Yes, it could be those things.

 

It could also be a few dozen other things.

 

Like electrical faults, failing ignition module, vacuum leaks, fouled plugs, water getting somewhere it shouldn't.

[eightytwoturbo]

Ive done all of the above, even cleaned all electrical with electric cleaner and let it all dry out good. No difference what so ever im really getting fed up with this honestly, my car will not go any faster than a go cart when its running in these situations, and only will boost to 2psi.

 

Seems as if a gas problem though, because it accelerates faster when im light on the throttle but when I'm WOT it wont move, I also get intake pop every now and then, this is my daily driver and its driving me nuts ! Any more input would be great ... thanks

[sweetleaf]

Put a fuel pressure gauge on it.. Then you'll know ( :

[eightytwoturbo]

Put a fuel pressure gauge on it.. Then you'll know ( :

 

know what? faulty pump?

[eightytwoturbo]

Also wanted to add that my car idles at 1000 rpms, this is a bit high eh? Has a sputter in the idle too.

[COZY Z COLE]

If you have a FSM go to the EFI troubleshooting part and follow the steps. If you don't it would be wise to obtain one and use it.

 

 

LARRY

[eightytwoturbo]

Wow I have done almost everything for the EFI, all my injectors are firing, I have dropped my gas tank and had it professionally cleaned.. And its running even worse today im seriously just pissed off, I do not know what else to do except for trying new fuel pump or new injectors.

 

Its running like a 2 horsepower go cart, takes about 30 minutes to get to 60mph on the way home. I know this has something to do with fuel for sure, it seems to pick up acceleration when you let off the gas like its getting not enough or too much fuel. Could this even be my AFM??? But since it only happens every few days then I didnt think so???

 

SO if anyone thinks they know, I am willing to try anything at this point, because I am fed up and want to give up and maybe sell it... this problem has been off and on for about 2 months and no one knows!

[icewtr]

Ya know my 84 300zx did this same thing and it turned out to be the throttle position censor...

[MatMan]

Not a Z, but my 76 BMW 3.0 CSi every once in a while felt like it was dragging an anchor. It turned out to be a sticky mass air sensor gate. I had to open up the thing, clean it out good, and lube the hell out of it because I don't have the $240 for a "possibly" good used one.

[MY77Z]

sorry to hear that, had the same problem back when i had the L28, changed everything but nothing changed the crappy way she ran, i took it to a Z wiring wizard here in kuwait, he told me nothing is wrong with the car, its a wiring problem, next day, she ran like a new car.

[eightytwoturbo]

Heh no one knows, even a mechanic that came over to look at it/and drive it. Really odd, this is my luck though with cars, I dunno about my TPS ive replaced it once with a junkyard TPS off a N/A, would this make a difference?

[DCZ]

Heh no one knows, even a mechanic that came over to look at it/and drive it. Really odd, this is my luck though with cars, I dunno about my TPS ive replaced it once with a junkyard TPS off a N/A, would this make a difference?

 

N/A and turbo have different TPS so this could be the problem, or at least part of the problem. If you read the FSM you will see that those parts do not function the same.

[Daeron]

Please do not go stabbing in the dark. These cars are designed logically. The computer needs functioning input from ALL sensors, and it needs all of its "output" devices operating properly too.. "doing almost everything for the FI" means that you have wiggled all connectors. go to http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm, download the "EFI Bible," get yourself a multimeter, and check each component under the hood.

 

It really will not take as much time as you have already spent trying to figure this out, and you only have two possible outcomes:

 

1. You find your problem, and fix it, in fairly short order.

 

2. You are actually stumped, and have a fair reason to be asking for help.

 

Service manuals are the technicians second best friend. His BEST friend is years and years of experience with this particular system, but we do not all have that. (I don't, and I am assuming you don't) So, in other words, until you read the book, and do everything by the book, you don't really have much of a right to say "I've done everything and I am stumped!"

 

I am TRYING not to come off like an ass here, but the fact is pretty simple. Until you read the book, you do not know how to test each component.

 

I just re read and noticed that your 280 is a turbo; You might want to find a factory service manual instead. Try http://www.carfiche.com. In any case, you cannot treat this like an issue that will go away by throwing junkyard parts at it under an assumption that you have a fuel supply problem. Every fuel supply problem I have had in my 280 was caused by a malfunctioning sensor or a bad wire, causing the computer to get the wrong input, and the computer PURPOSEFULLY was feeding the engine too much or too little fuel. Well, one time my fuel pump died on me, but I had that diagnosed within 2 minutes.

[nbesheer]

Does teh EFI bible pertain to 1983 280ZX FI systems as well ?

