masterhufflpuff

Hey everybody!

I'm fairly new to the forums, been lurking, reading trying to find answers. For my most current issue I couldn't find the kind of answer i was looking for.

Quick background info on the car, i've had it for close to about a month now, it's a 1983 280zx turbo 5 speed manual. I bought the car in a sorry condition, it's a project car not a daily. Originally it ran up until just last week it wouldn't start up. The car would attempt to, but it wouldn't 'catch' which to me screamed fuel issue, only because I had redone all the spark plugs and wires, and it had driven fine after that. The previous owner did not take very good care of it, rust on the body, vacuum hoses that are barely plugged, sub-par wiring jobs, poorly mounted intercooler, the only thing that seems right is the blow-off valve. It's run off a z31 ECU as well.

Ok so onto what i looked at, I rechecked all my spark plugs to make sure there weren't any faulty ones, they're all brand new NGK BPR6ES-11, along with NGK ne-61 wires. The gaps were all fine, and they seemed to be sparking correctly by the looks of the leads.

So as I was driving to school and thinking about it, it occurred to me that it was possible that it was not getting enough fuel, initial thought was the fuel pump. I disconnected the fuel filter and had my buddy turn the key, fuel jumped out of the lower hose that goes into the filter, then i put the filter back on, but left the top hose (going to the engine) off, then had my buddy turn the key again, no fuel came out. So that lead me to think that the filter was bad, which wouldn't surprise me in the slightest seeing how the car had been taken care of before...I replaced it with a new WIX fuel filter. Had the same issue still, it would come out the lower hose when the fuel filter was off, but would not go through the filter, so that ruled out the filter.

So the fuel wasn't being shot with enough pressure to go through the filter was my next thought, only problem is I'm not too familiar with checking fuel pressure. I have a Bosch fuel pressure tester gauge, but i'm not really sure on how to hook it to the car, the FSM says to hook it to the hose after the fuel pump, and to the metal tubing going to the engine, but my gauge doesn't have an input/output, it just has an input hose, and a bleed off hose/pressure release button.

So really, what this long post is asking, is how do I check my fuel pressure with that. If it's even possible, or is there a different place to check it?

Let me know if y'all need any more details!

Thanks!
-Huff

rogerz

first explain to me how you can tell you are getting spark by looking at the exterior of the spark plug wires. I'd really like to know that trick.

go to the hardware store and buy a brass tee with barbs that fit your fuel hose. insert that in the fuel line that goes from your filter to your fuel ring. then figure out how to hook the gage up to the port on the tee that is open. but if your pump can't push gas thru the filter I think your pump is shot.

masterhufflpuff

What I mean when i say they look like they're sparking ok by the looks of the leads is the burn pattern created by the arc is natural and normal, it has the brown/white/black scorch. I did not anywhere say that i was just looking at the outside of them.

That's my thoughts as well, is there another place it could be getting clogged after the fuel pump? even thought it will still shoot out the tube?

NismoPick

Welcome to ZDriver!

I'd personally skip the fuel pressure test... if there's no fuel coming out after the filter, there's no fuel to check pressure, right?

Let's start with:
-Is the fuel pump getting 12v+ power?
-Is the pump priming for 5 seconds when you turn the key to ON?

Please post more info / pics of the car... if it's had the Z31T ecu swap done, it's probably a familiar car on the forums / FB.

masterhufflpuff

Awesome to hear from you NismoPick, from what i've seen on the forums here you're the man with the plan.

I'll check the voltage as soon as i get home today, it's highly likely it's not getting the full 12V because my battery cable clamps are absolutely gnarly, and not in the good way.

The pump is definitely priming prior to start, I can hear it well.

I was able to start the car yesterday, so I took it around the block a few times, in neutral/clutch in the car would want to idle out so i'd have to make sure to feather the gas a little, this also seems to tell me it's not getting optimal amounts of fuel.

What types of pictures would help? Most of the work the guy did on it was very amateurish so I will warn you now, it may hurt your eyes. And what other info would be of help in this situation?

Thanks!

masterhufflpuff

Alright, got under the car and tested the voltage. I tested the wires going directly into the pump because I couldn't find anything in the FSM on how to test the pump from an easy location. It looks like there's 2 wires going into it, one of them read over 12 volts, the other one didn't read. I think that's a good sign in terms of power.

Is it possibly clogged, or is it just a bad pump?

Thanks guys!

rogerz

could be clogged suction. the wire with no volts should test continuity to ground. if you ground that post you should hear the pump run. If it runs and still no flow pull the pump and check the suction hose. be prepared for a flood of gas and have some way to catch it and plug the hose. in most peoples lexicon if you say you looked at the leads it means you looked at the wire itself but sound like you are looking at the end of the plug where the electrodes are

masterhufflpuff

It's getting power, and it's pumping fuel, I'm just thinking it's not enough fuel because it will tend to want to either idle low, below 500 rpm, or just all together die.

rogerz, if it's clogged suction, is that the hose going from the gas tank to the fuel pump, or from the fuel pump to the engine? and what's going to be a good way to plug the hose?

thanks!

masterhufflpuff

Update here, I went ahead and replaced both the battery, and the cables because the battery had to be charged almost daily, and I figured since the cables were in such bad shape (they were the cheap kind), I might as well replace them too otherwise i'd most likely be ruining the new battery.

I have not had any trouble since the new battery and it's been a couple of days. Is it a possibility that the old battery was giving out weird amounts of power? Where one minute it's putting out normal, then the next it's low? Especially with the bad cables on top of a bad battery...

Anyway thanks for the help everyone!
-Huff

William Wyrick

Did you change the filter in the tank or clean it? i just run in to that trouble.