2000 Silhouette Random start problem

[jwelch54]

My Silhouette (115Kmi) does not start every once in a while. It happens when I have been driving it, shut it off, then try to start it. The starter cranks and and cranks, but does not start. Then if I wait 5 min to 45 minutes it starts. My mechanic thought it may be the key FOB, but both keys have the same problem. I just replaced the fuel sender/pump assembly, but this was happening before, so it is not the fuel pump.

[94 Jimmy]

How does the engine sound when your trying to start it, does it just crank with no indication that it's trying to start, or does it seem to be almost but not quite ready to run. The first would indicate no spark or no fuel, the second would indicate you have both, but not enough of one or the other.
Get a can of starter fluid at the car parts store. If it won't start on starter fluid you don't have any spark. This is a quick way of checking if you are losing spark or fuel pressure. It's not a fix, just a diagnostic tool.
Also Autozone and other parts stores will read your computer codes to see if any are set. An intermittent failure will often not set the MIL (Check Engine) light.
When did you get a tune up last, if you have over 60 or 70 thousand miles the oxygen sensor could be bad and causing the engine to run rich/lean and cause poor starting when hot.
Just a few thoughts.
Good Luck
94

[jwelch54]

Thanks for the help. The starting fluid would be a good diagnostic. The check engine light never comes on, it cranks like crazy, but does not start. Wait a while and it starts up. My mechanic thinks he found a loose ground on the power relay. It did not start for him, and no iformation about bad sensors came up on the diagnostics. I am not sure why that would only effect the starting while warm. We will see.