[eightytwoturbo]

Please do not go stabbing in the dark. These cars are designed logically. The computer needs functioning input from ALL sensors, and it needs all of its "output" devices operating properly too.. "doing almost everything for the FI" means that you have wiggled all connectors. go to http://www.atlanticz.ca/zclub/techtips/EFI&fuel.htm, download the "EFI Bible," get yourself a multimeter, and check each component under the hood.

 

It really will not take as much time as you have already spent trying to figure this out, and you only have two possible outcomes:

 

1. You find your problem, and fix it, in fairly short order.

 

2. You are actually stumped, and have a fair reason to be asking for help.

 

Service manuals are the technicians second best friend. His BEST friend is years and years of experience with this particular system, but we do not all have that. (I don't, and I am assuming you don't) So, in other words, until you read the book, and do everything by the book, you don't really have much of a right to say "I've done everything and I am stumped!"

 

I am TRYING not to come off like an ass here, but the fact is pretty simple. Until you read the book, you do not know how to test each component.

 

I just re read and noticed that your 280 is a turbo; You might want to find a factory service manual instead. Try www.carfiche.com. In any case, you cannot treat this like an issue that will go away by throwing junkyard parts at it under an assumption that you have a fuel supply problem. Every fuel supply problem I have had in my 280 was caused by a malfunctioning sensor or a bad wire, causing the computer to get the wrong input, and the computer PURPOSEFULLY was feeding the engine too much or too little fuel. Well, one time my fuel pump died on me, but I had that diagnosed within 2 minutes.

 

 

Uhm, Ive read it through, and not to be a ass but you have said with 10 other people have told me. "Read the EFI Bible" Yeah well it hasnt helped me, ive checked almost everything possible electrical with a multimeter. Im not trying to be a douche but I have quite a lot of time on my hands after work its all Ive done is READ and ive gotten no where from checking things in the "EFI Bible". I have NOT thrown junkyard parts on my car, but my TPS became corroded so I replaced the plug with a N/A TPS not knowing this till later down the road, so thats why I was nicely asking if this could be a problem... ?

 

This is my daily driver so its very frustrating asking for a ride everyday when your car runs like pure crap, sorry if I came off as ignorant but im just getting stressed! I will try to get a service manual, my haynes seems to really do me no good.

[Pop N Wood]

Sometimes you just have to bite the bullet and take it into a shop. Especially if you need it for work.

 

This type of thing is difficult to troubleshoot over the web so it is not like I am not being helpful.

[Daeron]

Hey man, no offense taken. I just hate to see people proceed in a manner that isnt careful and methodical.. because I have done it FAR too many times myself, and missed the simple stuff.

 

It is hard to tell from a thread whether you are going at it methodically or not sometimes, and I just wanted to be sure you arent beating your head into a wall needlessly... thats all. I wouldn't have posted if I weren't trying to help you.. and sometimes, it takes a little douche-baggery to get the message of "read your manual" across. I apologize, since apparently this was NOT one of those cases.

 

Do you have a factory service manual relevant to your year? Honestly, I was halfway through typing my post when I remembered your screen name, and realized we were talking about a turbo ZX here.. BUT instead of altering my "douch-baggery" I just appended the comment at the end, and the reference to carfiche. Seriously though, in my experience if you have gone through all of the manufacturer's tests of all the electronic components, and they all pass muster (and I mean ALL) then the problem is usually caused by one of those "how could I be so stupid" things like bad plug wires, clogged fuel filter, etc... SO in conclusion if you HAVE tested every component out to spec, maybe it is time to step back and re analyze the basic things that you have been presuming were "good" this whole time.

 

Again, my apologies. The entire post WAS conditional on "if you haven't read the book," because I couldn't tell from your posts whether or not you had.

 

Good luck.

[eightytwoturbo]

OK *UPDATE*

 

I went to a local shop that deals with Nissan and other import's for like 35 years. My timing was off and said I needed a new distributor cap and rotor.

 

OK so I get that replaced nothing changed, and the guy had no clue what else it could be, but when I arrived at the shop he said he tried pinching off the fuel line at the fuel pressure regulator and it ran like a champ. So he said I needed a new fuel pressure regulator.

 

OK so I get that replaced nothing changed, at this point I'm already furious because I waited a week just for the regulator and this is my daily driver.

I took the car home just because I was spending too much money on just trying pointless things.

 

My friend that owns a turbo 260Z came over to help me try to find out whats going on, after about a hour he decided it was my fuel pump not putting out enough pressure because you can run it without the regulator pinched off and it runs A lot better but not perfect.

 

But the fuel pressure was checked 2 times before and was slightly low but good. Once at this shop and once by myself personally.

 

OK so I get the fuel pump replaced today along with a new fuel rail and guess what? Nothing changed.... WTF COULD THIS BE? Relay or injector is about the only thing left, ive dumped over $900 just trying to fix a fuel problem. ANY ADVICE would be HELP please!