> >
> >> > i have a problem with my geo metro 93 1.0 5sp man
> >> >
> >> > when the engine is hot it misses at above speed idle under light > >> > load
> >> > sometimes it even stumble if i let the gas pedal and step on it > >> > fast.
> >> > I have checked my cyl compression with throttle plate closed and i
> >> > have 140psi on all 3 cylinders i have changed the sparkplugs,ign
> >> > wires,rotor, cap and checked ign timing it was ok .I have no > >> > trouble
> >> > code store in ecu, checked the fuel pump pressure it is ok 18 psi
> >> > idle ,26 psi engine off ignition key on engine doesnt consume any > >> > oil
> >> > and has real good acceleration i get good gas milage too i have
> >> > checked the egr valve and its modulator EVAP emission circuit no
> >> > problem there changed all engine sensor with good used one,i have
> >> > looked at vacuum leak no problem there too i had only things i have
> >> > not changed are fuel pump ,injector ,pressure regulator.
> >> >
> >> > is there a way to check the throttle stop screw to see if it is at > >> > spec
> >> >
> >> > i have notice that when i look at the ignition timing mark(2)sometime
> >> > it jumped as much as 4 to 6 degres more than spec at idle speed
> >> > it suprised me could it be possible that my ECU has a problem :( > >> >
> >> > except for this symtom my car is perfect
> >> >
> >> > if anyone has any idea please let me know
> >>
> >> (2) looking at the timing mark with timing light with service connector
> >> ether jumpshort or not the mark still jumps back an forth randomly > >
> >i have just finish to check the cylinder compression on cold engine with
> >all 3 sparkplug remove and wide open throttle
> >
> >reading 185 psi on all 3 cyl
>
> Sounds dumb, but flush the engine, change the oil (5W-30 or even
> 5W-20), then get some carb cleaner and clean out the throttle body /
> mass airflow meter. If that doesn't do it, replace the oxygen sensors
> (new ones would be best). Only then should you consider the ECU. >
> Where in the world are you? I've had problems like that when I've
> used the wrong grade of oil - even with the right grade of oil for the
> season, but extreme cold temperatures will do that to the oil, slowing
> down the mechanicals and causing the engine to do wierd things like > that.
>
> Vuarra
>
> Quid quid latine dictum sit altum videtur.
> (That which is said in Latin sounds profound.)
i am currently running on 5w30 i have been warned to used that grade of motor oil if i dont want any problem with the valve lifters witch are prone to stick on high milage car ( my car has around 122000 miles on speedo now) and when the lifters stick the exhaust valve burns :( so i am more carefull about motor oil now
by the way today my problem got worst i was comming back to home when my car gradualy lost power it hapen 3 times before i was home on a 20 mile trip on a rainy and cold day with the heater fan on at slow speed when it happed the first time the engine stall then restarted and everything was back to normal until 5 min later the same thing happen but no stall this time then again the car engine suddently came back to normal now that it is worst it will be easyer to troubleshoot the problem witch i think is a bad electrical contact on a connector somewhere on the car or a bad efi relay or the ECU/ECM itself