G20 stumbling from 1000-3200 RPMs w/ flat accel

Apr 21st, 2003, 03:56 PM

I've put in new plugs, air filter, fuel filter and a few other basic `just-bought-a-used-car' things. I've tested the TPS voltage, the MAF ground, and I've cleaned the pipes that go to the BPT valve. I can't seem to figure out why my car is stumbling at low RPM's and the acceleration is flat all the way across the board. I don't think it's the EGR problem becuase when I disconnect it from the BPT and plug the vac line, there is no change what so ever. I don't think it's bad compression becuase I can still go up a steep hill without issue. and here's the kicker. when the car is cold (presumably when the computer is in closed loop mode) it runs great! when it warms up a bit (switches over to open loop mode) it runs crappy. It's completely not noticable if I'm very light on the gas, but the second I start to get on it, I sputters (below 3200) and is flat (not preforming like a SR20DE should). any ideas before I take it to the (gasp) dealer for diag? I'm thinking possibly MAF, but I don't want to throw parts at it if I'm not sure.

1 WICKED SE-R · Apr 25th, 2003, 03:47 PM

do you have an intake on it?
if you do do you have the temp probe installed in the filter itself?
if not, then you should this shows the ecu the temp of the air coming in the car.
reason for the hesitation when it is warmed up.
the ecu doesnt notice it at cold temps/
make sure you have the temp installed in the filter or the stock air box which ever one you have

hope this helps

urbanracerone · Apr 27th, 2003, 02:18 PM

Check your o2 sensor! or maybe your timing is off, I had the same problem with my SE-R TEAM G4L NYC

May 15th, 2003, 08:21 AM

timing is probably off. when i messed with my timing it did the same thing

May 15th, 2003, 09:54 AM

the funniest thing happened. it fixed itself. hahaha. I'm inclined to think that when the previous owner power washed the motor, the water that was in the spark plug wells caused the stumbling. all better now

thanx for all the feedback!

urbanracerone · May 15th, 2003, 10:00 AM

Yo i e-maile you got it?

May 15th, 2003, 10:07 AM

no, I don't think so. try again.