Re: (update) HELP geo metro 93 misses at light load and low speed

> nanotech1 wrote: > > > > 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

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

Reply to
nanotech1
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check for dry electrolytic capacitors in ECU. (use an ESR tester)

Reply to
Ariel

i have open up my ecu box and fund out that there is six electrolytic capacitors on the pcb i am sure that on or two of those is doing me troubles it is making the same symtom has a dry cap,cold it is going well but as soon it ( the ecu ) is warming up then the troubles begins

i found a web site that does recommand changing cap after 7 years of service especially if ecu is in a cold to hot environment

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i know that it may be out topic for this NG but it may help a lot for anyone who has ecu related problems and some electronics skill

Reply to
nanotech1

Have you tried spraying those parts with chiller spray (or an upside down can of air) and noticed if the problem went away?

BTW, you are supposed to check your compression with the throttle plate WIDE OPEN.

Reply to
Drizzle

i didnt had the time yet

Reply to
nanotech1

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