QuestionQUESTION: I have a 91 Geo Storm (Isuzu Impulse),automatic, 12 valve SOHC that I purchased a few months ago. It only has 24000 miles on it, and it runs great with the only problem being that it is very hard to start and most times impossible to start when below about 25 degrees outside. When above that temperature it starts right up and runs and idles great. So far the things I have done are:
new battery
new spark plugs
new plug wires
new pcv valve
new air filter
new fuel filter
new throttle position sensor
new coolant temperature sensor
cleaned throttle body
cleaned idle air control valve
tried gas from 3 different stations
dumped plenty of heet into gas tank
new timing belt, timing is right on
cleaned (but didn't replace) intake air temperature sensor on manifold
new cap and rotor
When I first turn the key on I can hear the fuel pump running for 2-3 seconds.I have also taken the ECU out and opened it up and looked at it and didn't see any signs of water damage or anything pulled apart. Any other ideas on what could be wrong and causing it to not start? I am in MT where it is below 25 degrees in the morning about 9 months out of the year and so really need to get this figured out. Any thoughts are appreciated.
ANSWER: Well the fuel pump solenoid or fuel pump could be faulty. Also did you replace your battery cables when you replaced your battery? If it cranks over but will not start that is either a fuel problem, timing problem or ignition problem. I kind of think it is a fuel problem though. the choke could be mis-adjusted or you could have defective spark plugs.(very unlikely though) I would check on the above things and let me know what happens or if you need more assistance I am always here to help okay John? Have a great evening.
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QUESTION: Thanks for your suggestions. I didn't replace the battery cables, but checked the connections for corrosion and made sure they were tight and clean. It cranks over really good so don't think those are the problem. I have tried 2 new sets of spark plugs, that didn't help. The timing is right at 10degrees, which is says on the hood label. What do you mean by the choke being mis-adjusted? It is fuel injected and so there is no choke. How do you check the fuel pump solenoid? The fuel pump can be heard when turning the key on, and since it does start great when warm out, I don't know how to check that to see if it is working less when cold old? Thanks.
ANSWER: Ohh I apologize I thought you had a choke operated system. Wrong question. Anyways The fuel pump solenoid is in the tank so it might be hard to check. Although you could do a voltage test and see how many volts are going to and from the pump when energized. The problem though sounds like either the timing is off or the fuel is not reaching the throttle body. My best bet would be to double check the timing and the idle air control valve. I will do some research on your specific car though tonight and see if I can't find anything okay? Thank you for your patience.
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QUESTION: Well last night I added yet more new parts. I installed a new Idle Air Control Valve and a new Ignition Control Module. Still didn't make a difference. I rechecked the timing, and it is still right on. When I first turn the key in the morning it catches and fires once, but doesn't start and just keeps turning over. I then press the gas pedal all the way to the floor (like for a flooded situation) and then it spits and sputters and finally starts. This works sometimes, sometimes after having to try several times, and sometimes it still doesn't work if below 15 degrees or so. It was about 25 above this morning and had to use the pedal to the floor method to start. Can't smell any gas like it is flooded and the spark plugs aren't overly wet. Does that give any more clues?
AnswerWell Honestly it could be a number of things like overly-worn valves. clogged fuel injectors. Bad ignition components Defective crank/cam sensor/s. The only thing I can think of though is that fuel is not reaching the throttle-body John. Air could be getting into your fuel lines causing a hard start especially in the mornings. I would check my fuel pump. You can check the voltage with a multimter to see how many volts the fuel pump is getting. If you need anynmore help though I will try to point you in the right direction. Thank you for your patience.
