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HybridZ

what did I do wrong after a tune up?


zdrift

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so i thought i would do a tune up on my 76 280z and i changed the sparkplugs and coil and all of a sudden it runs like crap, what happened it ran perfect before and now i cant seem to find out what is wrong with it, so i changed the cap rotor and wires as well still runs like crap i changed the air flow meter and it runs fine for like 5 seconds and then it cuts out, i wonder if i wired the coil backwards or is it the air and fuel system and should i start replacing things??? help me please:iospalo:

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Are you sure you got the wires all back in the correct holes on the dizzy cap? Or the replacement coil is shot. You might try lighting her up at night and then looking under the hood (without bright lights around) and see if you see some electrical sparking. Very seldom does something coincidental happen. Always ask yourself what is the last thing I did and then check that thoroughly.

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First step in troubleshooting is to step backward to get it to a state where it was before you had a problem. If you can't do that, try going back as far as you can before you attempt to 'fix' anything. Check if you've got the plug wires mixed up to begin with. Get a firing order diagram and make sure everything's going where it should.

 

If you have to swap old components back onto the car to eliminate possibilities, do it. It seems counterintuitive, but in some cases, it helps.

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ok so i checked and these are the problems that i kno

 

1 runs and drives but wont go, more gas i give it the less it wants to go

 

2 i can hear all the injectors firing really loud like, i mean they sound like ticking valves i know you can set a screwdriver against them and put your ear up to the handle to see if there working...in this case you dont need to

 

3 i have two remanfactured map/air sensor meters and if i plug in one the car runs like crap but stays running untill i throttle it, and if i plug the other one in the car runs fine but then dies after 5 sec or less

 

4 i can smell the rich mixture of gas and it seems like im not getting enough spark or ones not firing, i changed everything, spark plugs, cap, rotor, wires, and coil, now if i put the coil on back wards the car still does the same thing and runs like crap, so even if i try swaping the coil wires it doesn't help

 

5 the last thing is i know the water pump is warped and havent changed it but someone said something about water and temp sensors, and i dont know if that would do it, but the car doesn't overheat.

 

i dont know if it helps at all but i hope that this is useful to finding a cure for my baby, cause i want to drive it and make it run right, thanks for all the help guys!!!

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ok so i found out that the firing order was right and the reason is something that inter links with the map sensor/ air meter i messed with it and got the car to run i dont know if its the fuel pump or the meter or the computer or what but what happens is the car will run and idle fine then it will get to much fuel and then when i run it again it will run fine for a few seconds and then it would get too much air and not enough fuel, what do you think it is guys??

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I would say hold off on the Air Flow Meter, until you're positive that it's the AFM. I was having issues with my Z at one point and I thought it was the Air Flow Meter, I had two of them and it made very little difference. When trying to diagnose the problem that knocking on the AFM's cover would cause differences in the idle. In the end it turned out the ignition module/temp sensor had gone bad.

 

How does the car run while cold vs. warm? Also as people are saying clean up the connections to your water temp sensor, or at the very least unplug and then plug them back in a few times to help remove corrosion or possibly seat the connection better.

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ya thats what every one keeps saying, do you think it might be the sensor? cause i kno the wires are fagile and i did change the fan and fan clutch so maybe i knocked it loose or part of the wire broke?? ill check that tho, and see

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If it smells rich and is misfiring, just start pulling the plug wires one at a time, if you pull one off and it doesn't change the running problems at all, you found it. Maybe you accidently cracked the porcelian on a plug, or don't have one gapped right.

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well guys im really kreeped out cause i havent driven it in a couple of days and i started messing with it this moring and when i started it it ran perfect, it smelled like it was a little rich, but it was the same smell that it origanally smelled like when i first got it, but all i did was checked all the plugs on the temostat housing, but it did die down a few times but not once did it turn off i drove it around and it seemed ok, so ill check all my connections and sparkplug gappings, but thanks for everything guys ill keep you up dated on the status and if it still has problems

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well guys im really kreeped out cause i havent driven it in a couple of days and i started messing with it this moring and when i started it it ran perfect,

Welcome to my world.

 

 

Since your problem seems to have dissapeared and you dont know why, and you've tried to eliminate everything else, check your wiring. A loose, or damaged connection can cause a problem like that to appear and then dissapear. If it comes back, check your grounds first, then check the wiring at the mass airflow sensor, and if you havent found anything, take a look at the wiring to the ECU.

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I forgot about that. On my Z I have random issues were at times the Z because almost undriveable. It would idle poorly and then giving the car throttle it would bog down, start lean popping, and want to stall. My A/F gauge wasn't bouncing around indicating that the ECU wasn't balancing the mixture out. The first time this happened, I left the car alone. The next day it ran fine. It happened again eventually on my way home, eventually it got slightly better, but once I made it home the idle started to get real bad. Finally I just grabbed the ECU wiring and shook it some. Instantly everything smoothed out and went back to normal.

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ya i found it was a loose connection on the harness and im gonna try to see if its fixable cause im not sure how far down it it, hey does anyone kno were i can find a sw20(ps30) motor cause im dying for one, actually just the head....trying to build a crazy s30 motor

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