99 S10 problems on cold start

[NikeGirl26]

I have a 99 s10 4.3L that will not start when sitting overnight or for long periods of time. Had a problem with the fuel pump over the winter not engaging when the key was turned. Wiring harness was bad. put in a new fuel pump and it would still not prime. we couldnt figure out why but old pump still worked when we hooked it up to a 12 volt battery so we just ran a power wire from the pump to the battery with a toggle switch inside to turn the pump on and off. worked like a charm. Now the truck isnt wanting to start in the morning. Sometimes it takes 20 tries before it finally catches but sometimes i just get frustrated and put a little bit of gas directly in the engine and it fires no problem. While having the starting problems, my gas gauge stopped working. Wondering if its just not getting enough gas to the engine on start up? Engine light is on, took it to auto zone and they said that it was an ignition failure (um, yeah THATS not obvious) and told me to do a tune up. replaced the plugs but really dont want to go broke changing every part until i find the problem. Read something about air pressure sensor, could that be it?? Any help would be awesome for I'm a pretty smart girly mechanic, yet TOTALLY frustrated!!!!!

[Blazing95]

Nike Girl
Have you replaced the cap/rotor -?this is usually the first failed component.
I had the same problem with mine and found it to be the cap/rotor.
try that and let us know. Fuel gauge doesnt work or bounces around in dash gauge tells me its the fuel pump. You should not hve to put a jumper on it to get it to work..

Originally Posted by NikeGirl26

I have a 99 s10 4.3L that will not start when sitting overnight or for long periods of time. Had a problem with the fuel pump over the winter not engaging when the key was turned. Wiring harness was bad. put in a new fuel pump and it would still not prime. we couldnt figure out why but old pump still worked when we hooked it up to a 12 volt battery so we just ran a power wire from the pump to the battery with a toggle switch inside to turn the pump on and off. worked like a charm. Now the truck isnt wanting to start in the morning. Sometimes it takes 20 tries before it finally catches but sometimes i just get frustrated and put a little bit of gas directly in the engine and it fires no problem. While having the starting problems, my gas gauge stopped working. Wondering if its just not getting enough gas to the engine on start up? Engine light is on, took it to auto zone and they said that it was an ignition failure (um, yeah THATS not obvious) and told me to do a tune up. replaced the plugs but really dont want to go broke changing every part until i find the problem. Read something about air pressure sensor, could that be it?? Any help would be awesome for I'm a pretty smart girly mechanic, yet TOTALLY frustrated!!!!!