Car Hesitates and Stalls Sometimes on Startup

[roel03]

I have an S14 KA-T and it has started acting really weird.

The car hesitates where downshifting in traffic and getting back on the gas. Like it stumbles for a few seconds then accelerates.

Also sometimes when coming to a stop the revs drop about 2-300 RPM's. From 1000 to 700 or a little lower.

Also it just started doing this, but when I start it up it idles fine for a few seconds then it rocks and stalls. I have to start it 3-4 times for it to start normally.

I just replaced plugs and wires. No codes just code 55. Checked TPS and it is .32 at closed and 1.03 at WOT when the car is off. Everything else looked perfect on my DataScan.

The blow-off valve is recirculated and I am enthalpy ROM tuned.

Any ideas? Looking to get things back to normal ASAP.

[S14-SLIDER]

idk mabye ur maf or trottle body are going bad? turbo lag?

[Royal13]

Injectors possibly.. My friends KA24de started shaking violently one day, but only at idle and low rpm. It ended up being injectors.

[Rabboni]

For your tps did you mean 5.03 at wot? If youre only getting 1.03 volts at wot then you need to take a closer look at the tps.

[240sxvaj]

check your fuel pressure regulator and injectors. stock fpr and injectors (size)?

[roel03]

Stock fuel pressure regulator and 370cc injectors. I don't remember the WOT TPS value but I am sure of the .32 without depressing the pedal.

Now it has been stalling when I first turn it on consistently.

[roel03]

Also, I forgot to mention but it does this whenever it is cold outside or on first startup when the motor is completely cold. It only does the start up problem when it is cold outside.

[fender-startocaster]

Ive been experiencing the same symptoms and im not turbo.

[240sxvaj]

if i was you, i would upgrade your fuel system. such as fpr, fuel filter, fuel pump, and all the other fuel stuff. when i first turbo my kade, my fpr and injectors fucked up on me. so i decided to upgrade my whole fuel system. just my .02 cents

[roel03]

Fuel pump is upgraded to a Walbro 255. I will look into the injectors this week and pull each one and see if it changes anything.

How can I test the FPR?

Any other ideas guys?

[240sxvaj]

Fuel pump is upgraded to a Walbro 255. I will look into the injectors this week and pull each one and see if it changes anything.

How can I test the FPR?

Any other ideas guys?


i dont remember on how to test the fpr. i just replaced it with a nismo fpr w/ b fitting.

[roel03]

Just checked all of the injectors are working properly. If nothing else seems to do any good, I will also buy a Nismo FPR.

Any other suggestions??

[napz510]

[QUOTE=roel03;3765933]I have an S14 KA-T and it has started acting really weird.
TPS and it is .32 at closed

Your TPS setting is too low, should be atleast .44 in idle at 700 rpm.

Check your idle control valve and temp sensor also.

[roel03]

It ended up being a dirty throttle body. I cleaned it and the car purs.