When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm in the process of replacing my fuel injectors/fuel pressure regulator on my 1993 Trans Am LT1.
I used the fuel line disconnect tool to disconnect the 2 metal fuel lines from the drivers side near the schrader valve, disconnected all electrical connections, removed the vacuum line from the FPR, and removed the 4 bolts on top of the rails.
When I pull the rail up from each side, there seems to be something else in the back attached to the metal lines preventing it from being pulled out.
Most of the videos I've watched were 94+ and don't seem to have the same setup in back preventing it from coming out.
I did notice there are 2 (torx?) bolts near the back - but they seem almost impossible to get to without pulling the assembly out.
Any help would be very much appreciated - thank you so much
Not so sure about a '93, but my '96 Z/28 had a line to the fuel pressure regulator hooked on, in the back of the manifold.
Thanks for the reply leadfoot4,
I was having misfire and hard cold start issues recently - so I replaced the Opti and now it won't start at all. Checked the fuel pressure and it holds at 10-15psi @ key on engine off. Before tackling the fuel pump for the first time, I thought I'd replace the fuel pressure regulator and injectors first. Fuel filter was changed about 2 yrs ago.
I was able to get the rails off by removing the bracket holding the lines to the manifold. Unlike 94+ my hard lines came out with the fuel rails.
What is the best way of confirming the fuel pump is bad? I've been obsessively reading and some say there's a way to check it through a relay near the firewall?
Have you confirmed you are getting spark from the opti?
SS RRR,
Thanks for the reply.
I had someone crank it and took the plug/wire out of the cylinder - there was spark. I also confirmed a spark when I checked the wire from the top of the opti.
As you can probably tell - I'm still learning about all this. Is there another method I should use? Also is the 10-15 psi @ key on engine off a definite fuel issue, or could this have been caused from so many failed cranks?
yes 10-15 psi KOEO is way to low. Likely a fuel pump issue.
That's what I'm thinking too. IIRC you should have around 40psi KOEO. May be different with a '93 since they use a different injector than '94 and up. I believe they are 22lbs, but regardless that pressure is awfully low.
I bought these injectors on eBay (inb4 cheap ***)
22LB Camaro Corvette Firebird TPI Bosch Fuel Injector upgrade Design III 4 hole http://r.ebay.com/Zvw8s2
The gentleman selling them assured me that they're direct fit replacements - in fact he claimed that they're an upgrade. However they certainly don't look the same.
Clips aren't necessary. Install injectors onto fuel rail before placing on manifold.
Everyone has a different way of skinning this cat. Some say the clips keep the injectors from backing out, spraying fuel everywhere and causing a fire. I have had Bosch 3's on both of my wagons, and even popped a set into my BMW M5 - never used clips on any of them and never had a problem.
Installation: I place the injectors into the manifold first, then nudge each injector into the rail one-by-one as I set it into place. As the rail gets fully seated, I rotate each injector a bit and slide it deeper into the rail-socket - looking for a balance between the depth on the manifold and the depth on the rail.
Make sure you use new o-rings (they can be had at Advance/Autozone/Napa) if new ones were not provided by the seller. I spray my fingers with some WD40 and then rub them on the o-rings to facilitate installation. The WD40 is burned off once the engine gets to operating temps and everything stays put just fine. YMMV
SS RRR, atlantadan - thanks a lot for the replies.
When I was reassembling everything I noticed something interesting. There's a vacuum line attached to the 2 hard fuel lines that I don't believe was ever attached to anything. After feeling around back there, it looks as if there's 3 vacuum lines that attach to the (EGR Solenoid?) and the far right one is missing.
Is that where this line is supposed to attach? If so, my vacuum line won't reach back there - it's way too short lol
I am not sure how the '93 is configured, but I believe the line coming out of the fuel line cluster is for your EVAP solenoid.
Perfect - thank you sir.
Just reinstalled the new injectors, new fpr and changed the fuel filter (soaked in gas - FML)
Still won't start and my fuel pressure gauge only goes up to about 5 now and stays there.
I had an interesting thought today. When I changed the opti - I had a tough time getting the 3 bolts out of the crank pulley. It rotated counter clockwise a couple times (kept the serpentine belt on so everything rotated). I did mark where it was originally before I started, and thought I rotated it back to the starting position - but maybe I didn't? Won't this cause it not to start? I read something about TDC being off when this happens.
Timing reference is all done by the opti. If you install that incorrectly then you will have issues. Your damper can go on any way you install it because it is neutral balanced. Rotating assembly on the LT1 is internally balanced in the front and externally balanced in the rear via flywheel or flexplate.
IMO you should check into your fuel issue. Replacing the fuel pump is a pretty easy task if you want to take it out via the "trap door mod."
I actually cut out a trap door a while back when I thought my fuel pump was bad. Ended up being an Opti issue. I thought it may come in handy in the future
Does anyone have a good write up on how to replace the fuel pump?
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
1993 LT1 Fuel Rail Removal 
