mowermechanic

I just bought a 280Z... g/f couldn't get over selling the '77. point is, it is an automatic, tranny fluid, coolant, oil all good. 86,000 original miles. When i tried loading it on the autotransport, it would run for 3 seconds and die. Barely got it on. When i was unloading it, it ran rough (out of time, water in gas, bad spark plugs?) but it ran for a minute untill i shut it off (running too rough, not good for engine). When i turn the key to the "on" position, I can't hear the fuel pump whine, on the '77 I could? ANYTHING HELPS!! (car sat for 2 years?)

skittle

sounds like the fuel pump is going out. other than that try a tune job, and make sure the previous owner has the spark plug wires in the right location on the dizzy. That happened to me once... lol

BoulderZ

My $0.02: definitely sounds like a fuel issue. Easy test: get a can of starter fluid. If, while running rough, you spray just a bit in to the intake and it runs smoothly, then you know you're not getting fuel. But, I'd do the stuff below, first, to avoid pulling more bad fuel and dirt up into the system from the tank.

If the car sat for two years, the gas is definitely bad. Drain the tank, change the fuel filter, and try to empty out the fuel rail, supply and return lines. Maybe even carefully blow them out with very low pressure compressed air. Fill with a good amount of quality, new fuel (at least 5 gallons, the solution to pollution is dilution!).

Keep your fingers crossed that the injectors didn't get clogged. But the fact that it's running rough in a way that sounds like it's missing makes it sound like one or more of them is clogged. So, just have it in mind that you may need be in for cleaning them. Absolute worst case is you have to drop the tank and get it cleaned out, which isn't really all that difficult, just smelly and awkward.

good luck,
Dave

mowermechanic

i stole a "good" ignition off my 80-83 280zx parts car (cap, rotor, and plug wires). I drained the tank, flushed the lines, and installed new spark plugs. New fuel filter. Now the car backfires.... "detonation". ignition timing or cam timing off? Mabe I installed plug wires wrong on the dizzy...... but i've double checked already, i'll triple check. (mebe injectors? backfiring though.... hmm)

snwbrderphat540

that can be caused by the AFM, ignition timing, the vacume advance is hooked up right? and alos yeah be sure the firing order is right. lol.

did you change the fuel filter?

mowermechanic

Changed the fuel filter. But i found a filter inbetween the gastank and the fuel pump. I should change that. I got the car running again, but it runs rough, but i'm sure of the timing now 153624 and the wires are all correct on the plugs.... autolite, it's all they had. I bought a chiltons... (they were supposed to get me haynes, and the plug wires on the dizzy in the chiltons diagram were all 1 counterclockwise, and it doesn't run when i hook it up the way the chilton book says. I"M RETURNING IT TOMMORROW. The engine runs for about 7 seconds, then peter's out.... i think the fuel pump builds up the pressure.. but when the engine is running, it can't keep up (bad fuel pump) i'm thinking. Would running too lean cause it to detonate? (running out of fuel pressure)

snwbrderphat540

if you put it under load yes. also, make your self a fuel pressure guage. its pretty simple to do.

Spraguepsycho1

Sounds like possibly a previous owner installed an extra filter between the tank and the pump, possibly due to junk in the tank messing up the original fuel pump. It could be plugged and not letting the gas gravity feed to the pump fast enough for the pump to keep up with the engine. I'd change it if for no other reason than to make sure the pump doesn't go out completely if it's not already bad.

mowermechanic

THERE MIGHT BE HOPE!!.... so i read in another forum, that the fuel pump pumps when the ign. is turned to "start" (bypassing control systems), but the only time the pump pumps when the key is "on" is if the afm is registering air flow, (engine running). So i took off the fuel hose after the fuel filter, and turned key, fuel comes out(that's why the car starts), but when i leave the key "on", and move the afm (i took the cover off) the pump doesn't turn on (car doesn't stay running), and i even tried hotwireing the afm (contacts might have been dirty) and that wasn't it either. On my '76 280z (manual) there was a (fuel pump?) wire behind the passenger seat that came disconnected every so often (car would die) but there was only two wires. On this '76 (auto) there are like 4 or 5 wires behind the passenger seat, and what looks like a huge relay inbetween it all, and 2 wires are disconnected... ...but they don't go to each other?!??! I"M SO CONUSED!! I HATE IT WHEN PEOPLE PUT THEIR HANDS INTO STUFF THEY HAVE NO EXPERIENCE ON!!

