CEL @ 1500 or less RPM

MMamdouh · Post by **MMamdouh** » Thu Mar 02, 2006 7:41 am

Hi all

we are having a problem with the 2.0 Nubira engine, it throws a CEL once the RPM drops past 1500... if you rev it over 1500 for some 30 seconds the CEL turns off but comes back on again once the RPM drops.

i know we should scan it and get the code but i need a preliminary idea first so that no one tryes to rip me off in the attempt to fix it.

Thanks for your help.

MMamdouh

chronoti · Post by **chronoti** » Thu Mar 02, 2006 12:27 pm

egr issues, it's normaly only open at crusing, so reving up the engine engauges it. i say it's sticking open.

or o2 sensor low reading untill it warms up enough to give feed back

MMamdouh · Post by **MMamdouh** » Thu Mar 02, 2006 1:54 pm

we thought it was a TPS or IAC issue so we tested the TPS from my car and the problem was still their but not as acute as it used to be... we also cleaned up the IAC and that didn't improve things.

O2 sensor was cleaned few weeks ago... no idea if it is bad or not, EGR issue seems intresting and we will check it soon.

any more ideas??

MMamdouh

MMamdouh · Post by **MMamdouh** » Thu Mar 02, 2006 5:47 pm

did a quick search in the parts manual and foind out that the TPS is the same for the 1.5 and 2.0 engines... we tried mine (1.5) yeaterday on the 2.0 engine and the car still had that issue.

the IAC however got a different part number yet both IAC's are exactly identical, we tried it anyways and still the same problem exists.

i checked the EGR and it doesn't seem to be stuck open or so... the O2 sensor seems to be functioning well on the Air/fuel ratio meter.

any suggestions??

MMamdouh

Audacity Racing · Post by **Audacity Racing** » Thu Mar 02, 2006 11:11 pm

what is the thermostat saying the car's temp is?

MMamdouh · Post by **MMamdouh** » Thu Mar 02, 2006 11:48 pm

normal temp.

also the car rises its idling speed at some times to be some 1200RPM on its own and some other times the RPMs go back and forth between 1500 and 2000.

not really sure but the exhaust smells like it is a bit rich yet the O2 sensor reading on the Air/Fuel ratio menter shows it is a bit lean.

when idle is hig the fans work more frequently than normal but thats expected when the car idles at 1500 RPM at all times.

MMamdouh

kroz123 · Post by **kroz123** » Fri Mar 03, 2006 4:32 am

should the car be idleing at 1500RPM seems a bit high to me, It's drinking alott of fuel.
Isn't it?

Sry for the off-topic can't help you really don't know much about engines.

MMamdouh · Post by **MMamdouh** » Fri Mar 03, 2006 1:02 pm

the 2.0 engine is supposed to idle at 900 RPM or so iam told... 1500 RPM is way wrong and affects drivability and fuel consumption.

MMamdouh

mister_g · Post by **mister_g** » Fri Mar 03, 2006 1:22 pm

IAC or TPS wireing is fault. Normal thing on daewoo....

Post by **Efratech** » Fri Mar 03, 2006 2:37 pm

give a nice clean to the IAC with a carb cleaner spray.

Audacity Racing · Post by **Audacity Racing** » Fri Mar 03, 2006 3:30 pm

is the tps and the butterfly set right?

MMamdouh · Post by **MMamdouh** » Fri Mar 03, 2006 4:36 pm

mister_g wrote:IAC or TPS wireing is fault. Normal thing on daewoo....

we did a terst for both:

we took off the TPS while the engine was running and turned the little peice inside it, the engine increased its revs prportional to how much we twist the thing so i guess the TPS is working.

with the engine off we took out the IAC and turned the ignition on, the IAC's rod was movung back and forth so the thing is working as well.

i guess this rules out wiring as both devices do communicate with the ECU as shown in the mentioned tests but something is acting funny with one or both of them.

MMamdouh

MMamdouh · Post by **MMamdouh** » Fri Mar 03, 2006 4:37 pm

Efrain A. wrote:give a nice clean to the IAC with a carb cleaner spray.

i did that myself and it didn't improve any thing plus my IAC out of the 1.5 SOHC didn't solve the problem when put on the 2.0 engine.

MMAmdouh

MMamdouh · Post by **MMamdouh** » Fri Mar 03, 2006 4:40 pm

Audacityracing wrote:is the tps and the butterfly set right?

set right as in what??

the end of the butterfly axel is correctly engaged to the TPS... thiugh that the TPS can be rotated as an adjustment major (as you rotate distributers to adjust timing) but their is no way you can do that as the 2 screws that holds the sensor gives no play to rotate the thing whatsoever.

if you mean something else than that i think you mean please advice.

MMamdouh

RichieOzzie · Post by **RichieOzzie** » Sat Mar 04, 2006 11:16 am

I have heard somewhere that one of the wires to the TPS fracture, but I am not sure which one it would be. Maybe chack for fractured wires, these will become prevlent when the Motor is Bouncing about the Engine-bay.
So there#s one I dea, I will do some research on it for you.