Let's discuss some potential problems that can affect gas ovens.
First off, a 'delayed spark' is essentially an igniter that doesn't ignite as fast as it should. This issue puts your oven at risk of literally blowing up or at least catching on fire. If you experience a delayed spark in your gas oven, definitely get it checked by a professional right away.
The delay is normally caused by clogging in the ignition ports. The best way to identify such an issue is to audibly, physically and visually observe your appliance. Do you hear gas flowing through? Do you smell gas? Do you feel it? If you answered no to all of those questions, contact an oven repair expert and get your delayed ignition fixed the right way.
The gas valve might be opening before it needs to as well. If so, the gas odor will come out because it's being pushed out: However, the ignition won't happen and the gas leak will put your health and home at risk. This issue happens when the igniter doesn't reach a hot enough temperature to spark into a flame once gas releases through the valve.
It's also possible that your gas valve has a tiny pinhole where gas can leak out of, which is enough to pose a serious risk. The gas leaks are toxic to inhale and in time can lead to sudden death of anyone in your home.
A carbon monoxide detector is a must for anyone with a gas oven in their home. The detector will indicate the level of gas polluting your home (if any) which is an immediate warning sign of a gas leak issue - if it reaches a concerning level an alarm will sound and you should call 9-1-1 and leave the home immediately.
Is your oven failing to heat up? If so, the reason for this will vary depending on whether you own an electric or gas oven. For electric units, the problem could be with the heating elements, temperature-sensing bulb, thermostat, selector switch or relays. For a gas oven, the problem could also be due to an issue with the gas ignitor, gas valve or your supply source. Speak with an oven repair professional to diagnose your problem if it's not easily identified. If you suspect gas isn't reaching your oven, contact your provider to have your supply line inspected.