WvW survival help please

I've been running Warrior in guild group WvW. I bashed people with my hammer and all is well. Now they asked me to run Engineer. I had a Engineer that I ran thru the Tyria campaign long before even HoT but haven't played since. I spent a ton of Heroics and set up the Metabattle build.

We stack on tag and if the enemy bombs first, I'm down before the tag gives the order to move. I'm sure it's a L2P issue. Can anyone offer any constructive advice?

Thanks

Well uhm... what are you even running? Because if it's a meta engineer, it should be full minstrel scrapper healbot. If you go down first that's a serious l2p issue, yes, because in a stacked group that should technically be impossible. Others should drop way before you, scrappers can outlive the fb frontline. Just keep healing, use the elixir gun occasionally, stay in medkit like 90% of the time and just cycle heals constantly. Dont forget your AoE stab on the bulwark when you push.

It could be a l2p issue, it could be bad positioning on the part of the squad.
What you describe seems like your group is being bombed "even before the tag gives the order to move", which means your group is not baiting bombs and is just standing there reacting to enemy attacks.
The other possibility is that you get focused by long range attackers because you're not well stacked (an issue passive invulnerabilities on warrior can somewhat take care of).
So my advice is:

• Check that you're running the appropriate build for wvw organized play, currently it is full minstrels with antitoxin runes, which is very tanky, it might change after the patch, but it wouldn't change too much.
• Your role as a support scrapper is to direct the cones of your skills towards your team and position supportive areas "where they will be" during a fight, this means that you shouldn't be standing in front of the team, certainly not in ahead of the commander, but rather well stacked behind the tag and always pointing the cones towards your companions, sometimes this means letting them run ahead of you, sometimes this means flanking your team.
• You have some skills that help you survive during the first engage, whether you are running hammer or shield, you have a block available, you should pair this with bulwark gyro, the effect will be a burst of barrier plus blocks (you'll receive a portion of your allies received damage, negated by the blocks).
• Dodge! enemy engage often involves Winds of Disenchantment and Sand Shades, this areas are big and noticeable and you should dodge out of them, just remember not to dodge away from your team, if your group is well organized, you'll be dodging to the back of your enemies. Always remember that at this point your allies will have been corrupted and will have tons of conditions on them, so you have two options depending on whether there was an enemy Winds of Disenchantment or not, if there was, it means your allies might have lost their stability to corruption (turns into fear and separates your squad), run cleansing gyro while traversing this damage and chances are you'll clear fear as soon as it is placed. If there are no WoD, place med kit skill 3 "cleansing field" where you'll land, so allies that land there or stand there get those conditions cleansed, and of course, use elixir gun's fumigate on cd, always pointing it towards your group.
• If you are still being bombed first, check your ping, you might experience high latency before fights (pretty common on wvw), try to position yourself tad bit to the back if this is the case to give yourself more time to react. You do not have the survivability of a warrior, with a spellbreaker you can easily run into an enemy zerg and survive getting out of it, with a scrapper you cannot do that, it doesn't matter how tanky people perceive scrapper to be, it is not immortal, and barrier/high toughness/high hp means nothing when 10 or more people are hitting you, invulnerability is the only thing that matters in that case, and you carry none (no resistance, no physical invulnerability, no elixir s), so you need to change your mindset when playing this class and adapt to its limitations.

I hope this helps, I currently have no videos of current builds for scrapper, just one where I was testing a silly build with kinetic stabilizers, but if it serves you, you can find me on youtube by my nickname.