240SX with SR20DET and having problems

[DanielIser]

Ok here goes.

I did the whole thing all by myself with minor help from a couple friends. After letting the car just idle for a couple of hours I decided to take it for a test drive. Everything was perfect. It was a very smooth enjoyable ride. After putting about 30 miles on it though it began to sputter at low RPM. Between 1500 and 2200 to be exact. If I give it gas it blows right through it with no problem. But if i try to pull out slow or something it will sputter and jump like it is starving or something. It also will shut off everynow and then when downshifting to stop. And when in 3rd 4th or 5th gear and trying to hold a steady speed it wont do it. You can accelerate just fine but if you let off the gas to steady the speed it just lets off all the way, then when you push the gas again it jumps pretty hard. I took it to several people around town and some said fuel pump or fuel injectors, but that doesnt explain how it works fine if you hit the gas. I have quickly went over all of the i/c piping and vacuum lines and havent found a leak yet, will thouroghly inspect tommorow. I even thought maybe it was just working out the kinks, but I now have 750 miles on it and it is still doing it. Please help!!!!

[DanielIser]

Sorry forgot to tell what I have.

Greddy VSPL FMICHKS SSQVTRUST Intake system3" Downpipe and Testpipe, exhaust soon to come

[candela]

Sounds ignition related to me man. I would work from the plugs back to see if you can solve it (assuming you did use NEW plugs when you swapped)...

[DanielIser]

If you are refering to Spark Plugs and wires, I did not do the spark plugs (stupid me, knew i forgot something) but there are no spark plug wires, coilpacks instead. I will do the spark plugs tonight though thanks.

[180fan]

you could always check the coil packs too. I hear it's pretty common for coilpacks to go bad.

[DanielIser]

Well i changed the spark plugs today and no better. What is the best way to check for a bad coil pack? Any help here is very much appreciated. Thanks

[Supafly]

check for boost/air leaks after the air flow meter

[DanielIser]

Not to sound stupid or anything but I have just become dumbfounded by this. What is a Air Flow Meter?

[emperor_lunchbox]

the airflow meter is the Mass Airflow sensor. it generally bolts up to the intake.

[DanielIser]

Thats what I figured but I always just knew it as MAFS thanks though!

[DGA]

Pull out your fuel injectors and replace the O-rings on them. If you have a small tear in one of those, the fuel will rush by, and at 40psi that is a lot of fuel at low speeds. When you stomp on the gas pedal everything feels fine because the engine demans all the gas that it can get, so there are no problems. At low speed you are getting way too much fuel to burn properly. The O-rings, will run you almost nothing at the dealership. If you decide to replace these, make sure you lube them up before you put them in, otherwise they will rip again. Same thing has happened to me before.

[DanielIser]

I think i figured it out today. I unplugged the TPS and it got rid of all of the problems. So now I gotta figure out how to make it work with the TPS plugged in because my gas mileage sucks now!