snwbrderphat540

might be the micro switch in the afm. make sure the track is making contact. sounds like either a wiring or afm problem.

mowermechanic

track? contact? there is a tab on the assm. for the flap, when it rotates from normal position, it closes the switch....

snwbrderphat540

yeah, that "flap" needs to be making contact, try gently pushing on the assmblies in the afm cover with the key on the ON position and listen for the fuel pump.

mowermechanic

the "flap" contacts. And i've even hotwired it with a few different screwdrivers.... mebe they are too big... mebe i should try a paper clip, or scrap piece of wire. And if it's not that, does the fuel pump wiring go behind the passenger seat? because there's 4 or 5 wires behind the passenger seat, a 1 x 4 x 3 relay and 2 wires are disconnected, and no they don't go to each other, imma double check the flap tho.

snwbrderphat540

you could always eliminate the AFM setup and just make your own fuel pump harness to a relay to a switch in your car. does the car even run right do you know? hard wire a battery to the fuel pump and start her. then see where your at.

mowermechanic

it has a little bit of a lope to it (not camshaft lope) but it runs smooth enough on idle untill it "peters" out. i'll try the hardwire, and if that works, that means i have to rewire my fuel pump. Thanks mayno.

snwbrderphat540

doesnt mean you HAVE to re-wire your fuel pump, but it wont hurt anything. could just be an AFM problem. but yeah, at elast try the hardwire and if it stay running, you know thats the problem for sure at least.

skittle

make sure you put in a fuse and hook it up right so you don't forget to turn it off.

mowermechanic

SHE'S ALIVE!! I got her runnin' (hotwired fuel pump with toggle and fuse). She runs rough tho. Almost like it's slightly retarded (timing) or mabe injectors. I dunno. But where does the fuel pump wiring go? Because i see it starts as a green wire with a light blue stripe, but can't find where it goes into the cabin.... I'd like to get the original wiring and related components working, because the '77 was nothing but toggle switches and hobby boxes from radio shack. I vowed to never do that to a vehicle again.

snwbrderphat540

drain the gas. put in new gas with sea foam for the injectors, run some through the manifold. change the spark plugs, cap, rotor, and wires. and yes check the timing. then you might just need to drive her pretty hard for a bit.

mowermechanic

I drained the gas, and lines, and put in regular chevron (4 gallons) and "seafoam" (1 ounce per gallon), doesn't even read above E on gas gauge.... prolly could put in some more. I will run some seafoam through the pcv valve hose into the intake manifold tomorrow. Cap and rotor are both new from NAPA.... "echlin"? Spark plugs, new, hate to say it, are autolites.... they had no NGK OR nippon denso. The plug wires i stole from an '81 280ZX and they look relatively new "7mm". Inductive timing light here I come.... .... and replace vacuum lines and rubber boot to TB would help too i assume. Where is a good place for calipers? NAPA?

mowermechanic

WHERE DO THE FUEL PUMP WIRES COME INTO THE CABIN!?!?!.... The positive is a green wire with a light blue stripe..... can't find where it goes into the cabin.... Also would rebuilding the AFM (cleaning air passage, resetting carbon strip wiper arm) make a difference whether the fuel pump turns on or not? (hard wired to fuse panel right now) Brake cleaner is coming next (to clean electrical connections. HAPPY NEW YEAR YA'LL

skittle

for calipers or anything like that use rockauto.com way cheaper than other places.

mowermechanic

Thanks.... i'll prolly go through the whole brake system.

mowermechanic

THOSE PARTS ARE SO CHEAP!! THANKS!! Still need to find all the fuel pump relays (if there is more than one) in the car, i can't find them, yes i have a wiring diagram, no it doesn't show when the wires go from outside to inside. WHY DON"T WIRING DIAGRAMS SHOW WHEN A WIRE GOES FROM OUTSIDE TO INSIDE!!(the car)

TBK1

Dont forget you have a F I relay under the dash, drivers side! Also fuseable links can cause this same problem ( the four under the plastic covers)