1990 240sx poor idle and it died

[240ight]

Ok! I need some advise on what to start looking for. My 90 nissan 240 died on me on my way to work last week. I towed it back to my house tried jumping it and nothing. Took the battery to Autozone and it tested bad, so I took the alternator out and that tested bad too so I bought them both. After replacing them I tried starting the car and it did right away . After a few minutes like 2-3 it started idling low and rough and died. So I tried starting it again and nothing but the motor does turn over it just wouldn't start. I tried again later on and started again but only for a few minutes. when on, I tried reving it and it backfired really loud . I check the spark plugs and replaced them and new wires too. could it be the fuel filter? what about the back firing? a sensor? Please help. where should I start? thanks in advance for any suggestions.

[boriquaS13]

Sounds like you have fuel delivery issue you need to check fuel pressure and make sure its ok.

[240ight]

How do I go about checking that?

[Ninja Turtle]

make sure your MAF didnt accedently get disconnected. or if dirty, give it a clean

[240ight]

Ok. I have replaced fuel filter distrib cap and spark plugs and new wires too. Car starts fine after a few seconds (like 20 or so) idle is really rough and sounds like car is dying and then does. If i try to give it a little gas it dies faster. Before i replaced the fuel filter it would at least rev before dying now it just dies. What else can I check. If I cant get it running I will end up towing to a shop this weekend sucks!

[180fan]

check over your TPS voltages.

btw don't put "please help" for a title.

[240ight]

alright here is some updates but i still need some help. I took to a mechanic he said it was the fuel pump so he replaced and started but motor really shaky and backfired alot and not full power so he said it was an injector # 3 not working so I replaced it but nothing it sounds like it backfires through the intake also i noticed when i rev a bit of smoke coming through what appears to be the 4th spark plug. i took the spark plug wire out and it is firing but nothing but when i took # 3 wire out it almost dies till i put back isn't that what is supposed to happen? how come not with 4 changed spark nothing then I disconected injector 4 and no difference then i tried 3 and almost died until plugged back. so i toght maybe its the injector so i changed that but nothing. what could be the problem? anybody?

[rogoman]

Looks like maybe you have two problems.

- backfiring is usually caused by incorrect ignition timing; can also be caused by a major vacuum leak.

- #4 cylinder is dead which is caused by either a dead fuel injector or no ignition.

[240ight]

so if i have replaced the fuel injector what else can I check? Thanks for you guys input

[240ight]

anyone have any suggestions?

[leveloneae86]

bump for the man im in the same position.

[blackknight1320]

I have just recently ran into this problem if your car is a single cam. Does this happen only when you cold start or after the engine warms up?

[wa-chiss]

ok. You might be linking two different problems together. Don't worry I did/do it too. I had the same thing happen to me but on both #3&4 cylinders. Check the compression in cyl 4. I did a comp test on 3 & 4 on my car and got 0 psi. I took the valve cover off and found my cam in 2 peices. The car would start, run rough, almost die, not rev good, backfire, etc. I too could pull out the wires and nothing would change in the way it ran. I don't think it's fuel related cause it's only on cyl 4. Also check the plug in cyl 4. It might be fouled.