1976 280Z Engine won't start

[Cybidium]

It's been a while.

I finished my tank so now it's like new. I installed the new tank and put some fresh gas in it. When I turned the key it still wouldn't start I just hear the engine cranking but nothing else.

I check the fuel pump and it's definitely pushing the gas the the injectors.

Any help from here would be great.

[76Datsun280z]

It's been a while.

I finished my tank so now it's like new. I installed the new tank and put some fresh gas in it. When I turned the key it still wouldn't start I just hear the engine cranking but nothing else.

I check the fuel pump and it's definitely pushing the gas the the injectors.

Any help from here would be great.

I might get a bunch of disagreements here, but hold the gas pedal down and crank the car over and see if it starts. Don't pump the pedal, just hold it and and crank it over and see what happens.

Also, check your spark plugs. Foulded up spark plugs can cause hard starting, so if that suggestion doesn't work, you may want to clean them or better yet replace them and I bet there's a pretty good chance it would go after that. Let us know what happens!

[sblake01]

I might get a bunch of disagreements here, but hold the gas pedal down and crank the car over and see if it starts. Don't pump the pedal, just hold it and and crank it over and see what happens.

I won't voice my disagreement until you explain what you think that process accomplishes on a fuel injected car.

[Jeff G 78]

Did you change the fuel filter again after the tank refresh? What about the filter (screen) in the fuel pump? If yes to both, then you might have clogged injectors. Mine were clogged shut after my car sat for several years. I sent them out to be cleaned, but they were too far gone, so I bought a new flow-matched set. If yours turn out to be clogged, you might consider going to a new billet fuel rail and O-ring injectors from a more common car. Our injectors are expensive and tough to work with due to the style of hose and mounting.

Try hitting your car with starter fluid to see if it will at least fire momentarily. If so, fuel flow is still likely your problem. Have you verified that you have good flow at the fuel rail? Remove the rubber hose that goes between the filter and steel rail and put it into a clear jar. Remove the coil wire and turn the engine over. You should get a consistant flow of nice clean fuel. If not, one of the filters is clogged, or the pump isn't primed. After I cleaned my pump screen, it took quite a while to prime the pump.

[76Datsun280z]

I won't voice my disagreement until you explain what you think that process accomplishes on a fuel injected car.

Well, I'm thinking that one of the possibilities that it's not starting (other than fouled plugs) that the car may be flooded. By pressing the gas pedal down, this will inturn send a message to the computer to shut the fuel off because the computer "thinks" that the engine is flooded while you are holding the pedal down, therefore shuts the fuel down while you hold the accelerator about half way.

And I totally admit, I am by all means no expert mechanic at this stuff, but from previous experience working on cars with with family and such, this has worked in the past.:ninja:

[Cybidium]

Ok, I got a can of starter fluid and sprayed aprox 3 seconds of it into the manafold and the car starts really roughly for about 1.5 seconds and dies. I guess this tells me it's either a plug problem or a fuel problem right ?

Next thing i'll do is check to see if i'm getting good flow after the second filter, before it enters the fuel rod.

I'll keep you updated.

[sblake01]

Sound like a fuel delivery problem. You need to hook up a pressure guage and see what the pressure is while you're cranking it and for the breif time it runs on starting fluid. If it doesn't show roughly 37-38 psi the you have a fuel delivery problem. Oh, and Austen, the Z efi system doesn't work that way. If the Z starts when you do that it's really just coincidence since vaccum which is basically non existent until the car actually starts is more important that the throttle position. At best, that would richen the fuel mixture since you'd be moving the throttle position sensor to the full throttle position.

[Cybidium]

Thanks for the tip Blake but It seems like the fuel pump is working fine and I should be getting enough PSI to at least get the car started. I unhooked the line after the filter in the engine and it’s easily pushing fuel into my container.

I’m thinking it’s an injector issue and might see if the damn things are clogged or ever opening.

[76Datsun280z]

Thanks for the info Blake on the efi, that makes sense.

Any how, do yourself a favor Cybidium and replace those plugs as that will atleaste emliminate part of this issue and should help in getting it started. Also, maybe your fuel pressure regulator might be something to look into?

[sblake01]

Thanks for the tip Blake but It seems like the fuel pump is working fine and I should be getting enough PSI to at least get the car started. I unhooked the line after the filter in the engine and it’s easily pushing fuel into my container.

I’m thinking it’s an injector issue and might see if the damn things are clogged or ever opening.

I still think you need to actually check the fuel pressure. Hook up a guage and get an actual number. The pressure could be say 15 psi and it would push fuel into a container but it wouldn't be enough to start and run the car. Been there, done that. At least check it then if I'm wrong then you can rule that out and move to the next step knowing at least that your fuel pressure is okay.

[Cybidium]

I checked the PSI and after I crank the engine a couple of times it gets to the mid 30's, takes about 5 seconds.

I was thinking about replacing all six fuel injectors but it doesn't really seem realistic for all six to fail at the same time, granted they're pretty dirty (i'll post a picture later) and might just need a good cleaning. I will check the Injector forums for tips on how to clean the injectors.

I think an important factor that I didn't metion earler is that my oil had gas in it.

[sblake01]

If you've got good fuel pressure but gas in the oil you most likely have one or more leaking fuel injectors. Are the spark plugs wet?