I installed a new plenum on my 97 Bonneville yesterday. When I went to reconnect the injectors to the fuel rail, they wouldnt go back in place. Am I not putting enough pressure on them or is there a special tool or trick to it? I wanted to inspect the injectors while the plenum was out but couldnt get them to come out either. You guessed it, this is my first venture in this area.

Chas.

I installed a new plenum on my 97 Bonneville yesterday. When I went to reconnect the injectors to the fuel rail, they wouldnt go back in place. Am I not putting enough pressure on them or is there a special tool or trick to it? I wanted to inspect the injectors while the plenum was out but couldnt get them to come out either. You guessed it, this is my first venture in this area.

Chas.

First make sure all the injector o rings are un
place, then use wd40 on the o rings and install
will pop right in
then use the 4 10 mm nuts to hold down

Just so I have it straight, I have to remove the fuel rail again and set them each in place using WD-40, then bolt down? Or remove the injectors and set in place with WD-40 then bolt down ?

Chas.

as long as you dont have a vac leak or a fuel leak you are all right. the tabs that go over the studs for mounting the fuel rail will be almost flush with the intake when installed correctly. the nuts just keep it there

GM prefers you use motor oil to lubricate the O-rings. I'm not sure exactly what's in WD40, but some oils make some rubber parts swell or harden. If they don't go in pretty easily with motor oil, the O-rings should be replaced.

The way they are installed at the engine plant is to install the injectors in the rail first, then put the assembly on the engine. Also, use the clips that hold the injectors in the rail if you have them. Proper injector targeting is dependent on these, but there should not be any leaks if they are gone as long as the rail isn't bent. However, the engine may run slightly better with the clips since it was calibrated this way.

Hope this helps.

John

O rings are not rubber
neoprene
WD40 will not hurt the orings, nor will transjel

I work at the manufacturer of the injectors. I can assure you that the original O-rings that came on the car are two different Fluorocarbon (Viton) blends, (different low temperature qualities so you don't get a fuel leak at really cold temps). Neoprene would not be a good choice, as it has poor fuel and oil resistance properties, unless there is a new blend I'm not aware of.

John

I ended up buying a new O-ring kit from the dealer. I didnt realise it at the time but the O-rings were quite thermal stressed and there was no way I was going to chance a leak resulting in a fire. The instructions stated that the two different colored upper and lower were now the same material in the kit provided. I asked the guy at the counter as to what is recommended to ease the installation and he said their mechanics used motor oil. I took the injectors out, stood them upright in a shallow bath of injector/gas treatment and wiped them to a bright shine. The oil made the installation a breeze and before I knew it, I fired the car up and its been running great. I waited until I was certain there were no leaks appearing before I drained the old coolant and just last evening, replaced it with Prestone "Orange". The engine is running a little cooler now, about 180ºF. It was averaging in the mid 190's before I replaced the Plenum.
Thanks for all your valuable input in this (again) Travis. And thank you for too John for your info on the injectors as well. I can never have enough tech info.

Chas.