Popped in a new fuel pump and now wont start

[Mobious9]

(this may take a while)

I bought my 83 280zx na 2+2 about a month ago. It ran fine, i drove it daily. It has about 208 thousand miles on it and was "re-built" at 150. the guy i bought it from just had it sittin in his yard. 500 bucks, couldnt complain

 

So i notice a small fuel leak coming from one of the hoses on the fuel pump underneith , i ended up replacing the whole thing.

 

To make a long story short,(whick is still long) the car used to idle down to REALLY low rmps when in drive sitting at a light. This would also happen sometimes when she was running for about 15-20 minutes in the drive way in park.

 

The car would idle down, and when i went to give it some gas, it would sputter really hard then come to. but this would happen often, over and over.

 

If the car was sitting still running or at a light, and i went to give it gas the car might, well eventually, sputter and then shut completely off after a coupl times.

So you see y i may have thought it was the fuel pump.

 

Well it kept doing that, so the next couple of things i fixed were the:fuel pressure regulator, Fuel fillter, distrubitor cap and button, msd blaster 2 coil, 8.5mm cables, ngk plugs,EGR, air fillter(tune up)basicly

 

The sad and confusing then is, after all this is done, i go to start it up, it starts right up and runs better than ever. i take her around the block, acceleration is good so i take it up to high rpms, everythings good. but when returning to low rpms then stopping at a light she starts to drag again. luckly i was around the corrner because it sputtered and dragged right into my driveway.

I turn it off then on to let it run, it sounded almost lik the fireing order was off by lik one or two,but it wasnt because i checked lik 6 times. then it finally shuts off. and i havent been able to crank her sence, about a week.

i dont think its the starter because the crank and belts are moving...

 

So basicly before i fork out the money to have it towed and then looked at by a machanic that may have never touched one of these before, i was wondering if one of you guys, who no damn near everthing about these cars could help out. i didnt want to post this anywhere where it would become an eyesore but i had to get the word out

 

please help someone thanks

[nismopick]

Reasons an engine won't start:

 

#1... Improper amount of fuel (either not enough or too much).

 

#2... No spark.

 

#3... No air.

 

Do you still have spark? Do you have fuel pressure?

[nbesheer]

just curious what pump did you put into it ? My pump just died (the impeller started grinding) so I pulled a couple from the junk yard till I got one that worked lol. but yeah it sounds just like when mine died. might try another pump

[Z-8]

Are you getting vapor lock? If the fuel lines are heating up, causing vapor lock, that might give you the symptoms you have now.

[Mobious9]

Well, im pretty sure im getting spark, i did that test where you take the lead plug, try to start the car while placing the plug agenist the valve cover. You can see a purple-bluish spark gap between the two, i dont no if that means it was running rich or not.

As far as the pressure, i havent checked that out yet. But when i turnning the pump on and off a couple of times you can smell fuel in the front where the engine is. I guess because i may have flooded it, i dont know.

 

What i do know is, i got the replacement fuel pump made by Master from autozone, they said it was rated up to 90psi. The old one i had still works, its just i thought the car wasnt getting enough fuel causeing it to sputter and shut off.

 

This only happened when the car got hot, like in the afternoon. It hardly never happened in the morning where the temp outside was around 50-60.

 

Now the funny things is, i thought it was vapor lock too, even though i dont no what the symptoms are, i heard that 280's were good for getting vapor lock in the injectors. I guess thats why they designed that fan on the engine over the intake.

But while im talking about the fan, one time i shut the car off and the fan kept going for about 30mins. that was the first and last time that has ever happened. i dont no if thats what its supposed to do or not, i have no clue.

The car usely gives me trouble when its hot.

but i still dont no why, if it was vapor lock, the car refuses to start?

 

What tha hell is going on!

[Thumper]

Sounds like an injector problem. Check that all six are firing when cranking. Get someone to turn over the motor will you listen to the injector with a stethoscope (or long screwdriver) and see if they fire. If they don't then check the connections and then do a leak down test. Also you might want to pull the fuel rail and watch the injectors fire to make sure you have a spray pattern. You might want to check spark just to make sure as well though. Pull the spark plugs see if wet (rich, black) dry (lean, white). Good Luck

[Mobious9]

Sounds like an injector problem. Check that all six are firing when cranking. Get someone to turn over the motor will you listen to the injector with a stethoscope (or long screwdriver) and see if they fire. If they don't then check the connections and then do a leak down test. Also you might want to pull the fuel rail and watch the injectors fire to make sure you have a spray pattern. You might want to check spark just to make sure as well though. Pull the spark plugs see if wet (rich, black) dry (lean, white). Good Luck

 

OK thanks, but what am i supposed to listen for, nothing? or what do they sound like when their fireing properly.

What is the leak down test?

I pulled each plug about the week after i popped them in to check the gap and i found that they were sult black, so what dose that mean?

i guess and injector problem is better then not knowing, i hope replacing them isnt to hard so i can avoid the machanic ya'no.

[Thumper]

OK thanks, but what am i supposed to listen for, nothing? or what do they sound like when their fireing properly.

What is the leak down test?

I pulled each plug about the week after i popped them in to check the gap and i found that they were sult black, so what dose that mean?

i guess and injector problem is better then not knowing, i hope replacing them isnt to hard so i can avoid the machanic ya'no.

 

Sounds like you don't have a book on your z. It has what a leak down test is. In order to properly work on your z you need a manual. The injectors will click like a relay about 3 times a second.

[darbbackwords]

I have said very little on here, but as Thumper said "Pull the spark plugs see if wet (rich, black)" then you said "I pulled each plug about the week after i popped them in to check the gap and i found that they were sult black, so what dose that mean?" from my understanding to make your plugs that black in one week means you are running very rich.. a book is a cheap but big help.

[SilentNight1647]

Clear fuel filters are your friend when you need to know if you've got fuel. It sounds to me like you've got a junk pump if it's not even trying to light.

[Mobious9]

Guess i got to get ah book. you guys are right the book should help, i guess wish i could get my hands on the shop manual cant find those anywhere.