1996 Toyota Tacoma 2.7l 4x4.
I got this truck in the spring and it has been running well. However, about a month and a half ago, I could not start it after I had driven it. After waiting for 10 minutes or so, it started and I had no problems with it for a couple of weeks. Then it happened again. I had driven it 20 miles and could not get it to start. I had to wait 10-20 minutes, and then it started.
In the two weeks it is happening more often. I notice a smell like old gas when it won't start. I have replaced the coil, the plugs, the plug wires, the rotor and the distributor cap because I thought it was spark related (because I was troubleshooting with a broken plug wire I found out).
When it turns over, it will sometimes ALMOST start. Once it is started it
runs fine. Waiting has always allowed me to start the vehicle, but sometimes I have to wait up to twenty minutes. It always starts when I first use the vehicle and the engine hasn't warmed up.
I did replace the head gasket and although I was very careful, I wondered if there was a head bolt that had loosened and when things expanded some coolant was getting in the engine. I have started monitoring the coolant level and have not noticed anything.
I know these are hard to diagnose at a distance, but if anyone has ANY ideas of what it MIGHT be, I would appreciate any thoughts. TIA.