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How Difficult is the Injector replacement procedure for the 1990 ZR-1 ?
Hello Forum Friends,,,,
Considering the Purchase of a ZR-1 currently on the board here at the Forum and was wondering how tough it really is ? I have owned a few Corvettes over the last 20 years in various states of condition and love working on them myself. I prefer buying them from the Forum members here if possible. I have a reasonable skill set but understand my limits. The LT-5 is a bit more complex then a typical C4 set up. Or is it? Did some searching on the injectors repair and replacement on the standard L-98 motor....Is it the same process just double? Thanks Very Much for any advice or experiences from forum members who have done it.
Considering the Purchase of a ZR-1 currently on the board here at the Forum and was wondering how tough it really is ? I have owned a few Corvettes over the last 20 years in various states of condition and love working on them myself. I prefer buying them from the Forum members here if possible. I have a reasonable skill set but understand my limits. The LT-5 is a bit more complex then a typical C4 set up. Or is it? Did some searching on the injectors repair and replacement on the standard L-98 motor....Is it the same process just double? Thanks Very Much for any advice or experiences from forum members who have done it.
Cheers
Deane
Hello Deane,
My first piece of advice would be to go to the ZR1 Specialist web site and get Marc Haibec's DVD on pulling the plenum. Its money well worth it. About 8 or 9 years ago I did my first plenum pull on my 92 Z without the dvd... I have a solid mechanical foundation and many tools that I have aquired from when I used to turn wrenches in the field many moons ago... so with some help from some members here and on the ZR1 Net Registry, I was able to get it done fairly easily. I took my time to be sure. I would suggest FIC injectors or Accel. Most of the owners use those. I have FIC in the current 90 I have. Its not hard per se', just have to be careful with the 30 year old plastic and rubber parts under there... they become brittle over time. There are several other operations you can perform while under there also.... Tightening down injector housings, checking the secondary vacuum canisters/actuators, the PCV breather box gasket and maybe replace whatever vacuum lines that may need replacing also.
Also, make sure the V is cleaned out as well as the drain tube that dumps out the bottom of the engine near the bell housing... Check & clean starter connections as well...
Thanks Very Much for your reply I will do just that and follow your lead....I also noticed after I posted that the Sticky LT-5 Tech Notes have ALOT of information to read.....
I would not let an impending injector upgrade prevent you from getting a ZR1. I have had mine just shy of 3 years and it is the coolest car I ever had. Most of the work you can do yourself.
Make sure to undo the gas cap to vent the pressure and have some rags on hand. Prob a job best done in the driveway versus the garage. The schrader valve is a bit misleading at least mine was anyway. I “relieved” the pressure and got a tiny squirt of gas out and that was it. Once I took the lines off the rail it was a completely different story. Definitely have a small gas can or jug ready to dump the lines into so they can drain whatever pressure is left in them.
Some people can lift out the whole rail assembly with injectors attached no problem. Mine were IN THERE, as in I took all the retaining clips out and lifted the rails off the injectors (more gas). I had to use vice grips with a cloth towel around the injectors and some coercing to get them to come out of the injector housings, so I’m positive any true force pulling up on the rails the way they were would’ve resulted in sheering/breaking parts.
If you can work on your own cars this is just another job. When the injectors died in my 91 @8000 original miles having somebody else work on the car was never an option. I started asking questions,got the parts and took plenty of pictures. As stated Marc H’s DVD is a must. I’ve done the plenum pull several times and don’t have to rely on ant aids to do the job. Any and all questions you might have,somebody will have an answer.
First time I pulled mine was a little intimidating, but then no big deal the next time when I pulled the motor to have the heads ported and replace the cams. Like anything take your time, read up on the procedure and mark everything your first time. The registry has tons of people to answer any questions.
I'm going to offer a little quick tip because I found this out the hard way and seeing Z51JEFF's spottless engine with the tape around fittings reminded me. When you disconnect the vacuum fittings from each side of the plenum, it may be helpful to pull the rubber connections off the hard lines, prior to lifting the plenum off. Or at the very least, wrap some tape around them to secure it to the hard line. I say this because while I had no issue with the plenum coming off, once I proceeded to place the plenum back on, the passenger side vacuum rubber connection on the hard line caught the plenum just right, popped off and well.....I got to watch it comically roll around the opening of the runner and then drop right down into the injector housing. I had just taken the tape off the runners of the housing to put the plenum on after I had installed new gaskets for the housings. Luckily, the valve in the intake wasn't open too much, so I was able to remove the housing and fish it out with some needle nose pliers.
Not a fun time being that close to being done and have something so silly happen. That being said, if you're going to have the rails off the car, it may be a good time to replace the injector housing gaskets if you have oil pooling between the head and the housing. I did this and mine have been bone dry ever since. I snagged some injector fastener clips from Jerry (8 of them). I could've bought all 16 he had in stock but decided to leave some for the next person that may need them. I picked them up as a just in case because it's not the sturdiest metal, and I've had some clips crack in half when trying to push them around the injector to secure it into the rail. The job of doing the injectors isn't the worst part to me, it's the little silly stuff that can happen and cause a snag.
With all the great advice here not much I can add. having removed the plenum of many LT5's all I can add is take your time, take pictures of every step just to be sure of the part and hose routing. be ready to do lots of clean-up. be very careful of the plastic clips on the electrical connectors as the tend to get brittle with age. I've been running Accell injectors for many years with no issues. Good luck.
Thank you for the recap of the actual shop experience. There is no worse feeling job well done satisfaction lost due to a random mishap... I will defiantly identify and secure the connectors....
Respectfully,
Deane
Guys,
Based on all your positive feedback here I'm going forward with the potential purchase. I have contacted our forum member TKay13 about his ZR-1 currently listed for sale here. As mentioned in the ad it does need some maintenance (Tires,Injectors, Window Switches, Air Bag Updates various electrical etc...) to bring it up to standards. Verification of performance upgrades and history would be helpful ....TKay13 mentioned that this Car was sold to his Grandfather by one of the Forum members here....Does anyone here recognize this Car?
Guys,
Based on all your positive feedback here I'm going forward with the potential purchase. I have contacted our forum member TKay13 about his ZR-1 currently listed for sale here. As mentioned in the ad it does need some maintenance (Tires,Injectors, Window Switches, Air Bag Updates various electrical etc...) to bring it up to standards. Verification of performance upgrades and history would be helpful ....TKay13 mentioned that this Car was sold to his Grandfather by one of the Forum members here....Does anyone here recognize this Car?
Respectfully,
Deane
I went and saw this car this past Saturday he told me the car was purchased by his grandfather at the meccum auction in 2013.
Last edited by G8nightman; 06-25-2019 at 10:30 AM.
06-20-2019, 03:41 PM
How Difficult is the Injector replacement procedure for the 1990 ZR-1 ?
