Car dies when releasing gas pedal, and runs badly

[bartyb]

This is on a 92 s13 with hicas and MT, I never came across this problem, to start the car, I have to give it some gas, otherwise it just cranks and doesn’t start, and same thing to keep it running, if I release the gas pedal it just dies, and when I keep it around 1200rpm or more it does run, but very badly with a huge black smoke coming from the exhaust. Any ideas what can be the cause of this? Idle Air Control Valve, Maf, fuel pressure regulator? Thanks

[rogoman]

Could be one of several reasons:- leaking fuel injector(s)- bad FPR- bad CTS

[1987zx]

i'm having the same problem here...

so far its come down to the injectors and possible idle valve problem..still working on it...

dont mean to hijack your thread but... is it possible to blow you injectors? or whats causing it to blow...

i've replace # 3 cyliner injector two times and after a day of driving it keeps coming to the same conclusion..reading on other three injectors or 11.6 ohms but # 3 is 12.2+whats causing it to go out on me???

93 240sxn/a170k miles

[rogoman]

It's possible that a higher voltage spike is showing up on the wire. Trace the #3 wire from the injector to the ECU, making sure the insulation is OK.

[bartyb]

Swaped a working maf, didn't change anything, changed the ground that went into the engine head as it was cut by rust, and when I removed the fuel pump fuse to check the regulator and mesure pressure, the car kept on running, after a good minute I gave it some gas and it kept running, so turn off engine, I open the fuel pump cover in the trunk, and found the black wire loose, it's supposed to be conencted to the top plate of the fuel pump assembly. I just unbolted one of the top plate bolts (the small ones) grinded around it to make a good contact and adding a ring/ground grommet to the loose wire I just bolted back the bolt. Now that didn't solve the problem ,so my question is: is the whole top plate gounded, perhaps it's still making a bad contact, at leats now when I remove the fuel pump fuse the engine dies, so I figure it's conencted properly and my problem resides with either the injectors of the iacv?

Thanks for the help.

[bartyb]

Well, just incase this could help someone else some day, I checked/replaced the following without any improvement:

engine coolant temperature sensorMafsIIAVI redid all engine grounds and the one for the fuel pump cover plate which was disconnected by rust causing the car to run even without the fuel pump fuse. All vacuum linesdistributor/wireschecked for leaky injectors and make sure they all work by removing the railchecked fuel pressure and regulator, spark plugsthrottle body and it's sensorall engine wiring

So I was begining to scracth my head and go home but I told myself I'd do one last thing before, and that was changing the ECU for the one in my car. It fixed the problem. There was no engine light or anything, and the car was running as if it was running on 3 cylinders, but all 4 were running, very unusual. Now it's only a matter of finidng an ECU.

Thanks again for the help.

[donnie89240sx]

i am having that exact same problem i went to a junk yard and grabbed a ecu out of a car just like mine but it makes my car run on 3 cylinders and it runs better i been scratchin my head for 3 weeks tryin to find out wth was going on. i appreciate it very much i am going to go tomorrow and get the ecu out of the car my motor came out of and try that. i thank you very much