Today i took my injectors out of my 90 gxl to have RC Engineering rebuild them for me. While i have half the motor apart is ther anything i should look for in particular? What about changing certain parts?

 

Check the fuel rail injector sockets.
They must be perfectly clean & smooth.
Sometimes a small piece if the old O-ring will be left bonded to the socket.

Oil the O-ring, so they don't get scratched when you install them in the rail.

 

make you sure you mark where every vaccuum line goes and put it back, you could also replace the vac lines and I would replace fuel line as well.

 

Check your oil injector lines. They are brittle and crack. Easy to replace while you have the UIM off. Do a search, there's a great thread on replacement.

 

If you aren't replacing all your vac lines, make sure you have some just in case. I can't tell you how many I broke just by grabbing them, also be gentle with the plugs, I broke a couple of those too.

 

I'd ditch the rat's nest while you got it apart, remove the thermowax and plug up the coolant nipples and do the throttle body mod while your at it. Do you already have your egr removed? If not - now's the time to do it. ~rich

 

well, i got my injectors back and installed them, changed some vac. lines, put all the manifold stuff back on and when i go to start the car back on it starts fine but then dies instantly. but if i hold the gas at above 3000 rpm the car will rev fine up to redline. i am kind of sketchy on the way i put the injectors on: RC engineering didnt have any replacement grommets to put on the bottom of the injector. i used some thinner o-ring look alikes to replace them. oculd this cause a problem? is there anything that i might have hooked up wrong? as anyone ever had this problem?

 

From what I've read, the TB mod is pretty useless on NA cars. I also wouldn't really recommend removing the thermowax as it helps cold starting. The rats nest removal is not necessary, but helpful in the long run. You can research these on your own and make the choice yourself.
As for what to do, go and get one of the universal vac line kits (I think they have them at autozone) and replace all of the vac lines. Also, check the omp, coolant and fuel lines. Make sure to check the vac spider as well. I had a vac leak I couldn't ever find and it turned out to be one of the ones from the front of the tb where it connected to the rats nest.

 

Theres a good chance the they caused a vac leak. I was going to say the AFM wasn't hooked up right until i red the rest of the post, because then it wouldn't run at all.