Hey forum I'm getting ready to replace the fuel injectors on my 85 and I have never done them before. I am pretty inexperience when it comes to working on cars but I figured I need to start in order to make my car affordable. Do you guys have any tips/plans for how to do this? Any help would be greatly appreciated.

 

I've done C4 injectors four times now. in fact, I've done my 85 twice now. not a hard job, but a lot of detailed work. step 1, get a FSM, and read over the procedure several times before you start. along the way, you may need to get a couple of inexpensive tools to make the job a bit easier. have all your parts, gaskets, etc in place before starting the job. take plenty of digital pics as you go. be methodical - bag, tag, and label everything - be neat and organized. DO NOT throw everything into a big box. while you have everything apart, consider other items, such as the EGR valve, pressure regulator, new O-rings in the fuel rail, valve cover gaskets, etc, etc, etc. unless you're a seasoned mechanic, just take your time. do not try to rush this job. I treat every nut and bolt as a piece-part restoration.

it's kind of hard to give you a step by step procedure here - all you need is a bit of common sense, and some technical know how. replacing the injectors you can either clean the first generation bosch (which BTW are a decent injector), or replace them with rebuilt boschIII's. Jon @ FIC can set you up with either the cleaning service, or the boschIII's, along with any gaskets, and other service items you'll need.

if and when you run into an issue, keep this thread open and post a how-to question. plenty of members here with a lot of hands on experience.

 

Thanks for the help Joe. I'll try and do as much research as I can.

 

Pull the throttlebody, plenum, and runners. 4bolts hold the fuelrail down. Do not pressure the fuel pump prior to disassembly to reduce fuel spillage. The clips holding the injectors to the rail can be kind of tricky, so be careful not to ruin them. If you are replacing with a newer Bosch type 3 you won't need the clips. Jon has Bosch 280-155-715's for $189 that flow right at 24 lbs.

 

the gm fsm is the best....it has step by step instruction....just reverse to install...there are quite a few videos online...corvette central/ etc. to watch before attempting....like they say ..not a hard job, just a lot of steps and a few correct tools....good luck.....by the way, I put the new 22# injectors in my 85...raised the fuel pressure....they work great...from jon at FIC

 

Use PB Blaster on the bolts a couple of times and let them soak for a while. Some of the torx bolts are difficult to get a grip on so use some air pressure to blast the crud out of their "holes".
This is also a great time to remove the intake manifold and re seal it as it will eventually leak.
Purchase a long torx bit with a 3/8 drive as it will come in very handy. Also think about going to a place such as Fastenal with your runner to plenum bolts and buy some with hex heads. Then purchase a ball tip long extension in the correct size to help with your install. This will make your job go much easier.
Take pictures as you go and once again I will add to the above advice - replace those fuel rail O rings! You don't want those old, hardened ones in there under high fuel pressure.
A tip on releasing the clips that hold the fuel injector wiring to the injectors. Just push in on them and that will release the connectors.
I took the black plastic wire covers off and covered the wiring with split, colored plastic conduit (blue to match my plug wires) and thought that made things look a bit neater. Mine is a 91:

 

Just thought of more.
Good time to clean the throttle body, replace the thermostat, do the throttle body bypass mod and clean up and respray the plenum, runners, manifold and valve covers. Might as well clean the crud between the radiator and AC condenser and rent a pressure washer to clean up the engine bay. Well worth the time and effort.
And (this could go on forever) replace the water pump, flush the radiator and block and install new hoses. New spark plugs and wires too! Rebuilt distributor time?
Be sure not to let your significant other see the receipts for all the parts either
These type of projects have a way of morphing into a blown 383 with aftermarket heads, headers, cam and performance intake.

 

Thanks for all the help guys! This will definitely be next weekends project.

 

- been there, done that - TWICE!

BTW, here's a couple of "specialty" tools I mentioned in my previous post. aside from the standard 3/8th drive torx socket set, I bought a 3/8 drive T40 that's about 6 inches long, and I RTV'd together a T40 bit into a 1/4" drive X 1/4" swivel socket. found both extremely helpful in removing the plenum.





here's my latest - started out fixing an oil leak, and ended up with a corsa cat-back, with lots and lots of stuff in between -

 

Here is a pretty good How To video on how to change out your injectors on A Corvette L98 engine.


Be sure to talk to John Banner at Fuel Injection Connection in Cummings, GA to purchase your replacement injectors or better yet, have your OEM injectors rebuilt and balanced.

P.

 

LOL i did that video
Yes contact Jon Banner at http://www.fuelinjectorconnection.com
They are THE BEST !

 

The Bosch 111 injectors are slightly shorter than the standard injectors and narrow, when i fitted them to my vette i assembled everything and found fuel squirting out the top of the injector/fuel rail.
Without the clips holding the injectors in the fuel rail and without the extra o ring at the bottom of the injector the fuel pressure tends to push the injector down into the inlet manifold and can cause a leak.
It did it on a couple and i managed to fit the clips and that worked fine.
(That was before i found out about the extra O rings so they do not get pushed down into inlet manifold)


I now know FIC uses two o rings on the base of the injectors and one on the top, where is the original injectors the body hits the manifold and never bottoms into it.

I recommend you replace the fuel pressure regulator diaphragm, and fit the fuel rails and bolt them down have the runners in place but not bolted down yet . Then fit the fuel pipes and test the fuel injectors by turning the ignition on before assembling the runners. Is a pain to have to the job twice.

 

Hey guys, while i was taking everything apart my project came to a screeching halt. There are two stripped torque bolts on the passenger side that i cannot get removed. Any help or tips?

 

I would also like to replace my injectors. I know there are many threads on this topic. I’ve been reading as many threads as I could find in the forum. I feel I can tackle this job by taking my time, I’m just uncertain about the injector type to use. I did take the Forums advice and call fuel injector connection. They kinda left the decision up to me as what to use, new or remanufactured Bosch 3’s, ( not real concerned about difference in cost. I just want to do it right. ), or should I send my originals in to have serviced there. I’ve been watching videos and see that the originals have clips to hold them in and the Bosch’s do not. I can go on and , again, I just want to make sure I do this in the best way that I can. Thank you in advance for the help!

 

This thread is eight years old and the OP hasn’t been active on the Forum for five years. You may have better response by starting a new thread.