Another idle issue thread: sputters, misfires and stalls bellow 2000rpm.

[Pijus]

Hey Supramania,

I bought an 89 UK Spec. Turbo with r154 to do my engine swap, before I take engine out I want to figure out why it cant idle.

When i start engine it sputters, misfires few seconds then rpm drops and car stalls,
if you keep pedal depressed, at <2000rpm engine sputters, misfires, feels like only 5 or 4 cylinders are working…. but when you reach 2000rpm everything just fine, engine runs smooth just like it should.

I tried to drive it,- same situation <2000rpm it runs rough, at 2000+rpm it revives and boost just fine all the way up.

Things that I’ve already done:
Checked timing, adjusted TPS, checked all vacuum hoses and then swaped all those parts from my other 100% running 7mgte: AFM; Coils; Wires; Spark plugs; Igniter.

Car is 100% stock., no codes in the dash, from the spark plugs color I could say engine should be running a little bit rich.

Stil no luck, maybe could be something with fuel?

Thanks, Pijus

 

[80083r]

Fuel pressure? Diagnostics on AFM?

Keep in mind I'm a newbie at automotive troubleshooting - but logic dictates check 3 things first:
1. Air (got enough? too much?)
2. Fuel (pressure/flow - blockage that is overcome by sufficient pressure?)
3. Spark (not enough "juice" to spark right until alternator is revved up? weak battery?)

 

[hvyman]

Did you pull codes or just check for a check engine light?

 

[Pijus]

yes i've pulled codes, there was 51 & 52 when i bought it so i did KS rewire and TPS calibration, now no codes but still no luck ;/

AFM is 100% working, i tried 2 of them, battery is also new.

Fuel pressure is unknown for me since i dont have fpr.

 

[BryanDyer]

After you did the rewire and calibration did you check for codes again to make sure they cleared?